Chapter 85. Acute Pancreatitis in the Critically Ill

• Hypoperfusion injury is the most important of many possible causes of pancreatitis in the ICU setting.
• Serial computed tomography is most useful in confirming the diagnosis and in following the inflammatory process.
• The likelihood of multisystem failure is high, and preventive measures must be instituted early.
• Initial treatment is supportive, with aggressive fluid and electrolyte replacement and close monitoring of hemodynamic, pulmonary, and renal status.
• Surgical intervention is indicated for deteriorating patients with a surgically correctable lesion and in patients with complications of the disease, such as major hemorrhage, abscess, or symptomatic pseudocyst.
• Close supervision by an experienced abdominal surgeon in collaboration with an intensivist is important in recognizing the indications for surgical exploration.

Acute pancreatitis can be a frustrating disease to diagnose and treat. Causes are myriad and poorly understood, pathologic variation is great, diagnosis is often difficult, and treatment in most cases is nonspecific and supportive only. Pancreatitis usually presents as a self-limiting disease from which the patient recovers without complication or intervention. In its most severe form (approximately 10% of cases), it is a potentially lethal disease that is complicated by multisystem failure and sepsis, often requires sophisticated intensive care and judiciously timed surgical débridement, and has a mortality rate of up to 30% to 40%.1–4 Most intensivists therefore are quite familiar with the patient who presents with acute necrotizing pancreatitis and who may occupy a bed for many months, often ultimately dying of septic complications5 that are generalized or are related to the secondary infection of pancreatic necrosis.6

The subject of this chapter is the increasingly recognized entity of acute pancreatitis in the patient who is already critically ill from other causes. Discussion will focus on the associated diseases reported to date, the pathogenesis of this unusual form, its recognition, and its management.

Many causes of acute pancreatitis have been recognized, the most common being alcohol and gallstones. Table 85-1 lists the reported causes of acute pancreatitis.

Whatever the initiating cause, the pathogenetic mechanism common to all forms of acute pancreatitis seems to be an intense systemic inflammatory response syndrome (SIRS) caused by the release of activated pancreatic enzymes7,8 and mediated by cytokines, immunocytes, and the complement system. Inflammatory cytokines (such as tumor necrosis factor) cause macrophages to migrate into tissues distant from the pancreas, including lungs and kidneys. Immunocytes attracted by cytokines released ...