Acute Pyelonephritis: Clinical Characteristics and the Role of the Surgical Treatment

Dong-Gi Lee, Seung Hyun Jeon, Choong-Hyun Lee, Sun-Ju Lee, Jin Il Kim, and Sung-Goo Chang

Department of Urology, School of Medicine, Kyung Hee University, Seoul, Korea.

Acute Pyelonephritis

• Annual incidence is 250,000 cases in US• Incidence of hospitalized APN is 11.7 cases per

10,000 population among females and 2.4 cases per 10,000 population among males

• Renal parenchyma damaged sepsis• Treatment of APN: current characteristics of

the community, causative bacterial spectrum, and antibiotic resistance patterns.

Acute Pyelonephritis• AB resistance is on the gradual increase• Ampicillin and trimethoprim/sulfamethoxazole

(TMP/SMX): – first-line antibiotics not showing effective sensitivity

any longer• Complicated APN shows high-(+) rate with blood

culture and more severe clinical symptoms than those of simple APN.

• Current clinical characteristics and the necessity of surgical treatment in 1,026 cases of APN patients for the past 5 yrs.

Materials & Methods• n = 1026 patients in Kyung Hee University Medical

Center (Jan 2000-Dec 2004)– Medical records: clinical symptoms, causes, causative

microorganisms, antibiotic sensitivities, and curative urological procedures

• 3 of the following 5 criteria: – 1) clinical symptoms of APN (chilling, nausea, vomiting,

flank pain)– 2) CVA tenderness– 3) leukocytosis (higher than 10,000/µL)– 4) fever (higher than 38.5 )℃– 5) WBC count ≥5 cells/hpf on centrifuged urine sediment

Materials & Methods• Identification of bacteria and AB sensitivity were assessed

by disk diffusion test • In diagnosing complicated APN, group examined the

presence of following diseases: – structural and functional abnormalities (urinary tract stone

disease, neurogenic bladder, vesicoureteral reflux, obstructive uropathy, prostate disease)

– underlying diseases which contribute to the persistence of infection (DM, immunosuppressive state, cystic renal disease).

• T-test: comparison of continuous variables between independent two groups

• Pearson chi-square test : analysis of the comparison of the frequency, criterion of the determination of significance was p<0.05

Patient Characteristics

• Among 1026, 118 M, 908 F; M:F ratio 1:7.7• Mean age 45.5±17.8 yr, – M 49.0±19.2 yrs, F 45.0±17.5 yrs– Diff. between genders not detected (p>0.05)

• In males, group of over 60 was 38.1%, which was the most prevalent age group

• Particularly, females in their 20s and 30s were 38.6% of the entire female patients.

Clinical Presentation

• Flank pain: – R kidney 56.3%, L kidney 32.9%– both kidneys 10.7%,

• Duration of fever: 3.1 days• Duration of flank pain: 3.7 days• Duration of the CVA tenderness: 4.2 days• No statistical difference between gender

Complicating Factors

• 32.7% of total APN (335 cases, 73 men, 262 women) were complicated APN.

• Among the complicated APN, the cases with structural and functional abnormality were 214 patients (63.9%), the cases with underlying medical diseases were 106 patients (37.9%), and the cases caused by the urologic manipulation were 8 cases (2.4%).

Underlying disease of complicated acute pyelonephritis

Complicating Factors

• In complicated APN, the duration of the flank pain and the CVA tenderness was significantly longer than in simple APN

• Complicated APN M:F ratio (1:3.6) was higher than that of the simple APN M:F ratio (1:1.14)

Radiologic Findings

• Abdominopelvis UTZ: performed on 788 cases (76.8%)– 428 cases (54.3%) showed normal findings– 360 cases (45.7%) showed abnormal findings• nephromegaly (18.8%)• hydronephrosis (12.1%)• renal stone (4.2%)• renal cyst (2.9%)• ureter stone (2.1%)

Bacterial Culture and AB Sensitivity

• 504 cases (49.1%): bacteria were isolated by urine culture

• Escherichia coli was the most prevalent bacteria found in urine culture, 84.3%

Bacterial Culture

Curative Urological Procedures

• In treating complicated APN, urological procedures were performed on 94 cases (9.2%)– most frequent procedure: urinary lithotripsy (42

cases, 44.7%)– percutaneous nephrostomy (23 cases, 24.5%),

clean intermittent catheterization (14 cases, 14.9%), ureteroneocystostomy (10 cases, 10.6%), nephrectomy (5 cases, 5.3%) and percutaneous pus drainage (3 cases, 3.2%).

Discussion

• UTI more prevalent in females– prevalent age range: 20-30 yrs (38.6% in our

study)

• Many studies: young women who are sexually active, use diaphragms or spermicide UTI

• Proportion of female cases >60 yrs is 23.7%– DM and cerebral vascular disease due to aging

Cultured Bacteria

• E. coli: 84.3% cause for UTI• In cases with risk factors such as neurogenic

bladder, kidney transplantation, urethral stricture– Pseudomonas was cultured– microorganism was found in 80% of the male

population, which was prevalent

AB Sensitivity• AB resistance of ampicillin and TMP/SMX is higher

than that of western countries.• AB sensitivity test to E. coli– Ampicillin: 27.7%– Ampicillin/sulbactam: 77.1% – Ciprofloxacin: 79.0%– TMP/SMX: 44.7%– Amikacin: 92.1%– Gentamicin: 77.1%

• In other countries, it has been reported that antibiotic sensitivity for TMP/SMX was 67-83.2%, 78-98.1% for ciprofloxacin and 25-82.3% for ampicillin.

Antibiotic Sensitivity

Sepsis

• Sepsis: lethal complication• Present in 10.1% of the population• In cases where bacteria were isolated in blood

culture– the duration of flank pain was significantly longer

than other cases.

Antibiotic Use

• efficacy of ampicillin or TMP/SMX as the first-line treatment is very low.

• Ciprofloxacin showed 79.1% sensitivity against E. coli, and 88.3 % against K. pneumoniae– can be recommended as the first-line oral therapy

Complicated UTI• 32.7% of the population• Structural or functional disorders

– urinary tract stone disease– vesicoureteral reflux– neurogenic bladder– ureteral obstruction– benign prostate hyperplasia

• Among 335 complicated APN patients, 94 patients received the curative urologic procedures.

• To treat urinary tract stones, ESWL, ureteroscopic stone removal or other lithotripsy were performed in 42 cases

• In hydronephrosis due to ureteral obstruction, percutaneous nephrostomy was performed in 23 cases

Conclusion

• One third of APN is complicated APN, and over 60% of its origin is urological diseases.

• Bacteria were isolated in urine culture in 49.1%– Use of ABs without prescription prior to admission.

• AB resistance shows a trend on the rise; – Particularly, ABresistance to ampicillin and TMP/SMX

is high therefore– reconsideration of their selection as first-line drugs is

required.