A Retrospective Study On Hospitalized Patients With Urinary Tract Infection In The Department Of Nephrology

[Objective](1)To analyze the clinical features and predisposing factors of hospitalized patients with urinary tract infection(UTI) in the department of nephrology;(2)To investigate the distribution and the drug resistance of the pathogens which lead to urinary tract infection; (3)To find out the features of nosocomial urinary tract infection.[Methods] 156 hospitalized UTI patients in the department of nephrology in our hospital from Aug 2012 to Aug 2013 were enrolled and their clinical and laboratory data was collected. Then we described the clinical features and the predisposing factors of UTI.Furthermore, the distribution and the antibiotic resistance of the pathogens were analyzed.[Results](1) Among the 156 UTI patients,26 were males (16.7%), and 130 were females (83.3%).The age was between 18-92 years old (mean age 58.98±18.20 years old). The male to female ratio of UTI in each age group was:≤40 years old,1:12.5;41-59 years old,1:5.14;≥60 years old,1:4.06.(2) Among 156 UTI patients, there were 93 patients with upper UTI (59.6%) and 63 patients with lower UTI (40.4%).(3) The incident rate of urinary irritation in upper and lower UTI was 57.0% and 69.8% respectively (p>0.05).Fever,osphyalgia,enteron symptom and fatigue were more common in upper UTI than those in lower UTI(p<0.01).In upper UTI patients, fever and osphyalgia were more common than urinary tract irritation.Gross hematuria was more common in lower UTI(p<0.01),while the physical signs of UTI such as percussion tenderness over kidney region and tenderness points on ureter were more common in upper UTI(p<0.01).(4) The incidence of urine leukocytes increase in upper UTI was higher than that in lower UTI (80.6% VS 66.7%，p<0.05).The positive rate of the urine nitrite in UTI was merely 30%,and there was no difference between the upper and lower UTI(p> 0.05).The incidence of β2-microglobulin (β2-MG) increase accounted for 77.4% in upper UTI, which was significantly higher than that in lower UTI(p<0.01).But in lower UTI,the incident rate of β2-MG increase was also very high, up to 33.3%.Increased peripheral WBC count, acceleration of erythrocyte sedimentation rate(ESR) and elevated C-reactive protein(CRP) were more common in upper UTI than those in lower UTI (p<0.01).(5) In 93 cases of upper UTI, complications were a total of 32 cases, accounting for 34.4%.Among them,18 cases with acute kidney injury (AKI),11 with septicemia,1 with septic shock, and 2 with paranephric abscess. In 63 cases of lower UTI, there were two cases of complications, accounting for 3.2%.Both of them were AKI and no other complications. The complications were more common in upper UTI than in lower UTI(p<0.01).(6) 119 patients were complexity urinary tract infection, accounting for 76.3%.(7) The top five predisposing factors in complexity urinary tract infections were: chronic kidney disease(CKD)(80.7%),urinary obstruction(62.2%),menopause(56.3%),anemia(47.9%),and diabetes(36.1%).The top three reasons of urinary obstruction were:urinary calculi (31.1%),hyperplasia of prostate. gland(15.1%)and bladder-neck obstruction(5.9%).In patients with CKD,52.1% were CKD stagel-3,16.8% were CKD stage4-5 without renal replacement treatment, and patients undergoing hemodialysis or peritoneal dialysis accounted for 11.8%.(8) Gram-negative bacteria was still the main pathogens causing UTI, accounting for 71.9%,followed by Gram-positive bacteria and fungus, accounting for 23.6% and 4.5% respectively. The most major pathogen was Escherichia coli, accounting for 39.3%, followed by Enterococcus, accounting for 20.2%.The infection rate of Escherichia coli producing extended spectrum beta lactamases (ESBLs) was high, reaching to 68.6%.(9) Gram-negative bacteria was general resistant to penicillins and cephalosporins.More than 50% Escherichia coli was resistant to every generation cephalosporins.Some Pseudomonas aeruginosa was resistant to carbapenem antibiotics (antibiotic resistance rate 16.7%). Gram-negative bacteria was highly sensitive to Amikacin, while generally resistant to gentamicin.Both Gram-negative bacteria and Gram-positive bacteria had low antibiotic resistance to Fosfomycin (≤16.7%). Enterococcus was resistant to ampicillin and levofloxacin (antibiotic resistance rate>40%),but highly sensitive to nitrofurantoin,vancomycin, teicoplanin and linezolid.(10) The characteristics of nosocomial urinary tract infection in the hospitalized patients in the department of nephrology:① more common in female and elderly, the upper UTI was more than the lower UTI(10:1);② be easy to cause missed diagnosis because of the atypical clinical manifestations.③laboratory examinations were lack of specificities, and the true bacteriuria should be used as a diagnostic ’gold standard’.④ all the nosocomial UTI were complicated UTI and accompanied many predisposing factors.⑤ patients were in serious conditions and accompanied many complications.[Conclusion] UTI of hospitalized patients in the department of nephrology was more common in female and elderly. The upper UTI was more than the lower UTI.The clinical manifestation in upper UTI was mostly systemic symptoms, while in lower UTI was urinary irritation. Blood, urine abnormalities and complications occurred more in upper UTI. Complexity urinary tract infection had a high proportion and many predisposing factors. Gram-negative bacteria were still the main pathogens causing UTI, followed by Gram-positive bacteria and fungus. The situation of antibiotic resistance was serious. The nosocomial urinary tract infection was particularity, requiring close attention in clinical practice.