Retrospective Cohort Analysis of the Effect of Antimicrobial Stewardship on Postoperative Antibiotic Therapy in Complicated Intra-Abdominal Infections: Short-Course Therapy Does Not Compromise Patients’ Safety

Two Days Versus Five Days of Postoperative Antibiotics for Complex Appendicitis: Cost Analysis of a Randomized, Noninferiority Trial

OBJECTIVE

To compare costs for 2 days versus 5 days of postoperative antibiotics within the antibiotics after an aPPendectomy In Complex appendicitis trial.Background:Recent studies suggest that restrictive antibiotic use leads to a significant reduction in hospital stays without compromising patient safety. Its potential effect on societal costs remains underexplored.

METHODS

This was a pragmatic, open-label, multicenter clinical trial powered for noninferiority. Patients with complex appendicitis (age ≥ 8 years) were randomly allocated to 2 days or 5 days of intravenous antibiotics after appendectomy. Patient inclusion lasted from June 2017 to June 2021 in 15 Dutch hospitals. The final follow-up was on September 1, 2021. The primary trial endpoint was a composite endpoint of infectious complications and mortality within 90 days. In the present study, the main outcome measures were overall societal costs (comprising direct health care costs and costs related to productivity loss) and cost-effectiveness. Direct health care costs were recorded based on data in the electronic patient files, complemented by a telephone follow-up at 90 days. In addition, data on loss of productivity were acquired through the validated Productivity Cost Questionnaire at 4 weeks after surgery. Cost estimates were based on prices for the year 2019.

RESULTS

In total, 1005 patients were evaluated in the "intention-to-treat" analysis: 502 patients were allocated to the 2-day group and 503 to the 5-day group. The mean difference in overall societal costs was - €625 (95% CI: -€ 958 to -€ 278) to the advantage of the 2-day group. This difference was largely explained by reduced hospital stay. Productivity losses were similar between the study groups. Restricting postoperative antibiotics to 2 days was cost-effective, with estimated cost savings of €31,117 per additional infectious complication.

CONCLUSIONS

Two days of postoperative antibiotics for complex appendicitis results in a statistically significant and relevant cost reduction, as compared with 5 days. Findings apply to laparoscopic appendectomy in a well-resourced health care setting.

2 days versus 5 days of postoperative antibiotics for complex appendicitis: a pragmatic, open-label, multicentre, non-inferiority randomised trial

BACKGROUND

The appropriate duration of postoperative antibiotics for complex appendicitis is unclear. The increasing global threat of antimicrobial resistance warrants restrictive antibiotic use, which could also reduce side-effects, length of hospital stay, and costs.

METHODS

In this pragmatic, open-label, non-inferiority trial in 15 hospitals in the Netherlands, patients with complex appendicitis (aged ≥8 years) were randomly assigned (1:1) to receive 2 days or 5 days of intravenous antibiotics after appendicectomy. Randomisation was stratified by centre, and treating physicians and patients were not masked to treatment allocation. The primary endpoint was a composite endpoint of infectious complications and mortality within 90 days. The main outcome was the absolute risk difference (95% CI) in the primary endpoint, adjusted for age and severity of appendicitis, with a non-inferiority margin of 7·5%. Outcome assessment was based on electronic patient records and a telephone consultation 90 days after appendicectomy. Efficacy was analysed in the intention-to-treat and per-protocol populations. Safety outcomes were analysed in the intention-to-treat population. This trial was registered with the Netherlands Trial Register, NL5946.

FINDINGS

Between April 12, 2017, and June 3, 2021, 13 267 patients were screened and 1066 were randomly assigned, 533 to each group. 31 were excluded from intention-to-treat analysis of the 2-day group and 30 from the 5-day group owing to errors in recruitment or consent. Appendicectomy was done laparoscopically in 955 (95%) of 1005 patients. The telephone follow-up was completed in 664 (66%) of 1005 patients. The primary endpoint occurred in 51 (10%) of 502 patients analysed in the 2-day group and 41 (8%) of 503 patients analysed in the 5-day group (adjusted absolute risk difference 2·0%, 95% CI -1·6 to 5·6). Rates of complications and re-interventions were similar between trial groups. Fewer patients had adverse effects of antibiotics in the 2-day group (45 [9%] of 502 patients) than in the 5-day group (112 [22%] of 503 patients; odds ratio [OR] 0·344, 95% CI 0·237 to 0·498). Re-admission to hospital was more frequent in the 2-day group (58 [12%] of 502 patients) than in the 5-day group (29 [6%] of 503 patients; OR 2·135, 1·342 to 3·396). There were no treatment-related deaths.

INTERPRETATION

2 days of postoperative intravenous antibiotics for complex appendicitis is non-inferior to 5 days in terms of infectious complications and mortality within 90 days, based on a non-inferiority margin of 7·5%. These findings apply to laparoscopic appendicectomy conducted in a well resourced health-care setting. Adopting this strategy will reduce adverse effects of antibiotics and length of hospital stay.

