Intestinal Perforation Treatment & Management

The mainstay of treatment for intestinal perforation is surgery.^[14] Emergency medical care includes the following steps:

• Establish intravenous access, and initiate crystalloid therapy in patients with clinical signs of dehydration or septicemia.
• Do not give anything by mouth.
• Start intravenous administration of antibiotics to patients with signs of septicemia. Antibiotics should cover aerobic and anaerobic organisms. The goals of antibiotic treatment are to eradicate infection and to minimize related postoperative complications.

However, if symptoms and signs of generalized peritonitis are absent, a nonoperative policy may be used with antibiotic therapy directed against gram-negative and anaerobic bacteria.^{[15, 16]}

Antibiotics

Antibiotics have proven effective in decreasing the rate of postoperative wound infection and in improving outcome in patients with intraperitoneal infection and septicemia.

Metronidazole (Flagyl) is typically used in combination with an aminoglycoside to provide broad gram-negative and anaerobic coverage. It is reduced to a product that interacts with deoxyribonucleic acid (DNA) to cause a loss of helical DNA structure and strand breakage, resulting in inhibition of protein synthesis and cell death in susceptible organisms. Adult dosing is 7.5 mg/kg IV before surgery. Pediatric dosing is 15-30 mg/kg/d IV divided bid/tid for 7 d. It is a pregnancy category B drug.

Gentamicin (Garamycin, Genoptic, Gentacidin) is an aminoglycoside antibiotic with gram-negative coverage. It is used in combination with both an agent against gram-positive organisms and one that covers anaerobes. Although it is not the DOC, 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 CrCl and changes in volume of distribution. It may be given IV/IM. In adults, the loading dose before surgery is 2 mg/kg IV; thereafter, dosing is 3-5 mg/kg/d divided tid/qid. In infants, dosing is 7.5 mg/kg/d IV divided tid. In children, dosing is 6-7.5 mg/kg/d IV divided tid. It is a pregnancy category C drug.

Cefotetan (Cefotan) is a second-generation cephalosporin that inhibits bacterial cell wall synthesis by binding to 1 or more of the penicillin-binding proteins. It inhibits the final transpeptidation step of peptidoglycan synthesis, resulting in cell wall death. Adult dosing is 2 g IV once before surgery. In children < 3 months, dosing is not established. In those >3 months, dosing is 30-40 mg/kg IV once before surgery. It is a pregnancy category B drug.

Cefoxitin (Mefoxin) is also a second-generation cephalosporin that inhibits bacterial cell wall synthesis by binding to 1 or more of the penicillin-binding proteins. It inhibits the final transpeptidation step of peptidoglycan synthesis, resulting in cell wall death. Adult dosing is 2 g IV once before surgery, followed by 4 doses of 2 g IV q4-6h. In children < 3 months, dosing is not established. In those >3 months, dosing is 30-40 mg/kg IV before surgery, followed by 3 doses of 2 g IV q4-6h for 24 h. It is a pregnancy category B drug.

Cefoperazone sodium (Cefobid) is a third-generation cephalosporin that inhibits bacterial cell wall synthesis by binding to 1 or more of the penicillin-binding proteins. It inhibits the final transpeptidation step of peptidoglycan synthesis, resulting in cell wall death. Adult dosing is 2-4 g/d IV divided q12h. Pediatric dosing is 100-150 mg/kg/d IV divided q8-12h, not to exceed 12 g/d. It is a pregnancy category B drug.

The goals of surgical therapy are as follows:

• To correct the underlying anatomical problem
• To correct the cause of peritonitis
• To remove any foreign material in the peritoneal cavity that might inhibit WBC function and promote bacterial growth (eg, feces, food, bile, gastric or intestinal secretions, blood)

• Correct any fluid or electrolyte imbalance. Replace extracellular fluid losses by administering Hartmann solution or a similar solution that has an electrolyte composition similar to plasma.
• Central venous pressure (CVP) monitoring is essential in critically ill and/or elderly patients, in whom cardiac impairment may be exacerbated by large fluid loss.
• Administer systemic antibiotics (eg, ampicillin, gentamicin, metronidazole), making a best estimation regarding the likely organisms.
• Nasogastric suction is required to empty the stomach and reduce the risk of further vomiting.
• Urinary catheterization is used to assess urinary flow and fluid replacement.
• Administer analgesics, such as morphine, in small intravenous doses, preferably as a continuous infusion.

Operative management depends on the cause of perforation. Perform urgent surgery either on patients not responding to resuscitation or following stabilization and maintenance of adequate urine output. All necrotic material and contaminated fluid should be removed and accompanied by lavage with antibiotics (tetracycline 1 mg/mL). Decompress distended bowel via a nasogastric tube.

Laparoscopic or laparoscopic-assisted (minilaparotomy) surgery is also being increasingly used with outcomes comparable with conventional laparotomy. Experience and the advancement in accessories have enabled endoscopic repair of a significant number of intestinal perforations, such as iatrogenic perforation. Management of such cases needs to be individualized to the patient.

