Blunt Abdominal Trauma Clinical Presentation

Initially, evaluation and resuscitation of a trauma patient occur simultaneously. In general, do not obtain a detailed history until life-threatening injuries have been identified and therapy has been initiated. The initial assessment begins at the scene of the injury, with information provided by the patient, family, bystanders, or paramedics, or police.

Important factors relevant to the care of a patient with blunt abdominal trauma, specifically those involving motor vehicles, include the following:

• The extent of vehicular damage
• Whether prolonged extrication was required
• Whether the passenger space was intruded
• Whether a passenger died
• Whether the person was ejected from the vehicle
• The role of safety devices such as seat belts and airbags
• The presence of alcohol or drug use
• The presence of a head or spinal cord injury
• Whether psychiatric problems were evident

Important elements of the pertinent history include the following:

• Allergies
• Medications
• Past medical and surgical history
• Time of last meal
• Immunization status
• Events leading to the incident
• Social history, including history of substance abuse
• Information from family and friends

The mnemonic AMPLE (A llergies, M edications, P ast medical history, L ast meal or other intake, and E vents leading to presentation) is often useful as a means of remembering key elements of the history.

A history of out-of-hospital hypotension is a predictor of more significant intra-abdominal injuries. Even if the patient is normotensive at arrival in the emergency department (ED), he or she should be considered to be at increased risk.

Primary survey

Resuscitation is performed concomitantly and continues as the physical examination is completed. Priorities in resuscitation and diagnosis are established on the basis of hemodynamic stability and the degree of injury. The goal of the primary survey, as directed by the Advanced Trauma Life Support (ATLS) protocol, is to identify and expediently treat life-threatening injuries. The protocol includes the following:

• Airway, with cervical spine precautions
• Breathing
• Circulation
• Disability
• Exposure

It is imperative for all personnel involved in the direct care of a trauma patient to exercise universal precautions against body fluid exposure. The incidence of infectious diseases (eg, HIV, hepatitis) is significantly higher in trauma patients than in the general public, with some centers reporting rates as high as 19%. Even in medical centers with relatively low rates of communicable diseases, safely determining who is infected with such pathogens is impossible.

The standard barrier precautions include a hat, eye shield, face mask, gown, gloves, and shoe covers. Unannounced trauma arrival is probably the most common situation that leads to a breach in barrier precautions. Personnel must be instructed to adhere to these guidelines at all times, even if it means a 30-second delay in patient care.

Secondary survey

After an appropriate primary survey and initiation of resuscitation, attention should be focused on the secondary survey of the abdomen. The secondary survey is the identification of all injuries via a head-to-toe examination. For life-threatening injuries that necessitate emergency surgery, a comprehensive secondary survey should be delayed until the patient has been stabilized.

At the other end of the spectrum are victims of blunt trauma who have a benign abdomen upon initial presentation. Many injuries initially are occult and manifest over time. Frequent serial examinations, in conjunction with the appropriate diagnostic studies, such as abdominal computed tomography (CT) and bedside ultrasonography, are essential in any patient with a significant mechanism of injury.

The evaluation of a patient with blunt abdominal trauma must be accomplished with the entire patient in mind, with all injuries prioritized accordingly. This implies that injuries involving the head, the respiratory system, or the cardiovascular system may take precedence over an abdominal injury.

The abdomen should neither be ignored nor be the sole focus of the treating clinician and surgeon. In an unstable patient, the question of abdominal involvement must be expediently addressed. This is accomplished by identifying free intra-abdominal fluid with diagnostic peritoneal lavage (DPL) or focused assessment with sonography for trauma (FAST). The objective is rapid identification of those patients who need a laparotomy.

The initial clinical assessment of patients with blunt abdominal trauma is often difficult and notably inaccurate. Associated injuries often cause tenderness and spasms in the abdominal wall and make diagnosis difficult. Lower rib fractures, pelvic fractures, and abdominal wall contusions may mimic the signs of peritonitis. In a collected series of 955 patients, Powell et al reported that clinical evaluation alone has an accuracy rate of only 65% for detecting the presence or absence of intraperitoneal blood.^[5]

In general, accuracy increases if the patient is reevaluated repeatedly and at frequent intervals. However, repeated examinations may not be feasible in patients who need general anesthesia and surgery for other injuries. The greatest compromise of the physical examination occurs in the setting of neurologic dysfunction, which may be caused by head injury or substance abuse.

