Analysis Of Risk Factors Of Urosepsis Owing To Percutaneous Nephrolithotomy

Forewords:Renal calculus is one of the common and frequently-occurring disease in urology. Percutaneous nephrolithotomy (PCNL), which is a minimally invasive urological surgery, is frequently used for treating Urinary calculi. And PCNL has become the first choice for renal stones since it was firstly promoted in 1976, because of its high efficiency, safety, high stone clearance rate, etc. The increasingly progress of image technology and endoscopic equipment made percutaneous nephrolithotomy safe and effective. As the minimally invasive techniques were extensively developed, more and more urologists concerned about its postoperative complications. A series of infectious complications, such as fever, pyelonephritis and even urosepsis often appeared after percutaneous nephrolithotomy, which often increased the in-hospital time and cost of treatment, and even mortality. In a number of studies about complications of percutaneous nephrolithotomy, urosepsis is reported as the most causes of perioperative death. So that urosepsis catches many urologists’attention. It has been reported that there were about 21.0%-32.1% patients fever after PCNL. Most of fever was transitory, but there still were about 0.3%-4.7% of patients develop into urosepsis, which can lead to septic shock and multiple organ failure, and even death. We used antibiotics preoperative to prevent infection, but we couldn’t completely prevent urosepsis.Urosepsis is that sepsis caused by urinary tract infection.it is one of the common critical disease in urinary department. Its fatality rate is about 20%～42%. As the development of diagnosis and treatment for urosepsis, the rescue rate of urosepsis increased. However, since the mobidity of urosepsie is gradually rising, the death toll are rising. The reason for urospesis after percutaneous nephrolithotomy is still not clear. It is generally believed that bacteria and endotoxin containing in the infusion fluid back refluxed into the blood when performing PCNL. Stones are the carriers of bacteria and endotoxin. In the process of operation, bacteria and endotoxin were released into the urine. What’s more, in order to keep clear vision and rush out of the macadam, a lot of physiological saline was used for perfusion. As the perfusion pressure rises, the perfusion fluid can regurgitate through various ways, including pelvic venous regurgitation, pelvic renal tubular regurgitation, pelvic lymph regurgitation, and renal pelvis interstitial regurgitation. The bacteria and endotoxin were contaned in the urine and refluxed into the blood stream, causing systemic inflammatory response. Bacteria and endotoxin make the body to release excessive inflammatory mediators, such as TNF-a, IL-1, IL-6, IL-8 and so on. These factors make vascular endothelial cell injury and blood platelet adhere through activation of neutrophils. Further more the neutrophils released oxygen free radical and lipid metabolites resulting in tissue damage. Bacteria and endotoxin and the body’s inflammatory response, the immune system, and interaction between blood coagulation reaction, cause airframe multiple organ damage.Many factors may affect infectious complications of percutaneous nephrlithotomy, such as operation time, urinary tract bacteria, the severity of the obstruction and infectious stones. Although we carefully prepared preoperative, urosepsis is still unpredictable. Infection always comes from the stone itself. In addition to highly suspicious indicators, it is really difficult to predict the exact source of infection preoperative. Therefore, in order to reduce the morbidity and mortality of urosepsis, understanding of the risk factors of urosepsis owing to percutaneous nephrolithotomy in urine source sex of for sepsis, and for forecasting the occurrence of urinary source sex sepsis and give timely intervention is important.Affect the percutaneous nephroscope lithotomy postoperative infection of many factors, such as operation time, urinary tract bacteria, the severity of the obstruction and infectious stones directly affect urine source sex the incidence of sepsis and septic shock.Although a careful preoperative preparation, the urine source sex sepsis is unpredictable. Infection always comes from the stone itself. In addition to highly suspicious indicators, it is really difficult to predict the exact source of infection preoperative. Therefore, in order to reduce the morbidity and mortality, understanding of the risk factors of urosepsis owing to percutaneous nephrolithotomy is of great importance. Realizing the risk factors will contribute to forecast the occurrence of urinary source sex sepsis and give timely intervention.However, there are only a few retrospective study discussing several risk factors, and multiple research conclusions are not consistent. What is need is to put together these risk factors, and then retrospectively analyzed. And then we explore the relationship of risk factors and postoperative urosepsisv and the impact mechanism. Knowing this may help us to guide the clinical treatment, to avoid the occurrence of postoperative complications and to improve the security of PCNL.Objective:The medical records of whom suffered percutaneous nephrolithotomy in our department from January 2013 to January 2014 were collected. Logistic regression analysis was applied