Endourology and Stones Predictive Value of Leukocytosis for Infectious Complications After Percutaneous Nephrolithotomy Ibrahim Halil Bozkurt, Ozgu Aydogdu, Tarik Yonguc, Omer Koras, Volkan Sen, Serkan Yarimoglu, and Tansu Degirmenci OBJECTIVE
METHODS
RESULTS
CONCLUSION
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 2.01 106 cells/mL and 11.9 3.31 106 cells/mL, respectively. The average postoperative WBC count increased by 4.2 2.99 106 cells/mL 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/mL and an increase greater than 5.25 106 cells/mL, respectively. Our 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/mL WBC count and absolute difference in WBC count from baseline of 5.25 103 106 cells/mL were significantly associated with post-PCNL sepsis development. Further studies are needed to determine the significance of leukocytosis for infectious complications after PCNL. UROLOGY 86: 25e29, 2015. 2015 Elsevier Inc.
P
ostoperative infection is a potentially devastating complication after percutaneous nephrolithotomy (PCNL). In several studies examining the outcomes of PCNL, sepsis was detected as a leading perioperative cause of death.1,2 Thus, it is important to diagnose the infection as early as possible after PCNL. But in the early postoperative period, clinicians usually find nonspecific indicators of infection. Although leukocytosis may be a sign of developing infection in the early postoperative period, it may also be part of normal surgical response.3 In the early postoperative period, patients frequently have an elevated white blood cell (WBC) count. Elevations in postoperative WBC values may trigger an expensive and unguided workup in search of an early infection.
Financial Disclosure: The authors declare that they have no relevant financial interests. From the Department of Urology, Izmir Bozyaka Training and Research Hospital, Izmir, Turkey Address correspondence to: Ibrahim Halil Bozkurt, M.D., F.E.B.U., Department of Urology, Izmir Bozyaka Training and Research Hospital, Saim Cikrikci, Street No. 59, Bozyaka, Izmir, Turkey 35170. E-mail: [email protected] Submitted: February 18, 2015, accepted (with revisions): April 23, 2015
ª 2015 Elsevier Inc. All Rights Reserved
We aimed to investigate the natural history of WBC values and incidence of leukocytosis after PCNL, factors associated with development of postoperative leukocytosis, and predictive value of WBC count for infection.
METHODS 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. A detailed history, including past renal surgery, nephrostomy insertion, and recurrent urinary tract infection, was obtained from all patients. Preoperative laboratory investigations included urine analysis, midstream urine culture, complete blood count, and renal function tests. The stones were evaluated with low-dose computed tomography and/or excretory urography preoperatively. If the culture was negative, the patient was given a single dose of prophylactic intravenous broad-spectrum antibiotic at anesthesia induction and continued until the time of nephrostomy removal. Patients who had positive cultures (>100.000 cfu/mL) were treated with appropriate antibiotics based on sensitivity profile for at least 7 days. The PCNL procedure was postponed until a negative culture was obtained after http://dx.doi.org/10.1016/j.urology.2015.04.026 0090-4295/15
25
SPSS 21.0 (Chicago, IL) software package. The independent sample t test, chi-square test, and Fischer exact test were used for statistical comparisons. Statistical significance was set at a P value of 12.0 106 cells/mL.4 WBC count was followed daily for patients with positive urine culture and/or postoperative fever until leukocyte levels turned to normal limits. All patients were followed-up postoperatively for systemic inflammatory response syndrome (SIRS) criteria (leukocyte count 12,000; fever >38 C or 90 per minute; respiratory rate >20 per minute) and blood cultures were provided as indicated.4 SIRS was diagnosed in patients who met 2 or more criteria. Sepsis is defined as the presence of a source of infection together with SIRS.4 Statistical analyses were performed with 26
Leukocytosis was detected in 133 of the 303 patients (43.9%). The mean preoperative and postoperative WBC counts were 7.73 2.01 106 cells/mL and 11.9 3.31 106 cells/mL, respectively. Struvite stones were detected in 14 of the patients (4.6%). The mean preoperative WBC value was 8.9 1.68 106 cells/mL in these patients. The average postoperative WBC count increased by 4.2 2.99 106 cells/mL over the first 2 postoperative days. After reaching peak, the WBC value declined to a level slightly higher than preoperative level (Fig. 1). WBC counts were available for all patients on postoperative days 1 and 2, for 232 patients on postoperative day 3, and for 102 patients on postoperative 4. Table 1 summarizes demographic characteristics of the patients and correlation of risk factors with SIRS according to the development of leukocytosis. Patients who developed postoperative leukocytosis had significantly higher mean preoperative WBC value (8.71 vs 6.96 106 cells/mL; P
METHODS
RESULTS
CONCLUSION
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 2.01 106 cells/mL and 11.9 3.31 106 cells/mL, respectively. The average postoperative WBC count increased by 4.2 2.99 106 cells/mL 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/mL and an increase greater than 5.25 106 cells/mL, respectively. Our 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/mL WBC count and absolute difference in WBC count from baseline of 5.25 103 106 cells/mL were significantly associated with post-PCNL sepsis development. Further studies are needed to determine the significance of leukocytosis for infectious complications after PCNL. UROLOGY 86: 25e29, 2015. 2015 Elsevier Inc.
