Perforated Viscus

Perforated Viscus Objectives

Upon completion of this module, the learner will be able to:

  • Describe the classic history and physical examination findings for a perforated viscus
  • Discuss the advantages and limitations of the different radiologic studies utilized in the diagnosis a perforated viscus
  • Describe the treatment priorities for perforated viscus
  • Recognize the acuity of a perforated viscus and the need for rapid diagnosis and treatment

Acute gastrointestinal perforation should be considered as one of the life-threatening causes of acute abdominal pain in the ill patient. As in the case of a ruptured aortic abdominal aneurysm or mesenteric ischemia, a patient with a perforated viscus needs to be expediently diagnosed, simultaneously resuscitated, and receive timely surgical consultation. Despite advances in surgical and post-surgical care, mortality remains 30-50%. Reliance on historical and clinical findings is paramount when the initial studies may not reveal the characteristic radiological signs of pneumoperitoneum.

Classic Presentation

The patient with a perforated viscus classically presents with sudden and severe abdominal pain. The pain may initially have a focal location – especially in perforated peptic ulcers ? but a generalized peritonitis shortly ensues as the leakage of air, chemical and bacterial products contaminates the peritoneum. On abdominal exam, the patient may have board like rigidity, involuntary guarding, and significant diffuse rebound tenderness.

Rapid contamination of the perforated site with a chemical and bacterial milieu may set up a SIRS syndrome with the patient appearing acutely toxic, significantly hypotensive, tachypneic, tachycardic and febrile. These patients are in shock or even present as moribund. It is essential to include other life threatening causes of acute abdominal pain in the differential such as AAA/aortic dissection and mesenteric ischemia.

In time, localization of the anatomic site of perforation may occur with pain in a particular location due to peritoneal defenses with abscess formation. One example could be the case of a ruptured appendix presenting days after the original perforation with persistent RLQ pain and localized rigidity.

Immunocompromised patients and critically ill patients with other co-morbid states are at greater risk for perforation, yet may have less obvious presentations of acute abdominal pain. Patients with large volume pneumoperitoneum from iatrogenic accidents such a perforated colon during routine colonoscopy may not have the obvious rigid abdomen or toxic appearance until later in the disease process.

Diagnostic Testing

Plain radiography

Plain radiography has a sensitivity demonstrating pneumoperitoneum ranging from 30 to 80%, thus making it a questionable initial study for identifying a perforated viscus. Having the patient sit upright or in left lateral decubitus positions for at least 10 minutes will allow free air to rise to its highest elevation in the body thus increasing sensitivity.

Proponents of plain radiography as an initial screening exam point to the speed in which a plain film can be accomplished compared to CT. Thus, a patient may more expediently go to surgery with a positive plain x-ray film. Plain radiography also has the advantage of being obtainable portably at the bedside with little interruption in patient monitoring or care. Critics of plain radiography relate that 50 % of patients with a perforated viscus on laparotomy had no findings of pneumoperitoneum of plain film and that 10-14% of pneumoperitoneums may have a non surgical cause.

CT scan

Computerized Tomography is currently the most sensitive and specific imaging technique in evaluating a perforated viscus. Its numerous advantages include detecting extremely small volume pneumoperitoneum, retroperitoneal air, potential locations of the actual site or organ that has perforated and finally providing alternative diagnoses if no free intra-abdominal air is identified.

Many oral and IV protocols exist with sensitivities for detecting a perforated viscus in the 95-98 % range. Its use necessitates the patient leaving the ED sometimes for a prolonged period of time which is a consideration to make in an unstable patient undergoing resuscitation.

Bedside Ultrasound

Recently, attention has been made to using bedside ultrasound as another highly sensitive modality in looking for pneumoperitoneum. Characteristic ultrasound signs have been repeatedly demonstrated as evidence of a pneumoperitoneum. The “ring down” artifact and enhancement of the peritoneal stripe over the liver can be used in experienced hands to achieve an almost 93 % sensitivity. Thus as more ultrasound experience is developed, looking for pneumoperitoneum may join current FAST and aortic exams in evaluating the patient with acute abdominal pain.

In the video to the left (courtesy of Dr. Blaivas), pneumoperitoneum is seen as the hypoechoic (dark) space between two hyperechoic (bright) lines above the liver in this RUQ FAST view. It doesn’t move with respirations. This is the “enhancement of the peritoneal stripe sign.”