to study the risk factors of urospesis owing to percutaneous nephrolithotomy. And then to explore the correlation of urosepsis and explore gender, age, preoperative urinary tract infections, stone diameter, staghron stones, renal biopsy colostomy, channel size, gravel equipment, operation time, staghorn stone and postoperative correlation of sepsis.Methods:1. Clinical data:The medical records of whom suffered percutaneous nephrolithotomy in our department from January 2013 to January 2014 were collected.The inclusion criteria included:those patients who had been confirmed as kidney stones or upper ureteral stones by abdominal CT, and then patients had been performed PCNL.The exclusion criteria included:patients with tumors, hematopathy, diabetes mellitus, those taking oral immune suppressants, patients with a horseshoe kidney, polycystic kidney or ureteropelvic junction stricture, those having a heart rate greater than 90 beats/min before surgery, those with heart or kidney failure, preoperative fever treated with antibiotics, those having a tubeless PCNL, a second PCNL.2. Indicators:(1) general message:age, gender. (2) preoperative middle urine culture: to understand the positive bacterium;(3) renal function:serum creatinine level;(4) urinary tract urinary tract CT scan and intravenous urography:to realize the location size and numbers of the renal stone,;(5) size of percutaneous channel:16-20 F;(6) lithotriptor equipment:holmium laser, ultrasonic lithotriptor;(7) operation time;(8) vital signs:temperature, pulse, respiration, blood pressure;(9) blood routine:WBC, percentage of neutrophil; (10) Postoperative calcitonin concentration.3. The risk factors assignment:(1) gender:male=0;female=1;(2) age:< 40=1,40 to 59= 2,> 60=3;(3) urine cultures preoperative:negative=0, positive=1;(4)serum creatinine (umol/L):< 110=0,>110=1;(5) stone diameter (cm):2.5= 0 or less,> 2.5=1;(6) staghorn stones:no=0, yes=1;(7) the channel size:standard channel=0, microchannel=1;(8) gravel equipment:Holmium laser=0, ultrasonic lithotriptor=1; (9) Operation time (min):90=0 or less;> 90=1.4. Grouping:Patients were devided into groups and sepsis groups according to whether the patient had urosepsis.5.Statistical method:We used SPSS13.0 statistical software to process the data. We chose gender, age, preoperative urine culture, serum creatinine, diameter, staghorn stone, channel size, gravel equipment, operation time as risk factors of urosepsis for single factor analysis. The Independent-Samples t-test, Pearson χ2 test were used to analyze the normally distributed data. The Mann-Whitney U-test and Spearman correlation test were used for the skewed data. The relative risk (odds ratio, OR) was used in a multivariable logistic regression analysis to find the key risk factors for the development of urosepsis after PCNL. P< 0.05 for the difference was statistically significant.Results:1. Two hundred and four patients were included in this study. Among them,there were 140 men and 64 women, whose mean age was 49 years old(ranged from 29 to 75years). Eighty four patients were performed via standard channel and 120 operations were performed via micro channels. Fifty one patients had staghorn stones.Before operations the urine culture positive rate was 14.7%(30/204). The creatinine level ranged from 46 to 340 μmol/L. Average stone diameter was (2.3±0.8)cm, (ranged from 1.0 to 7.0cm). Mean operative time was (68.4±26.9)min(rang 23-219min). Blood transfusion didn’t need for all patients. Adjacent viscera’s injury, such as colon and pleural, didn’t appear in all patients.2. Of 204 patients,9(4.4%) suffered urosepsis, including 7 female patients and 2 male patients. Their mean age was (52.6±15.2) years old(ranged from 20 to 73 years old). There operations were performed via standard channels and six operations were performed via standard channels and four operations were performed via micro channels. Five patients had staghorn stones. Urine culture positive rate was 77.8% (7/9). The average stone diameter was(2.5±0.6cm)(ranged from 1.8 to 3.5cm). Mean operative time was (86±53)min (ranged from47 to 219min)3. Of all 204 patients,30 patients(14.7%) had preoperative middle urine culture positive.Gram negative bacteria accounted for about 73.3%(22/73). Among them, e. coli is the most common, accounting for about 53.3%(16/30).And gram positive bacteria accounted for 26.7%(8/30). Among them golden ordinary aureus accounted for 10%(3/30) and the epidermis staphylococcus accounted for about 6.7%(2/30).4. In univariate analysis, significant associations was observed between female gender (P=0.005), positive urine culture (P<0.01),staghorn stone(P=0.045), operative time>90min (0.042) and urosepsis following PCNL.5. In multivariate analysis, female gender (OR=6.001,95%CI 1.190～30.276, P =0.03) and positive urine culture (OR=19.647,95% CI 3.918～98.562, P<0.01) were identified as independent risk factors for post PCNL urosepsis.Conclusion:Urosepsis is a serious complication of PCNL. It could be life-threatening, although its incidence is low. Fully understanding the risk factors is helpful to prevent its occurrence. This study shows that female gender and preoperative positive urine culture are the risk factors of urosepsis following percutaneous nephrolithotomy. So, we should be more vigilant and take more closely monitoring postoperative to prevent the occurrence and progress of urosepsis.