Systemic Inflammatory Response Syndrome After Flexible Ureteroscopic Lithotripsy: A Study of Risk Factors

Objective: To evaluate the risk factors for systemic inflammatory response syndrome (SIRS) after flexible ureteroscopic lithotripsy (FUL). Materials and Methods: Patients who underwent FUL between October 2012 and November 2013 were studied. Complete data was available for 260 adult patients who met this criteria. Preoperative and intraoperative risk factors that potentially contribute to SIRS were compared in patients who developed postoperative SIRS and those who did not. Furthermore, multivariable logistic regression analysis was performed and the odds ratio (OR) and 95% confidence interval (CI) were calculated to identify the independent risk factors for SIRS after FUL. Results: The incidence of SIRS after FUL was 8.1%. In the univariate test analysis, significant correlation between SIRS and four factors was noted: sex of the patient (P<0.001), stone size (P=0.001), irrigation flow rate (P<0.001), and irrigation volume (P<0.001). Multivariable logistic regression analysis identified stone size (OR=1.691; 95% CI,0.879-3.255), small-caliber ureteral access sheath (UAS) (OR=2.293; 95% CI, 0.730-7.200), irrigation flow rate (OR=1.161; 95% CI, 1.096-1.230), and struvite calculi (OR=3.331; 95% CI, 0.971-11.426) as independent risk factors for SIRS after FUL. Conclusions: We recommend that the length of lithotripsy be well controlled in patients with large stone burden and struvite calculi. Staging procedures are also required. Additionally, irrigating with a low flow rate and low pressure and using a large-caliber UAS for better drainage are required to keep a low renal pelvic pressure during FUL procedures.