1. Acute Pancreatitis

2. Must have:

Gallstones  (40%)

Alcohol  ( 35%)

One of:

ERCP 9iatrogenic)

Trauma

Drugs

3. Normal anion gap metabolic acidosis with partial compensation

anion gap = 12

Expected CO2 = 35 mmHg

likely hyperchloraemic, due to 0.9% saline therapy

4. GI losses – diarrhoea

Saponification – deposition of K (and Ca ) salts

shift and renal losses

5. Biliary obstruction (ERCP)

Early necrotic infection

Multi-organ failure with deterioration despite optimal critical care

Extensive (>50%) sterile necrosis

Peritonitis (search for alternate diagnosis -?laparoscopy)

Significant haemorrhage (embolization)