A Streamlined Approach to Optimize Perioperative Antibiotic Prophylaxis in the Setting of Penicillin Allergy Labels

A nurse-driven penicillin allergy risk score in the preoperative setting was associated with increased cefazolin use perioperatively

STUDY OBJECTIVE

To characterize and assess the effects of a preoperative, nurse-driven penicillin allergy risk stratification tool on rates of perioperative cefazolin and second-line antibiotic use.

DESIGN

Quasi-experimental quality improvement study of penicillin-allergic surgical patients undergoing procedures for which cefazolin is indicated.

SETTING

Outpatient Perioperative Care Clinic (PCC) for preoperative surgical patients at a tertiary care center.

PATIENTS

670 and 1371 adult penicillin-allergic PCC attendants and non-attendants, respectively.

INTERVENTION

A paper penicillin allergy risk stratification questionnaire was administered during the PCC visit. Nurses were educated on its use.

MEASUREMENTS

Antibiotic (cefazolin, clindamycin, vancomycin) use rates in the 24 months before and 17 months after intervention implementation in November 2020 (November 2018 - April 2022) were assessed in penicillin-allergic PCC attendants with statistical process control charts. Multivariable logistic regression assessed antibiotic use rates pre- and post-intervention adjusting for age, sex, surgical specialty and penicillin allergy history severity. Similar analyses were done in penicillin-allergic PCC non-attendants.

MAIN RESULTS

Of 670 penicillin-allergic PCC attendants, 451 (median [IQR] age, 66 (Sousa-Pinto et al., 2021 [14])) were analyzed pre-intervention and 219 (median [IQR] age, 66 (Mine et al., 1970 [13])) post-intervention. One month after implementation, process measures demonstrated an upward shift in cefazolin use for PCC attendants versus no shift or other special cause variation for PCC non-attendants. There were increased odds of cefazolin use (aOR 1.67, 95% CI [1.09-2.57], P = 0.019), decreased odds of clindamycin use (aOR 0.61, 95% CI [0.42-0.89], P = 0.010) and decreased odds of vancomycin use (aOR 0.56, 95% CI [0.35-0.88], P = 0.013) in PCC attendants post-intervention. This effect did not occur in PCC non-attendants. There was no increase in perioperative anaphylaxis post-intervention.

CONCLUSIONS

A simple penicillin allergy risk stratification tool implemented in the preoperative setting was associated with increased use of cefazolin and decreased rates of second-line agents post implementation.

Quality corner: Safely using cephalosporins in almost all patients with penicillin allergies: Mini-review and suggested protocol to improve efficacy and surgical outcomes

Surgical site infections (SSI) are one of the most common gynecologic oncology postoperative complications and they have a significant deleterious impact on the healthcare system and in patients' outcomes. Cefazolin is the recommended antibiotic in women undergoing gynecologic surgical procedures that require that require prophylaxis. However, 10-20% of patients may report a penicillin allergy which can result in administration of a less effective antibiotic. This quality review evaluated the literature around this common perioperative issue and demonstrated that healthcare teams should consider the implementation of a protocol to safely use cefazolin in most patients with a penicillin allergy. Overall, literature shows this is a safe adjustment and would improve antimicrobial stewardship, decrease SSI rates, avoid acute kidney injury, and increase cost savings.

Perioperative Cefazolin for Total Joint Arthroplasty Patients Who Have a Penicillin Allergy: Is It Safe?

BACKGROUND

Cefazolin is the standard of care for perioperative antibiotic prophylaxis in total joint arthroplasty (TJA) in the United States. The potential allergic cross-reactivity between cefazolin and penicillin causes uncertainty regarding optimal antibiotic choice in patients who have a reported penicillin allergy (rPCNA). The purpose of this study was to determine the safety of perioperative cefazolin in PCNA patients undergoing primary TJA.

METHODS

We identified all patients (n = 49,842) undergoing primary total hip arthroplasty (n = 25,659) or total knee arthroplasty (n = 24,183) from 2016 to 2022 who received perioperative intravenous antibiotic prophylaxis. Patients who had an rPCNA (n = 5,508) who received cefazolin (n = 4,938, 89.7%) were compared to rPCNA patients who did not (n = 570, 10.3%), and to patients who did not have an rPCNA (n = 43,359). The primary outcome was the rate of allergic reactions within 72 hours postoperatively. Secondary outcomes included the rates of superficial infections, deep infections, and Clostridioides difficile infections within 90 days.

