Acute Pancreatitis: Approach, Evaluation and Management

Etiology of Acute Pancreatitis

Causes of Acute Pancreatitis include:

  • Gallstones (most cases)
  • Alcohol (most cases)
  • Idiopathic
  • Hypercalcemia
  • Hyperlipidemia
  • Autoimmune
  • Post ERCP
  • Trauma
  • Mumps
  • Drugs (e.g., azathioprine,steroids or diuretics)

The causes of acute pancreatitis can be recalled from the mnemonic GET SMASH’D: gallstones, ethanol, trauma, steroids, mumps, autoimmune diseases, scorpion stings, hypertriglyceridemia, and drugs (e.g., azathioprine or diuretics).

The Causes of Acute Pancreatitis
The Causes of Acute Pancreatitis

Clinical Features of Acute Pancreatitis

There may be a history of cholecystitis or other complications of gallstones. Alcohol intake should be ascertained.

The patient complains of:

  • Severe abdominal pain radiating to the back or shoulder, which may be relieved by sitting forward
  • There may be associated nausea and vomiting

On examination there is:

  • abdominal tenderness with guarding and rebound tenderness
  • tachycardia
  • fever
  • jaundice
  • hypotension, and sweating
  • bruising around the umbilicus (Cullen’s sign) or in the flanks (Grey-Turner’s sign)
Acute Pancreatitis - Pathogenesis, Symptoms and Clinical Findings
Acute Pancreatitis – Pathogenesis, Symptoms and Clinical Findings

Acute Pancreatitis - Causes, Pathology, Symptoms and Signs, Investigations, Management and Complications
Acute Pancreatitis – Causes, Pathology, Symptoms and Signs, Investigations, Management and Complications

Differential Diagnosis

  • Any cause of an acute abdomen (e.g., cholecystitis, mesenteric ischemia, and intestinal perforation).
  • Myocardial infarction
  • Dissecting aortic aneurysm

Investigations

The following investigations are important in the patient with acute pancreatitis:

  • Serum amylase: markedly raised (over 1000 IU/mL). Amylase is also raised with cholecystitis and perforated peptic ulcer, but usually to a lesser extent. Serum lipase is also elevated and is more specific than amylase.
  • Abdominal x-ray: gallstones, pancreatic calcification indicating previous inflammation, an absent psoas shadow due to retroperitoneal fluid, and a distended loop of jejunum (“sentinel loop”).
  • Serum calcium: may be low.
  • White cell count: usually raised.
  • ECG: to exclude myocardial infarction.
  • Arterial blood gases: metabolic acidosis.
  • CXR: widened mediastinum in aortic dissection; gas under the diaphragm in perforated peptic ulcer.
  • Abdominal CT: assess severity.

READ MORE: Imaging of Acute Pancreatitis – to Image or Not to Image

Management of Acute Pancreatitis

Management is usually conservative.

  • Intravenous fluids should be given to maintain the circulating volume, and a central venous catheter may be helpful for assessing the volume of fluid required. If the patient is in shock (systolic blood pressure <90 mmHg), plasma expanders will be required.
  • Pain relief is with intravenous or intramuscular opiates (e.g., pethidine, 50-150 mg 4 hourly, or pentazocine, 30-60 mg 4 hourly, meperidine, fentanyl, or morphine with an antiemetic such as prochlorperazine, 12.5 mg 8 hourly).
  • A nasogastric tube should be inserted. TPN may be required.
  • Blood tests, especially metabolic panel, glucose, and calcium, should be monitored.
  • Surgery should be considered for suspected hemorrhagic necrosis of the pancreas.
  • Some give H2-receptor antagonists, prophylactic antibiotics, or peritoneal lavage, although these measures are of unproven value.
Approach to Severe Acute Pancreatitis
Approach to Severe Acute Pancreatitis

READ MORE: Recognizing and Treating Severe Acute Pancreatitis (SAP)

Complications and Prognosis

Ranson’s criteria are used to predict the severity of acute pancreatitis. Mortality is 5-10%, but recurrence is uncommon in patients who recover.

Ranson criteria to predict severity of acute pancreatitis
Ranson criteria to predict severity of acute pancreatitis

Complications include :

  • shock
  • renal failure
  • sepsis
  • respiratory failure
  • hypocalcemia due to the formation of calcium soaps
  • transient hyperglycemia
  • pancreatic abscess requiring drainage
  • pseudocyst (i.e., fluid in the lesser sac presenting as a palpable mass)
  • persistently raised serum amylase or liver function tests, and fever

Patients should be investigated to exclude gallstones, and alcohol should be avoided.

Complications of acute pancreatitis
Complications of acute pancreatitis