The Practice of Antimicrobial Stewardship in Thoracic Surgery and its Effectiveness (2024)

Abstract

This study examines the effects of the bundle of antimicrobial stewardship measures forprophylactic antibiotics among thoracic surgery patients. A local protocol, based oncurrent guidelines starting from December 2014, was developed by the Infection Control andThoracic Surgery Teams. The effects of this protocol were assessed by monitoring a totalof 1380 patients before and after its implementation from January 1, 2011, to December 31,2022.

Keywords: Antimicrobial stewardship, prophylactic antibiotic, thoracic surgery

Introduction

Surgical site infections (SSIs) are a significant global problem, and their burdenincreases with emerging antimicrobial resistance. Globally, around 12.3% of surgicalpatients suffer from SSIs annually, with higher rates in low-income countries (23.2%)compared to high-income countries (9.4%) (1).Inappropriate antibiotic use not only escalates the rate of antimicrobial resistance butalso leads to unnecessary costs and potential side effects (2-5).

The American Society of Health-System Pharmacists (AHSP) established the standards forsurgical antibiotic use in 2013, with the World Health Organization (WHO) and the Centersfor Disease Control and Prevention (CDC) strongly recommending against the postoperativecontinuation of prophylactic antibiotics in 2016 and 2017 (6-8). Despite these clear recommendations, the prevalenceof prolonged prophylactic antibiotic use in surgical operations (>24 hours) ranges from29.5% in developed countries to 92.5% in Africa (9).The evidence supporting the need for postoperative continuation to reduce SSIs is limited (4).

This study aimed to achieve the following objectives: 1) enhance compliance with the localsurgical prophylaxis guideline, 2) reduce unnecessary antimicrobial consumption before andafter surgery, and 3) monitor the long-term impact of these interventions.

Materials and Methods

This study was conducted at a non-profit foundation hospital prospectively in İstanbul witha 300-bed capacity spanning from 2011 to 2022. In December 2014, a local surgicalprophylaxis guideline (LSPG) was developed for all surgical patients based on the currentAHSP guideline (7). The primary objective of theLSPG was to reduce the misuse and excessive consumption of antibiotics both before and aftersurgery.

The LSPG outlined several key rules as follows:

1. The prophylactic antibiotic should be selected from the LSPG.

2. The prophylactic antibiotic should be administered within 60 minutes before theincision and discontinued within a maximum of 24 hours. The duration of prophylacticantibiotic use was calculated based on the time between the first and last dose.

3. In cases where the operation duration exceeds two times the half-life of theprophylactic antibiotic, a repeat dose should be administered during the operation.

The Infection Control Team (ICT) closely monitored the thoracic surgery team's compliancewith the LSPG, specifically focusing on single-dose or a maximum of 24-hour cefazolinantibiotic prophylaxis, excluding drainage operations. Monthly evaluations of each surgicalantibiotic prophylaxis intervention were conducted in conjunction with the thoracic surgeryteam.

The study compared all antibiotic prophylaxis procedures applied before (between January 1,2011, and December 31, 2014) and after (between January 1, 2015, and December 31, 2022) theimplementation of the LSPG intervention among thoracic surgery patients. The impact of theLSPG intervention on the rate of SSIs and the appropriateness of antibiotic selection interms of type, dose, and duration was evaluated. Descriptive statistics were presented withmean, standard deviation, and percentages. Bivariate analyses were conducted by Chi-squaretests. The statistical significance was set as p<0.05.

Results

A total of 1380 surgical prophylaxis practices performed by the thoracic surgery teambetween January 1, 2011, and December 31, 2022, were evaluated. Among these, 44% of thepatients were women (n=607), with a mean age of 56 years (SD=16.81; range=2-100 years).Notably, 65.43% of the patients had at least one chronic disease (n=903), and the meanAmerican Society of Anesthesiologists (ASA) score was 2.55 (SD=0.72). The average length ofhospital stay was 6.41 days (SD=13.96). In terms of the reason for surgery of patients, 40%of patients had lung cancer, 20% presented with lung nodules or tumors, and 17% hadhemothorax/pneumothorax (Table 1).

Implementation of the LSPG significantly improved the overall appropriate prophylacticantibiotic practice rate (choice, dose, and duration) from 26.50% to 86.40% (min:25%,max:100%), (p<0.001) (Table 1, Figure ​Figure11-​-2).2). Moreover, therate of appropriate antibiotic prophylaxis dose increased from 55.57% to 76.21% (p<0.001) (Table 1), while the occurrence of prolongedantibiotic prophylaxis decreased from 61.97% to 3.96% (Table 1, Figure 1).

