Pancreatitis is a typically painful inflammation of the pancreas which can present as an acute disease or have a chronic nature. The overall incidence of pancreatitis is between 4.8 and 24.2 per 100,000 persons. It is usually caused by gallstones or alcohol, but can be idiopathic, and may on rare occasions have a hereditary nature. Less common causes of pancreatitis include infections (mumps), trauma (steering wheel injury during MVA), tumors, post-ERCP, autoimmune, and adverse effects of medication.
Pancreatitis results from an insult or injury which activates digestive zymogens such as trypsin in the pancreatic acinar cells. Pancreatic proenzymes can become activated by endotoxins, toxins, ischemia, infections and anoxia. The activated pancreatic enzymes then begin a process of autodigestion which leads to edema, interstitial hemorrhage, vascular damage, coagulation, formation of thrombi, cellular necrosis and pain. These processes end with fibrosis and pancreatic insufficiency. Local pancreatic autodigestion can extend into generalized a systemic inflammatory response resulting in shock, ARDS and multi-organ system failure. During autodigestion, fat necrosis binds calcium, causing hypocalcemia.
The diagnosis of pancreatitis is made by a combination of complaints of chronic abdominal pain, often described as radiating straight through to the back, a history of risk factors, laboratory findings (high amylase and lipase) and radiologic features (abdominal plain film and CT). Amylase, a pancreatic digestive enzyme which is also present in the salivary glands, may be elevated but is nonspecific and may even be normal in acute pancreatitis. Lipase is another digestive enzyme, also found in gastric and intestinal mucosa and hepatic tissue, but its specificity for pancreatitis is considered better than for amylase (90% vs. 75%). Because lipase is cleared by the kidney, renal failure will elevate its levels.
Films of the chest and abdomen can show the calcification of chronic pancreatitis, and for acute pancreatitis, a sentinel loop, elevated hemi-diaphragm, and pleural effusions may be present. An ultrasound can rule out gallstones, as can a CT, which is also useful for grading the severity of disease and prognosis. CT can also locate phlegmons, abscesses and pseudocysts.
Unresolved issues include chemoprevention of endoscopic retrograde cholangiopancreatography-induced acute pancreatitis, the indications for antibiotic prophylaxis in severe acute pancreatitis and nutritional supplementation with probiotics and synbiotics.
A wide range of medications have been linked to pancreatitis and, in the absence of alcohol and other obvious causes, need to be ruled out: Of all cases of acute pancreatitis, 1.2 to 1.4% are due to toxic effects of medication. Following is a list of drugs linked to pancreatitis:
Amiodarone and amlodipine
Antibiotics (macrolides, sulfa, fluoroquinolones, rifampin, INH, dapsone)
Antiepileptics (carbamazepine, valproic acid, topiramate)
Diuretics such as hydrochlorothiazide (HCTZ)
GI agents, including H2 blockers and proton pump inhibitors (omeprazole)
Hyperlipidemic drugs : statins