The most reliable signs and symptoms in alert patients are pain, tenderness, gastrointestinal hemorrhage, hypovolemia, and evidence of peritoneal irritation. However, large amounts of blood can accumulate in the peritoneal and pelvic cavities without any significant or early changes in the physical examination findings. Bradycardia may indicate the presence of free intraperitoneal blood in a patient with blunt abdominal injuries.

The respiratory pattern should be observed because abdominal breathing may indicate spinal cord injury. A sensory examination of the chest and abdomen should be performed to evaluate the potential for spinal cord injury. Spinal cord injury may interfere with the accurate assessment of the abdomen by causing decreased or absent pain perception.

The abdominal examination must be systematic. The abdomen is inspected for abrasions or ecchymosis. Particular attention should be paid to injury patterns that predict the potential for intra-abdominal trauma (eg, lap belt abrasions, steering wheel–shaped contusions). In most studies, lap belt marks have been correlated with rupture of the small intestine and an increased incidence of other intra-abdominal injuries.

Ecchymosis involving the flanks (Grey Turner sign) or the umbilicus (Cullen sign) indicates retroperitoneal hemorrhage, but this is usually delayed for several hours to days.

Visual inspection for abdominal distention, which may be due to pneumoperitoneum, gastric dilatation secondary to assisted ventilation or swallowing of air, or ileus produced by peritoneal irritation, is important.

Auscultation of bowel sounds in the thorax may indicate the presence of a diaphragmatic injury. Abdominal bruit may indicate underlying vascular disease or traumatic arteriovenous fistula.

Palpation may reveal local or generalized tenderness, guarding, rigidity, or rebound tenderness, which suggests peritoneal injury. Such signs appearing soon after an injury suggest leakage of intestinal content. Peritonitis due to intra-abdominal hemorrhage may take several hours to develop.

Fullness and doughy consistency on palpation may indicate intra-abdominal hemorrhage. Crepitation or instability of the lower thoracic cage indicates the potential for splenic or hepatic injuries associated with lower rib injuries.

Tenderness on percussion constitutes a peritoneal sign. Tenderness mandates further evaluation and probably surgical consultation.

Rectal and bimanual vaginal pelvic examinations should be performed.^[6] A rectal examination should be done to search for evidence of bony penetration resulting from a pelvic fracture, and the stool should be evaluated for gross or occult blood. The evaluation of rectal tone is important for determining the patient’s neurologic status, and palpation of a high-riding prostate suggests urethral injury.

The genitals and perineum should be examined for soft tissue injuries, bleeding, and hematoma. Pelvic instability indicates the potential for lower urinary tract injury, as well as pelvic and retroperitoneal hematoma. Open pelvic fractures are associated with a mortality rate exceeding 50%.

A nasogastric tube should be placed routinely (in the absence of contraindications, eg, basilar skull fracture) to decompress the stomach and to assess for the presence of blood. If the patient has evidence of a maxillofacial injury, an orogastric tube is preferred.

As the assessment continues, a Foley catheter is placed and a sample of urine is sent for analysis for microscopic hematuria. If injury to the urethra or bladder is suggested because of an associated pelvic fracture, then a retrograde urethrogram is performed before catheterization.

With respect to the primary and secondary surveys, pediatric patients are assessed and treated—at least initially—as adults. However, there are obvious anatomic and clinical differences between children and adults that must be kept in mind, including the following:

• A pediatric patient’s physiologic response to injury is different.
• Effective communication with a child is not always possible.
• Physical examination findings become more important in children.
• A pediatric patient’s blood volume is smaller, predisposing to rapid exsanguinations.
• Technical procedures in pediatric patients tend to be more time consuming and challenging.
• A child’s relatively large body surface area contributes to rapid heat loss.

Perhaps the most significant difference between pediatric and adult blunt trauma is that, for the most part, pediatric patients can be resuscitated and treated nonoperatively. Some pediatric surgeons often transfuse up to 40 mL/kg of blood products in an effort to stabilize a pediatric patient. Obviously, if this fails and the child continues to be unstable, laparotomy is indicated.

Tertiary survey

The concept of the tertiary trauma survey was first introduced by Enderson et al to assist in the diagnosis of any injuries that may have been missed during the primary and secondary surveys.^[7] The tertiary survey involves a repetition of the primary and secondary surveys and a revision of all laboratory and radiographic studies. In 1 study, a tertiary trauma survey detected 56% of injuries missed during the initial assessment within 24 hours of admission.^[8]