Predictive Value of Leukocytosis for Infectious Complications After Percutaneous Nephrolithotomy

ObjectiveTo investigate the natural history of white blood cell (WBC) values and incidence of leukocytosis after percutaneous nephrolithotomy (PCNL), factors associated with development of postoperative leukocytosis, and predictive value of WBC count for infection.MethodsA total of 303 patients who underwent PCNL for renal stones were included in the recent study. Electronic medical records of the patients were reviewed retrospectively to collect daily serum leukocyte counts and perioperative cultures. WBC count was followed daily for patients with positive urine culture and/or postoperative fever until leukocyte levels turned to normal limits.ResultsLeukocytosis was detected in 133 of the 303 patients (43.9%). The mean preoperative and postoperative WBC counts were 7.73 ± 2.01 × 106 cells/μL and 11.9 ± 3.31 × 106 cells/μL, respectively. The average postoperative WBC count increased by 4.2 ± 2.99 × 106 cells/μL over the first 2 postoperative days. Receiver operating characteristic curve analysis resulted in an area under the curve of 0.87 and 0.80 for postoperative WBC count and absolute WBC count difference, respectively. The thresholds provided by the analysis were 14.05 × 106 cells/μL and an increase greater than 5.25 × 106 cells/μL, respectively.ConclusionOur data show postoperative leukocytosis is common after PCNL and represents a normal physiologic response to surgery. Our study demonstrated that 14.05 × 103 × 106 cells/μL WBC count and absolute difference in WBC count from baseline of 5.25 × 103 × 106 cells/μL were significantly associated with post-PCNL sepsis development. Further studies are needed to determine the significance of leukocytosis for infectious complications after PCNL.