Penetrating Abdominal Trauma 

Updated: Jan 13, 2017
Author: Patrick Offner, MD, MPH; Chief Editor: John Geibel, MD, MSc, DSc, AGAF 

Overview

Practice Essentials

Penetrating abdominal trauma typically involves the violation of the abdominal cavity by a gunshot wound (see the image below) or stab wound.

Penetrating abdominal trauma. Tangential gunshot w Penetrating abdominal trauma. Tangential gunshot wound to the liver.

Signs and symptoms

Signs and symptoms of penetrating abdominal trauma depends on various factors, including the type of penetrating weapon or object, the range from which the injury occurred, which organs may be injured, and the location and number of wounds.

Close-range injuries transfer more kinetic energy than those sustained at a distance, although range is often difficult to ascertain when assessing gunshot wounds. A gunshot wound is caused by a missile propelled by combustion of powder. These wounds involve high-energy transfer and, consequently, can involve an unpredictable pattern of injuries. Secondary missiles, such as bullet and bone fragments, can inflict additional damage. Stab wounds are caused by penetration of the abdominal wall by a sharp object. This type of wound generally has a more predictable pattern of organ injury. However, occult injuries can be overlooked, resulting in devastating complications.

See Clinical Presentation for more detail.

Diagnosis

See the list below:

  • Initial examination (primary survey, or ABCDEs) in patients with penetrating abdominal trauma includes assessment of the following:

  • Airway, breathing, circulation (ABCs): Includes vital signs

  • level of consciousness (D, disability): To detect neurologic deficits

  • Location(s) of the wound(s) (E, exposure): Inspect all body surfaces, and document all penetrating wounds

  • Type of penetrating weapon or object

  • Amount of blood loss

The secondary survey is a complete head-to-toe physical examination in hemodynamically stable patients and includes external inspection with respect to anatomic landmarks; abdominal evaluation for tympany, dullness to percussion, bowel sounds, and/or distention; and a digital rectal and genitourinary evaluation. In patients with life-threatening injuries, the secondary survey may be delayed for operative therapy.

Immediate surgical exploration is warranted for evidence of significant intra-abdominal injury, especially vascular trauma, such as the following:

  • Hypotension (with or without abdominal distention)

  • Narrow pulse pressure

  • Tachycardia

  • High or low respiratory rate

  • Signs of inadequate end organ perfusion

  • Peritoneal signs (eg, pain, guarding, rebound tenderness) and/or peritonitis

  • Diffuse and poorly localized pain that fails to resolve

Laboratory testing

In case emergent operation is necessary, all patients with penetrating abdominal trauma should undergo certain basic laboratory testing, as follows:

  • Blood type and cross-match

  • Complete blood count (CBC)

  • Electrolyte levels

  • Blood urea nitrogen (BUN) and serum creatinine level

  • Glucose level

  • Prothrombin time (PT)/activated partial thromboplastin time (aPTT)

  • Venous or arterial lactate level

  • Calcium, magnesium, and phosphate levels

  • Arterial blood gas (ABG)

  • Urinalysis

  • Serum and urine toxicology screen

Imaging studies

The following imaging studies may be used to evaluate patients with penetrating abdominal trauma:

  • Chest radiography: To rule out penetration of the chest cavity

  • Abdominal radiography in 2 views (anterior-posterior, lateral)

  • Chest and abdominal ultrasonography: Focused assessment with sonography for trauma (FAST); includes 4 views (pericardial, right and left upper quadrants, pelvis)

  • Abdominal CT scanning (including triple-contrast helical CT): Most sensitive and specific study in identifying and assessing liver or spleen injury severity[1]

Other radiologic studies that may be useful include the following:

  • Skeletal survey: To detect any associated fractures

  • Brain CT scanning: To detect any coincident head injuries

  • Retrograde urethrogram/cystogram: To detect any urethral or bladder injury

  • Intraoperative intravenous pyelography: To assess contralateral renal function in patients with kidney damage necessitating nephrectomy

Procedures

The following may be diagnostic and/or therapeutic procedures in patients with penetrating abdominal trauma:

  • Gastric decompression in intubated patients: To prevent aspiration

  • Foley catherization: To monitor fluid resuscitation

  • Peritoneal lavage (open or closed): To identify hollow viscus or diaphragmatic injury

  • Tube thoracostomy: To relieve hemothorax/pneumothorax

  • Local wound exploration: Diagnostic aid to determine the track of penetration through the tissue layers

  • Laparoscopy: To evaluate and treat intra-abdominal injuries, including stab wounds to the anterior abdomen or those with uncertain peritoneal penetration

See Workup for more detail.

Management

The approach to patients with penetrating abdominal trauma depends on the following factors:

  • Mechanism and location of injury

  • Hemodynamic and neurologic status of the patient

  • Associated injuries

  • Institutional resources

Most trauma centers use an algorithm with multiple diagnostic modalities whose uses are based on the pattern of injuries and the clinical status of the patient.

Gunshot wounds are associated with a high incidence of intra-abdominal injuries and nearly always mandate laparotomy. Stab wounds are associated with a significantly lower incidence of intra-abdominal injuries; therefore, expectant management is indicated in hemodynamically stable patients.

Pharmacotherapy

The following medications may be used in the management of patients with penetrating abdominal trauma:

  • Analgesics (eg, morphine sulfate, fentanyl citrate)

  • Anxiolytics (eg, lorazepam, midazolam hydrochloride)

  • Antibiotics (eg, cefotetan, metronidazole hydrochloride, gentamicin sulfate, vancomycin hydrochloride, ampicillin sodium-sulbactam sodium)

  • Neuromuscular blocking agents (eg, succinylcholine, vecuronium bromide)

  • Immune enhancement (eg, tetanus toxoid adsorbed or fluid)

See Treatment and Medication for more detail.

Background

Penetrating abdominal trauma typically involves the violation of the abdominal cavity by a gunshot wound (GSW) or stab wound. The management of penetrating abdominal trauma has evolved greatly over the last century.

Before World War I, penetrating trauma was managed expectantly and was nearly uniformly fatal. Laparotomy became the treatment of choice during World War I, but mortality remained high. By World War II, early laparotomy resulted in a survival rate close to 50%.

The 1950s afforded availability of antimicrobials, better understanding of fluid replacement, and faster transport from the scene, which further increased survival rates. By the late 1950s, mandatory laparotomy was the rule for the management of patients with abdominal penetrating trauma.

In 1960, Shaftan suggested selective management of patients with abdominal stab wounds after observing an increased rate of laparotomies without identifiable injuries. More recently, expectant management has also been used in the treatment of specific GSWs to the abdomen.

The introduction and refinement of diagnostic procedures and imaging studies, including peritoneal lavage, laparoscopy, computed tomography (CT), and focused ultrasonography, have directed the evolution of penetrating abdominal trauma management.

There has been a substantial evolution in patient management. Resuscitation protocols reflect the impact of appropriate crystalloid administration, the immunomodulatory properties of blood transfusions, and an understanding for physiologic end points of resuscitation.

Damage control surgery (abbreviated laparotomy with physiologic resuscitation in the intensive care unit and staged abdominal reconstruction; see the images below) and treatment of abdominal compartment syndrome have had major impacts on care of the severely injured.

More recently, the damage control concept has been extended to resuscitation of severely injured patients with significant hemorrhage. Termed damage control resuscitation or hemostatic resuscitation, this approach arose from the recognition of early coagulopathy of trauma and its importance. Damage control resuscitation principles include early implementation of massive transfusion protocols with fixed blood product ratios, avoidance of large-volume crystalloid administration, and appropriate use of permissive hypotension.

Technologies allow less invasive and more rapid and specific diagnostic evaluations. Selective operative management and increasing application of angioembolization have served to further reduce surgical intervention. Refinement of evidence-based clinical pathways has allowed for a judicious allocation of resources.

See the gunshot wound images below.

This is an operative photograph of an extremely ra This is an operative photograph of an extremely rare injury: a midureteral transection from a gunshot wound. The patient was shot with a MAC-10 machine gun and sustained liver injury as well as injuries to the duodenum, colon, terminal ileum, sigmoid colon, rectum, gallbladder, bladder, and left femur. He underwent a damage control operation and survived his injuries after 3 subsequent operations.
This liver injury was sustained by the patient sho This liver injury was sustained by the patient shot with a MAC-10 machine gun. The injury has been opened to control bleeding branches of the portal and hepatic veins as well as the hepatic arterial radicles. Several biliary ducts were ligated, and the back wall of the gallbladder can be identified in the depths of the wound. A cholecystectomy was required for management of the wound.

