PL 18. Post-percutaneous nephrolithotomy septic shock and severe hemorrhage: A study of risk factors

With the technical development of new endoscopic and auxiliary instruments, percutaneous minimally invasive therapy for renal calculi is becoming widely used. Refinement of technology and increasing experience in the last decade has led to increased safety and efficacy. However, complications may still exist. Infection and bleeding are two of the most dangerous complications of percutaneous nephrolithotomy (PCNL). It is often said that "Infection robs life and bleeding threatens the kidney". Although a few groups have investigated risk factors for post-PCNL septic shock or severe renal bleeding, respectively, without studies comprehensively discussed both of them together. Our related article will be published in Urologia Internationalis (Impact factor: 0.924). The purpose of our study is that to identify the risk factors predicating septic shock and severe hemorrhage in percutaneous nephrolithotomy (PCNL). We retrospectively analyzed 420 renal calculi patients who underwent ultrasoundguided percutaneous nephroscope/ureteroscope holmium laser lithotripsy procedures from March 2005 to May 2011 in the First Hospital of Jilin University. The entire procedure was performed under general anaesthesia. After placing the patient in lithotomy position, retrograde ureter catheterization with a 5-French openended ureter catheter was performed. All other procedures were completed in the prone position. Using a combination of ultrasound and fluoroscopy guide, the coaxial needle was placed in the desired calyx. A working channel was established using the plastic dilator system to either F18 or F26.

Then, the F9 ureteroscope or a F20 nephroscope was placed directly into the kidney through the established tract. The Lumenis 60w lithothiptor was used to fragment the renal stone. Stone clearance was determined by a combination of fluoroscopy and ultrasound at the end of the procedure. A double J tube was placed within the ureter. At the end of the procedure, a clamped 14F or 20F Foley catheter was palced as a nephrostomy tube and it was opened within 24 hours. We rechecked KUB or ultrasound 1 or 2 days post-operation. And the nephrostomy tube was removed if there was no extravasation and larger residual stones at approximately 4 days post-operation. We routinely removed the double J tube about 1 month postoperation in the Out-patient Clinic. Of 420 patients, 10 (2.4%) encountered septic shock and 4 (1%) had severe hemorrhage. The two significant risk factors for infectious shock were preoperative urine white cell count (WBC) and operation time. For septic shock, there was no significant difficult between the use of standard nephroscope or less slender ureteroscope (P=0.973). For severe bleeding, absence of hydronephrosis and puncture times was significant risk factors. Operation time over 90 minutes was associated with both septic shock and sever renal bleeding (P=0.017). In contrast, the risk of encountering severe renal bleeding was higher if the nephroscope rather than the ureteroscope was used (P=0.045). From the above data, we know operation time was a risk factor for both septic shock and severe hemorrhage. Pre-operative anti-inflammatory therapy could reduce the possibility of septic shock after PCNL. The patients without hydronephrosis before operation were more likely to suffer severe renal bleeding. Reducing the intraoperational puncture time can reduce the probability of severe post-PCNL hemorrhage. The diameter of the instrument did not influence the occurrence of septic shock. However, the use of comparatively gross nephroscope passage was likely to result in severe renal bleeding.

Our study also has same disadvantages. The number of cases of septic shock and severe renal hemorrhage in the study was comparatively small, which result in lack of enough confidence on statistical analysis of the data. The reasons of fewer patients are as follows: One reason is comparatively shorter study period. Another reason is comparatively lower incidence rate of septic shock and severe renal hemorrhage in PCNL.