FUNDING

The Netherlands Organization for Health Research and Development.

Implementation of Antibiotic Stewardship Improves the Quality of Blood Culture Diagnostics at an Intensive Care Unit of a University Hospital

Background: Bloodstream infections increase morbidity and mortality in hospitalized patients and pose a significant burden for health care systems worldwide. Optimal blood culture diagnostics are essential for early detection and specific treatment. After assessing the quality parameters at a surgical intensive care unit for six months, we implemented a diagnostic stewardship bundle (DSB) to optimize blood culture diagnostics and then reevaluated its effects after six months. Material and Methods: All patients ≥18 years old and on the ward were included: pre-DSB 137 and post-DSB 158. The standard quality parameters were defined as the number of blood culture sets per diagnostic episode (≥2), the rate of contamination (2–3%), the rate of positivity (5–15%), the collection site (≥1 venipuncture per episode) and the filling volume of the bottles (8–10 mL, only post-DSB). The DSB included an informational video, a standard operating procedure, and ready-to-use paper crates with three culture sets. Results: From pre- to post-interventional, the number of ≥2 culture sets per episode increased from 63.9% (257/402) to 81.3% (230/283), and venipunctures increased from 42.5% (171/402) to 77.4% (219/283). The positivity rate decreased from 15.1% (108/714) to 12.8% (83/650), as did the contamination rate (3.8% to 3.6%). The majority of the aerobic bottles were filled within the target range (255/471, 54.1%), but in 96.6%, the anaerobic bottles were overfilled (451/467). Conclusions: The implementation of DSB improved the quality parameters at the unit, thus optimizing the blood culture diagnostics. Further measures seem necessary to decrease the contamination rate and optimize bottle filling significantly.

Comparison of Duration and Empiric Antibiotic Choice of Post-Operative Treatment in Abdominal Sepsis

Background: Although abdominal foci are the second most common source of sepsis, only few studies focus on the optimal length of post-operative antibiotic therapy in critically ill patients with abdominal sepsis. The aim of this study was to compare the outcomes of short versus long antibiotic therapy as well as broad-spectrum penicillin versus carbapenem in patients with abdominal sepsis. Patients and Methods: We performed a single center retrospective study in patients with abdominal sepsis who underwent emergency surgery. The study was conducted in a tertiary hospital in Germany during 2016-2018. We reviewed the duration of post-operative antibiotic therapy and the initially used agent, comparing patients treated shorter or longer than seven days with or without source control. Depending on the empirically given antibiotic, a subgroup analysis was conducted comparing patients treated with piperacillin-tazobactam versus carbapenems. Results: Longer duration of post-operative antibacterial treatment (>7 days) was not substantially advantageous. The group with a longer course of antibiotic therapy had more severe post-operative complications (82.4% [n = 61] vs. 62.5% [n = 20]; p = 0.01) requiring longer critical care support (18 days vs. 11 days; p = 0.027), prolonging the length of stay (28 days vs. 20 days; p = 0.044). Surgical re-interventions were more frequent in the long-course arm (70.3% vs. 40.6%; p = 0.004). The subgroup analysis comparing piperacillin-tazobactam versus carbapenems confirmed more severe complications (86.3% vs. 67.5%; p = 0.04) for the carbapenem arm. Conclusions: Post-surgical continuation of antibiotic agents beyond seven days was observed with more post-operative complications and delayed recovery. Piperacillin-tazobactam seems to be a potent alternative for patients with abdominal sepsis.

Cefazolin Might Be Adequate for Perioperative Antibiotic Prophylaxis in Intra-Abdominal Infections without Sepsis: A Quality Improvement Study

Background: The adequate choice of perioperative antibiotic prophylaxis (PAP) could influence the risk of surgical site infections (SSIs) in general surgery. A new local PAP guideline was implemented in May 2017 and set the first-generation cefazolin (CFZ) instead the second-generation cefuroxime (CXM) as the new standard prophylactic antibiotic. The aim of this study was to compare the risk of SSIs after this implementation in intra-abdominal infections (IAIs) without sepsis. Methods: We performed a single center-quality improvement study at a 1500 bed sized university hospital in Germany analyzing patients after emergency surgery during 2016 to 2019 (n = 985), of which patients receiving CXM or CFZ were selected (n = 587). Propensity score matching was performed to ensure a comparable risk of SSIs in both groups. None-inferiority margin for SSIs was defined as 8% vs. 4%. Results: Two matched cohorts with respectively 196 patients were compared. The rate of SSIs was higher in the CFZ group (7.1% vs. 3.6%, p = 0.117) below the non-inferiority margin. The rate of other postoperative infections was significantly higher in the CFZ group (2.0% vs. 8.7%, p = 0.004). No other differences including postoperative morbidity, mortality or length-of-stay were observed. Conclusion: Perioperative antibiotic prophylaxis might be safely maintained by CFZ even in the treatment of intra-abdominal infections.