RESULTS

The rate of allergic reactions was 0.1% (n = 5) in rPCNA patients who received cefazolin, compared to 0.2% (n = 1) in rPCNA patients who did not (P = .48) and 0.02% (n = 11) in patients who have no rPCNA (P = .02). Allergic reactions were mild in all 5 rPCNA patients who received cefazolin and were characterized by cutaneous symptoms (n = 4) or dyspnea in the absence of respiratory distress (n = 1) that resolved promptly with antibiotic discontinuation and administration of antihistamines and/or corticosteroids. We observed no differences in the rates of superficial infections (0.1 versus 0.2%, P = .58), deep infections (0.3 versus 0.4%, P = .68), or C difficile infections (0.04% versus 0%, P = .99) within 90 days in rPCNA patients who received cefazolin versus alternative perioperative antibiotics.

CONCLUSIONS

In this series of more than 5,500 patients who had an rPCNA undergoing primary TJA, perioperative prophylaxis with cefazolin resulted in a 0.1% incidence of allergic reactions that were clinically indolent. Cefazolin can be safely administered to most patients, independent of rPCNA severity.

LEVEL OF EVIDENCE

III.

Cefazolin as the mainstay for antibiotic prophylaxis in patients with a penicillin allergy in obstetrics and gynecology

Cefazolin is the most common antibiotic used for prophylaxis in obstetrics and gynecology. Among those with a penicillin allergy, alternative antibiotics are often chosen for prophylaxis, given fears of cross-reactivity between penicillin and cefazolin. Alternative antibiotics in this setting are associated with adverse sequelae, including surgical site infection, induction of bacterial resistance, higher costs to the healthcare system, and possible Clostridium difficile infection. Given the difference in R1 side chains between penicillin and cefazolin, cefazolin use is safe and should be recommended for patients with a penicillin allergy, including those who experience Immunoglobulin E-mediated reactions such as anaphylaxis. Cefazolin should only be avoided in those who experience a history of a severe, life-threatening delayed hypersensitivity reaction manifested as severe cutaneous adverse reactions (Steven-Johnson Syndrome), hepatitis, nephritis, serum sickness, and hemolytic anemia in response to penicillin administration. In addition, >90% of those with a documented penicillin allergy do not have true allergies on skin testing. Increased referral for penicillin allergy testing should be incorporated into routine obstetric care and preoperative assessment to reduce suboptimal antibiotic prophylaxis use. More education is needed among providers surrounding penicillin allergy assessment and cross-reactivity among penicillins and cephalosporins to optimize antibiotic prophylaxis in obstetrics and gynecology.

Management of Penicillin Allergy in the Perioperative Setting

The selection of perioperative antibiotic prophylaxis is challenging in patients with a history of penicillin allergy; as such, we present a literature review exploring current best practices and the associated supporting evidence, as well as areas for future research. Guidelines recommend the use of alternative agents in patients with an IgE-mediated hypersensitivity reaction, but those alternative agents are associated with worse outcomes, including an increased risk of surgical site infection, and higher cost. More recent data suggest that the risk of cross-reactivity between penicillins and cephalosporins, particularly cefazolin, is extremely low, and that cefazolin can be used safely in most penicillin-allergic patients. Studies have therefore explored how best to implement first-line cefazolin use in patients with a penicillin allergy label. A variety of interventions, including preoperative allergy de-labeling with incorporation of penicillin skin testing, use of patient risk-stratification questionnaires, and utilization of clinician algorithms to guide antibiotic selection intraoperatively, have all been shown to significantly increase cefazolin utilization without a corresponding increase in adverse events. Further studies are needed to clarify the most effective interventions and implementation strategies, as well as to evaluate whether patients with severe delayed hypersensitivity reactions to penicillin should continue to be excluded from receipt of other beta-lactams.

