Despite well established guidelines and the known efficacy of antibiotic prophylaxis for reducing the risk of SSI, there continues to be wide variation amongst antibiotic prophylaxis practices. Therefore, we performed this study to assess the perspectives of providers at our institution regarding some of these practices including preoperative antibiotic choice, dosing, and timing. We determined that there is no clear consensus regarding the effectiveness of vancomycin and cefazolin for antibiotic prophylaxis since 30% of providers agreed and 65% disagreed that both antibiotics are equally effective. Similarly, there was also no consensus on the antibiotic choice for patients with a penicillin allergy since 50% of those surveyed agreed with vancomycin, 28% agreed with clindamycin, and the remaining 22% disagreed with both alternatives. In contrast, providers did generally agree with necessity of weight based dosing and timely infusion of vancomycin.
Overall, the results from this study indicate that there is no clear consensus amongst the providers at our institution when it comes to which antibiotic to administer for prophylaxis against SSI despite institutional guidelines developed by surgical service leadership. Several institutions from all over the world have determined that antibiotic prophylaxis is often inadequately administered. In a study from China that included 53 hospitals and a total of 14,525 procedures, Ou et al. determined that in only 9.4% of the procedures was antibiotic prophylaxis appropriate and correct in all steps, which included antibiotic choice, dose, dosing strategy, time of administration and duration of prophylaxis.6 Similarly, Hawkins et al. found that although 99% of the patients studied were correctly given or withheld prophylactic antibiotics, complete adherence to antibiotic guidelines was only present in 48% of cases in a study involving 143 pediatric procedures.7 In fact, weight-based dosing was present in only 77% of cases, the timing of administration as correct in only 73% of cases, and only 7% of cases were appropriately re-dosed.7 Similarly, in a study from France including 1,312 procedures, Muller et al. determined that non-compliance to the French national recommendations was evident in 44% of cases.8 Most notably, the appropriate antibiotic for patients with a beta-lactam allergy was incorrect in 45% of cases and the timing of antibiotic prophylaxis relative to incision time was too close in almost 35% of cases.8 In addition, in a study from Australia involving 1033 lower extremity arthroplasty procedures, Friedman et al. determined that the optimal antibiotic choice, cefazolin alone, was administered in only 75% of patients.9 Therefore, although well-established antibiotic prophylaxis guidelines exist, great variability and poor compliance are major obstacles to adequate prophylactic antibiotic administration.
The explanations for our results are multifactorial. One reason for the lack of consensus in terms of appropriate antibiotic choice may be due to the fact that best practice guidelines are not widely displayed throughout preoperative and operative areas at our institution. Therefore, lack of awareness could be a potential contributor to our results. Another potential explanation is that since there is no formal education or training for both orthopaedic surgery and anesthesia team members regarding the topic of antibiotic prophylaxis, providers at our institution may not possess the most up-to-date knowledge in regards to this topic. Furthermore, as antibiotic resistance and drug allergies continue to increase in our communities, there is a need to continually educate health care providers on the most current literature available. Thus, an educational gap could be another contributing factor to our results. Lastly, there is also no antibiotic prophylaxis checklist at our institution to help standardize prophylaxis practices.
In contrast to antibiotic choice, there was agreement at our institution that cefazolin and vancomycin dose should be weight adjusted. This consensus is most likely explained by the fact that the electronic medical record (EMR) at our institution prompts physicians to use weight-based dosing when ordering prophylactic antibiotics. We also determined that providers agreed that vancomycin infusion at the time of incision at our institution is often not adequate for antibiotic prophylaxis. This has severe implications because it is well documented that patients with inadequate vancomycin infusion have a significantly higher risk of SSI compared to patients where infusion is complete prior to incision. In a study by Cotogni et al. involving 741 cardiac surgery patients, patients where vancomycin infusion was violated (i.e surgical skin incision was performed before the end of vancomycin infusion) had greater than five times increased odds of SSI compared to patients where vancomycin infusion was completed prior to incision.10 Through our survey, we learned that this finding was most likely due to many factors such as problems with antibiotic availability from the pharmacy, missing infusion equipment in the preoperative areas, problems with the preoperative nursing staff, no EMR order, or a lack of patient IV access which delayed the start of antibiotic infusion.
Based on the results from this study, we have determined that there may be many potential areas for improvement at our institution when it comes to antibiotic prophylaxis. However, results of quality improvement programs to improve antibiotic prophylaxis have been mixed. In a study from the University of Texas at Houston, Putnam et al. implemented three cycles of interventions from 2011 to 2014 to improve antibiotic prophylaxis.11 A few of their interventions included modifying their pre-incision checklist to include all four elements of antibiotic administration (i.e. type, dose, timing, redosing), assigning the anesthesia team the role of antibiotic administration, and distributing and displaying prophylaxis guidelines.11 After the interventions, the researchers found that although redosing compliance significantly improved, overall adherence and adherence to the correct dose and timing was unchanged. Furthermore, antibiotic type errors significantly increased after the interventions.11 Similarly, in a study from Australia, Knox and Edye compared preintervention antibiotic prophylaxis practices to compliance after implementation of an interventional program that included displaying prophylaxis guidelines in surgical areas and advertising appropriate prophylaxis practices throughout their institution.12 After the intervention, the researchers determined that overall adherence was unchanged with adherence at 18% preintervention and 15% postintervention.12 In a study from Canada by So et al., the researchers also compared preintervention antibiotic prophylaxis compliance to postintervention compliance.13 Their interventions included posting antibiotic protocols in the operating room (OR), having only recommended antibiotics readily available in the OR, educating resident physicians during orientation, including prophylactic antibiotics at time out, and both computerized alerts and emails to physicians when protocols were not followed. 13 In contrast to the studies mentioned above, the researchers found that within the field of orthopaedics, complete compliance to established guidelines drastically increased from 4.5% preintervention to 54% postintervention.13 Furthermore, the greatest improvement was in regards to the duration of antibiotics, where compliance improved from 9.5% preintervention to 75% postintervention.13 Similarly, in a study from Egypt, Saied et al. developed and taught a two-day curriculum designed to educate anesthesiologists and surgeons at five institutions about proper antibiotic prophylaxis practices, specifically focusing on the time and duration of antibiotic administration.14 The researchers determined that compared to preintervention antibiotic prophylaxis practices, the optimal timing of the first dose significantly improved in three of the five institutions and the optimal duration of prophylaxis improved by 25% in all five institutions, postintervention.14 Therefore, based on the studies mentioned above, implementation of a multifactorial quality improvement strategy that includes an educational component may be beneficial to improve antibiotic prophylaxis adherence.
Our study has several important limitations. First, the study is purely qualitative since we gathered provider data with the use of a questionnaire. Second, the purpose of this study was to only assess the antibiotic prophylaxis perspectives at our institution; we did not perform a retrospective analysis to determine the actual adherence to antibiotic prophylaxis guidelines at our institution. Therefore, although we found no clear consensus amongst our providers when it comes to which antibiotic to administer for prophylaxis against SSI, we cannot determine if this finding directly translates to poor adherence to antibiotic guidelines at our institution. Third, our study is subject to selection bias since our sample size of 73 providers is small and we only surveyed providers involved with the care of orthopedic patients. Lastly, it is important to mention that these results are based on responses from providers only at one institution.