Nevertheless, penetrating abdominal organ injury patterns and survival have plateaued over the past decade. Death from refractory hemorrhagic shock or exsanguination in the first 24 hours remains the most common cause of mortality. Damage control surgery is being used more frequently with improved early survival but with a concurrent increase in late morbidity. More study is needed to determine if wider application of massive transfusion protocols and damage control resuscitation principles will improve outcome further.

Anatomy

In evaluating patients with penetrating abdominal trauma, the abdomen is classically divided as follows:

  • Anterior abdomen - Anterior costal margins to inguinal creases, between the anterior axillary lines

  • Intrathoracic abdomen or thoracoabdominal area - Fourth intercostal space anteriorly (nipple) and seventh intercostal space posteriorly (scapular tip) to inferior costal margins

  • Flank - Scapular tip to iliac crest, between anterior and posterior axillary lines

  • Back - Scapular tip to iliac crest, between posterior and axillary line

This anatomic classification is important in guiding the clinician’s suspicion for specific organ injury.

Intraperitoneal abdominal organs include the solid organs (ie, spleen, liver) and the hollow viscus organs (ie, stomach, ileum, jejunum, transverse colon).

Retroperitoneal organs include the duodenum, pancreas, kidneys, ureters, urinary bladder, ascending and descending colon, major abdominal vessels, and rectum.

Pathophysiology

A GSW is caused by a missile propelled by combustion of powder. These wounds involve high-energy transfer and, consequently, can involve an unpredictable pattern of injuries. Secondary missiles, such as bullet and bone fragments, can inflict additional damage. Military and hunting firearms have higher missile velocity than handguns, resulting in even higher energy transfer.

In penetrating abdominal trauma due to gunshot wounds, the most commonly injured organs are as follows[2] :

  • Small bowel (50%)

  • Colon (40%)

  • Liver (30%)

  • Abdominal vascular structures (25%)

The image below is of a patient who sustained a gunshot wound to the spleen.

This 22-year-old woman sustained a gunshot wound t This 22-year-old woman sustained a gunshot wound to the left flank. At exploration, she had a through-and-through laceration of her spleen. The bleeding was arrested by finger compression of the splenic hilum while it was mobilized. A splenectomy was performed because the bullet went through the hilum.

The severity of shotgun wounds depends on the distance of the victim from the weapon. The mass of a shot pellet is minimal, and thus its velocity decreases rapidly after the shell leaves the barrel of the gun. When the distance is less than 3 yd, the injury is considered high velocity; if the distance exceeds 7 yd, most of the buckshot penetrates only the subcutaneous tissue.

Stab wounds are caused by penetration of the abdominal wall by a sharp object. This type of wound generally has a more predictable pattern of organ injury. However, occult injuries can be overlooked, resulting in devastating complications.

In penetrating abdominal trauma due to stab wounds, the most commonly injured organs are as follows[2] :

  • Liver (40%)

  • Small bowel (30%)

  • Diaphragm (20%)

  • Colon (15%)

A stab wound is shown in the image below.

The patient's small intestine clearly protrudes th The patient's small intestine clearly protrudes through his anterior abdominal wall following a stab wound caused by a machete. The operative repair and recovery were uneventful.

The mechanism that underlies the penetrating trauma (eg, gunshot wound, stab wound, impalement) relates to the mode of injury (eg, accidental or intentional injury, homicide, suicide). Homicide or intentional injury is the predominant mode of abdominal injury in this patient population. Accidental injury is most common in pediatric home firearm injuries but is uncommon by comparison to the overall levels of homicide and intentional injury. Suicide via penetrating abdominal trauma is uncommon.

The images below depict 2 patients with impalement injuries.

Note that the resident is carefully maintaining th Note that the resident is carefully maintaining the position of the impaled stop sign post, so as not to dislodge the shaft. The shaft was removed in the OR along with the patient's right colon.
A 34-year-old man flipped over the handlebars of h A 34-year-old man flipped over the handlebars of his motorcycle and landed on a wrought-iron fence. His helmet was knocked off when he landed. The medics cut the fence apart and transported the patient and fence to the ED (see image). On presentation, the patient's vital signs are as follows: rectal temperature, 95.3°F; heart rate, 126 beats per minute; respiration rate, 24 (labored); and blood pressure, 94/62 in his left arm. Intubation, bilateral upper extremity intravenous access, 2000 mL intravenous fluid, AP CXR, and operation is the correct sequence in which to resuscitate the patient to address the ABCs.

Etiology

Gunshot wounds, considered high-velocity projectiles, are the most common cause (64%) of penetrating abdominal trauma, followed by stab wounds (31%) and shotgun wounds (5%).

Penetrating abdominal trauma may result from urban violence. Domestic violence crosses all socioeconomic barriers and is an important consideration in the evaluation of injuries sustained at home and those reportedly involving the patient's family or significant other.

From a global perspective, penetrating abdominal trauma in most settings results principally from military actions and wars.

Penetrating abdominal trauma may be iatrogenically introduced. Documented complications of diagnostic peritoneal lavage include injuries to the underlying bowel, bladder, or major vessels such as the aorta or vena cava. Fortunately, the incidence of such complications is relatively small.

Epidemiology

United States statistics

In the United States, suicide and homicide consistently rank in the top 15 causes of death. According to data published by the National Vital Statistics Reports, 11,406 homicide deaths occurred from firearm injuries in 2009 and 18,689 deaths from self-inflicted GSWs.[3] Forty percent of homicides and 14% of suicides by firearm involved injuries to the torso.

Tracking trauma is the purview of the National Center for Injury Prevention and Control (NCICP). Data collected by this organization suggest that traumatic injury is the third overall leading cause of death and the number one cause of death in persons aged 1-44 years. Penetrating abdominal trauma affects approximately 35% of those patients admitted to urban trauma centers and 1-12% of those admitted to suburban or rural centers.[4]

International statistics

According to age-adjusted rates from 1990 to 1995, firearm mortality rates across the world vary widely, from 0.05 in Japan to 14.24 in the United States. Firearm-associated homicide mortality was highest in Mexico at 10.35; firearm associated suicide was highest in the United States at 6.3. The frequency of penetrating abdominal injury across the globe relates to the industrialization of developing nations, weapons available, and, significantly, to the presence of military conflicts. Therefore, frequency varies.

Racial differences in incidence

Age-adjusted firearm death rates are 2-7 times higher for non-Hispanic black males than for males of other ethnicities. For non-Hispanic whites, most firearms deaths are due to suicide.

Race distribution in patients with penetrating abdominal trauma depends significantly on the location of the receiving hospital. Urban centers predominantly receive young African-American and Hispanic males more frequently than young white males due to population demographics in these areas. A similar distribution occurs for their female counterparts.

Although quantifying the death rate for penetrating abdominal trauma by race is difficult, the relative risk of death for penetrating injury in general is known. African-American males have a 3-fold increase in relative risk of death compared with their white male counterparts. African-American females have a 2.5-fold increase in relative risk of death compared with their white female counterparts.

Suburban centers tend to receive a greater proportion of youthful to middle-aged white males as their predominant patient population because of regional demographics.[5]

Sex- and age-related differences in incidence

Males constitute the great majority of patients with penetrating trauma injuries across the United States and the world. In some areas of the United States, approximately 90% of patients with penetrating trauma are male. Injuries are the leading cause of death in patients aged 1-44 years.[6]

Prognosis

The death rate from penetrating abdominal trauma spans the entire spectrum (0-100%), depending on the extent of injury. Patients with violation of anterior abdominal wall fascia without peritoneal injury have a 0% mortality rate and minimal morbidity rate, while those with multiorgan injury complexes presenting with hypotension, base deficit less than -15 mEq/L HCO3, core temperature less than 35° C, and development of coagulopathy have a dramatically increased mortality rate mandating "damage control" resuscitation.[7]

An average mortality rate for all patients with penetrating abdominal trauma is approximately 5% in most level 1 trauma centers, but this population is necessarily biased, given the higher acuity seen at such centers, thus skewing the data.

