The Impact of Patient-Reported Penicillin Allergy on Risk for Surgical Site Infection in Total Joint Arthroplasty

The use of perioperative cephalosporin prophylaxis in patients who have a pre-existing penicillin allergy

BACKGROUND

Studies have shown an association between a reported penicillin allergy and an increased risk of surgical site infection. The risk is due to avoidance of cephalosporins and to the use of alternative classes of antibiotics in surgical prophylaxis. The aim of this study was to examine the safety of using cephalosporins in patients with a penicillin allergy label.

METHODS

Patients with a primary or revision hip or knee arthroplasty in a tertiary care hospital between March 2020 and February 2023 were identified (n = 14,939). Information on prophylactic antibiotics, pre-existing antibiotic allergy labels before the operation, and all recorded new antibiotic allergy labels within 2 weeks after the operation was gathered. The prophylactic antibiotic use in patients with and without a penicillin allergy label was compared. In addition, all new antibiotic allergy labels recorded after the operation were verified from the electronic health records.

RESULTS

A total of 1,435 (9.6%) patients had a previous penicillin allergy label. The majority of patients (14,838 of 14,939; 99.3%) received cephalosporin prophylaxis, as did most of the patients with a label of penicillin allergy (1,395 of 1,435; 97.2%). Six perioperative allergic reactions were recorded; none of these were anaphylactic reactions. In 5 cases, the allergic reaction occurred in patients receiving cefuroxime, none of whom had a previous penicillin allergy.

CONCLUSION

This study found cephalosporin antibiotic prophylaxis to be safe in patients with a pre-existing penicillin allergy label.

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.

Surgical prophylaxis in pediatric orthopedic patients with penicillin allergy: a multicentered retrospective prognostic study

Up to 20% of orthopedic surgeons still avoid the use of cephalosporins in patients with penicillin allergies despite its reported safety in the adult and general surgery pediatric population. The primary objective is to determine the incidence of adverse effects and allergic reactions when using cephalosporins in pediatric orthopedic patients labeled as penicillin-allergic as compared to those without previously reported penicillin allergy. A multicenter retrospective chart review was performed across three level 1 trauma centers from January 2013 to February 2020 to identify penicillin-allergic as well as non-penicillin-allergic pediatric patients treated for orthopedic injuries. Data were collected regarding patient demographics, antibiotic administered, timing of antibiotic administration, reported drug allergy, and described allergic reaction. Postoperative or intraoperative allergic reactions to antibiotics, surgical site infections, and complications were recorded. A total of 2289 surgeries performed by four fellowship-trained surgeons were evaluated. Eighty-five patients diagnosed with penicillin allergy were identified and underwent 95 surgeries and 95 patients without previously reported penicillin allergy underwent 95 surgeries. One patient, with a documented history of anaphylaxis to cefazolin, sustained an anaphylactic reaction intraoperatively to cefazolin. There were no other reported reactions, surgical site infections, or complications. There was no statistically significant difference in rate of allergic reaction in patients with previously reported penicillin allergy treated with cefazolin and those with no previous reported reaction ( P > 0.05). Prophylaxis with cephalosporins is not associated with increased risk for allergic reaction. Cephalosporins can be safely administered to pediatric patients with penicillin allergy undergoing orthopedic intervention. Level of evidence: Level II, Multicenter Retrospective Prognostic Study.

Is Penicillin Allergy a Clinical Problem? A Systematic Review of Total Joint Arthroplasty Procedures With Implications for Patient Safety and Antibiotic Stewardship

BACKGROUND

Patients undergoing total joint arthroplasty (TJA) who report penicillin allergy (PA) are frequently administered second-line antibiotics, although recent evidence suggests that this may be unnecessary and could increase infection risk. Many institutions have aimed to improve antibiotic deployment via allergy testing and screening; however, there is little standardization to this process. This review aimed to evaluate (1) antibiotic selection in patients who report PA and assess the impact of screening and testing interventions, (2) rates of allergic reactions in patients who report PA, and (3) the association between reported PA and screening or testing programs and odds of surgical site infection or periprosthetic joint infection.

