Spontaneous bacterial peritonitis (SBP) is a bacterial infection of ascitic fluid in patients with decompensated cirrhosis. The modifier ‘spontaneous’ distinguishes this from surgical peritonitis. The infecting organisms are usually enteric gram-negatives which have translocated from the bowel. Symptoms of infection occur in most patients with SBP, including fever, abdominal pain, mental status changes, and ileus. A high index of suspicion should exist for SBP in patients with cirrhosis and ascites. Diagnostic abdominal paracentesis can be undertaken with minimal risk and should be performed in all patients admitted to the hospital, during times of worsening clinical appearance, or when gastrointestinal bleeding occurs. The ascitic fluid polymorphonuclear cell count is the most sensitive test in evaluating for infection. Cultures of the ascitic fluid are helpful in identifying the organism and are best performed by bedside injection of blood culture bottles. Ascites total protein, lactate dehydrogenase, and glucose levels can assist in distinguishing SBP from secondary peritonitis. Empirical therapy is recommended after paracentesis if suspicion for infection exists. Cefotaxime is the best-studied antibiotic for this purpose and has excellent penetration into ascites with no nephrotoxicity. Prophylaxis should be limited to high-risk settings. Mortality rates in SBP have declined dramatically, largely due to earlier detection and improved therapy.

Gastrointestinal tuberculosis is defined as infection of the peritoneum, hollow or solid abdominal organs, and abdominal lymphatics with Mycobacterium tuberculosis organisms. Gastrointestinal tuberculosis is relatively rare in the United States and is the sixth most common extrapulmonary location. Populations at risk include immigrants to the United States, the homeless, prisoners, residents of long-term care facilities, and the immunocompromised. The peritoneum and the ileocecal region are the most likely sites of infection and are involved in the majority of cases by hematogenous spread or through swallowing of infected sputum from primary pulmonary tuberculosis. Pulmonary tuberculosis is apparent in less than half of patients. Patients usually present with abdominal pain, weight loss, fever, anorexia, change in bowel habits, nausea, and vomiting. The diagnosis is often delayed and is usually made through a combination of radiologic, endoscopic, microbiologic, histologic, and molecular techniques. Antimicrobial treatment is the same as for pulmonary tuberculosis. Surgery is occasionally required.

The LLQ is preferable to the ML infraumbilical location for performing paracentesis.

Serum NT-proBNP seems to be an extremely powerful marker in distinguishing ascites due to cirrhosis from ascites due to heart failure. Serum NT-proBNP may potentially replace the more invasive testing presently in use.

A 45-year-old Caucasian female was admitted for confusion with three months of progressively worsening upper abdominal pain and swelling. She denied recent trauma, heavy lifting, or coughing spells. Her past medical history included left nephrectomy and splenectomy for a motor vehicle accident at age 12, and orthotopic liver transplantation at age 43 for cirrhosis due nonalcoholic steatohepatitis. On presentation, her weight was 84 kg, and her abdomen was distended and diffusely tender. She was somnolent but arousable and did not have asterixis. Laboratory examination revealed a white blood cell count of 29.5 ϫ 10 6 /mL, total bilirubin 8.3 mg/L, aspartate aminotransferase 67 IU/L, alanine aminotransferase 12 IU/L, alkaline phosphatase 278 U/mL, prothrombin time 14.4 seconds, and creatinine 6.