Survival from penetrating abdominal trauma has not measurably changed in the past decade, largely because of death within 24 hours resulting from irreversible hemorrhagic shock and exsanguination. More than 80% of deaths occur within 24 hours of admission, 66.7% at the initial operation associated with abdominal vascular injury. In contrast, survival from penetrating abdominal injury without vascular injury remains high.[8]

Temporal distribution of deaths in penetrating trauma is significantly different from that in blunt trauma. The majority of deaths from penetrating trauma occur between 1 and 6 hours from admission. In contrast, the highest number of deaths from blunt trauma occurs beyond 72 hours postadmission and the lowest number occurs during the first hour.[8]

Consequently, deaths caused by penetrating trauma are significantly more likely to occur in the emergency department or the operating room than deaths caused by blunt trauma, which predominantly occur in the ICU. Hypoperfusion and its sequelae are the usual cause of death within the first 72 hours, whereas ICU deaths 2 or more weeks later are usually from complications related to sepsis, the systemic inflammatory response syndrome (SIRS), or multiple organ dysfunction syndrome.[8]

General factors that predict increased mortality from penetrating abdominal trauma include the following:

  • Female sex

  • Long interval between injury and operation

  • Presence of shock on admission

  • Coexisting cranial injury

The death rate is markedly influenced by prehospital hypotension, massive hemorrhage, arrest in the field or on presentation, acidosis with an initial pH less than 7, lactate level greater than 20 mmol/L, or base deficit more negative than -15 mEq HCO3.[8]

In a series by Nicholas and colleagues of 250 patients with penetrating abdominal trauma and positive laparotomies, the overall survival was 86.8%.[9] Mortality was found to be associated with the number of organs injured, vascular injury, and the need for damage-control surgery, emergency department thoracotomy, or operating room thoracotomy.

While damage-control surgery has been used with some success in the management of patients with extensive abdominal trauma, it is associated with significant morbidity, including sepsis, intra-abdominal abscess, and gastrointestinal fistula, according to Nicholas et al.[9]

Patients who present to the ED in the early postoperative period with abdominal pain or signs of infection should be strongly considered for CT scan and surgical consultation.

Injury patterns differ depending on the weapon. Low-velocity stab wounds are generally less destructive and have a lower degree of morbidity and mortality than gunshot wounds and shotgun blasts. Gunshot wounds and other projectiles have a higher degree of energy and produce fragmentation and cavitation, resulting in greater morbidity.[9]

Patient Education

Paramount importance must be placed on patient, family, and support system education if the medical community wishes to proactively reduce the incidence of violent injury in our society. Such an educational initiative should begin with the initial evaluation in the ED.

No single solution exists for every hospital or community; individualization is the key. Healthcare providers should be an integral part of reducing violence in society.

For patient education information, see the Wounds Center, as well as Puncture Wound.

 

Presentation

History

The history provides clues to the most likely injury patterns and potential management priorities. Emergency medical services (EMS) personnel are often essential in providing a history, especially in a critically ill patient or one with altered mental status.

A common acronym describing important information to gather when taking the history is AMPLE, as follows:

  • Allergies

  • Medications

  • Prior illnesses and operations

  • Last meal

  • Events and environment surrounding injury

The anatomic location of injury and type of weapon (ie, gun, knife) direct the diagnostic process. Information such as the number of gunshots heard or the number of times the patient was stabbed, and the patient’s position at the time of injury help describe the trajectory and path of the injuring object.

Close-range injuries transfer more kinetic energy than those sustained at a distance, although range is often difficult to ascertain when assessing gunshot wounds.

Blood loss at the scene should be quantified as accurately as possible from EMS personnel. However, research has shown that this assessment is very difficult and rarely reliable. The character of the bleeding (eg, arterial pumping, venous flow) may assist in determining whether major vascular injury has occurred.[10]

The initial level of consciousness or, for moribund patients, the presence of any signs of life at the scene (ie, pupillary response, respiratory efforts, heart rate or tones) is vital to determine the prognosis and to guide resuscitative efforts. Particularly important is the patient's response to therapy en route to the ED. Evidence of hypotension in the field should raise suspicion for intra-abdominal injury.

Injuries from possible abuse

Pediatric, pregnant, or geriatric patients whose injury occurs in the home may be victims of child abuse, domestic violence, or elder abuse, respectively. Failure to inquire about possible abuse or neglect in such cases is an error of omission and one for which the physician may be held legally accountable.

Mandatory reporting may be required for each of these types of abuse, although specific reporting requirements vary by patient population and locale. For example, statewide databases include external cause of injury codes (E-codes) for the coding and tracking of these injury mechanisms.

Physical Examination

Assessment of the patient begins at the scene of the incident by EMS personnel. Upon arrival at the emergency department (ED), communication of the incident history and the patient’s vital signs to the emergency or trauma team is of paramount importance.

The initial physical examination begins with visual assessment of the patient during transport into the ED, with particular focus on the ABCs. Rapid determinations regarding respiratory effort, perfusion, external hemorrhage, and consciousness level are usually easily made. Confounding injuries or medical problems, such as tension pneumothorax or acute myocardial infarction, need be excluded.

Initial vital signs assist in determining injury severity and need for operative intervention. Hypotension, narrow pulse pressure, tachycardia, high or low respiratory rate, or signs of inadequate end organ perfusion in the setting of penetrating abdominal trauma provide evidence of significant intra-abdominal injury, especially vascular trauma, and warrant immediate surgical exploration.

Examination of the abdomen in a patient who is awake may indicate peritoneal signs, such as pain and guarding and rebound tenderness. Hemodynamically stable patients with penetrating abdominal trauma and peritonitis can be assumed to have a hollow visceral perforation and may have significant intra-abdominal hemorrhage. Thus, peritonitis on physical examination is a trigger for emergent intervention regardless of vital signs.

Peritoneal signs develop when the peritoneal envelope and the posterior aspect of the anterior abdominal wall are both inflamed. The peritoneal or retroperitoneal blood and organ contents inflame deeper nerve endings (visceral afferent pain fibers) and result in poorly defined pain. Irritation of the parietal peritoneum leads to somatic pain, which tends to be more localized; however, the diffuse nature of intra-abdominal spillage often leads to diffuse findings.

Referred pain may provide a clue to organ damage. For example, left shoulder pain may result from a damaged spleen with subphrenic blood.

Abdominal distention in an unresponsive patient may indicate active internal bleeding. In hypotensive patients, this may be an indication for immediate exploration. Focused Assessment With Sonography for Trauma (FAST) examination can be useful in this situation to detect massive hemoperitoneum.

Rectal examination is performed on all patients with penetrating abdominal trauma, because blood per rectum and, in males, high-riding prostate can indicate bowel injury and genitourinary tract injury, respectively. Notation of blood at the urethral meatus is also a sign of genitourinary tract injury.

Physical examination includes inspection of all body surfaces, with notation of all penetrating wounds. Multiple wounds may represent either entrance or exit wounds and must not be labeled as such, since multiple missiles or foreign objects may be retained within the body.

Wounds located on the anterior abdomen can be explored locally to determine whether they penetrate the peritoneum. On the flank area and back area, exploration is more difficult and less reliable. Therefore, flank and back wounds are not explored and are considered penetrating unless obviously superficial.

When immediate operative intervention is not requisite, further evaluation ensues with laboratory testing and diagnostic and imaging studies.

Patients without recordable cardiac activity upon presentation should not be further resuscitated.

Primary survey

The primary survey is defined by the mnemonic ABCDE: Airway, Breathing, Circulation, Disability, and Exposure/Environment. Although described sequentially, much of this evaluation may be performed simultaneously and problems identified are managed immediately.

The airway is assessed immediately for patency, protective reflexes, foreign body, secretions, and injury. Breathing is assessed by determining the patient's respiratory rate and by subjectively quantifying the depth and effort of inspiration.

The circulation assessment begins with an evaluation of the patient's mental status, skin color, and skin temperature. Patients in significant hemorrhagic shock will progress from anxiety to agitation and finally coma if their blood loss continues unabated. The traditional vital signs of heart rate, blood pressure, and respiratory rate are not sensitive or specific for hemorrhagic shock.

Disability is assessed early to document neurologic deficits before giving sedation or paralytics. The Glasgow Coma Score and the gross motor and sensory status of all 4 extremities should be determined and recorded. The physician should recognize the need for cerebroprotection measures in cases of brain injury. Hypotension and hypoxemia exacerbate secondary brain injury and increase mortality by 50% in patients with traumatic brain injury.

Exposure is particularly important in the patient with a traumatic mechanism of injury, in whom it may disclose additional, potentially life-threatening injuries. Complete exposure and head-to-toe visualization is mandatory in a patient with penetrating abdominal trauma. This includes the buttocks, posterior legs, scalp, posterior part of the neck, and perineum. There is little to be gained by practicing spinal immobilization unless spinal injury is obvious.

Once the primary survey is complete, a complete head-to-toe physical examination is performed as an integral part of the secondary survey, including digital rectal and genital examinations. This detailed examination may need to be delayed until after operative therapy has corrected obvious life-threatening injury.

Secondary survey and injury assessment

External inspection for injuries with respect to anatomic landmarks aids identification of possible intracavitary injury.