METHODS

PubMed, EBSCOhost, and Google Scholar electronic databases were searched on February 4, 2023 to identify all studies published since January 1, 2000 that evaluated the impact of PA on patients undergoing TJA (PROSPERO study protocol registration: CRD42023394031). Articles were included if full-text manuscripts in English were available, and the study analyzed the impact of PA and related interventions on TJA patients. There were 11 studies evaluating 1,276,663 patients included. Interventions were compared via presentation of key findings regarding rates of clinically relevant or high-risk PA reported upon screenings or testings, cephalosporin utilizations, allergic reactions, and postoperative infections (surgical site infection and periprosthetic joint infection).

RESULTS

All 6 studies found that PA screening and testing markedly increase the use of first-line antibiotics. Testing showed low rates of true allergy (0.7 to 3%) and allergic reaction frequency for patients who have reported PA receiving cephalosporins was between 0% and 2%. Although there were mixed findings across studies, there was a trend toward second-line antibiotic prophylaxis being associated with a slightly higher rate of infection in PA patients.

CONCLUSIONS

Using PA screening and testing can promote antibiotic stewardship by safely increasing the use of first-line antibiotics in patients who have a reported PA.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Impact of penicillin allergy labels on surgical site infections in a large UK cohort of gastrointestinal surgery patients

Objectives

Studies in the USA, Canada and France have reported higher surgical site infection (SSI) risk in patients with a penicillin allergy label (PAL). Here, we investigate the association between PALs and SSI in the UK, a country with distinct epidemiology of infecting pathogens and range of antimicrobial regimens in routine use.

Methods

Electronic health records and national SSI surveillance data were collated for a retrospective cohort of gastrointestinal surgery patients at Cambridge University Hospitals NHS Foundation Trust from 1 January 2015 to 31 December 2021. Univariable and multivariable logistic regression were used to examine the effects of PALs and the use of non-β-lactam-based prophylaxis on likelihood of SSI, 30 day post-operative mortality, 7 day post-operative acute kidney injury and 60 day post-operative infection/colonization with antimicrobial-resistant bacteria or Clostridioides difficile.

Results

Our data comprised 3644 patients and 4085 operations; 461 were undertaken in the presence of PALs (11.3%). SSI was detected after 435/4085 (10.7%) operations. Neither the presence of PALs, nor the use of non-β-lactam-based prophylaxis were found to be associated with SSI: adjusted OR (aOR) 0.90 (95% CI 0.65-1.25) and 1.20 (0.88-1.62), respectively. PALs were independently associated with increased odds of newly identified MRSA infection/colonization in the 60 days after surgery: aOR 2.71 (95% CI 1.13-6.49). Negative association was observed for newly identified infection/colonization with third-generation cephalosporin-resistant Gram-negative bacteria: aOR 0.38 (95% CI 0.16-0.89).

Conclusions

No evidence was found for an association between PALs and the likelihood of SSI in this large UK cohort, suggesting significant international variation in the impact of PALs on surgical patients.

Second-Line Antibiotic Agents in Patient-Reported Penicillin or Cephalosporin Allergy Have No Negative Impact on Antibiotic Resistance After Hip and Knee Arthroplasty

BACKGROUND

The aim of the present study was to compare causative bacteria and their antibiotic resistance profiles in patients developing a periprosthetic joint infection (PJI) based on preoperative prophylactic antibiotic regimens in primary total hip (THA) and primary total and unicompartmental knee arthroplasty (TKA/UKA).

METHODS

We reviewed all cases of PJI occurring after primary THA and primary TKA/UKA, between 2011 and 2020 in a tertiary referral hospital. The standard preoperative prophylactic antibiotic for primary joint arthroplasty was cefuroxime and recommended second-line agent was clindamycin. Patients were divided by the replaced joint and analyzed independently.

