Usefulness of serum N-terminal-ProBNP in distinguishing ascites due to cirrhosis from ascites due to heart failure.

BACKGROUND: Ascites due to cirrhosis may be difficult to distinguish from ascites due to heart failure by clinical features alone. More invasive testing is usually necessary, such as measurement of the hepatic venous pressure gradient, or paracentesis with measurement of the ascitic fluid total protein. AIM: The aim of this study is to determine the diagnostic accuracy of serum NT-proBNP (N-terminal-pro-brain-type natriuretic peptide) in distinguishing patients with ascites from heart failure or cirrhosis. METHODS: Using a bank of previously collected fluid, we measured the serum and ascitic NT-proBNP levels in 58 patients with known cirrhosis, and 18 patients with known heart failure. Patients with both disease processes were excluded. The total protein levels in ascites was also measured and compared with serum NT-proBNP levels. RESULTS: The median serum NT-proBNP level was 165.7 pg/mL (range, 29.9 to 1795) in the cirrhosis group and 6100 pg/mL (range, 1110 to 116,248) in the heart failure group (P<0.001). Similar values were also found when using ascitic fluid NT-proBNP levels. Using a value of 1000 pg/mL, the sensitivity of serum NT-proBNP in ruling out cirrhosis as the cause for ascites was 100%. CONCLUSIONS: 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.

Spontaneous bacterial peritonitis.

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.

Choosing the location for non-image guided abdominal paracentesis.

OBJECTIVES: The optimal location for paracentesis has not been studied scientifically. The evolving obesity epidemic has changed the physique of many patients with cirrhosis and ascites such that needles inserted into the abdominal wall may not reach fluid. We aimed to determine the location for paracentesis that would have the thinnest abdominal wall and the deepest amount of fluid. METHODS: Ultrasound measurements of abdominal wall thickness and depth of ascites were recorded in two locations, the infraumbilical midline (ML) and the left lower quadrant (LLQ), in 52 patients with cirrhosis and ascites admitted to a single inpatient liver unit. RESULTS: The abdominal wall was significantly thinner (1.8 vs. 2.4 cm; P<0.001) and the depth of ascites greater (2.86 vs. 2.29 cm; P=0.017) in the LLQ as compared with the infraumbilical ML position. In the left lateral oblique position, the difference in the depth of ascites was more pronounced when comparing the LLQ with the infraumbilical ML (4.57 vs. 2.78 cm; P<0.0001). CONCLUSIONS: The LLQ is preferable to the ML infraumbilical location for performing paracentesis.

Gastrointestinal tuberculosis.

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.