Common physical examination recommendations include evaluation for tympany (a bell-like or percussive note upon gently tapping on the abdomen), dullness to percussion, and bowel sounds. Abdominal distention, not clearly due to "bagging" or swallowed air, may be an indicator of an intra-abdominal catastrophe. A vascular injury is often found in combination with hollow or solid viscus penetration or devitalization.

The physical examination is a more reliable indicator for surgical intervention with penetrating abdominal trauma than with blunt trauma. At many trauma centers, repeated abdominal examinations are the preferred approach for managing hemodynamically stable patients with penetrating abdominal stab wounds.

When selective nonoperative management is used, the indications for operative intervention include the development of hemodynamic instability or the development of increasing pain, peritoneal findings (eg, point tenderness, involuntary guarding, rebound tenderness), or diffuse and poorly localized pain that fails to resolve.

Evisceration has historically been a clear indication for operative management. However, some centers replace eviscerated omentum and serially observe or image these patients.

Impaling objects may tamponade otherwise uncontrolled hemorrhage if the object resides within or crosses a major vessel or solid organ such as the portal vein or liver. Therefore, penetrating objects should not be removed except where definitive treatment can be provided.

For patients with abdominal stab wounds, a policy of observation and serial examination with discharge in 10-12 hours of patients with negative findings has been proposed. While studies have shown promising results, this approach has not been fully validated in multiple centers.[11]

Special Considerations

Pregnancy

The evaluation of penetrating trauma in the pregnant patient needs to be a coordinated, multidisciplinary effort. Trauma in pregnancy is currently a leading cause of nonobstetric maternal death, and maternal death is the most common cause of fetal death. However, while maternal death rate following penetrating abdominal trauma is 10%, fetal death rate nears 80%.

Anterior abdominal penetrating injury commonly results in injury to the uterus and fetus in the last half of pregnancy. Gunshot wounds have a higher mortality for both mother and fetus.[12]

As pregnancy advances into the second trimester, the gravid uterus moves into the abdominal cavity and out of the protected position in the bony pelvis wherein a pregnancy-specific pattern of injury develops. Superiorly displaced visceral organs are less likely to be injured overall, but they are at greater risk when penetrating trauma involves the upper abdomen. Penetrating trauma to the upper abdomen is worrisome for maternal bowel injury, and many authorities strongly believe that upper abdominal injuries should be operatively managed.

Conversely, the uterus and fetus are at significantly increased risk for direct injury as they grow toward the diaphragm. This likely results from the protective effect of the large, muscular uterus on visceral organs. Because trauma over the uterus has a higher risk of fetal injury, an individualized approach has been advocated and may be better suited for lower abdominal injuries.

Gunshot wounds produce transient shock waves and cavitations in displacement of kinetic energy to body tissue, causing more severe injury than a low-velocity knife injury. Stab wounds to the abdomen are less common than gunshot wounds in the pregnant patient, and they have a lower mortality for both mother and fetus.

Fetal mortality generally results from either premature delivery or direct fetal injury by the foreign body. As in blunt trauma, the biophysical status of the fetus should be evaluated by ultrasonography early in the resuscitation after maternal injuries have been stabilized.

The standard of care is to prioritize the emergent treatment of the gravid patient above that of her fetus. However, a definitive role exists for perimortem cesarean section.

Usual criteria for perimortem cesarean section include a fetus of more than 26 weeks' gestational age (fundal height >26 cm above the pubic symphysis or halfway between the xiphoid and the umbilicus) and a dead or moribund mother. In one review of predictors of fetal survival following such a procedure, more than 70% of surviving fetuses were delivered within 5 minutes of maternal death.

Perimortem cesarean section is a heroic attempt at fetal preservation; the viable fetus that is greater than 26 weeks and has heart tones has a 40-70% chance of survival. More than a 20-minute delay between maternal death and fetal delivery usually results in fetal demise. Care must be taken when interpreting this data, as many of the patients included in the studies of perimortem cesarean sections had experienced blunt trauma.[13]

Well-planned preparation is essential to ensure fetal survival should a postmortem cesarean section be indicated. Ideally, an obstetrician should perform the procedure; however, a trauma surgeon or the ED physician also may deliver the fetus in this circumstance, especially when no obstetric support is emergently available.

Every woman who sustains penetrating abdominal (or other) trauma should be questioned specifically about domestic violence. The incidence of domestic violence increases during pregnancy and is clustered during the third trimester.

Geriatric patients

Geriatric patients respond to trauma and shock differently than their younger counterparts, owing to the presence of comorbid conditions, decreased physiologic reserve, elasticity of the vascular system, and concomitant medication use. The decreased physiologic reserve reduces the ability to respond to injury or tolerate aggressive resuscitation, while polypharmacy can alter the hemodynamic response to shock and complicate the patient’s clinical picture. Therefore, the unique characteristics of the geriatric patient often result in under-evaluation of risk and resuscitation status because the absence of tachycardia and hypotension is often misleading. Serum lactate measurements are a better reflection of shock and the response to resuscitative efforts than traditional vital signs in elderly patients.

Trauma in the elderly population should always prompt a search for underlying causes if the precipitating cause is not readily apparent (eg, assault).

Elder mistreatment should always be considered when evaluating trauma to older persons that occurred at their residence. A home safety evaluation as part of a social service inquiry into the appropriateness of home support systems should be conducted.

Pediatric patients

Penetrating injuries account for 10-20% of all pediatric trauma admissions at most centers. Gunshot wounds are responsible for the overwhelming majority of penetrating traumatic injuries and have a significantly higher mortality rate than do blunt mechanisms.

Management approaches have been derived largely from the adult experience. A paucity of literature is dedicated to pediatric penetrating abdominal trauma. However, application of adult strategies to similar life-threatening injuries in the pediatric population has been generally found appropriate.[14]

Adult trauma facilities usually have the capability to triage, treat, and stabilize pediatric trauma patients. Transfer guidelines should be established delineating what types of injury complexes are appropriate for the surrounding pediatric facilities.

Consider child abuse during the evaluation of all pediatric trauma patients with suspicious injuries or circumstances. Social workers well versed in investigating child abuse are invaluable in this situation.

Evidence preservation

Gunshot and stab wounds are usually reportable injuries at the time of the incident, though this may vary by jurisdiction. In the trauma room, care should be taken not to destroy the clothing and in particular to cut around and not through bullet holes, to turn over to law enforcement any foreign body recovered from the patient, and to describe precisely, or even to photograph, any entrance or exit wounds.

Iatrogenic injury

Truthful documentation of iatrogenic injury that occurred during an indicated course of therapy is the best policy. Technical complications are known to occur with a finite frequency. The key is to identify that an error was made and that it was corrected in a timely fashion. This information should be documented extensively in the medical record, explained to the family, and communicated to the appropriate section head and risk management specialist.

Missed injury

Missed injuries occur most commonly in minimally or maximally injured patients (especially patients transferred from nondesignated facilities); the former is due to minimal physical findings, while the latter is due to appropriate diversion of attention to life-threatening priorities. A team approach to caring for trauma patients coupled with algorithmically driven care plans, including the performance of a tertiary survey, minimizes missed injuries.

Many missed injuries are of little consequence in terms of disability or hospital length of stay. However, a missed intestinal injury that results in fulminant peritonitis and sepsis carries a prohibitive cost to the patient, physician, and hospital. When in doubt, obtain a consultation from the trauma service or a reliable imaging study to rule in or out the concerns of injury. This practice serves to further document medical thought processes and may uncover an otherwise occult injury.

 

DDx

Diagnostic Considerations

Problems to be considered in patients with penetrating abdominal trauma include the following:

  • Coagulopathy

  • Comorbid medical conditions

  • Concomitant closed head injury

  • Concomitant penetrating chest injury

Differential Diagnoses

 

Workup

Approach Considerations

The approach to patients with penetrating abdominal trauma depends on whether the injury is a gunshot wound (GSW) or a stab wound and the patient’s hemodynamic status. GSWs are associated with a high incidence of intra-abdominal injuries and nearly always mandate laparotomy. Stab wounds are associated with a significantly lower incidence of intra-abdominal injuries; therefore, expectant management is indicated in hemodynamically stable patients.

Many protocols have been developed for determination of abdominal wall penetration of stab wounds to the torso, one of which is shown in the diagram below.

Management of penetrating abdominal trauma. CT = c Management of penetrating abdominal trauma. CT = computed tomography; DPL = diagnostic peritoneal lavage; RBC = red blood cells.

Patients with penetrating abdominal trauma generally require complete laboratory profiles in case of need for emergent operation. Many imaging modalities can be useful in the evaluation of a patient with penetrating abdominal trauma. The imaging needs of each patient differ, depending on hemodynamic stability and associated injuries.