RESULTS

In the THA group, culture-positive PJI was detected in 61 of 3,123 (2.0%) cefuroxime-administered cases and 6 of 206 (2.9%) noncefuroxime-administered cases. In the TKA/UKA group, culture positive PJI was identified in 21 of 2,455 (0.9%) cefuroxime-administered cases and in 3 of 211 (1.4%) noncefuroxime administered cases. The most commonly isolated bacteria in both groups were coagulase negative staphylococci (CNS). There were no statistically significant differences of pathogen spectrum depending on the preoperative antibiotic regimen detected. Antibiotic resistance of isolated bacteria was significantly different in 4 of 27 (14.8%) analyzed antibiotics in THA and in 3 of 22 (13.6%) analyzed antibiotics in TKA/UKA. In all cohorts, a high occurrence of oxacillin-resistant CNS (50.0 to 100.0%) and clindamycin-resistant CNS (56.3 to 100.0%) has been observed.

CONCLUSION

The use of the second-line antibiotic did not influence the pathogen spectrum or antibiotic resistance. However, an alarmingly high proportion of CNS strains was resistant to clindamycin.

Prevalence of reported penicillin allergy and associations with perioperative complications, length of stay, and cost in patients undergoing elective cancer surgery

Objective

Up to 10% of patients report penicillin allergy (PA), although only 1% are truly affected by Ig-E-mediated allergies. PA has been associated with worse postoperative outcomes, but studies on the impact of reported PA in cancer patients are lacking, and especially in these multimorbid patients, a non-complicated course is of utmost importance.

Methods

Retrospective analysis of patients undergoing elective oncological surgery at a tertiary reference center. Data on surgical site infections (SSI), postoperative complications (measured by Clavien-Dindo classification and Comprehensive Complication Index (CCI)), hospitalization duration, and treatment costs were collected.

Results

Between 09/2019 and 03/2020, 152 patients were identified. 16/152 patients (11%) reported PA, while 136/152 (89%) did not. There were no differences in age, BMI, Charlson Comorbidity Index, and smoking status between groups (p > 0.4). Perioperative beta-lactam antibiotics were used in 122 (89.7%) and 15 (93.8%) patients without and with reported PA, respectively. SSI and mean numbers of infections occurred non-significantly more often in patients with PA (p = 0.2 and p = 0.47). The median CCI was significantly higher in PA group (26 vs. 51; p = 0.035). The median hospitalization duration and treatment costs were similar between non-PA and PA groups (4 vs 3 days, p = 0.8; 16'818 vs 17'444 CHF, p = 0.4).

Conclusions

In patients undergoing cancer surgery, reported PA is common. Failure to question the unproven PA may impair perioperative outcomes. For this reason, patient and provider education on which reactions constitute a true allergy would also assist in allergy de-labeling. In addition, skin testing and oral antibiotic challenges can be performed to identify the safe antibiotics and to de-label appropriate patients.

Effect of non-cephalosporin antibiotic prophylaxis on the risk of periprosthetic joint infection after total joint replacement surgery: a retrospective study with a 1-year follow-up

Background

Cephalosporins are recommended as first-line antibiotic prophylaxis in total joint replacement surgery. Studies have shown an increased risk for periprosthetic joint infection (PJI) when non-cephalosporin antibiotics have been used. This study examines the effect of non-cephalosporin antibiotic prophylaxis on the risk for PJI.

Methods

Patients with a primary hip or knee replacement performed from 2012 to 2020 were identified (27 220 joint replacements). The primary outcome was the occurrence of a PJI in a one-year follow-up. The association between perioperative antibiotic prophylaxis and the outcome was examined using logistic regression analysis.

Discussion

Cefuroxime was used as prophylaxis in 26,467 operations (97.2%), clindamycin in 654 (2.4%) and vancomycin in 72 (0.3%). The incidence of PJI was 0.86% (228/26,467) with cefuroxime and 0.80% (6/753) with other prophylactic antibiotics. There was no difference in the risk for PJI with different prophylactic antibiotics in the univariate (OR 1.06, 95% CI 0.47-2.39) or multivariable analysis (OR 1.02, 95% CI 0.45-2.30).

Conclusion

Non-cephalosporin antibiotic prophylaxis in primary total joint replacement surgery was not associated with an increased risk for PJI.

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.

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.