Laboratory studies

These should be ordered with the goal of gathering information critical for the surgical control of the perforation site thus type and screen/cross, initial hemoglobin/hematocrit, platelet and coagulation studies should be considered as a minimum. Additional laboratories such as the WBC, blood gas, lactic acid, renal and liver function, lipase/amylase and urinalysis are also of value in guiding diagnosis, resuscitation, and post-surgical care.

How do I make the diagnosis?

The ill appearing patient presenting with acute severe abdominal pain and a characteristic abdominal exam should be considered to have a perforated viscus. Further bedside ultrasound examination that reveals no AAA or fluid collections thought to be hemoperitoneum should heighten that suspicion. Use of a portable upright CXR or left lateral decubitus abdomen view that reveals a pneumoperitoneum or even specific signs on bedside ultrasound may rule in a perforated viscus, thus necessitating an immediate surgical consultation. If a pneumoperitoneum is not ruled in by these methods then further CT imaging is done in conjunction with the surgeon while resuscitation therapies are continued.

Treatment

The initial management of a perforated viscus focuses on resuscitation, appropriate antibiotic selection, and immediate surgical consultation. The acutely ill patient with a suspected perforated viscus should be placed in the Emergency Department resuscitation area with use of the ED safety net (2 large bore IVs, oxygen, monitoring equipment). Immediate use of crystalloid fluids generally start at 2 Liters wide open flow and further aggressive fluids delivered to establish tissue perfusion.

Antibiotic selection tends to follow suspected sites of perforation as lesions of the foregut (stomach, first portion duodenum, PUD) tend to have lower bacterial colonization compared to the distal organs such as the ileum and colon. The colon has significantly more anaerobic organisms than the foregut, thus necessitating broader empiric coverage. In general, a perforated viscus should have antibiotic coverage to treat gram negative, gram positive, and anaerobic organisms. Some appropriate choices include ciprofloxacin and metronidazole, piperacillin/tazobactam, or imipenem.

Surgical management of the site of perforation involves immediate involvement of a general surgeon whenever perforation is suspected. The majority of patients will require a laparotomy in the OR with complete exploration of the GI tract and extensive decontamination of spilled contents with repair of the perforated site.

Few exceptions to this may include self sealing lesions – such as a duodenal PUD perforation being covered by omentum – which may not require laparotomy. However, those decisions are best left to the surgeon to decide with ongoing resuscitation in the ED and rapid transfer of the patient to the OR or ICU.

Alternative methods of source control are being investigated such as the use of endoscopic clips and other devices when an iatrogenetic injury to the colon occurs during colonoscopy. In addition, interventional radiology offers percutaneous drainage of abscesses as adjuncts to surgical source control and may serve as the only mechanical invention needed in limited situations such as well defined colonic diverticular abscesses.

Disposition

  • OR
  • ICU
  • Interventional Radiology
  • Stable patients with abscesses secondary to colonic perforation that can be drained by interventional radiology may be candidates for floor admission

Pearls and Pitfalls

  • 50% of patients with perforated viscus during laparotomy may demonstrate no pneumoperitoneum on plain x-rays
  • Conversely 10-14% of patients with pneumoperitoneum may have a non surgical cause of free air
  • Early surgical consultation for source control with simultaneous resuscitation and antibiotics are the mainstays to therapy

Credits

  • Written by: Jeff Van Denmark, University of Texas, Southwestern, Dallas Texas
  • Edited by: David Gordon, Duke University, Durham, North Carolina

Selected References

  • Blaivas M, Kirkpatrick AW, Rodriguez-Galvez M, Ball CG. Sonographic depiction of intraperitoneal free air. J Trauma. 2009 Sep;67(3):675.
  • Gajic O, Urrutia LE, Sewani H, Schroeder DR, Cullinane DC, Peters SG. Acute abdomen in the medical intensive care unit. Crit Care Med. 2002 Jun;30(6):1187-90.
  • Jones R. Recognition of pneumoperitoneum using bedside ultrasound in critically ill patients presenting with acute abdominal pain. Am J Emerg Med. 2007 Sep;25(7):838-41
  • Langell JT, Mulvihill SJ. Gastrointestinal perforation and the acute abdomen. Med Clin North Am. 2008 May;92(3):599-625, viii-ix. Review.
  • Mularski RA, Sippel JM, Osborne ML. Pneumoperitoneum: a review of nonsurgical causes. Crit Care Med. 2000 Jul;28(7):2638-44. Review.

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