P
ostoperative infection is a potentially devastating complication after percutaneous nephrolithotomy (PCNL). In several studies examining the outcomes of PCNL, sepsis was detected as a leading perioperative cause of death.1,2 Thus, it is important to diagnose the infection as early as possible after PCNL. But in the early postoperative period, clinicians usually find nonspecific indicators of infection. Although leukocytosis may be a sign of developing infection in the early postoperative period, it may also be part of normal surgical response.3 In the early postoperative period, patients frequently have an elevated white blood cell (WBC) count. Elevations in postoperative WBC values may trigger an expensive and unguided workup in search of an early infection.
Financial Disclosure: The authors declare that they have no relevant financial interests. From the Department of Urology, Izmir Bozyaka Training and Research Hospital, Izmir, Turkey Address correspondence to: Ibrahim Halil Bozkurt, M.D., F.E.B.U., Department of Urology, Izmir Bozyaka Training and Research Hospital, Saim Cikrikci, Street No. 59, Bozyaka, Izmir, Turkey 35170. E-mail: [email protected] Submitted: February 18, 2015, accepted (with revisions): April 23, 2015
ª 2015 Elsevier Inc. All Rights Reserved
We aimed to investigate the natural history of WBC values and incidence of leukocytosis after PCNL, factors associated with development of postoperative leukocytosis, and predictive value of WBC count for infection.
METHODS 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. A detailed history, including past renal surgery, nephrostomy insertion, and recurrent urinary tract infection, was obtained from all patients. Preoperative laboratory investigations included urine analysis, midstream urine culture, complete blood count, and renal function tests. The stones were evaluated with low-dose computed tomography and/or excretory urography preoperatively. If the culture was negative, the patient was given a single dose of prophylactic intravenous broad-spectrum antibiotic at anesthesia induction and continued until the time of nephrostomy removal. Patients who had positive cultures (>100.000 cfu/mL) were treated with appropriate antibiotics based on sensitivity profile for at least 7 days. The PCNL procedure was postponed until a negative culture was obtained after http://dx.doi.org/10.1016/j.urology.2015.04.026 0090-4295/15
25
SPSS 21.0 (Chicago, IL) software package. The independent sample t test, chi-square test, and Fischer exact test were used for statistical comparisons. Statistical significance was set at a P value of 12.0 106 cells/mL.4 WBC count was followed daily for patients with positive urine culture and/or postoperative fever until leukocyte levels turned to normal limits. All patients were followed-up postoperatively for systemic inflammatory response syndrome (SIRS) criteria (leukocyte count 12,000; fever >38 C or 90 per minute; respiratory rate >20 per minute) and blood cultures were provided as indicated.4 SIRS was diagnosed in patients who met 2 or more criteria. Sepsis is defined as the presence of a source of infection together with SIRS.4 Statistical analyses were performed with 26
Leukocytosis was detected in 133 of the 303 patients (43.9%). The mean preoperative and postoperative WBC counts were 7.73 2.01 106 cells/mL and 11.9 3.31 106 cells/mL, respectively. Struvite stones were detected in 14 of the patients (4.6%). The mean preoperative WBC value was 8.9 1.68 106 cells/mL in these patients. The average postoperative WBC count increased by 4.2 2.99 106 cells/mL over the first 2 postoperative days. After reaching peak, the WBC value declined to a level slightly higher than preoperative level (Fig. 1). WBC counts were available for all patients on postoperative days 1 and 2, for 232 patients on postoperative day 3, and for 102 patients on postoperative 4. Table 1 summarizes demographic characteristics of the patients and correlation of risk factors with SIRS according to the development of leukocytosis. Patients who developed postoperative leukocytosis had significantly higher mean preoperative WBC value (8.71 vs 6.96 106 cells/mL; P
