| 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.5Clostridium difficile infection (CDI) is an important healthcare-associated infection. Antibiotic use increases the risk of CDI for at least 3 months6 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.7In 2009, the Scottish government issued a new target for all health boards to reduce CDI by at least 30% over 2 years.8 The Scottish Antimicrobial Prescribing Group also produced recommendations for all National Health Service (NHS) boards to restrict the use of antibiotics associated with a high risk of CDI.9 As part of a widespread antibiotic policy change at NHS Tayside, orthopedic antibiotic prophylaxis was changed from cefuroxime to gentamicin and flucloxacillin. After concerns raised by nephrologists and a small uncontrolled study in the Dumfries and Galloway region of Scotland that described an increased rate of AKI in patients after orthopedic surgery after this policy change,10 it was felt that further investigation was required.This study aimed to use robust methodology, in a larger, population-based study of adult patients undergoing orthopedic implant surgery, to evaluate the effect of the policy change on postoperative AKI. It is noteworthy that patients who underwent repair of a neck of femur (NOF) fracture received coamoxiclav as antibiotic prophylaxis after the policy change because of concerns raised by orthopedic surgeons with regard to administering gentamicin in this particular patient group. This analysis was then extended to evaluate postoperative AKI in other surgical specialties (urology, vascular, gastrointestinal, and gynecology) that had changed to a gentamicin-based regimen. |