A Self-Sustaining Antibiotic Prophylaxis Program to Reduce Surgical Site Infections

Background: Our multi-institutional healthcare system had a higher-than-expected surgical site infection (SSI) rate. We aimed to improve our peri-operative antibiotic administration process. Gap analysis identified three opportunities for process improvement: standardized antibiotic selection, standardized second-line antibiotic agents for patients with allergies, and feedback regarding antibiotic administration compliance. Hypothesis: Implementation of a multifaceted quality improvement initiative including a near-real-time pre-operative antibiotic compliance feedback tool will improve compliance with antibiotic administration protocols, subsequently lowering SSI rate. Methods: A compliance feedback tool designed to provide monthly reports to all anesthesia and surgical personnel was implemented at two facilities, in September 2017 and December 2018. Internal case data were tracked for antibiotic compliance through June 2021, and these data were merged with American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) data at the case level to provide process and outcome measures for SSIs. Implementation success was evaluated by comparing protocol compliance and risk-adjusted rates of superficial and deep SSI before and after the quality improvement implementation. Results: A total of 20,385 patients were included in this study; 11,548 patients in the pre-implementation and 8,837 in the post-implementation groups. Baseline patient and operative characteristics were similar between groups, except the post-implementation group had a higher median expected SSI rate (2.2% vs. 1.6%). Post-implementation, antibiotic protocol compliance increased from 86.3% to 97.6%, and superficial and deep SSIs decreased from 2.8% to 1.9% (p < 0.001). The odds of superficial and deep SSI in patients in the post-implementation group was 0.69 (0.57, 0.83) times the odds of superficial and deep SSI in pre-implementation patients while adjusting for age, gender, diabetes mellitus, American Society of Anesthesiologists Physical Status (ASA) classification, wound class, smoking, and chronic obstructive pulmonary disease (COPD). Observed-to-expected ratios of superficial and deep SSI decreased from 0.82 to 0.48 after the intervention. Conclusions: Surgical antibiotic prophylaxis standardization and providing near-real-time individualized feedback resulted in sustained improvement in peri-operative antibiotic compliance rates and reduced superficial and deep SSIs.

Impact of Penicillin Allergy-Based Alternative Antibiotics on the Risk of Postoperative Central Nervous System Infection: A Retrospective Cohort Study

BACKGROUND

Central nervous system (CNS) infection is one of the most serious complications after neurosurgery. This study aimed to analyze the effect of penicillin allergy (PA) and alternative prophylactic antibiotics on risk of postoperative CNS infection in patients undergoing neurosurgery.

METHODS

Data of patients who underwent neurosurgical procedures from January 2015 to December 2021 were analyzed retrospectively. Patients with PA were compared with patients without PA in a 1:1 ratio. A multivariate logistic regression model was used to examine whether PA was a risk factor for postoperative CNS infection.

RESULTS

Overall, 15,049 eligible neurosurgical records were reviewed, from which 578 surgical records of 556 patients with PA were matched to 578 records of 570 patients without PA. Patients with PA showed significantly lower probability to receive prophylactic cephalosporins (55.9% vs. 98.8%, P < 0.01), but significantly higher probability to receive clindamycin (41.86% vs. 1.03%, P < 0.01), than patients without PA. Multivariate analysis revealed that patients with PA were more likely to experience postoperative CNS infection than patients without PA (odds ratio = 2.03; 95% confidence interval, 1.15-3.56; P = 0.014). The incidence of postoperative CNS infection returned to a level comparable to that in general population when patients with suspected PA received prophylactic cephalosporins.

CONCLUSIONS

PA is associated with higher risk of postoperative CNS infection in patients undergoing neurosurgery. This may be attributed to the use of alternative prophylactic antibiotics other than cephalosporins, especially clindamycin.

Outcome of preoperative cefazolin use for infection prophylaxis in patients with self-reported penicillin allergy

BACKGROUND

Cephalosporins are the preferred antibiotics for prophylaxis against surgical site infections. Most studies give a rate of combined IgE and non-IgE penicillin allergy yet it is recommended that cephalosporins be avoided in patients having the former but can be used in those with the latter. Some studies use penicillin allergy while others penicillin family allergy rates. The primary goal of this study was to determine the rates of IgE and non-IgE allergy as well as cross reactions to both penicillin and the penicillin family. Secondary goals were to determine the surgical services giving preoperative cefazolin and the types of self reported reactions that patients' had to penicillin prompting their allergy status.

METHODS

All patients undergoing elective and emergency surgery at a University Health Sciences Centre were retrospectively studied. The hospital electronic medical record was used for data collection.