Blood and Urine Studies

In case of need for emergent operation, all patients with penetrating abdominal trauma should undergo certain basic laboratory testing, as follows:

  • Blood type and crossmatch

  • Complete blood count (CBC)

  • Electrolyte levels

  • Blood urea nitrogen (BUN) and serum creatinine level

  • Glucose level

  • Prothrombin time (PT)/activated partial thromboplastin time (aPTT)

  • Venous or arterial lactate level

  • Calcium, magnesium, and phosphate levels

  • Arterial blood gas (ABG)

  • Urinalysis

  • Serum and urine toxicology screen

Patients who arrive in shock should be typed and cross-matched for 4-8 units packed red blood cells. The CBC provides a baseline value for later comparison, even though it may not reveal the extent of active bleeding. The basic chemistry profile reveals any baseline renal insufficiency or electrolyte abnormalities. Coagulation studies (PT with international normalized ratio [INR] and PTT) may indicate development of coagulopathy. The importance of early coagulopathy of trauma has recently been emphasized. Up to 30% of patients present to the ED with established coagulopathy prior to any resuscitation. Moreover, these patients have significantly increased mortality.

The ABG permits calculation of the anion gap (reference range, 8-12 mmol/L) and base deficit (reference range, ±4 mmol/L) as guides to hypoperfusion. It provides important information regarding acid-base balance and, thus, the hemodynamic stability of the patient.

Urine dipstick testing may reveal occult blood indicative of genitourinary tract injuries. Female patients should have urine pregnancy testing.

Ethanol and drug screens are also standard practice in trauma patients. Studies have shown that even brief intervention and counseling in patients at the time of admission for trauma injury has positive outcomes.

Plain Radiography

A chest radiograph is obtained on all patients because penetration of the chest cavity cannot be ruled out, even with abdominal stab wounds or even-numbered GSWs (ie, apparent entrance and exit wounds) outside the chest. Chest radiographs can reveal hemothorax or pneumothorax or irregularities of the cardiac silhouette, which can be a sign of cardiac injury or great vessel injury. Air under the diaphragm indicates peritoneal penetration. Chest radiography is relatively specific, although insensitive, for diagnosing diaphragmatic injury.

Abdominal radiographs in 2 views (ie, anterior-posterior [AP], lateral) are also obtained on all patients with GSWs to help determine missile trajectory and to account for retained missiles (ie, bullets, shrapnel, and foreign bodies) in patients with odd-numbered GSWs. If all foreign bodies are not accounted for, consider the possibility that the foreign body is intraluminal or intravascular, and thus is a potential source of emboli distant from the site of entrance.

Ultrasound

Ultrasonography has been widely used in the assessment of patients with blunt trauma, but it has only recently been used in the assessment of patients with penetrating injuries. In these cases, the study is performed using the focused assessment with sonography for trauma (FAST). FAST has gained acceptance in the evaluation of penetrating abdominal trauma because of its speed, noninvasiveness, and reproducibility in diagnosing intraperitoneal injury that requires laparotomy.

FAST uses 4 views of the chest and the abdomen (ie, pericardial, right upper quadrant, left upper quadrant, pelvis) to evaluate for pericardial fluid indicative of cardiac injury and for free peritoneal fluid. Free fluid in the abdomen can be a sign of hemorrhage secondary to liver or splenic laceration or, less commonly, of spillage secondary to hollow viscus injury.

While FAST has been found to be 94-98% specific for abdominal injury in penetrating abdominal trauma, its sensitivity of 46-67% is not good.[15, 16] That is, a positive FAST result in the setting of penetrating trauma is usually an indication for laparotomy due to the high positive predictive value for a therapeutic laparotomy. Unfortunately, a negative FAST result cannot rule out the need for laparotomy and cannot be relied on to exclude important intraperitoneal injury; these patients require further testing to rule out occult injury.[15, 17]

Sonographic evaluation of penetrating wounds also has been evaluated in the detection of fascial defects resulting from anterior abdominal stab injuries, reducing the need for local wound exploration. In one prospective trial, a positive fascial sonogram result obviated invasive wound exploration because such patients were then taken to the operating room (OR). However, a negative fascial sonogram result did not rule out a penetration of the peritoneum.[18, 19]

Computed Tomography

CT scanning is used in the evaluation of patients with stab wounds to the flank and the back and in the evaluation of selected patients with abdominal stab wounds and penetrating, nontangential GSWs. Abdominal CT is the most sensitive and specific study in identifying and assessing the injury severity to the liver or spleen.[1] The presence of a contrast blush on CT or ongoing hemorrhage is an indication for laparotomy or angiography and embolization.[20]

Triple-contrast helical CT has been evaluated as a diagnostic modality in hemodynamically stable patients with penetrating torso trauma. Oral, intravenous, and rectal contrasts are administered, and the images are reviewed for evidence of peritoneal penetration and visceral injuries.

Triple-contrast CT has been found to be 97% accurate in the evaluation of penetrating flank and back wounds. Exploration of these wounds is more difficult, less reliable, and therefore not indicated.[21] One study of CT with IV contrast only found it useful for patients with GSW to the abdomen selected for nonoperative management.[22]

Specific signs of peritoneal penetration on CT include the following:

  • A wound tract outlined by hemorrhage, air, or bullet or bone fragments that clearly extend into the peritoneal cavity

  • The presence of intraperitoneal free air, free fluid, or bullet fragments

  • Obvious intraperitoneal organ injury

The diagnosis of significant penetrating injury should not be delayed by routinely obtaining CT scans of the abdomen and pelvis. Instead, patients with an appropriate history, physical examination or vital sign abnormalities, in particular with a positive FAST, should undergo expeditious exploration.[23] There is no place for CT scanning in hemodynamically unstable patients with penetrating abdominal injury.

The primary limitation of CT is lack of sensitivity in diagnosing mesenteric, hollow visceral, and diaphragmatic injuries, all of which are common in penetrating trauma. Therefore, unless the wound is clearly superficial on CT scan, admission and serial observation is indicated, even with a negative CT result for injury.[24]

No absolute indications exist for CT in anterior penetrating trauma. Some centers use CT as a screening tool to complement physical examination, while others perform serial examination or diagnostic peritoneal lavage (DPL).

In a prospective study of 200 patients, CT was found to be 97% sensitive and 98% specific for peritoneal violation.[25] Laparotomy based on CT findings in 38 of these patients was considered therapeutic in 87%, nontherapeutic in 8%, and negative in 5%. These results were comparable to others obtained with the use of clinical examination, DPL plus local wound exploration, and DPL alone.[26, 27, 28]

Patient selection is extremely important when considering CT as a diagnostic adjunct in patients with penetrating abdominal trauma. The availability and quality of the CT scan and the experience of the examining radiologist are also key considerations.

Other Imaging Studies

Other imaging studies that may be used in patients with penetrating abdominal injury include the following:

  • Skeletal survey for associated fractures

  • CT scan of the brain for coincident head injuries

Retrograde urethrogram or cystogram in a stable patient who has blood at the urethral meatus or evidence of urethral or bladder injury from penetration

Intravenous pyelography is most often used intraoperatively to assess contralateral renal function in a patient with kidney damage necessitating nephrectomy. Nuclear medicine studies have no role in the acutely injured abdominal trauma patient.

Diagnostic/Therapeutic Procedures

In patients with penetrating abdominal trauma, certain procedures that are necessary for treatment may at times provide diagnostic information.

All patients undergoing endotracheal intubation require decompression of the stomach to decrease the risk of aspiration. Blood in the nasogastric tube can indicate upper gastrointestinal injury.

Foley catheterization insertion is required to monitor the fluid resuscitation status of the patient with penetrating abdominal trauma. The presence of blood in the urine is a sign of genitourinary tract injury.

Diagnostic Peritoneal Lavage

In the hemodynamically stable patient with penetrating abdominal injury, DPL can be used to identify hollow viscus or diaphragmatic injury. While very sensitive and specific, DPL requires a fair amount of time to perform, and it has been supplanted in many institutions’ protocols by FAST, CT scan, and/or laparoscopy. The primary disadvantages are invasiveness, inability to evaluate the retroperitoneum, moderate specificity for therapeutic laparotomy, and a significant false-positive rate.[29]

DPL can be performed via either a closed or open method. The bladder and stomach must be decompressed. The closed method involves a small skin puncture with blind insertion of a catheter over a guidewire (ie, Seldinger technique). The open method involves exposure of the peritoneum through a small infraumbilical incision and insertion of catheter under direct vision (ie, mini-laparotomy). A standard DPL catheter is shown in the image below.

