Predictive Value of Leukocytosis for Infectious Complications After Percutaneous Nephrolithotomy

Abstract

To 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. A 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. Leukocytosis was detected in 133 of the 303 patients (43.9%). The mean preoperative and postoperative WBC counts were 7.73 ± 2.01 × 10(6) cells/μL and 11.9 ± 3.31 × 10(6) cells/μL, respectively. The average postoperative WBC count increased by 4.2 ± 2.99 × 10(6) 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 × 10(6) cells/μL and an increase greater than 5.25 × 10(6) cells/μL, respectively. Our data show postoperative leukocytosis is common after PCNL and represents a normal physiologic response to surgery. Our study demonstrated that 14.05 × 10(3) × 10(6) cells/μL WBC count and absolute difference in WBC count from baseline of 5.25 × 10(3) × 10(6) 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.