RESULTS

8.9% of our patients reported non-IgE reactions to penicillin with a cross reactivity rate of 0.9% with cefazolin. 4.0% of our patients reported IgE reactions to penicillin with a cross reactivity rate of 4.0% with cefazolin. 10.5% of our patients reported non-IgE reactions to the penicillin family with a cross reactivity rate of 0.8% with cefazolin. 4.3% of our patients reported IgE reactions to the penicillin family with a cross reactivity rate of 4.0% with cefazolin.

CONCLUSIONS

Our rate of combined IgE and non-IgE reactions for both penicillin and penicillin family allergy was within the range reported in the literature. Our rate of cross reactivity between cefazolin and combined IgE and non-IgE allergy both to penicillin and the penicillin family were lower than reported in the old literature but within the range of the newer literature. We found a lower rate of allergic reaction to a cephalosporin than reported in the literature. We documented a wide range of IgE and non-IgE reactions. We also demonstrated that cefazolin is frequently the preferred antibiotics for prophylaxis against surgical site infections by many surgical services and that de-labelling patients with penicillin allergy is unnecessary.

Documented Penicillin Allergies Should Not Preclude Use of Preoperative Cefazolin in Hip and Knee Arthroplasty

INTRODUCTION

Perioperative cefazolin administration for total joint arthroplasty is a first-line antibiotic recommended by the American Academy of Orthopaedic Surgeons (AAOS) guidelines for the prevention of periprosthetic joint infections (PJIs). We aim to analyze the clinical viability of giving patients with a documented penicillin allergy (PA) a perioperative full-strength cefazolin "test dose" under anesthesia.

METHODS

This is a retrospective chart review of 2,451 total joint arthroplasties from a high-volume arthroplasty orthopaedic surgeon over a 5-year period from January 2013 through December 2017. This surgeon routinely gave patients with a documented PA a full-strength cefazolin test dose while under anesthesia instead of administrating a second-line antibiotic. The primary outcomes examined were allergic reaction and postoperative infection.

RESULTS

Cefazolin was given to 87.1% of all patients (1,990) and 46.0% of patients with a PA (143). The total rate of allergic reactions among all patients was 0.5% (11). Only one patient with a documented PA who received cefazolin had an allergic reaction. The reaction was not severe and did not require any additional treatment. In patients who had no reported allergies and received cefazolin, 0.3% (6) had an allergic reaction. There was no statistically significant difference in the rate of allergic reaction when comparing patients with and without a PA (P = 0.95). Patients receiving cefazolin had an overall PJI rate of 2.9% (57) versus those patients receiving antibiotics other than cefazolin who sustained a 5.5% PJI rate (16), which was statistically significant (P = 0.02).

CONCLUSION

This study found that utilization of a full-strength test dose of cefazolin in patients with a documented PA is a feasible, safe, and effective way of increasing the rate of cefazolin administration and thus mitigating the risk of PJIs.

The association between penicillin allergy and surgical site infection after orthopedic surgeries: a retrospective cohort study

Background

Cephalosporins are used as first-line antimicrobial prophylaxis for orthopedics surgeries. However, alternative antibiotics are usually used in the presence of penicillin allergy (PA), which might increase the risk of surgical site infection (SSI). This study aimed to analyze the relationship between SSI after orthopedic surgeries and PA among surgical candidates and related alternative antibiotic use.

Methods

In this single-center retrospective cohort study, we compared inpatients with and without PA from January 2015 to December 2021. The primary outcome was SSI, and the secondary outcomes were SSI sites and perioperative antibiotic use. Moreover, pathogen characteristics of all SSIs were also compared between the two cohorts.

Results

Among the 20,022 inpatient records, 1704 (8.51%) were identified with PA, and a total of 111 (0.55%) SSI incidents were reported. Compared to patients without PA, patients with PA had higher postoperative SSI risk (1.06%, 18/1704 vs. 0.51%, 93/18318), shown both in multivariable regression analysis (odds ratio [OR] 2.11; 95% confidence interval [CI], 1.26-3.50; p= 0.004) and propensity score matching (OR 1.84; 95% CI, 1.05-3.23; p= 0.034). PA was related to elevated deep SSI risk (OR 2.79; 95% CI, 1.47-5.30; p= 0.002) and had no significant impact on superficial SSI (OR 1.39; 95% CI, 0.59-3.29; p= 0.449). The PA group used significantly more alternative antibiotics. Complete mediation effect of alternative antibiotics on SSI among these patients was found in mediation analysis. Pathogen analysis revealed gram-positive cocci as the most common pathogen for SSI in our study cohort, while patients with PA had higher infection rate from gram-positive rods and gram-negative rods than non-PA group.