Impact of Patient-Reported Penicillin Allergy on Antibiotic Prophylaxis and Surgical Site Infection Among Patients Undergoing Colorectal Surgery

BACKGROUND

Surgical site infections are a major preventable source of morbidity, mortality, and increased health care expenditures after colorectal surgery. Patients with penicillin allergy may not receive the recommended preoperative antibiotics, putting them at increased risk for surgical site infections.

OBJECTIVE

This study aimed to evaluate the impact of patient-reported penicillin allergy on preoperative antibiotic prophylaxis and surgical site infection rates among patients undergoing major colon and rectal procedures.

DESIGN

This is a retrospective observational study.

SETTING

This study was conducted at a tertiary teaching hospital in Dallas.

PATIENTS

Adults undergoing colectomy or proctectomy between July 2012 and July 2019 were included.

MAIN OUTCOME MEASURES

The primary outcomes measured were preoperative antibiotic choice and surgical site infection.

RESULTS

Among 2198 patients included in the study, 12.26% (n = 307) reported a penicillin allergy. Patients with penicillin allergy were more likely to be white (82%) and female (54%; p < 0.01). The most common type of allergic reaction reported was rash (36.5%), whereas 7.2% of patients reported anaphylaxis. Patients with self-reported penicillin allergy were less likely to receive beta-lactam antibiotics than patients who did not report a penicillin allergy (79.8% vs 96.7%, p < 0.001). Overall, 143 (6.5%) patients had surgical site infections. On multivariable logistic regression, there was no difference in rates of surgical site infection between patients with penicillin allergy vs those without penicillin allergy (adjusted OR 1.14; 95% CI, 0.71-1.82).

LIMITATIONS

A limitation of this study was its retrospective study design.

CONCLUSIONS

Self-reported penicillin allergy among patients undergoing colorectal surgery is common; however, only a small number of these patients report any serious adverse reactions. Patients with self-reported penicillin allergy are less likely to receive beta-lactam antibiotics and more likely to receive non-beta-lactam antibiotics. However, this does not affect the rate of surgical site infection among these patients, and these patients can be safely prescribed non-beta-lactam antibiotics without negatively impacting surgical site infection rates. See Video Abstract at http://links.lww.com/DCR/B838 .IMPACTO DE LA ALERGIA A LA PENICILINA INFORMADA POR EL PACIENTE EN LA PROFILAXIS ANTIBIÓTICA Y LA INFECCIÓN DEL SITIO OPERATORIO ENTRE PACIENTES DE CIRUGÍA COLORECTAL.

ANTECEDENTES

Las infecciones del sitio operatorio son una de las principales fuentes prevenibles de morbilidad, mortalidad y aumento del gasto sanitario después de cirugía colorrectal. Es posible que los pacientes con alergia a la penicilina no reciban los antibióticos preoperatorios recomendados, lo que los pone en mayor riesgo de infecciones en el sitio operatorio.

OBJETIVO

Este estudio tuvo como objetivo evaluar el impacto de la alergia a la penicilina informada por el paciente sobre la profilaxis antibiótica preoperatoria y las tasas de infección del sitio operatorio entre pacientes sometidos a procedimientos mayores de colon y recto.

DISEO

Estudio observacional retrospectivo.

AJUSTE

Hospital universitario terciario en Dallas.

PACIENTES

Adultos sometidos a colectomía o proctectomía entre julio de 2012 a julio de 2019.

PRINCIPALES MEDIDAS DE DESENLACE

Elección de antibióticos preoperatorios e infección del sitio operatorio.

RESULTADOS

Entre los 2198 pacientes incluidos en el estudio, el 12,26% (n = 307) informó alergia a la penicilina. Los pacientes con alergia a la penicilina tenían más probabilidades de ser blancos (82%) y mujeres (54%) ( p < 0,01). El tipo más común de reacción alérgica notificada fue erupción cutánea (36,5%), mientras que el 7,2% de los pacientes notificó anafilaxia. Los pacientes con alergia a la penicilina autoinformada tenían menos probabilidades de recibir antibióticos betalactámicos en comparación con los pacientes que no informaron alergia a la penicilina (79,8% frente a 96,7%, p < 0,001). En general, hubo 143 (6,5%) pacientes con infecciones del sitio operatorio. En la regresión logística multivariable no hubo diferencias en las tasas de infección del sitio operatorio entre los pacientes con alergia a la penicilina frente a los que no tenían alergia a la penicilina (razón de probabilidades ajustada 1,14; intervalo de confianza del 95%, 0,71-1,82).

