What is it
Acute pancreatitis is an acute inflammatory process resulting from the pancreas digesting itself, caused by its own pancreatic enzymes. It may or may not subsequently involve other regional tissues, organs, or distant tissues.
Types
It can be clinically classified as mild or severe acute pancreatitis.In the mild form, systemic and local clinical changes are minimal. Pathological findings show edematous acute pancreatitis.
In the severe form, signs of organ failure are present, such as low blood pressure, respiratory failure, kidney failure, and gastrointestinal bleeding. Local complications like necrosis, abscess, and pancreatic pseudocyst may occur. Pathological findings are characterized by necrohemorrhagic acute pancreatitis.
Causes
The main causes of acute pancreatitis are gallstones and alcohol consumption. Other causes include: hyperlipidemia, hereditary pancreatitis, hyperparathyroidism, hypercalcemia, anatomical abnormalities (e.g., pancreas divisum), medications (chemotherapy, antiretrovirals), viral infections (e.g., Coxsackie virus), vascular diseases, surgical procedures (e.g., endoscopic retrograde cholangiopancreatography, post-abdominal or cardiac surgery), abdominal trauma and cystic fibrosis.
Symptoms
The patient typically experiences diffuse abdominal pain located in the upper abdomen, in a band-like pattern, radiating to the back. It starts mildly and progresses (within minutes to hours) to severe intensity, not relieved by lying down or using painkillers. It is often accompanied by nausea and vomiting.
Clinical signs may include: fever, dehydration, rapid heartbeat (tachycardia), low blood pressure, mild abdominal tenderness to peritoneal irritation, periumbilical and/or flank bruising.
Incidence
In Brazil and the U.S., the average incidence of acute pancreatitis is 19 and 65 cases per 100,000 people per year, respectively. In the U.S., 220,000 hospitalizations annually are due to acute pancreatitis.
Incidence increases with age and is more common in men. Gallstone-related acute pancreatitis incidence increases with age in both men and women, with the highest risk in women over 60. Patients with gallstones smaller than 5 mm, microstones, or biliary sludge are considered high risk for developing acute pancreatitis.
Diagnosis
A clinical history characteristic of acute pancreatitis combined with elevated serum levels of pancreatic enzymes (amylase and lipase) confirms the clinical-laboratory diagnosis. Inflammatory markers such as leukocytosis, elevated C-reactive protein, and procalcitonin may be present.
Imaging (CT scan or abdominal MRI) can be used to confirm the diagnosis, assess complications, monitor disease progression, and assist in differential diagnosis.
Differential diagnoses include: biliary colic, peptic disease, intestinal perforation, mesenteric ischemia, intestinal obstruction, myocardial infarction, aortic dissection and ectopic pregnancy.
Treatment
The goals of treatment for acute pancreatitis are: clinical support with fluid replacement (hydration), pain management, control of nausea/vomiting, early refeeding, support for systemic complications when present (infection, respiratory failure, kidney failure, low blood pressure, metabolic disturbances). Invasive procedures, including surgery, are reserved for specific indications based on the cause (e.g., gallstones – cholecystectomy) and the presence of local complications (necrosis, abscess, pseudocyst).
Prognosis
Among patients hospitalized for acute pancreatitis, 20–30% progress to the severe form. The overall mortality rate is estimated at 5%. However, in severe cases with sterile pancreatic necrosis, mortality approaches 10%, and can reach 30% when pancreatic necrosis is infected. Mortality is higher in older patients, those with early onset of local/systemic complications, and in cases of idiopathic or traumatic etiology.