A standard diagnostic peritoneal lavage (DPL) cath A standard diagnostic peritoneal lavage (DPL) catheter is secured in place following an open DPL. An aspirating syringe is attached to the catheter via extension tubing as the initial step in the evaluation for intraperitoneal blood.

Aspiration of gross blood or food particles is positive for peritoneal penetration and organ injury. If aspiration is negative, 1 liter of warm normal saline or lactated Ringer solution (20 mL/kg for pediatric patients) is infused rapidly and allowed to return by placing the intravenous bag on the floor.[29] The fluid is then sent for analysis (eg, cell count, differential, Gram stain, bilirubin, amylase, vegetable matter, fecal matter).

A positive test result varies with the mechanism of injury. A red blood cell (RBC) count of greater than 100,000/mm3 or white blood cell count of 100-500/mm3 count may be considered positive in a stab wound. However, if a diaphragmatic injury is possible, some physicians lower the value of a positive test to an RBC threshold of 5000/mm3. Because of the more serious nature of gunshot wounds, clinicians often use a similarly lower value for a positive test when there is concern a projectile has entered the peritoneal cavity.[29]

The lower the threshold for positivity, the more sensitive the test, but the higher the nontherapeutic laparotomy rate (ie, higher rate of false-positive result).

Tube Thoracostomy

Patients with penetrating wounds to the thoracoabdominal area may require chest tube placement. Absent or significantly decreased unilateral breath sounds necessitate immediate tube thoracostomy to relieve hemothorax/pneumothorax. In other patients, hemothorax/pneumothorax will be identified on chest radiograph.

Traditionally, large-bore (38-40F) chest tubes placed in the midaxillary line at the fifth intercostal space have been recommended for trauma indications. More recently, smaller (12F) pigtail catheters have been used for traumatic pneumothoraces and even hemothoraces. These catheters are more comfortable for the patient and easier to place. These catheters should probably be reserved for hemodynamically stable patients.

Time permitting, liberal local anesthesia is preferred in the patient who is awake. The tube is attached to 20-cm wall suction and a postprocedure chest radiograph is performed to confirm placement, adequate lung re-expansion, or complete drainage of pleural blood. A persistent pneumothorax accompanied by a large air leak may indicate a major bronchial injury requiring repair or further diagnostic evaluation with bronchoscopy. Residual clotted hemothorax is an indication for video-assisted thoracoscopic surgery (VATS) or open thoracotomy to fully evacuate the blood and clot.

Local Wound Exploration

In the trauma patient with an anterior stab wound, local wound exploration may be a valuable diagnostic aid, depending on the wound's mechanism and location. Stab wounds to the anterior abdomen are well suited for local wound exploration because many do not penetrate the fascia.

Exploration requires aseptic technique, good overhead lighting, and local anesthesia. The wound is enlarged as necessary so that the posterior fascia may be evaluated. If exploration either confirms that penetration has occurred or is inconclusive, the wound is considered intraperitoneal and must be evaluated further by DPL or more invasive procedures.

Gunshot wounds and those produced by thin instruments, such as an ice pick, are more difficult to explore and, accordingly, are generally considered intraperitoneal injuries.

Once the area is surgically prepared, draped, and anesthetized, the wound may be widened with gentle retraction and gently probed with a hemostat to determine whether a tract exists. If the wound is small, extending it to aid visualization is accomplished with a No. 10 blade scalpel. The rectus fibers may be separated by spreading in their direction using a hemostat or Kelly clamp. The posterior rectus sheath is easily identifiable as a white layer directly underlying the rectus musculature. If yellow fat or omentum is identified, a fascial violation is established.

Laparoscopy

Laparoscopy is a reasonably safe, effective procedure for the evaluation and treatment of hemodynamically stable patients with abdominal trauma, and it can reduce the number of nontherapeutic laparotomies performed. In thoracoabdominal stab wounds, laparoscopy aids in the diagnosis of diaphragmatic and other intra-abdominal injuries.

Patients with stab wounds to the anterior abdomen or with uncertain peritoneal penetration are also candidates for diagnostic laparoscopy. Gunshot wounds to the anterior abdomen with questionable penetration may be assessed this way.

Multiple studies have shown a reduction in unnecessary laparotomies in patients with a penetrating mechanism but no identifiable organ injury who underwent diagnostic laparoscopy. In one center with significant experience with diagnostic laparoscopy in penetrating abdominal trauma, laparoscopy was associated with decreased cost and length-of-stay when compared with open laparotomy (n=44).[19]

A retrospective study of 44 laparoscopies in patients with penetrating abdominal trauma found that half of were negative for penetration and resulted in avoidance of laparotomy.[30] A prospective study of 99 patients showed that diagnostic laparoscopy was negative in 62% of the patients with penetrating abdominal trauma, reducing the rate of unnecessary laparotomy from 78.9% to 16.9%.[31]

The successful incorporation of diagnostic laparoscopy into the management of patients with penetrating abdominal trauma depends on the selection of hemodynamically stable patients, the availability and ease of use of quality laparoscopic equipment, and the experience of the surgeon in using the technique for diagnostic purposes in traumatic injuries.

 

Treatment

Approach Considerations

The management of abdominal trauma varies according to the following factors:

  • Mechanism and location of injury

  • Hemodynamic and neurologic status of the patient

  • Associated injuries

  • Institutional resources

Management of the patient with penetrating abdominal trauma continues to evolve. After many years of obligatory exploration, expectant management of selected patients has become commonplace.

Much of the present controversy involves the determination of which patients or, more specifically, which injury patterns are suitable for expectant management. Several different methods have been used to establish the injuries present and therefore the need for operative intervention in patients with penetrating abdominal trauma. Most trauma centers use an algorithm with multiple diagnostic modalities whose uses are based on the pattern of injuries and the clinical status of the patient.

Prehospital Care

The scope of care that paramedics deliver at the scene of the injury has evolved in parallel with the changing standard of care in the hospital setting. Because most deaths occurred from exsanguination associated with prehospital hypotension, trauma system response has been designed to minimize care in the field and expedite transport to the emergency department (ED) and to reduce the time to definitive care.

Prehospital personnel must be well trained in properly assessing patients and in transporting them to the closest appropriate facility or trauma center. The receiving hospital should be notified as soon as possible by radio or ground line to give the ED time to prepare and to alert the appropriate staff.

The mode of transportation also must be considered. In an urban setting with multiple appropriate facilities, the best transport is probably by ground. In the rural setting, where the closest facility is typically 25 minutes or more away, trauma patients' best chance for survival may be transport by air ambulance.

Aggressive intravenous fluid administration to maintain or reach normotension is discouraged in patients with penetrating injury unless the patient manifests severe shock or prolonged transport is expected. Military data suggest that prehospital fluid administration can be guided by the patient’s mentation and the character of the radial pulse. Similarly, the recent military experience in the Middle East has led to a resurgence of interest in the use of tourniquets to control extremity hemorrhage in the prehospital setting.

Surgical Therapy

For discussion of surgical therapy, see Surgical Therapy for Penetrating Abdominal Trauma.

Consultations

In general, consultation with a general or trauma surgeon should be undertaken for victims of penetrating trauma.

At some centers, trauma surgeons perform the majority of operative repair, while at others, consultants may be involved as individual injuries are identified. For example, a vascular surgeon may repair major arterial and venous injuries or a urologist may address injuries to the bladder, kidneys, and ureters. Trauma surgeons, even if not directly performing care, should oversee the patient's care and postoperative course.

Transfer

ATLS guidelines exist to help direct the transfer of trauma patients to a designated trauma facility; however, the mode of transportation is not specified. Patients who are potentially unstable and who would require a long ground transport time (ie, >30 min) or a potentially problematic ground transport route (eg, across an inner city) may be better served by air ambulance transport. Airway control is always an important issue and must be addressed appropriately prior to transport.

In general, reasons to transfer patients to a regional resource trauma facility include (1) no operating room or surgeon is available; (2) the patient has multiple or multicavitary injuries; (3) the patient has requirements that cannot be met at the initial receiving facility (eg, neurosurgery, cardiopulmonary bypass, post–solid-organ transplant), or injuries that would overwhelm the initial facility (eg, massive transfusion requirement).

Patients who are unstable or have evidence of injury requiring immediate laparotomy, such as penetrating trauma with vascular injury, should not be transferred until they have had stabilizing surgical intervention. Obviously, if no surgeon is available, transfer may be the only course of action.

Practitioners must be cognizant of Emergency Medical Treatment and Active Labor Act (EMTALA)/Consolidated Omnibus Budget Reconciliation Act (COBRA) violations and document accordingly (see COBRA Laws and EMTALA). This legislation was enacted with the intention of removing economic considerations from important medical decisions in the ED.