Conclusion

Compared to patients without PA, patients with PA developed more SSI after orthopedic surgeries, especially deep SSI. The elevated infection rate could be secondary to the use of alternative prophylactic antibiotics.

Advances in immunoglobulin E mediated antibiotic allergy

PURPOSE OF REVIEW

The purpose of this review is to identify recent advances in our understanding and management of immunoglobulin E (IgE)-mediated antibiotic allergy.

RECENT FINDINGS

Antibiotics remain a leading cause of fatal anaphylaxis reported to the FDA. However, recent advances have defined the features of adult and pediatric patients without true IgE-mediated allergy or any mechanism of anaphylaxis when tested. This has created opportunities to use direct challenges to disprove these allergies at the point-of-care and improves antibiotic stewardship. Additional advances have highlighted cross-reactive structural considerations within classes of drugs, in particular the R1 side-chain of cephalosporins, that appear to drive true immune-mediated cross-reactivity. Further advances in risk-based approaches to skin testing, phenotyping, and re-exposure challenges are needed to standardize antibiotic allergy evaluation.

SUMMARY

Recent advances in defining true IgE-mediated drug allergy have helped to identify patients unlikely to be skin-test positive. In turn, this has identified patients who can skip skin testing and proceed to direct ingestion challenge using history risk-based approaches. The ability to identify the small number of patients with true IgE-mediated allergy and study their natural history over time, as well as the vast majority without true allergy will facilitate important and novel mechanistic discoveries.

Adherence and outcomes of a surgical prophylaxis guideline promoting cephalosporin use among patients with penicillin allergy

BACKGROUND

The study purpose was to assess adherence to a local surgical prophylaxis guideline in patients with reported penicillin allergies, which recommends cephalosporins as first-line prophylaxis.

METHODS

Adult patients with penicillin allergies admitted for a surgical procedure from July 2020 to June 2021 were retrospectively screened, and the first surgery per admission was included. The primary outcome was the proportion of surgeries using β-lactam prophylaxis. Additional outcomes included prophylaxis timing, hypersensitivity reactions, acute kidney injury, infectious complications, duration of stay, and 30-day mortality or readmission.

RESULTS

Among 597 procedures, 504 patients (84.4%) received a β-lactam for surgical prophylaxis, including 494 (82.3%) who received a cephalosporin. Patients in the non-β-lactam group were more likely to have a type I IgE-mediated penicillin allergy (48.4% vs 31.7%, P = .002); however, the majority with type I reactions still received β-lactams (78.0%), including in the setting of anaphylaxis or angioedema to penicillin (67.7%). Zero allergic reactions to prophylaxis antibiotics were reported in either group, and there were no significant differences in the proportion of patients receiving drugs associated with the management of allergic reactions. Receipt of non-β-lactams was associated with inappropriate prophylaxis timing (9.7% vs 3.2%, P = .005) and postprocedural acute kidney injury (7.5% vs 0.6%, P < .001). All other outcomes were nonsignificant between the groups.

CONCLUSION

Among surgical patients with a documented penicillin allergy, most received cephalosporin prophylaxis as recommended by institutional guidelines, with zero allergic reactions. Receipt of non-β-lactam prophylaxis was associated with worsened outcomes. Cephalosporin prophylaxis should be preferred for surgical patients, including in the setting of true penicillin allergy.

The Use of Electronic Health Records to Study Drug-Induced Hypersensitivity Reactions from 2000 to 2021

Electronic health records (EHRs) have revolutionized the field of drug hypersensitivity reaction (DHR) research. In this systematic review, we assessed 140 articles from 2000-2021, classifying them under six themes: observational studies (n=61), clinical documentation (n=27), case management (n=22), clinical decision support (CDS) (n=18), case identification (n=9), and genetic studies (n=3). EHRs provide convenient access to millions of medical records, facilitating epidemiological studies of DHRs. Though the goal of CDS is to promote safe drug prescribing, allergy alerts must be designed and used in a way that supports this effort. Ultimately, accurate allergy documentation is essential for DHR prevention.

