In this study, there were slightly more males than females, but there was no significant difference between SIRS and non-SIRS. A total of 30.1% of patients suffered SIRS, and no patients suffered sepsis. Current studies have shown that the incidence of SIRS after PCNL is between 10% and 30% (6, 14).The result is similar to the literature research results (15, 16), but higher than the study of Wang A]QL (12.5%) and Singh P(17.5%)(3, 9).
The patients with preoperative stone operation history accounted for 45.5%, indicating that the recurrence rate of renal stones was high, and the treatment was complicated. There were 9 patients with positive urine culture, and 24 patients with preoperative fever and concurrent infection. Although preoperative fever was a risk factor in univariate analysis, it did not enter the regression equation after multivariate analysis. The reasons were analyzed to find that, first, preoperative fever patients strictly underwent the anti-infective treatment, second, the patients who were found bacterial infection in urine routine and positive urine culture were also treated effectively, third, they did not undergo the operation until their test results were normal, so the preoperative fever failed to become a risk factor and no patients suffered sepsis.
The results of the study showed that there were two risk factors finally entering into the equation for SIRS after PCNL, one was diabetes and the other was operative time. Diabetes was a risk factor for SIRS after PCNL (17, 18). Zhu Zhenjie(18) believe that the incidence of SIRS after PCNL in patients with blood glucose above 7.1 mmol/L was more than twice that of patients with normal preoperative blood glucose, but the blood glucose value of patients with preoperative concurrent diabetes was controlled in the normal range, indicating that diabetes itself would bring certain risk of SIRS after PCNL, so even if the preoperative blood glucose was controlled in normal range, it still should be taken seriously as a postoperative risk factor. And the result of OR was similar with Zhu Zhenjie(17).
Operation time is a very important risk factor consistent with other studies (8). The prolongation of operation time, with the increase of the absorption of lavage fluid and toxin into blood, increases the chance of infection. A large amount of absorption of lavage fluid can make patients in a state of hypothermia, coagulation dysfunction, even increase the patient's circulatory load and disturb the balance of water and electrolyte. SIRS is more likely to occur after operation.Shortening the operation time is an important measure to prevent SIRS. Current Clinicians with the continuous improvement of endoscopy technology, the operation time is also decreasing. But in Chen L’s research the operation time did not enter the regression Eq. (6) .
7.1% of the patients suffered cast stones or staghorn stones. These stones were difficult to handle and prone to cause complications, so the rich clinical experience was required for surgeons. In addition, their operative time was relatively long, but they finally did not enter the regression equation.
With the doctor's attention to SIRS after percutaneous nephrolithotomyfor patients with stones, the continuous enhancement of operative skills and the improvement of preoperative preparation, although nearly one-third of patients suffered SIRS after percutaneous nephrolithotomy, the sepsis case was zero, indicating that PCNL operation is getting more mature and safy.The early symptomatic treatment for SIRS can prevent patients’ conditions from further development, so it is necessary to use predictive models to assess the patients, and then early observation and early treatment are performed to ensure patient safety after PCNL.
There were several limitations in our study. First, this is a retrospective study from single institute, which might lead to selection bias. Secondly, patient's data are not perfect, such as calculus load and stone composition analysis can’t be calculated, which affects the analysis of risk factors, so we could not provide a more comprehensive analysis. Finally, sample size is small and lacks representativeness. We needed to do large-scale prospective studies.