Risk of AKI with Gentamicin as Surgical Prophylaxis

Abstract

In 2009, the Scottish government issued a target to reduce Clostridium difficile infection by 30% in 2 years. Consequently, Scottish hospitals changed from cephalosporins to gentamicin for surgical antibiotic prophylaxis. This study examined rates of postoperative AKI before and after this policy change. The study population comprised 12,482 adults undergoing surgery (orthopedic, urology, vascular, gastrointestinal, and gynecology) with antibiotic prophylaxis between October 1, 2006, and September 30, 2010 in the Tayside region of Scotland. Postoperative AKI was defined by the Kidney Disease Improving Global Outcomes criteria. The study design was an interrupted time series with segmented regression analysis. In orthopedic patients, change in policy from cefuroxime to flucloxacillin (two doses of 1 g) and single-dose gentamicin (4 mg/kg) was associated with a 94% increase in AKI (P=0.04; 95% confidence interval, 93.8% to 94.3%). Most patients who developed AKI after prophylactic gentamicin had stage 1 AKI, but some patients developed persistent stage 2 or stage 3 AKI. The antibiotic policy change was not associated with a significant increase in AKI in the other groups. Regardless of antibiotic regimen, however, rates of AKI were high (24%) after vascular surgery, and increased steadily after gastrointestinal surgery. Rates could only be ascertained in 52% of urology patients and 47% of gynecology patients because of a lack of creatinine testing. These results suggest that gentamicin should be avoided in orthopedic patients in the perioperative period. Our findings also raise concerns about the increasing prevalence of postoperative AKI and failures to consistently measure postoperative renal function. Reported rates of postoperative AKI vary because of the heterogeneity of the populations studied. Uncomplicated AKI is associated with a mortality of 10%, rising to 50% in the context of multiorgan failure and up to 80% if RRT is required. 1,2 It was thought that the presence of AKI was a marker of coexisting pathology that increased mortality risk, but recent reports demonstrate AKI as an independent risk factor for mortality. 3,4 The increasing incidence of AKI and its long-term consequences have significant socioeconomic and public health effects globally. 5 Clostridium difficile infection (CDI) is an important healthcare-associated infection. Antibiotic use increases the risk of CDI for at least 3 months 6 and short courses of perioperative antibiotic prophylaxis have also been associated with an increased risk of CDI, particularly in the context of an established outbreak. 7

Surgical prophylaxis with gentamicin and acute kidney injury: a systematic review and meta-analysis

“…Table 1 contains the characteristics of the included studies. The study conducted by Bell et al consisted of 5 cohorts, with each cohort representing one surgical subspecialty (15). There were 4 study groups in each of the studies done by Challagundla et al (9) and Schneider et al (8), so we coupled each 2 study groups together in order to simplify the comparisons.…”

“…One study had high risk of bias in terms of appropriateness of eligibility criteria due to lack of exclusion criteria (11). In another study, only 47% and 52% of patients undergoing gynecologic and urologic operations respectively, were able to document postoperative renal function which raised a major concern over incomplete follow-up (15).…”

“…Bell et al showed that the majority of affected patients had transient stage1 AKI by Kidney Disease Improving Global Outcomes (KDIGO) classification and the median length of stay in patients with AKI was 8 days compared to 7 days in patients without AKI (15).…”

The Seen and the Unseen

“…In this issue of JASN, Bell et al explore the effects of a change in antibiotic prophylaxis designed to reduce the risk of Clostridium difficile infection (CDI) in surgical patients. 6 In 2009, the Scottish Antimicrobial Group Prescribing Group (SAPG), a national clinical forum supported by the Scottish Government Health Directorate, issued a document with a set of principles to guide surgical antibiotic prophylaxis. 7 The overall goal was to reduce the rate of healthcareassociated infections, principally CDI.…”

“…Now, Bell et al present a comprehensive population-based analysis of the consequences of this antibiotic policy change. 6 The authors, who include members of the SAPG, aimed to evaluate postoperative AKI in surgical patients after the change in antibiotic prophylaxis recommendations. Their study population included 12,482 patients undergoing orthopedic, vascular, gastrointestinal, and gynecologic surgical procedures.…”