LIMITACIONES

Diseño de estudio retrospectivo.

CONCLUSIONES

La alergia a la penicilina autoinformada entre los pacientes de cirugía colorrectal es común, sin embargo, solo un pequeño número de estos pacientes informan reacciones adversas graves. Los pacientes con alergia a la penicilina autoinformada tienen menos probabilidades de recibir antibióticos betalactámicos y más probabilidades de recibir antibióticos no betalactámicos. Sin embargo, esto no afecta la tasa de infección del sitio quirúrgico entre estos pacientes y se les puede recetar de forma segura con antibióticos no betalactámicos sin afectar negativamente las tasas de infección del sitio quirúrgico. Consulte Video Resumen en http://links.lww.com/DCR/B838 . (Traducción-Dr. Juan Carlos Reyes ).

Antimicrobial Stewardship in Total Joint Arthroplasty: Outcomes of a Collaborative Program Implementation

INTRODUCTION

Antimicrobial stewardship has been cited as a crucial component of orthopaedic surgical care; however, limited high-quality data exist to guide antibiotic use across the total joint arthroplasty continuum. Antimicrobial stewardship program (ASP) implementation and evaluation is needed in this space.

METHODS

We pursued a prospective, sequential cohort study of an interprofessional ASP for total joint arthroplasty (TJA) formed in late 2017 at the study institution. Twelve total evidence-based recommendations for protocol change were issued, with 11 accepted and implemented across three project phases spanning March 2018 to December 2019. The primary study outcome was the rate of optimal preoperative intravenous antibiotic selection as assessed for Baseline versus Postintervention time periods. Secondary outcomes included individual antibiotic utilization rates. Descriptive statistics were pursued for institutional surgical site infection (SSI) and postoperative acute kidney injury (AKI) rates across the affected time frame. A cost-benefit analysis of the ASP was estimated from the institutional perspective.

RESULTS

The rate of optimal preoperative antibiotic selection increased from 64.9% in the Baseline Period (February 2018, n = 57) to 95.4% in the Postimplementation period (June 2018 to December 2019, n = 1,220) (P < 0.001). The rates of second-line preoperative antibiotics and total perioperative antibiotic exposures decreased. Total SSI and AKI rates in primary elective TJA seemed to decrease from calendar year 2018 to 2019 (deep SSI 1.00% to 0.22%, superficial SSI 0.66% to 0.00%, and AKI 1.97% to 1.03%). The institution realized an estimated $197,050 cost savings per 1000 TJA procedures.

DISCUSSION

A comprehensive ASP for TJA was associated with an increased use of optimal preoperative antibiotic selection, decreased total antibiotic exposures, and cost savings, without apparent detriment to SSI or AKI rates.

The Impact of Patient-Reported Penicillin or Cephalosporin Allergy on the Occurrence of the Periprosthetic Joint Infection in Primary Knee and Hip Arthroplasty

Reducing the risk of periprosthetic joint infections (PJI) requires a multi-pronged strategy including usage of a prophylactic antibiotic. A history of penicillin or cephalosporin allergy often leads to a change in prophylactic antibiotic regimen to avoid serious side effects. The purpose of the present retrospective study was to determine incidence of PJI based on perioperative antibiotic regimen in total hip arthroplasty (THA), total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA). A review of all primary THAs, primary TKAs and primary UKAs, undertaken between 2011 and 2020 in a tertiary referral hospital, was performed. The standard perioperative antibiotic for joint arthroplasty (JA) in the analyzed tertiary hospital is cefuroxime. There were no differences in prophylactic antibiotic regimen over time. In 7.9% (211 of 2666) of knee arthroplasties and in 6.0% (206 of 3419) of total hip arthroplasties, a second-line prophylactic antibiotic was used. There was no statistically significant higher occurrence of PJI between the first-line and second-line prophylactic antibiotic in knee arthroplasties (p = 0.403) as well as in total hip arthroplasties (p = 0.309). No relevant differences in age, American Society of Anesthesiologists (ASA) score and body mass index (BMI) between the groups were observed.