Drug Allergy Delabeling Programs: Recent Strategies and Targeted Populations

Drug allergy delabeling programs have become an essential element of antibiotic stewardship. Development of delabeling programs involves careful selection of target patient population, thoughtful design of delabeling approach, stakeholder engagement, assembly of key team members, implementation, and evaluation of clinical and safety outcomes. Recent programs have targeted patients thought to be most likely to benefit from removal of inaccurate antibiotic allergy labels, those with β-lactam antibiotic allergies and high-risk populations likely to need β-lactam antibiotics as first-line treatment. This review provides an overview of current risk stratification methods and β-lactam cross-reactivity data and summarizes how different inpatient and outpatient delabeling programs have used these concepts in delabeling algorithms. β-Lactam delabeling programs for inpatients, pediatric patients, and programs utilizing telehealth have been implemented with good outcomes. This review also focuses on delabeling programs for high-risk populations likely to benefit from first-line β-lactam antibiotics. These populations include perioperative, prenatal, and immunocompromised patients. Delabeling programs have been successful in the inpatient and outpatient settings at enabling appropriate antibiotic use. This article reviews delabeling strategies utilized by these programs with a focus on highlighting elements key to their success and future areas for innovation.

A Simple Algorithmic Approach Allows the Safe Use of Cephalosporin in "Penicillin-Allergic" Patients without the Need for Allergy Testing

BACKGROUND

Patients who report a penicillin allergy are often given second-line antibiotic prophylaxis during total joint arthroplasty (TJA), with only a minority of patients undergoing additional consultations and allergy testing. In an effort to increase the use of cephalosporin prophylaxis in TJA, the present study aimed to assess the effectiveness of a simple, protocol-driven penicillin allergy screening program without the need for additional work-up.

METHODS

Following implementation of a questionnaire-based screening protocol in May 2019, all patients scheduled for primary TJA were risk-stratified into low or high-risk categories. The low-risk cohort received cefazolin, and the high-risk cohort received non-cefazolin antibiotics. Patients were monitored prospectively, and data on antibiotic usage and adverse outcomes were documented. The protocol group (n = 2,078) was propensity score matched 1:1 with a control group that included patients who underwent TJA in the same institution prior to implementation of the protocol. The primary end point was the efficacy of the protocol in reducing unnecessary use of non-cephalosporin antibiotics for prophylaxis. Secondary outcomes included the rate of surgical site infections and allergic reactions to the administered antibiotic.

RESULTS

A total of 357 patients (17.2%) reported a penicillin allergy in the protocol group compared with 310 patients (14.9%) with a recorded allergy in the control group (p = 0.052). The number of patients who received non-cephalosporin antibiotics was significantly lower in the protocol group (5.7% compared with 15.2% in the control group; p < 0.001), whereas there was no difference in the rate of total allergic reactions (0.8% compared with 0.7%, respectively; p = 0.857). Of the 239 low-risk patients (66.9%) in the protocol group, only 3 (1.3%) experienced a mild cutaneous reaction following cefazolin administration. There were no differences in the rates of superficial wound, deep periprosthetic, or Clostridioides difficile infections between the protocol and control groups.

CONCLUSIONS

A simple screening protocol allowed two-thirds of patients with a self-reported allergy to receive cefazolin without the need for additional consultations or testing. We believe this protocol can be safely implemented to increase the rate of cefazolin usage without a corresponding increase in the number of allergic reactions.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Anatomy of a successful stewardship intervention: Improving perioperative prescribing in penicillin-allergic patients

OBJECTIVE

To evaluate whether a series of quality improvement interventions to promote safe perioperative use of cephalosporins in penicillin-allergic patients improved use of first-line antibiotics and decreased costs.

DESIGN

Before-and-after trial following several educational interventions.

SETTING

Academic medical center.

PATIENTS

This study included patients undergoing a surgical procedure involving receipt of a perioperative antibiotic other than a penicillin or carbapenem between January 1, 2017, and August 31, 2019. Patients with and without a penicillin allergy label in their electronic medical record were compared with respect to the percentage who received a cephalosporin and average antibiotic cost per patient.

