Spontaneous bacterial peritonitis

Cirrhotic ascites is fluid accumulation in the peritoneal cavity driven by portal hypertension and splanchnic vasodilation, confirmed by a serum-ascites albumin gradient of 1.1 g/dL or more on diagnostic paracentesis. Management proceeds from sodium restriction and combination diuretics to large-volume paracentesis with albumin and TIPS for refractory disease, with every new or worsening episode screened for spontaneous bacterial peritonitis.

Cirrhosis is end-stage hepatic fibrosis with regenerative nodules, staged as compensated or decompensated by the onset of ascites, variceal hemorrhage, encephalopathy, or jaundice. Severity is graded by Child-Pugh class and MELD, and management centers on treating the underlying cause, surveillance for varices and hepatocellular carcinoma, and timely transplant referral once decompensation appears.

Hepatorenal syndrome is functional renal failure in a patient with cirrhosis and ascites, driven by splanchnic vasodilation and compensatory renal vasoconstriction, and it is diagnosed only after excluding shock, nephrotoxins, and structural kidney disease and after creatinine fails to improve with diuretic withdrawal and an albumin challenge. Treatment is a splanchnic vasoconstrictor (terlipressin first-line) with intravenous albumin as a bridge to liver transplantation, the only curative therapy.

Hepatic encephalopathy is a reversible spectrum of brain dysfunction from insufficient hepatic clearance and portosystemic shunting of gut-derived toxins, graded by the West Haven criteria and almost always triggered by an identifiable precipitant such as infection, gastrointestinal bleeding, constipation, or an electrolyte disturbance. Diagnosis is clinical, and management proceeds by treating the precipitant first, then titrating lactulose and adding rifaximin for recurrence prevention.

Acute upper gastrointestinal bleeding arises proximal to the ligament of Treitz and presents with hematemesis or melena, most often from peptic ulcer disease or bleeding gastroesophageal varices. Management sequences resuscitation, restrictive transfusion, IV proton pump inhibitor therapy, and, when varices are suspected, octreotide plus antibiotic prophylaxis, all before upper endoscopy within 24 hours, which is both diagnostic and therapeutic.

Acute appendicitis is luminal obstruction and infection of the vermiform appendix presenting as migratory periumbilical-to-right-lower-quadrant pain, diagnosed by the classic history and exam plus confirmatory imaging (CT in adults, ultrasound or MRI in children and pregnancy), and treated with prompt appendectomy or, in selected uncomplicated cases, antibiotics alone.

Hepatocellular carcinoma is a primary liver cancer that arises almost exclusively in cirrhosis and can be diagnosed non-invasively when multiphase CT or MRI shows arterial-phase hyperenhancement with portal-venous washout in a lesion at least 1 cm. Treatment is stratified by tumor burden, liver function, and vascular or extrahepatic spread, ranging from resection or ablation through transplantation and transarterial chemoembolization to systemic atezolizumab-bevacizumab for advanced disease.

Acute pancreatitis is acinar-cell autodigestion and inflammation of the pancreas, most often from gallstones or alcohol, diagnosed by the revised Atlanta criteria and graded mild, moderately severe, or severe by organ failure. Management centers on early goal-directed lactated Ringer's resuscitation, analgesia, early enteral feeding, and timed ERCP for gallstone pancreatitis with cholangitis, reserving antibiotics for confirmed infected necrosis.