Gastrointestinal, Hepatic, and Renal Emergencies
Core concepts
Understand the approach to acute abdominal pain, including the surgical abdomen and the danger of the elderly or immunosuppressed patient with atypical presentation. Know gastrointestinal bleeding: upper vs lower, resuscitation priorities, risk scoring, and when to use endoscopy. Recognize acute pancreatitis, bowel obstruction, and mesenteric ischemia.
In hepatic emergencies, know the complications of cirrhosis (variceal bleeding, ascites, hepatic encephalopathy, spontaneous bacterial peritonitis) and the management of fulminant hepatic failure. In renal emergencies, distinguish prerenal, intrinsic, and postrenal acute kidney injury; know indications for urgent dialysis (refractory hyperkalemia, pulmonary edema, uremic pericarditis, severe acidosis, toxic ingestions).
Traps
Questions test whether you can recognize mesenteric ischemia (pain out of proportion to exam) and whether you know that a normal lactate does not exclude it. Another trap: attributing abdominal pain in an elderly patient to "gastritis" when it is a ruptured AAA or ischemia. In renal failure, watch for hyperkalemia with ECG changes requiring immediate calcium.
Worked example / rule of thumb
A cirrhotic patient with fever and ascites: perform diagnostic paracentesis and start empiric antibiotics for SBP (ascitic PMN ≥250/mm³). Rule of thumb: "Pain out of proportion = ischemia until proven otherwise; dialysis when the A-E-I-O-U indications appear."