METHODS

A multidisciplinary team from infectious diseases, allergy, anesthesiology, surgery, and pharmacy surveyed anesthesiology providers about their use of perioperative cephalosporins in penicillin-allergic patients. Using findings from that survey, the team designed a decision-support algorithm for safe utilization and provided 2 educational forums to introduce this algorithm, emphasizing the safety of cefazolin or cefuroxime in penicillin-allergic patients without history of a severe delayed hypersensitivity reaction.

RESULTS

The percentage of penicillin-allergic patients receiving a perioperative cephalosporin improved from ∼34% to >80% following algorithm implementation and the associated educational interventions. This increase in cephalosporin use was associated with a ∼50% reduction in antibiotic cost per penicillin-allergic patient. No significant adverse reactions were reported.

CONCLUSIONS

An educational antibiotic stewardship intervention produced a significant change in clinician behavior. A simple intervention can have a significant impact, although further study is needed regarding whether this response is sustained and whether an educational intervention is similarly effective in other healthcare systems.

Classifying cephalosporins: from generation to cross-reactivity

PURPOSE OF REVIEW

To review the most recent literature studying the classifications, immunochemistry, and crossreactivity of allergy reactions to cephalosporins.

RECENT FINDINGS

Over the last five years, research interest has focused on three areas related to cephalosporin allergy: cross-reactivity among cephalosporins and with other beta-lactams; the incidence of adverse reactions in penicillin allergy patients or in reported penicillin allergy labels; and new cephalosporins structures involved in the immunological recognition.

SUMMARY

Meta-analysis of a substantial number of studies shows that cephalosporins are safer than previously thought. Evidence supports two main conclusions in that regard. First, there is a relatively low percentage of cross-reactivity between cephalosporins and other beta-lactams with penicillins in penicillin allergy patients. Second, there is a very low incidence of allergy reactions in nonselected as well as in selected penicillin allergy patients when cephalosporins are used prior to surgical intervention.On the other hand, few structures have been discovered related to the immune mechanism of cephalosporin allergy reactions, and these are far from being ready to use in clinical practice.

Antibiotic Stewardship Interventions Improve Choice of Antibiotic Prophylaxis in Total Joint Arthroplasty in Patients with Reported Penicillin Allergies

BACKGROUND

Most patients who report a penicillin allergy can tolerate cefazolin, the preferred prophylaxis in a total joint arthroplasty (TJA). Regardless, patients with a reported penicillin allergy are less likely to receive first-line perioperative antibiotics as a result of inaccurate penicillin allergy documentation and misconceptions regarding cross-reactivity between penicillin and cephalosporins. The over-reporting of penicillin allergies and the safety of cephalosporins in patients with reported penicillin allergies have been well established throughout the evidence [13].

QUESTIONS/PURPOSES

The study sought to answer two questions: (1) Do antibiotic stewardship interventions improve adherence to appropriate prophylactic antibiotic usage in patients with a documented penicillin allergy undergoing primary TJA? (2) What is the risk of allergic or adverse reactions secondary to cefazolin use in patients with a documented penicillin allergy?

METHODS

This was a single-center, retrospective study of orthopaedic patients older than 18 years who underwent a primary elective TJA at a 261-bed community hospital. The study had two periods: the preintervention period ran from March 1, 2017 to August 30, 2017 and the postintervention period was from March 1, 2019 to August 30, 2019. A total of 396 patients with a history of a documented penicillin allergy underwent a THA or TKA during the study periods. After reviewing every fourth patient with a history of a documented penicillin allergy who met study inclusion criteria and excluding those patients who had a codocumented cephalosporin allergy, a total of 180 patients with a documented penicillin allergy were evaluated (90 patients in the preintervention group and 90 patients in the postintervention group). To answer our first study question, regarding whether antibiotic stewardship interventions improve adherence to appropriate prophylactic antibiotic usage in patients with a documented penicillin allergy undergoing primary TJA, we evaluated appropriate antibiotic usage pre- and postintervention. To answer our second study question, concerning the risk of allergic or adverse reactions secondary to cefazolin use in patients with a documented penicillin allergy, we reviewed signs of allergic reactions in patients who received cefazolin for a primary TJA and had a documented penicillin allergy.

