The generally accepted standard of antibiotic therapy aimed at causative agent does not exclude the risk of acute obstructive pyelonephritis (AOP) to become chronic after the end of antibiotic therapy, resulting in a high incidence of relapses. To assess the outcomes of the AOP, we undertook a prospective clinical trial.
Materials and methods. The study comprised 51 consistently selected patients (12 men and 39 women) with AOP occurred as a result of unilateral ureteric calculus obstruction. Inclusion criteria for the study were as follows: no history of urological diseases, including urinary stones; the first presentation to the urologist with AOP; the level of the bladder bacteriuria before the drainage of the obstructed kidney ≥103 CFU/ml. Bladder urine samples were collected for bacteriological examination by catheterization. At one, 3 and 6 months after completion of the treatment of AOP, the patients underwent a general clinical examination, and midstream specimens of urine were collected from the patients for bacteriological analysis to control leukocyturia and bacteriuria.
Results. Eradication of causative uropathogens from urine occurred within 6 months in 96.1% of patients, and at that point, leukocyturia persisted in 23.5% of the patients. The decrease in detecting uropathogens in the urine was accompanied by an increase in the frequency of the presence in the urine of other aerobes and anaerobes, i.e., no sterile urine cultures were obtained from any patient. The rates of eradication of uropathogens were associated with the patients’ age, the duration of the pre-hospital stage of AOP, and the complicated course of AOP.

Keywords: acute obstructive pyelonephritis, leukocyturia, bacteriuria, uropathogens, prognosis