Initial Emergency Department Care

A team leader should direct resuscitation and coordinate all care. Depending on the institution, it may be an emergency physician, trauma surgeon, or one of their supervised residents. Given the potential for significant injury, a junior level physician should not lead care without direct oversight.

When the patient arrives in the ED, advanced trauma life support (ATLS) protocols are initiated.[32] The ABCDEs (airway, breathing, circulation, disability, exposure/environment) are assessed. The patient should be placed on a cardiac monitor, pulse oximeter, and 100% nonrebreather oxygen mask. Airway protection and ventilatory support are followed by circulatory resuscitation with fluid infusion.

Antibiotics should be administered to patients undergoing exploration.

Airway

Patients with severe shock or loss of ability to control their airway should be intubated to ensure appropriate oxygenation or ventilation. In general, occult cervical spine injury in penetrating trauma is highly unlikely. Unless there are clear deficits or associated blunt injury, cervical collars are rarely necessary and may hinder resuscitation.

Breathing

Tube thoracostomy or needle decompression should be undertaken immediately for patients with obvious pneumothorax. A patient who is otherwise stable, should have a chest radiograph performed in the trauma room. An upright positioned radiograph during expiration may provide the best evidence of pneumothorax. Ultrasonography for pneumothorax (as part of the Extended Focused Assessment With Sonography for Trauma [eFAST] or Focused Assessment With Sonography for Trauma [FAST] examination) has been shown to be highly accurate and may be used as the initial test, but it should be followed by a radiograph at some point.

Circulation

Resuscitation of the patient with penetrating abdominal trauma begins immediately upon arrival. Fluids should be administered rapidly. Normal saline or lactated Ringer solution can be used for crystalloid resuscitation.

Patients who present with hypotension are already in class III shock (30-40% blood volume loss) and should receive blood products as soon as possible; the same is true of patients with obvious significant bleeding. Consideration should be given to the early activation of massive transfusion protocols and damage control resuscitation in appropriate patients. Specific triggers for each remain to be better elucidated. Arterial access for continuous blood pressure monitoring is standard. Efforts should be made to limit hypothermia, including warm blankets and prewarmed fluids.

The route of intravenous access is important. Large-bore peripheral intravenous catheters (at least 2) in the upper extremities are the resuscitation lines of choice. These allow for rapid volume/blood infusion versus a central line where the infusion rate is slower.

Extensive debate exists in the literature on the amount and end points for resuscitation prior to definitive control of hemorrhage. Animal data and several studies in humans have suggested that "permissive hypotension"—actively or passively allowing the blood pressure to remain in the hypotensive range (ie, systolic pressure less than 90 mm Hg)—may prevent disruption of clot and dilution of clotting factors while maintaining adequate blood viscosity.

While no definite consensus exists, prevailing thought seems to promote limited resuscitation with avoidance of attempting to raise blood pressure to normal or near-normal levels until hemorrhage is definitively controlled.

Disability and exposure

A rapid and brief evaluation for neurologic deficits should be conducted.

All patients with penetrating trauma should be fully undressed. Complete exposure and head-to-toe visualization of the patient is mandatory in a patient with penetrating abdominal trauma. This includes the buttocks, posterior part of the legs, scalp, posterior part of the neck, and perineum. There is little to be gained by practicing spinal immobilization unless spinal injury is obvious.

Further intervention

Depending on the initial assessment, and in all seriously injured patients, a Foley catheter should be placed if possible to monitor urine output and to check for hematuria. In addition, a nasogastric tube (NGT) or orogastric tube (OGT) should be inserted to evaluate for intragastric blood and to decompress the stomach so as to reduce aspiration risk. Appropriate laboratory specimens should be immediately sent to the laboratory for evaluation.

After the initial evaluation, further evaluation depends on the hemodynamics and mechanism of wounds.

Expectant management

Although surgical management has generally been the standard of care for penetrating abdominal injuries, a study in 90 children by Cigdem et al concluded that in the absence of hemodynamic instability or signs of hollow viscus perforation, the majority of abdominal stab wounds and many gunshot wounds in children can initially be managed nonoperatively.[33]

In this study, patients with hemodynamic instability or signs of bowel perforation underwent immediate laparotomy; the remainder were followed with serial clinical examinations, radiologic evaluation, and hemoglobin levels. Of the 39 children who were managed surgically, 6 (15%) had no significant organ injury found during surgery; of the 51 patients who initially received conservative therapy, 2 children (3.9%) required surgery.[33]

Patients with blood on rectal examination who are otherwise being managed expectantly (mostly stab wounds) should undergo rigid sigmoidoscopy to rule out rectal injury.

Stab wounds

Unstable patients or those with clear-cut peritonitis should undergo exploratory laparotomy.

Stable patients may have local wound exploration to ascertain whether the peritoneum was violated. If this cannot be performed or if flank or thoracoabdominal wounds are present, other methods must be used.

Diagnostic peritoneal lavage (DPL) remains an option, but it is currently being used less frequently. A positive focused assessment with sonography for trauma (FAST) examination result has a high positive predictive value for a therapeutic laparotomy, but a negative FAST examination result cannot be relied upon to rule out injury.

In patients with thoracoabdominal injury, a chest radiograph should be obtained. If no signs of diaphragmatic injury are present, laparoscopy is usually advocated; although some surgeons will elect not to perform this on patient with a right-sided wound, given the low likelihood of delayed complications.

The use of CT scan is still controversial; some centers use it as a screening test in patients with anterior stab wounds, while others feel the cost-benefit ratio is not justified. A triple contrast CT should be performed on patients with penetrating flank wounds.

Essentially all nonoperative patients, except those who have a wound that clearly does not penetrate the abdomen, should be observed for serial examinations. The literature is beginning to support a shortened time frame of 12 hours, but most centers use about 24 hours.

Gunshot wounds

All unstable patients with gunshot wounds should proceed emergently to the operating room (OR). Abdominal and other radiographs (depending on the possible bullet course and number of wounds) should be taken at some point during the patient's care to account for all bullets.

In the past, all patients with gunshot wounds that were clearly nontangential were taken to the OR for exploration. An increasing body of literature supports CT imaging, with either triple contrast or intravenous contrast alone, to evaluate for intra-abdominal or retroperitoneal injury. This has been shown to significantly decrease the need for laparotomy without a concurrent increase in morbidity.

All hollow viscus injuries need emergent laparotomy. However, isolated liver or spleen injuries are sometimes observed or undergo angioembolization.

Patient disposition relates to the type of facility and to the mechanism of and potential for injury. The most common post-ED disposition for patients with penetrating abdominal trauma is to the OR. Any patient with an obvious reason for laparotomy (eg, evisceration, rigid abdomen, hypotension) should be taken directly to the OR following initial evaluation and resuscitation in the ED.

Some facilities do not have a surgical or OR team available 24 hours a day. In this case, these patients must be transferred to an appropriate facility. Similar concerns occur if the patient's injuries overwhelm the available resources at the receiving facility.

Emergency Department Thoracotomy

Victims of penetrating abdominal trauma who lose vital signs or who present with exsanguinating hemorrhage that is not controllable with direct external pressure are candidates for an ED left anterolateral-left thoracotomy. The purpose of this procedure is to relieve cardiac tamponade, control cardiac bleeding, obtain proximal aortic control, and provide open cardiac massage to improve cardiopulmonary cerebral resuscitation efforts.

This procedure is performed only in extremely selected circumstances, since survival from abdominal injury requiring a resuscitative ED thoracotomy is rare. It is much more effective if the arrest is due to cardiac injury with thoracoabdominal trauma. Patients who may be considered for thoracotomy are those who had vital signs on arrival or en route, with or without pulseless electrical activity (PEA) on the cardiac monitor. Thoracotomy is rarely successful in blunt trauma.

The surgical procedure is as follows:

  • After rapidly preparing and draping the entire chest, make a curvilinear incision from the left sternal border of the fifth intercostal space to the table, paralleling the course of the underlying rib.

  • Divide all tissues above the rib with the scalpel.

  • Halt respirations.

  • Using a finger or Kelly clamp, pierce the intercostal muscle bundle above the rib, then divide with a curved Mayo scissor for the length of the incision.

  • Reinflate the lungs.

  • Insert a rib spreader with a ratchet mechanism placed laterally.

  • Open the pericardium longitudinally to avoid injury to the pericardiacophrenic vessels and the phrenic nerve.

  • Subluxing the heart into the left chest allows for open massage.

