Bacteraemia during prostatectomy and other transurethral operations: influence of timing of antibiotic administration

Antibiotic prophylaxis in urologic interventions: Who, when, where?

BACKGROUND

Periprocedural prophylaxis in medicine encompasses the set of measures (physical, chemical, and pharmacological) used to reduce the risk of infection. Antibiotic prophylaxis (AP) refers to the administration of a short-term regimen of antibiotics shortly before a medical procedure to reduce the risk of infectious complications that can result from diagnostic and therapeutic interventions. The outspreading growth of multidrug-resistant bacterial species and changes in the bacterial local ecosystem have impeded the development of a unique scheme of AP in urology.

OBJECTIVES

To review the literature and current guidelines regarding AP for urological diagnostic and therapeutic procedures, and to define agents, timing, and occasions when administering pharmacological prophylaxis. Secondly, according to current literature, to open new scenarios where AP can be useful or useless.

RESULTS

Major gaps in evidence still exist in this field. AP appears useful in many invasive procedures and some sub-populations at risk of infectious complications. AP is not routinely recommended for urodynamic exams, diagnostic cystoscopy, and extracorporeal shock-wave lithotripsy. The available data regarding the use of AP during the transperineal prostate biopsy are still unclear; conversely, in the case of the transrectal approach AP is mandatory. AP is still considered the gold standard for the prevention of postoperative infective complications in the case of ureteroscopy, percutaneous nephrolithotomy, endoscopic resection of bladder tumor, endoscopic resection of the prostate, and prosthetic or major surgery.

CONCLUSION

The review highlights the complexity of determining the appropriate candidates for AP, emphasizing the importance of considering patient-specific factors such as comorbidities, immunocompetence, and the nature of the urologic intervention. The evidence suggests that a one-size-fits-all approach may not be suitable, and a tailored strategy based on the specific procedure and patient characteristics is essential.

From mucosal infection to successful cancer immunotherapy

The clinical management of advanced malignancies of the upper and lower urinary tract has been revolutionized with the advent of immune checkpoint blockers (ICBs). ICBs reinstate or bolster pre-existing immune responses while creating new T cell specificities. Immunogenic cancers, which tend to benefit more from immunotherapy than cold tumours, harbour tumour-specific neoantigens, often associated with a high tumour mutational burden, as well as CD8+ T cell infiltrates and ectopic lymphoid structures. The identification of beneficial non-self tumour antigens and natural adjuvants is the focus of current investigation. Moreover, growing evidence suggests that urinary or intestinal commensals, BCG and uropathogenic Escherichia coli influence long-term responses in patients with kidney or bladder cancer treated with ICBs. Bacteria infecting urothelium could be a prominent target for T follicular helper cells and B cells, linking innate and cognate CD8+ memory responses. In the urinary tract, commensal flora differ between healthy and tumoural mucosae. Although antibiotics can affect the prognosis of urinary tract malignancies, bacteria can have a major influence on cancer immunosurveillance. Beyond their role as biomarkers, immune responses against uropathogenic commensals could be harnessed for the design of future immunoadjuvants that can be advantageously combined with ICBs.

Effectiveness of appropriate antibiotic prophylaxis for transurethral resection of the prostate in the era of antibiotic resistance

The results of this study demonstrate the lower incidence of posttransurethral resection of the prostate (TURP) urinary tract infection (UTI) among patients receiving appropriate antibiotic prophylaxis (AAP) versus inappropriate antibiotic prophylaxis (27% vs 47%; P < .001). Preoperative urine culture procurement and APP are critical for post-TURP UTI prevention in the era of antibiotic resistance.

Clinical Practice Guideline for the Management of Asymptomatic Bacteriuria: 2019 Update by the Infectious Diseases Society of America

Asymptomatic bacteriuria (ASB) is a common finding in many populations, including healthy women and persons with underlying urologic abnormalities. The 2005 guideline from the Infectious Diseases Society of America recommended that ASB should be screened for and treated only in pregnant women or in an individual prior to undergoing invasive urologic procedures. Treatment was not recommended for healthy women; older women or men; or persons with diabetes, indwelling catheters, or spinal cord injury. The guideline did not address children and some adult populations, including patients with neutropenia, solid organ transplants, and nonurologic surgery. In the years since the publication of the guideline, further information relevant to ASB has become available. In addition, antimicrobial treatment of ASB has been recognized as an important contributor to inappropriate antimicrobial use, which promotes emergence of antimicrobial resistance. The current guideline updates the recommendations of the 2005 guideline, includes new recommendations for populations not previously addressed, and, where relevant, addresses the interpretation of nonlocalizing clinical symptoms in populations with a high prevalence of ASB.

