Systemic inflammatory response syndrome after percutaneous nephrolithotomy: an assessment of risk factors.

OBJECTIVES

To analyze the risk factors for systemic inflammatory response syndrome (SIRS) after percutaneous nephrolithotomy (PCNL) and to quantitatively predict the probability of SIRS after PCNL.

METHODS

Medical records on 209 patients who underwent PCNL were retrospectively analyzed. The chi2 test, the t-test and a logistic regression model were used to identify key risk factors of SIRS after PCNL. A predictive equation was then formulated to assess the risk of SIRS according to the results from the logistic model. Subsequently, the accuracy of the equation by calculating sensitivity, specificity, overall correct percentage, and positive and negative predictive values was tested.

RESULTS

The incidence of SIRS after PCNL was 23.4%. The key risk factors for SIRS following PCNL were: the number of tracts, receipt of a blood transfusion, stone size, and presence of pyelocaliectasis. Other factors added no independent risk to the development of SIRS. The calculated values for sensitivity, specificity, overall percentage correct, positive predictive value and negative predictive value were 44.9%, 95.0%, 83.3%, 73.3%, and 84.9%, respectively.

CONCLUSIONS

Number of tracts, receipt of a blood transfusion, stone size and presence of pyelocaliectasis are identified as the key risk factors for SIRS after PCNL. The predictive equation allows for an individualized and quantitative assessment of the probability of SIRS after PCNL.