Common risk factors in cirrhotic patients with ascites include: low protein level in ascitic fluid (<1 g/dL), upper GI bleeding, low complement concentration (complement 3) in ascitic fluid, renal failure, elevated serum bilirubin level (>4 mg/dL), use of proton pump inhibitors (PPI) in cirrhotic patients have an increased risk, Child-Pugh stage C, Model For End-Stage Liver Disease (MELD) ≥ 22.

Risk factors include:^[1]

• All cirrhotic patients with ascites
• Severe liver disease (Cirrhosis)^[2]
• Low protein level in ascitic fluid ^[3]
• Upper GI bleeding poses a risk of bacteremia and SBP in a cirrhotic patient with rates of infection ranging from 17 to 21%
• Ischemia- reperfusion of the gut during variceal hemorrhage has also been proposed to interfere with the normal function of the reticuloendothelial system and to increase permeability of the intestinal mucosa
• Survivors of a prior episode of SBP are at an increased risk of recurrence with a one-year probability of almost 70%
• Minimally invasive procedures such as intravenous and urinary bladder catheterization likely predisposes to bacteremia and SBP in the cirrhotics
• Low complement concentration (complement 3) in ascitic fluid ^[3][2]
• Renal failure
• Urinary tract infections
• Intestinal bacterial overgrowth ^[4]
• The use of non-selective beta blockers in cirrhotic patients with SBP should be discouraged since it is associated with an increased risk for hemodynamic compromise, prolonged hospitalization, hepatorenal syndrome, and acute kidney injury^[5]

Factors contributing to the infection include:

• GI bleeding
• Increased colonization of the small bowel with prominent bacterial translocation
• Decreased opsonic activity in blood and ascitic fluid
• Impaired complement
• Leukocyte dysfunction
• Reduced antibodies
• Increased immunosuppressive cytokines, endotoxin, TNF