Timing, dosing and duration of antimicrobial prophylaxis in urology: a study in guinea pigs with special reference to high-risk conditions

A study in guinea pigs was performed to investigate the importance of timing, dosage and duration of antimicrobial prophylaxis in urologic surgery. To simulate high-risk conditions, in one group a foreign body was implanted subcutaneously. The prostate and one kidney were cauterized and bacteremia was induced by intravenous injection of an Escherichia coli suspension. Various ciprofloxacin regimens were tested. The results indicate that antimicrobial prophylaxis is beneficial only if administered before or shortly after surgery. Full therapeutic dosage may not be necessary for prophylactic efficacy. Single-dose prophylaxis was as effective as multiple doses. Foreign body infection could be prevented by single-dose prophylaxis.

Norfloxacin prophylaxis for endoscopic urological surgery

A series of 140 patients, undergoing various types of urological endoscopic procedures, was divided into 2 equal, parallel, randomised groups. The first group of 70 patients, undergoing lower urinary tract surgery, was randomised, half to receive norfloxacin prophylaxis and half no antibiotic cover; the other 70 patients, undergoing percutaneous renal surgery, were randomised, half to receive norfloxacin and half cefuroxime. It was found that 26% of patients not receiving antibiotic prophylaxis and 11% on cefuroxime prophylaxis developed post-operative bacteriuria, with a high incidence of urinary tract infection (UTI). Only 1 patient of 70 on norfloxacin prophylaxis developed post-operative bacteriuria, which quickly responded to prolongation of norfloxacin therapy. Prior to surgery, 10% of all patients were found to have previously undetected bacteriuria. This group was at high risk of developing post-operative infection. Norfloxacin effectively prevented post-operative bacteriuria and urinary tract infection in these patients. This study suggests that norfloxacin is a safe and effective prophylactic antibiotic in all forms of urological endoscopic procedures.

Bacteremia during extracorporeal shock wave lithotripsy of renal calculi

An increasing incidence of bacterial endocarditis has been observed since the beginning of the last decade. An explanation for this fact is the expansion of diagnostic and therapeutic procedures in diverse medical disciplines. In a clinical study performed on 49 consecutive patients undergoing extracorporeal shock wave lithotripsy a 14.3% rate of bacteremia was detected during treatment. The bacterial spectrum consisted of gram-positive cocci, gram-negative cocci, Bacteroides capillosus and Proteus mirabilis. In principle, these results do not call for an antibiotic prophylaxis. Nevertheless, according to the recommendations of the American Heart Association and the Deutsche Gesellschaft für Herz- und Kreislaufforschung, patients with a cardiac risk predisposing to bacterial endocarditis must receive perioperative antibiotic prophylaxis.

Single dose, oral antibiotic cover for transurethral prostatectomy

A double-blind, randomised, placebo-controlled study was carried out to determine the incidence and significance of bacteriuria in 110 patients undergoing transurethral resection of the prostate (TURP) and to assess the effect of a single pre-operative dose of Ciprofloxacin, a 4-quinolone antibiotic. Fifteen (68%) of the 22 patients in the placebo group with a positive post-operative urine culture subsequently developed a clinically apparent urinary tract infection (UTI) or received antibiotics in view of a positive urine culture. Adequate prostatic concentrations of Ciprofloxacin were achieved in all who received the drug. A significant reduction in the number of positive post-operative urine cultures and urinary tract infections requiring antibiotic therapy was achieved in this group. Six patients (5.5%) developed clinical evidence of septicaemia, 5 of whom were in the placebo group. No organisms resistant to Ciprofloxacin were encountered. Prior to surgery, 19% of all patients were found to have previously unsuspected bacteriuria. Ciprofloxacin tended to reduce the chances of this group developing a UTI or requiring antibiotics. Further, there was a highly significant reduction in post-operative infective complications in those with sterile urine at the time of resection who had received the drug. This study suggests that antibiotic cover for TURP is of clinical benefit. Ciprofloxacin may prove suited to this purpose, although further experience with the drug is still required.

Antibiotic prophylaxis of urinary tract infection after transurethral resection of the prostate: a randomized study

Transurethral resection of the prostate is associated with a major risk of postoperative infection. To evaluate the clinical and bacteriological efficacy of antibiotic prophylaxis with a single dose of netilmicin sulfate, we conducted a randomized study in 100 patients with sterile preoperative urine undergoing transurethral resection of the prostate. Of these patients 95 were evaluated: 47 were randomized to the control group and received an intramuscular injection of 1.5 ml. of a 0.9 per cent solution of sodium chloride 1 hour preoperatively and 48 were given an intramuscular injection of 150 mg. netilmicin sulfate in a volume of 1.5 ml. 1 hour preoperatively. Of the patients 16 in the control group (34 per cent) and only 1 in the treated group (2 per cent) had bacteriuria (greater than 10(5) bacteria per ml.) (p less than 0.001). This difference also was significant 2 and 5 days postoperatively (p less than 0.05 and p less than 0.001, respectively). One patient in the control group had bacteremia compared to none in the treated group. Clinical signs of infection were less common in the treated group. Sensitivity studies revealed that all of the organisms tested were sensitive to netilmicin sulfate. High concentrations of netilmicin sulfate were found in the urine collected at operation (162 +/- 112 micrograms per ml. urine).