The value of procalcitonin compared to C-reactive protein and blood white cell count in early detection of sepsis following percutaneous nephrolithotomy

Objective To assess the value of procalcitonin (PCT) levels compared to C-reactive protein (CRP) levels and blood white cell count in early detection of sepsis following percutaneous nephrolithotomy. Methods This prospective observational study included 91 patients, including 59 male patients and 32 female patients, undergoing percutaneous nephrolithotomy between April 2014 and October 2015. Their mean age was (54±15)years old, ranging 15 to 88 years old. The average size of stone was (20.9±7.0)mm. Those patients were classified into two groups, based on whether the postoperative sepsis existed.In this group, 51 cases were concluded in the sepsis group and 40 in the non-sepsis group. A statistically significant difference between patients with and without sepsis was found in the hydronephrosis (44 vs. 25, P=0.009), urine white cell count [(402±970)/μl vs.(70±171)/μl, P 0.05). Blood white blood cell count, CRP, and PCT were measured in patients with an acute onset of sepsis. Diagnostic accuracy of PCT values was analyzed by the receiver operating characteristics (ROC) curve. Results A statistically significant difference between patients with and without sepsis was found in the PCT [(7.43±10.15)μg/L vs.(0.14±0.10)μg/L, P 0.05] between patients with and without sepsis.ROC curve analysis showed that blood white cell count and PCT concentrations had similar predictive values for the development of sepsis (area under the curve, 0.78 and 0.90, respectively) with the best cut-off values of blood white cell count for 12×109/L (sensitivity 50%, specify 88%)and 0.5 μg/L (sensitivity 64%, specify 100%)for PCT. 54 cases were performed blood culture, which showed positive in 12 cases and negative in 42 cases. The significant difference of PCT level could be noticed in two groups [(16.99 ±11.64)μg/ L vs. (3.77±7.23)μg/ L, P<0.05)]. No significant difference was found in CRP, Blood white cells count among those groups (P<0.05). ROC curve analysis showed that PCT concentrations had predictive values for the positive blood culture (area under the curve, 0.80) with the best cut-off values of 8 μg/L (sensitivity 71%, specify 88%) for PCT. Conclusions PCT was a useful marker for the diagnosis of the sepsis after percutaneous nephrolithotomy as compared with WBC and CRP. Key words: Procalcitonin; Sepsis; Infection; Percutaneous nephrolithotomy; Blood culture