Prediction of Urosepsis for Ambulatory Piezoelectric Shock Wave Lithotripsy

Extracorporeal shock wave lithotripsy (SWL) is being performed increasingly as an ambulatory procedure, potentially exposing patients to the risk of serious septic complications. In this study of 194 patients, there were no cases of serious urosepsis. Prelithotripsy urine culture had a false-negative rate of 30% in identifying significant bacteriuria. A history of urinary tract infection associated with calculus identified 60% of those at risk of developing bacteriuria as a result of stone fragmentation. The antibiotic sensitivity corresponded to previous infecting organisms in 85% of cases. Ninety-five per cent of stone-bearing patients with sterile urine had a urinary leukocyte count of less than 80/ml. Microscopy of the urine immediately prior to lithotripsy identified more than 90% of patients with infected urine. We conclude that serious urosepsis is not a significant problem in ambulatory lithotripsy of renal stones, but the risk of same may be further reduced by giving antibiotic cover to patients with a positive urine culture, a history of urinary tract infection, or positive microscopy findings prior to treatment.