In a study involving 934 patients with sigmoid diverticulitis, Ritz et al found that the risk of free perforation in acute sigmoid diverticulitis decreases with the increases in the number of previous episodes of sigmoid diverticulitis. They concluded that the first episode has the highest risk for a free perforation. Therefore, the indication for colectomy should not be made based on the potential risk of free perforation.^[17]

• Intravenous replacement therapy: The aim of intravenous replacement therapy is to maintain intravascular volume and hydrate the patient. Monitor by CVP measurement and urinary output.
• Nasogastric drainage: Perform nasogastric drainage continuously until drainage becomes minimal. At that stage, the nasogastric tube may be removed.
• Antibiotics: Continue administration of the antibiotics commenced preoperatively unless the results of cultures taken at the time of the operation reveal that the causative organisms are resistant to them.

  • The goal of antibiotic therapy is to achieve levels of antibiotics at the site of infection that exceed the minimum inhibitory concentrations for the pathogens present.
  • In the presence of intra-abdominal infections, gastrointestinal function is often impaired; therefore, oral antibiotics are not efficacious, and intravenous antibiotics are recommended.
  • If no obvious improvement in the patient's condition occurs within 2-3 days, consider the following possibilities:
    • The initial operative procedure was inadequate.
    • Complications have occurred.
    • A superinfection has occurred at a new site.
    • The dose of antibiotic is inadequate.
    • The antibiotics used do not provide adequate coverage for anaerobes and gram-negative organisms.
• Analgesics: Analgesics, such as intravenous morphine, should be given continuously or in small doses at frequent intervals.

For patients treated with a nonsurgical approach, follow-up care consists of the following:

• If the pain and fever settle within a few days, the patient can go home with a barium enema and sigmoidoscopy to be performed on an outpatient basis a few weeks later.
• Routinely perform colonoscopy if any doubt about the possibility of malignancy exists after barium enema examination.
• If the patient continues to be pyrexial and the pain does not settle or the lower abdominal mass is enlarged, ultrasound scan and a water-soluble contrast enema may be necessary.
• If abscess is visible on ultrasound examination, it may be drained under ultrasound guidance.
• If the infection process fails to settle despite adequate conservative treatment, operation is indicated (primary resection, irrigation, and primary anastomosis).

• Wound infection

  • Wound infection rates correlate with the bacterial load in the bowel, so this complication occurs more often with colonic perforation (eg, perforated diverticulitis).
  • The judicious use of prophylactic antibiotics has been demonstrated to reduce the incidence of wound infection in contaminated and potentially contaminated wounds.
• Wound failure

  • Wound failure (partial or total disruption of any or all layers of the operative wound) may occur early (ie, wound dehiscence) or late (ie, incisional hernia).
  • The following factors are associated with wound failure:
    • Malnutrition
    • Sepsis
    • Uremia
    • Diabetes mellitus
    • Corticosteroid therapy
    • Obesity
    • Heavy coughing
    • Hematoma (with or without infection)
• Localized abdominal abscess
• Multiorgan failure and septic shock

  • Septicemia is defined as proliferation of bacteria in the bloodstream resulting in systemic manifestations such as rigors, fever, hypothermia (in gram-negative septicemia with endotoxemia), leukocytosis or leukopenia (in profound septicemia), tachycardia, and circulatory collapse.
  • Septic shock is associated with a combination of the following:
    • Loss of vasomotor tone
    • Increased capillary permeability
    • Myocardial depression
    • Consumption of WBCs and platelets
    • Dissemination of powerful vasoactive substances, such as histamine, serotonin, and prostaglandins, resulting in capillary permeability
    • Complement activation and damage of capillary endothelium
  • Gram-negative infections are associated with a much worse prognosis than gram-positive infections, possibly because of associated endotoxemia.
• Renal failure and fluid, electrolyte, and pH imbalance
• Gastrointestinal mucosal hemorrhage: This complication is usually associated with failure of multiple organ systems and is probably related to a defect in the protective gastric mucosa.
• Mechanical intestinal obstruction: Mechanical obstruction of the intestine is most often caused by postoperative adhesions.
• Postoperative delirium: The following factors may cause a predisposition to postoperative delirium:

  • Advanced age
  • Drug dependency
  • Dementia
  • Metabolic abnormalities
  • Infections
  • Previous history of delirium
  • Hypoxia
  • Intraoperative/postoperative hypotension

Outcome is improved with early diagnosis and treatment. The following factors increase the risk of death:

• Advanced age
• Presence of preexisting underlying disease
• Malnutrition
• The nature of the primary cause of bowel perforation
• Appearance of complications

Medicolegal pitfalls include the following:

• Failure to diagnose bowel perforation and to provide appropriate care
• Failure to recognize the need for urgent surgical intervention and delay of surgical treatment for additional tests despite obvious changes in a patient's hemodynamic status and clinical findings