What are the calculations for Systolic Blood Pressure (SBP) in patients with ascites?

From the Guidelines

To diagnose spontaneous bacterial peritonitis (SBP) in patients with ascites, a paracentesis should be performed with ascitic fluid sent for cell count with differential, culture, and albumin measurement, and treatment should begin immediately with a third-generation cephalosporin like cefotaxime, as recommended by the most recent guidelines 1.

Diagnosis of SBP

The diagnosis of SBP is based on an ascitic fluid absolute neutrophil count of ≥250 cells/mm³, regardless of culture results 1.

• The serum-ascites albumin gradient (SAAG) should be calculated by subtracting the ascitic fluid albumin from the serum albumin, with a value ≥1.1 g/dL indicating portal hypertension as the cause of ascites.
• Ascitic fluid culture with bedside inoculation of blood culture bottles should be performed to guide the choice of antibiotic treatment when SBP is suspected 1.

Treatment of SBP

Treatment should begin immediately with a third-generation cephalosporin like cefotaxime, as recommended by the most recent guidelines 1.

• The choice of antibiotic should be guided by local resistance patterns and protocol 1.
• Albumin infusion may be considered in patients with renal dysfunction, bilirubin >4 mg/dL, or BUN >30 mg/dL to prevent hepatorenal syndrome, although the evidence for this is not as strong 2.

Prevention of SBP

Patients who have recovered from an episode of SBP should be considered for treatment with norfloxacin or ciprofloxacin to prevent further episodes of SBP, although the evidence for this is not as strong 1.

• Primary prophylaxis should be offered to patients considered at high risk, as defined by an ascitic protein count <1.5 g/dL, with the choice of antibiotic guided by local resistance patterns 1.

From the Research

SBP Calculations and Ascites

• The diagnosis of Spontaneous Bacterial Peritonitis (SBP) is typically made by analyzing ascitic fluid and looking for a polymorphonuclear (PMN) cell count of > 250 cells/mm3 3.
• The treatment of SBP usually involves the use of non-nephrotoxic broad-spectrum antibiotics, with cefotaxime being a commonly used option 4, 5.
• The dosage of cefotaxime can vary, but a common regimen is 2 g given intravenously every 8 hours for a total of 5 days 4, 5.
• The antibiotic regimen may need to be adjusted based on the results of ascitic fluid cultures, and other antibiotic regimens may be considered if the initial treatment is not effective 4, 6.

Risk Factors for SBP Development and Mortality

• Risk factors for SBP development include Child-Pugh stage C, ascitic fluid PMN count, and low serum sodium levels 7.
• Independent predictors of SBP development include Child-Pugh stage C (OR: 3.323; P = 0.009), ascitic fluid PMN count (OR: 1.544; P = 0.028), and low serum sodium (OR: 0.917; P = 0.029) 7.
• Risk factors for 30-day mortality after SBP diagnosis include MELD score (OR: 1.565; P = 0.001) and CRP levels (OR: 1.067; P = 0.037) 7.

Treatment Efficacy and Outcomes

• The efficacy of cefotaxime in treating SBP can be maintained with lower dosages than initially used, and the treatment is generally effective in resolving the infection 5.
• However, the in-hospital mortality rate remains high due to complications such as renal failure, and further studies are needed to reduce the incidence of these complications and improve survival 5, 6.
• The use of intravenous albumin and antibiotics for SBP has been shown to decrease the development of azotemia and hospitalization-related mortality 4.