0022-534 7 /90/1441-0015$02.00/0 THE JOURNAL OF UROLOGY Copyright© 1990 by AMERICAN UROLOGICAL ASSOCIATION, INC.
Vol. 144, July
Printed in U.S.A.
EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY OF KIDNEY STONES DOES NOT INDUCE TRANSIENT BACTEREMIA. A PROSPECTIVE STUDY HENRIK WESTH, FREDDY KNUDSEN, ANNE-MARGRETE HEDENGRAN, MERETE WEISCHER, PETER MOGENSEN, JENS THORUP ANDERSEN AND THE COPENHAGEN EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY STUDY GROUP* From the Departments of Clinical Microbiology, Urology, Anesthesiology and Radiology, Bispebjerg and Hvidovre Hospitals, University of Copenhagen, Copenhagen, Denmark
During 58 extracorporeal shock wave lithotripsies 161 blood cultures were drawn to evaluate the incidence of bacteremia during the procedure. Only 3 blood cultures drawn during the procedure yielded bacteria, in all cases probably skin flora contaminants. Post-lithotripsy fever was noted in 29% of the patients, and could not be associated with transient bacteremia and was not influenced by antimicrobial prophylaxis. Patients with a positive urine culture after extracorporeal shock wave lithotripsy may have an increased risk of septicemia. (J. Ural., 144: 15-16, 1990) The management of upper urinary tract calculi has been revolutionized by the introduction of extracorporeal shock wave lithotripsy (ESWLt). To avoid infectious bacterial complications from concomitant urinary tract infection or infected calculi, patients undergoing ESWL often are given prophylactic antibiotics. Despite this therapy bacteria already present in the urine or liberated from the calculus after fragmentation by ESWL, in combination with the local tissue trauma created by the shock waves, give rise to urosepsis in approximately 0.3% of the patients. 1 • 2 Fever of greater than 38C is seen in 15 to 23% of the patients depending on patient selection. 1 • 2 This fever might be caused by transient bacteremia that often accompanies other urological procedures 3 •4 and Streptococcus faecalis endocarditis has indeed been observed after ESWL in a patient with enterococcal urinary tract infection. 5 We evaluated the incidence of transient bacteremia during ESWL and subsequent urosepsis.
from a cubital vein after iodine disinfection before ESWL, after ureteral stenting (if performed), after 1,000 shock waves, 15 minutes later and 30 minutes later if the ESWL was not yet finished. Aliquots of 10 ml. of each 20 ml. sample of blood were inoculated for aerobic and anaerobic culture into 2 blood culture bottles§ and observed 6 days for growth. All bacteria were identified to the species level. Rectal temperature was monitored continuously during ESWL with a digital thermometer DM852 with probe AR 1.11 The temperature was noted at the same time as blood was drawn and if it increased more 0.5C from the baseline temperature. The highest temperature during the 24 hours after ESWL was registered. The patients were followed for post-ESWL complications for 1 month. Prophylactic antibiotics were administered to patients with either current or prior clinical urinary tract infection, or known infection stones, or if an indwelling catheter (percutaneous nephrostomy tube, ureteral stent or bladder catheter) was placed just before ESWL. The antibiotics used were selected either according to susceptibility testing of the clinical isolates or empirically using 2 gm. ampicillin twice daily in combination with 150 mg. netilmycin twice daily given intravenously just before ESWL and continued for 24 hours. Informed consent was obtained from all patients. The study received the approval of our regional ethics committee fulfilling the criteria of Helsinki Declaration IL
PATIENTS AND METHODS
During a 5-month period 55 inpatients underwent 58 ESWL treatments with the Siemens Lithostar. ESWL was done with the patient under local infiltration analgesia, most often combined with intravenous fentanyl. All patients were given intravenous fluid infusion and 20 mg. furosemide during ESWL. Only patients from the Copenhagen Municipality entered the study to ensure appropriate followup. Mean patient age was 62 years (range 20 to 81 years). Of the patients 22 reported a prior urinary tract infection, 24 had a urinary tract infection before ESWL, 5 had infection stones, 13 entered the study with an indwelling Double-Jt ureteral stent and in 4 the stent was placed immediately before ESWL. Five patients had a nephrostomy catheter (table 1). The stones were in the caliceal system or renal pelvis in 57 treatments and in the ureter in 1. Patients were examined for bacteriuria before and 1 day after ESWL. All urine specimens were plated on 5% horse blood agar and bromthymol-blue lactose agar using inocula of 1 and 10 µl. This method allowed for quantification with a lower limit of 100 bacteria per ml. urine. Bacteriuria was defined as more than 1,000 colonies of 1 species per ml. or more than 104 colonies if there were more than 1 species. Blood cultures were drawn
Urine cultures before ESWL were positive in 24 patients (41 %) (table 2) but only 20 of them were given antibiotics (table 1). Day 1 of antibiotic therapy eradicated the urinary tract infection in 11 of these patients. In 4 of 22 patients with initially sterile urine and no antibiotic treatment bacteria were cultured from the urine the day after ESWL. Relevant antibiotic treatment according to the department guidelines was missed in 7 of the 34 patients not treated with antibiotics, while all 24 who received antibiotics were treated relevantly. The patients received a median of 2,600 shock waves (range 800 to 6,000). Rectal temperature was continuously monitored during 48 treatments and in 5 of these a temperature fluctuation of 0.5 to 0.9C with 4 increases and 1 decrease in temperature was measured. No temperature measured during ESWL was higher than 37.9C. The next day rectal temperature was signif-
Accepted for publication January 24, 1990. * Participants: V. Hvidt, H.-G. Iversen, R. I. Hansen, K. FeldtRasmussen, I. Walther M!llller, P. Klarskov, J. Miskowiak, 0. S. Nielsen andL. Baek. t Dornier Medical Systems, Inc., Marietta, Georgia. :j: Medical Engineering Corp., New York, New York.
§ Septi Chek, Roche Laboratories, Nutley, New Jersey.
II Ellab A/S, R!lldovre, Denmark.
WESTH AND ASSOCIATES TABLE 1. Demographic characteristics Antibiotics Group (24 treatments)
Pre-ESWL urinary tract infection Pre-ESWL urinary culture missed Infection stone Ureteral stent Nephrostomy catheter Largest stone diameter (mm.): 1-10 11-20 >20
No Antibiotics Group (34 treatments)
18 14 2
TABLE 2. Urinary tract infection in 58 ESWL treatments AfterESWL
Total No. Cases
Before ESWL Pos. Culture
11* 4* 1*
24 32 2
Pos. culture No growth Not done Totals
* One patient from each of these groups experienced urosepsis (pathogens isolated from blood and urine) 1 to 6 days after ESWL with P. aeruginosa, Strept. faecalis and Staph. epidermidis, respectively. TABLE 3. Blood culture results No Growth Before ESWL After ureteral stenting After 1,000 shock waves 15 mins. later 30 mins. later Totals
41 2 161
40 2 157
* Staph. epidermidis.
t Propionibacterium acnes. icantly higher (p