In Patients With CBD Stones, Cholecystectomy Wound Infection Rates Similar With Broad- vs Narrow-Spectrum Antibiotics

By Patricia A. Sheiner MD

May 19, 2022

NEW YORK (Reuters Health) - In patients with common bile duct (CBD) stones undergoing same-admission cholecystectomy, surgical site infection rates are low and similar with broad- and narrow-spectrum antibiotics, observational data suggest.

Patients who received broad-spectrum (BS) antibiotics had longer hospital stays and a higher risk of acute kidney injury (AKI), however.

Dr. Brett M. Tracy of The Ohio State University Wexner Medical Center in Columbus and colleagues in the EAST Common Bile Duct Stones Study Group prospectively collected data on 891 patients over age 17 undergoing cholecystectomy at 12 centers.

Diagnosis of acute biliary pancreatitis was made by an elevated serum amylase three times greater than normal with or without radiographic evidence of pancreatitis. Choledocholithiasis diagnosis was made by an elevated serum bilirubin with or with or without an ultrasound demonstrating a dilated CBD or stone in the CBD. A concomitant diagnosis of cholecystitis was also noted.

As reported in the Journal of the American College of Surgeons, 51.7% of the patients received BS antibiotics, most commonly piperacillin/tazobactam (59.4%) and fluoroquinolones (23.4%). The remaining patients received narrow-spectrum (NS) antibiotics, most often first-generation (59.8%) or second-generation (36.7%) cephalosporins.

The median antibiotic duration was significantly longer in the BS group compared to the NS group preoperatively (3 vs 2 days; p<0.001), postoperatively (2 vs 1 days; p=0.01), and overall (6 vs 4 days, p=0.01).

Among patients receiving preoperative BS antibiotics, 17 were postoperatively transitioned to NS antibiotics. Among patients receiving preoperative NS antibiotics, 16 patients were postoperatively transitioned to BS antibiotics. Anyone who received BS antibiotics were included in the BS group.

Compared to the NS group, patients in the BS group on average were older (56.3 vs 46.7 years, P<.0001), had a higher Charlson Comorbidity Index (p<.001), and were more likely to be male (36.4% vs 29.3%, p=0.02). They also had higher rates of choledocholithiasis (64% vs 56.7%, p<0.001) and cholecystitis (19.1% vs 9.1%, p<0.001) and were more likely to undergo endoscopic retrograde cholangiopancreatography (ERCP) preoperatively (63.% vs 36.4% p<.001).

The two groups had similar rates of surgical site infections (BS 0.9%, NS 0.5%; p=0.7); this was also true in patients with concomitant cholecystitis. There was one superficial infection and two intraabdominal abscesses in the BS group vs two intraabdominal infections in the NS antibiotic group. There was no difference in 30 day readmissions, with a total of 5 in each group.

The BS group had a longer median length of stay (4 days, r 3-6 vs 4 r 2-5. P<0.001) and longer median duration of preoperative antibiotic therapy (3 days vs 2 days; p<.001) and postoperative therapy (2 days vs 1 days; p=0.01). The authors suggest the increase in LOS and antibiotic therapy could be attributed to the higher rate of preoperative ERCP in the BS group.

There was a significant increase in AKI in the BS antibiotic group (5% vs 1.4%, p=.001), particularly in patients who received piperacillin/tazobactam (RR 2.4; p=.02). In a multivariate regression analysis, increasing Charlson Comorbidity index and BS antibiotics were both independent risk factors for AKI. The increase of AKI in the BS antibiotic group may also account for the increase LOS seen in this group, the authors suggest.

They acknowledge potential limitations to their study; for example, they did not account for disease severity in patients with concomitant cholecystitis or exclude patients who developed other postoperative infections. They also wonder if surgical site infections were underreported given that patients could have presented to a different medical center.

"Patients are usually started on antibiotics for choledocholithiasis if they have concomitant cholangitis and/or cholecystitis (i.e., biliary infections). We already excluded patients with cholangitis... so the use of BS antibiotics would presumably be due to concomitant cholecystitis," Dr. Tracy told Reuters Health by email. "However, despite the BS patients being 'sicker' (older, more ERCPs), there was no difference in outcomes when stratified by cholecystitis."

"Although we cannot comment on whether BS antibiotics prevented post-operative SSIs because of our study design," he added, "we can only infer that BS antibiotics were not superior to NS antibiotics in patients with choledocholithiasis with or without cholecystitis."

SOURCE: Journal of the American College of Surgeons, online May 3, 2022.