  • Retract the left lung superiorly using a moist laparotomy pad, and divide the inferior pulmonary ligament using Metzenbaum scissors.[34]

  • The tissues overlying and just lateral to the vertebral bodies contain the aorta, esophagus, thoracic duct, and countless nerves. Usually, blunt dissection frees the aorta enough to place a Satinsky or long, curved DeBakey clamp. In certain circumstances, the aorta is not identified easily, and the aorta and esophagus must be clamped en masse in a patient who is in extremis.

  • Warm saline is essential to prevent cooling of the heart, and pressor support usually is needed as well.[34]

  • The image below shows a patient after a thoracotomy.

    An ED thoracotomy has been performed, and the aort An ED thoracotomy has been performed, and the aorta is cross-clamped. Note the proper positioning of the ratchet mechanism of the rib spreader to allow extension of the incision to the right chest for a clamshell thoracotomy if needed. This patient arrived with a weak pulse and a systolic blood pressure of 40 mm Hg and promptly died on the ED stretcher. An ED thoracotomy was performed for cardiopulmonary-cerebral resuscitation.
 

Medication

Medication Summary

In general, medications used to treat victims of penetrating abdominal trauma fall into discrete categories. Analgesics, anxiolytics, antimicrobials (skin and enteric flora), immune boosters (tetanus booster), and neuromuscular blockers comprise the major classes of pharmacotherapeutic agents used for these patients.

Analgesics

Class Summary

Pain control is essential to quality patient care. Appropriate and sufficient pain control is important. Concerns still exist regarding pain control in patients undergoing observation. A reasonable protocol should be developed by institutions in consultation with the trauma service or consulting surgeon. Postoperatively, analgesics are essential to ensure patient comfort, promote pulmonary toilet, and enable physical therapy regimens. A review of opioid equivalents and conversions may be found in the following reference article:  http://emedicine.medscape.com/article/2138678-overview

Morphine sulfate (MS Contin, Duramorph, Astramorph, Avinza, Infumorph, Kadian, MorphaBond, Arymo ER)

Morphine is the drug of choice for analgesia due to reliable and predictable effects, safety profile, and ease of reversibility with naloxone. Various IV doses are used; the dose is commonly titrated until desired effect is obtained. Postoperatively, oral morphine sulfate extended-release formulations may be prescribed for severe pain, with immediate release preparations used for breakthrough pain. Arymo ER is a morphine sulfate abuse-deterrent derivative.

Fentanyl citrate (Duragesic, Onsolis, Actiq, Fentora, Abstral, Ionsys, Lazanda, Onsolis, Sublimaze, Subsys)

Fentanyl is a potent narcotic analgesic with much shorter half-life than morphine sulfate. This agent is a common choice for procedural sedation analgesia. It is excellent for analgesic action of short duration during anesthesia and immediate postoperative period. It is also an excellent choice for pain management and sedation, with short duration (30-60 min) and easy to titrate.

Fentanyl is easily and quickly reversed by naloxone. After the initial dose, subsequent doses should not be titrated more frequently than q3h or q6h thereafter. Most patients are controlled with 72-h dosing intervals when using transdermal dosage form, although some patients require 48-h dosing intervals.

Anxiolytics

Class Summary

Patients with painful injuries usually experience significant anxiety. Anxiolytics allow the clinician to administer a smaller analgesic dose to achieve the same effect.

Lorazepam (Ativan, Lorazepam Intensol)

Lorazepam is a sedative-hypnotic with short onset of effects and relatively long half-life. By increasing the action of gamma-aminobutyric acid (GABA), a major inhibitory neurotransmitter in the brain, lorazepam may depress all levels of the CNS, including the limbic and reticular formation. This agent is an excellent choice when the patient must be sedated for longer than 24 h.

Antibiotics

Class Summary

Antibiotic prophylaxis is proven to reduce postoperative surgical infections after penetrating abdominal trauma.

The Eastern Association for the Surgery of Trauma (EAST) Practice Management Guidelines Work Group has published evidence-based consensus guidelines addressing the use and duration of antimicrobial prophylaxis after penetrating abdominal trauma. They recommended, in the absence of hollow viscus injury, administering a single dose of a broad-spectrum antimicrobial agent that provides both aerobic and anaerobic coverage.

No specific agent is recommended, but it may be a single agent with beta-lactam coverage or combination therapy with an aminoglycoside and clindamycin or metronidazole. In patients with a hollow viscus injury, antimicrobial prophylaxis should be extended to 24 hours.[35]

While some controversies still exist regarding therapy for seriously injured patients, for the emergency physician, the key point is to start antibiotics in the ED. If the patient requires emergent laparotomy and must be rapidly transported, it may be done upon arrival in the operating room.

Cefotetan (Cefotan)

Cefotetan is a second-generation cephalosporin with activity against some gram-positive cocci, gram-negative rod infections, and anaerobic bacteria. It inhibits bacterial cell wall synthesis by binding to one or more of the penicillin-binding proteins; it inhibits the final transpeptidation step of peptidoglycan synthesis, resulting in cell wall death.

Infections caused by cephalosporin- or penicillin-resistant gram-negative bacteria may respond to cefotetan. Antibiotics have proved effective in decreasing the rate of postoperative wound infection and improving outcome in patients with intraperitoneal infection and septicemia.

Metronidazole hydrochloride (Flagyl, First-Metronidazole 100, First-Metronidazole 50, Metro)

Metronidazole is an imidazole ring-based antibiotic active against various anaerobic bacteria and protozoa. It is used in combination with other antimicrobial agents (except for Clostridium difficile enterocolitis).

Gentamicin

An aminoglycoside antibiotic for gram-negative coverage, gentamicin is used in combination with an agent against gram-positive organisms and one that covers anaerobes. This is not the drug of choice. Consider gentamicin if penicillins or other less toxic drugs are contraindicated, when clinically indicated, and in mixed infections caused by susceptible staphylococci and gram-negative organisms.

Dosing regimens are numerous; adjust dose based on creatinine clearance and changes in volume of distribution. Gentamicin may be administered IV or IM.

Vancomycin hydrochloride (Vancocin, First-Vancomycin 25, First-Vancomycin 50, Vancomycin + SyrSpend PH4)

A potent antibiotic directed against gram-positive organisms and active against enterococcal species, vancomycin is useful in the treatment of septicemia and skin-structure infections. It is indicated for patients who cannot receive or who are unresponsive to penicillins and cephalosporins or who have infections with resistant staphylococci.

For penetrating abdominal injuries, vancomycin is combined with an agent active against enteric flora and/or anaerobes. To avoid toxicity, the current recommendation is to assay trough levels after the third dose, with the sample drawn 0.5 h prior to next dosing. Use creatinine clearance to adjust dose in patients with renal impairment.

Vancomycin is used in conjunction with gentamicin for prophylaxis in penicillin-allergic patients undergoing GI or GU procedures.

Neuromuscular Blocking Agents

Class Summary

Many patients with penetrating abdominal trauma require urgent airway control. Neuromuscular blocking agents produce paralysis and are administered immediately after the induction agent in rapid-sequence intubation.

Succinylcholine (Anectine Chloride, Quelicin)

Succinylcholine is a prototypical depolarizing neuromuscular blocker; it is ultra–short-acting and predictable in onset (< 1 min) and duration (4-6 min). This agent is highly ionized and relatively fat-insoluble; it does not readily cross placenta. Pediatric patients must be pretreated with atropine to avoid bradycardia and cardiac arrest. Bradycardia may also occur in adults but more commonly is associated with administration of either a higher dose or a second dose.

Vecuronium (Norcuron)

Vecuronium is a prototypical, nondepolarizing, neuromuscular blocking agent that reliably results in muscular paralysis. For intubation and maintenance of paralysis, a continuous infusion may be used. Infants are more sensitive to neuromuscular blockade activity; recovery is prolonged by 50%, although the same dose is used. Vecuronium is not recommended for use in neonates.

Immune Enhancement

Class Summary

Penetrating abdominal trauma resulting in wounds contaminated with either dirt or debris or wounds caused by metallic objects carry a risk of Clostridium tetani infection. Tetanus results from elaboration of an exotoxin by C tetani.

A booster injection in previously immunized individuals is recommended to prevent this potentially lethal syndrome.. Patients who may not have been immunized against C tetani products (eg, immigrants) should receive tetanus immune globulin (Hyper-Tet).

Tetanus toxoid adsorbed or fluid

This agent induces active immunity against tetanus in selected patients. The immunizing agents of choice for most adults and children older than 7 years are tetanus and diphtheria toxoids. It is necessary to administer booster doses to maintain tetanus immunity throughout life. Pregnant patients should receive only tetanus toxoid, not a diphtheria antigen-containing product. In children and adults, this agent may be administered into the deltoid or midlateral thigh muscles. In infants, the preferred site of administration is the mid thigh laterally.