Additionally, the mean duration of antibiotic prophylaxis decreased from 61.05 hours to19.36 hours (max:69 h, min:7 h) over the 12-year study period (p<0.001)(Table 1, Figure 2).Despite these interventions placed on antimicrobial prophylaxis before and after surgery, nocases of SSI were reported during both periods. Furthermore, the mortality rate remainedunchanged (p=0.671), and the length of hospital stay showed a decreasingtrend, although not statistically significant (p=0.054), with the meanlength of stay reducing from 7.3 days to 5.8 days (Table 1).

Discussion

The results of this study provide valuable insights into the impact of prolongedprophylactic antibiotic restrictions on SSIs in thoracic surgery patients in a country witha higher rate of SSIs caused by multidrug-resistant pathogens. Current literature supportsthe use of prophylactic antibiotics to reduce the rate of SSIs, with some exceptional cases(10, 11),but emphasizes the importance of limiting its use to a maximum of 24 hours. Prolongedantibiotic prophylaxis has been shown to give no additional benefits compared todiscontinuation (4). Zay Ya et al. proved thatantimicrobial stewardship programs were associated with reducing the consumption ofantibiotics (12). Batlle et al. conducted a study insurgery departments, and they got similar results (13).Moreover, Díaz-Madriz et al. asserted that effective antimicrobial stewardship increases therate of appropriate prophylactic antibiotic selection and the percentage of optimalduration, with no severe surgical site infection and severe adverse reaction (14).

Despite these studies, compliance with current prophylaxis practices appears to berelatively low, with some studies reporting that compliance rates are as low as 8% globallyand also in Turkey (9, 15). The reasons for inappropriate antimicrobial consumption amongphysicians could be related to the lack of education of physicians and the population, lackof political will, poor implementation of stewardship programs, and lack of access tolaboratory services (16). However, this study'sfindings demonstrate a remarkable improvement in compliance with current guidelines throughthe implementation of the LSPG.

Upon adopting the LSPG recommendations in 2015, the total compliance with the guidelinereached 100% (Figure 1, Figure 2),and the mortality rate remained unchanged over the 8-year period (from 2015 to 2022) (Table 1). Furthermore, no SSI cases were detected both before(2011 to 2014) and after (2015 to 2022) the implementation of LSPG. The study also comparedantibiotic duration, appropriate dose, and overall compliance with LSPG before and after itspractice. Remarkably, the implementation of LSPG resulted in a significant reduction inprophylactic antibiotic duration, from an average of 61 hours to 19 hours (p<0.001),and an increase in the rate of appropriate prophylactic antibiotic doses from 55% to 67% (p<0.001).The overall compliance rate with LSPG significantly improved from 26% to 86% (p<0.001)after its implementation (Table 1).

Furthermore, a comparison of patient characteristics between the two groups (before andafter LSPG practice) revealed interesting differences. Patients in the “after” group werefound to be older (57 vs. 54 years; p=0.001) and had a higher prevalence ofcomorbidities (68% vs. 54%; p<0.001) compared to the previous patientgroup. Conversely, the previous group had a lower ASA score (2.45 vs. 2.61; p<0.001).Despite the potentially higher risk profile in the “after” group, the successfulimplementation of LSPG resulted in positive outcomes in terms of SSIs and compliance rates.

The rate of prolonged antibiotic use in Türkiye was reported as 91.7% (15), aligning with findings from other regions with varying ratesreported in the literature, ranging from 29.5% in developed countries to 92.5% in Africa (9). This highlights the significance of interventionslike LSPG to improve antibiotic usage practices and combat the growing threat ofantimicrobial resistance.

As a result of this study, it is evident that compliance with current prophylaxisguidelines does not increase the risk of SSIs or mortality. On the contrary, adherence toLSPG or discontinuation of prolonged surgical prophylaxis can lead to reduced hospitallength of stay and decreased antibiotic consumption. This, in turn, can mitigate theeconomic burden, the risk of antimicrobial resistance, and the unseen side effectsassociated with antibiotic usage over time. However, it is essential to acknowledge thatthis study's limitations include focusing on a specific surgery patient group in a singlecenter, which may not fully represent all surgery patient groups. However, we presentedmoderate to strong evidence for the implementation of the antimicrobial stewardship programsfor surgical prophylaxis.

In conclusion, we demonstrated the importance of adhering to current guidelines anddiscontinuing prophylactic antibiotics beyond the recommended timeframe to effectivelyprevent SSIs in a region where the prevalence of multidrug resistance is high. With properimplementation of LSPG, we observed that compliance rates with appropriate antibiotic usesignificantly increased, with no cases of SSIs during the study period.

Acknowledgement

We are thankful to hospital management for their support.

Additional Information

References