Background: Spontaneous bacterial peritonitis (SBP) is a complication of cirrhosis and often followed by liver decompensation. Acute kidney injury (AKI) frequently occurs and is the reason for the increased mortality rate in cirrhotic patients.
Objective: To evaluate the incidence rate of AKI and the prediction of one-month mortality in hospitalized SBP- cirrhotic patients.
Materials and Methods: One hundred and twenty-three cirrhotic patients with SBP were included in a retrospective cohort study. Renal injury was defined by AKIN criteria. The AKI patients were assessed for severity, reversibility, hospital complications, length of hospital stay and mortality. Mean length of time of follow-up for all patients was 30 days. Kaplan-Meier survival for 30 days mortality by Cox regression model was calculated accordingly to the renal injury.
Results: The mean age of patients was 57.8+12.2; 62 (50.4%) were male. Most of them (78.7%) were Child-Pugh C cirrhosis. More than half of the patients (52%) were alcoholic cirrhosis with mean MELD score of 20.6+5.8. Mean length of hospitalization was 15+8.4 days. AKI occurred in 53.7% of the patients (83.3%, 7.6% and 9.1% for AKIN criteria 1, 2 and 3 respectively). The AKI group experienced non-liver related complications, septic shock and death in hospitalization proportionately greater than the other [(7.6% vs. 0%, p = 0.034); (33.3% vs. 14%, p = 0.013); (34.8% vs. 17.5%, p = 0.031), respectively]. Among three AKI sub-groups, there were no significant differences regarding MELD score (p = 0.16), episode of albumin infusion (p = 0.31), reversibility of kidney functions (p = 0.88) or intrahospital 30 days mortality (p = 0.56). The Kaplan-Meier survival showed a significant increase in 30 days mortality of AKI patients as compared to the others. (33.3% vs. 15.7%, p = 0.022). Multivariate cox regression analysis indicated that an AKI episode can predict 30 days mortality to be 2.42 times higher than non-AKI patients after adjusted mean Child-Pugh score. (adjusted HR 2.42, 95% CI 1.11 to 5.25).
Conclusion: AKI is a condition which can predict increased 30 days mortality and is associated with non-liver related complications in decompensated SBP-cirrhotic patients.

Keywords: Spontaneous bacterial peritonitis, Acute kidney injury, Cirrhosis