RESULTS

Postintervention antibiotic use was more appropriate (91% [82 of 90] versus 54% [49 of 90], risk ratio 1.67 [95% confidence interval 1.37 to 2.04]; p < 0.01), particularly in patients with nonsevere allergy (preintervention: 47% [36 of 76] versus postintervention: 96% [76 of 79]; p < 0.01). No patients had signs of an allergic reaction related to cefazolin, including eight patients with severe penicillin allergy.

CONCLUSION

A multifaceted antibiotic stewardship intervention increased the appropriateness of antibiotic prophylaxis in elective primary TJA. Patients with nonsevere penicillin allergies, even those reporting hives or local swelling, tolerated cefazolin. Antibiotic stewardship interventions can be implemented across institutions to expand cephalosporin use in patients with a reported penicillin allergy within orthopaedic TJA patients.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Safety of administering cefazolin versus other antibiotics in penicillin-allergic patients for surgical prophylaxis at a major Canadian teaching hospital

BACKGROUND

Cefazolin surgical prophylaxis is associated with better patient outcomes; however, its use in penicillin-allergic patients is controversial. We evaluated the safety of cefazolin as surgical prophylaxis in penicillin-allergic patients, including those with anaphylaxis histories.

METHODS

We conducted a pre and postintervention quality improvement evaluation of an institution-wide policy change at a tertiary-care hospital, before (October 2017-January 2018), during (February 2018-September 2018), and after (October 2018-October 2019) transition to routine cefazolin prophylaxis for penicillin-allergic patients, including those with anaphylaxis histories but excluding severe delayed reactions (eg, Stevens-Johnson syndrome). Retrospective data was collected on all surgical prophylaxis patients with penicillin-anaphylactic histories between October 2017 and September 2018. From October 2018, we prospectively reviewed adverse events with cefazolin. Primary outcome was adverse events in penicillin-allergic patients receiving cefazolin perioperatively.

RESULTS

From October 2017 to October 2019, 27,467 operations were performed. Of 220 patients with penicillin-anaphylactic histories reviewed prior to the full policy change, no statistically significant differences were reported in allergic reactions (P = .70), surgical site infections (P = 1.00), or adverse events (P = .32) with cefazolin compared to other antibiotics. Postpolicy implementation, cefazolin usage increased 18.2%, while vancomycin and clindamycin decreased by 11.4% and 62.0%, respectively. No anaphylaxis was documented in penicillin-allergic patients receiving cefazolin in either the review or quality assurance follow-up after the change. Of 3 patients developing reactions to cefazolin, none had histories of penicillin allergy. Surgical site infection rates were similar between pre and postpolicy time periods (P = .842).

CONCLUSION

Administration of cefazolin in penicillin-anaphylactic patients for surgical prophylaxis appears to be safe.

Suspected penicillin allergy: risk assessment using an algorithm as an antibiotic stewardship project

Background

Beta-lactam antibiotics (BLA) are the treatment of choice for a large number of bacterial infections. Putative BLA allergies are often reported by patients, but rarely confirmed. Many patients do not receive BLA due to suspected allergy. There is no systematic approach to risk stratification in the case of a history of suspected BLA allergy.

Methods

Using the available stratification programs and taking current guidelines into account, an algorithm for risk stratification, including recommendations on the use of antibiotics in cases of compellingly indicated BLA despite suspected BLA allergy, was formulated by the authors for their maximum care university hospital.

Results

The hospital is in great need of recommendations on how to deal with BLA allergies. Patient-reported information in the history forms the basis for classifying the reactions into four risk categories: (1) BLA allergy excluded, (2) benign delayed reaction, (3) immediate reaction, and (4) severe cutaneous and extracutaneous drug reaction. Recommendations strictly depend on this classification and range from use of full-dose BLA or use of BLA under certain conditions (e.g., two-stage dose escalation, non-cross-reactive BLA only) to prohibiting all BLA and the use of alternative non-BLA. In case of suspected immediate or delayed allergic reactions, there is an additional recommendation regarding subsequent allergy testing during a symptom-free interval.

Conclusion

Triage of patients with suspected BLA is urgently required. While allergy testing, including provocation testing, represents the most reliable solution, this is not feasible in all patients due to the high prevalence of BLA allergies. The risk stratification algorithm developed for the authors’ hospital represents a tool suitable to making a contribution to rational antibiotic therapy.