Total Shoulder Arthroplasty: Antibiotic Allergies Increase Risk of Postoperative Complications

BACKGROUND

Periprosthetic infections after total shoulder arthroplasty (TSA) are associated with devastating complications and prolonged treatment. Patients with identified antibiotic allergy (ABX) may be at increased risk for complications because of suboptimal preincisional prophylaxis. This study aims to quantify the risk of postoperative outcomes and complications for patients undergoing TSA with a history of ABX.

METHODS

Retrospective cohort analysis of patient data was conducted using the PearlDiver Patient Records Database. Patients who underwent TSA for osteoarthritis were identified using Current Procedural Terminology and International Classification of Diseases codes and were stratified based on self-reported (1) penicillin, (2) sulfonamide, or (3) other antibiotic allergies. We analyzed patient demographics, comorbidities, 90-day medical complications, and rate of revision at 30 days, 90 days, 1 year, and 2 years.

RESULTS

In total, 85,606 patients who underwent TSA for osteoarthritis from 2010 to 2018 were identified, of whom 7,836 (9.15%) had a reported ABX. Univariate analysis found the ABX cohort was younger (67.5 versus 67.7 year; P = 0.042), more often female (67.57% versus 54.79%; P < 0.001), and more likely to have Elixhauser comorbidities than nonallergic control subjects. Multivariate analysis found patients who reported ABX had increased likelihood of periprosthetic joint infection (PJI) within 30 days (odds ratio [OR]: 3.129), 1 year (OR: 2.016), and 2 years of surgery (OR: 2.221). Patients with reported ABX had increased likelihood of postoperative anemia (OR: 1.126), blood transfusion (OR: 1.238), and readmission (OR: 1.585) within 90 days of surgery. Patients with penicillin allergy had a greater incidence of revision due to PJI at 30 days (OR: 4.811), 90 days (OR: 2.91), 1 year (OR: 2.105), and 2 years (OR: 2.72). Rates of reported ABX increased from 2010 to 2018 (8.60% to 10.91%; P = 0.001) in patients undergoing TSA.

CONCLUSION

Patients undergoing TSA with a history of ABX had a higher risk of readmission, postoperative anemia, blood transfusions, and PJI. These findings support critical assessment and clarification of reported allergies before TSA and possibly the use of preoperative allergy testing.

LEVEL OF EVIDENCE

Level 3 therapeutic study.

Surgical site infection rates are higher among elective colorectal surgery patients receiving non–beta-lactam–based antimicrobial prophylaxis: A retrospective chart review

We compared the odds of acquiring surgical site infection (SSI) for clean-contaminated colorectal surgeries between intravenous β-lactam–based prophylaxis (BLP) versus alternative antimicrobial prophylaxis (AAP). We calculated the odds of acquiring an SSI using logistic regression; adjusted odds ratios (ORs) with 95% confidence intervals (CIs) are reported. Increased odds of SSI were detected with AAP versus BLP (OR, 2.15; 95% CI, 1.33–3.50; P = .002).

Preoperative Prophylactic Antibiotics in Total Hip and Knee Arthroplasty: What, When, and How

Although there are numerous nonpatient-related factors that may help reduce infection risk, the proper use of prophylactic antibiotics is most responsible for reducing infection. The role of prophylactic antibiotics is to reduce early periprosthetic joint replacement, which is accomplished by having adequate antibiotic tissue levels at the time of skin incision. The goal of this section of the symposium is to review current antibiotic recommendations, how to manage patients with a self-reported penicillin allergy, review the use of dual antibiotics, discuss the use of antibiotics in the outpatient total joint setting, as well as very briefly discuss the administration of intraosseous antibiotics in knee arthroplasty.

Risk factors associated with surgical site infections following joint replacement surgery: a narrative review

Background

Surgical site infection following joint replacement surgery is still a significant complication, resulting in repeated surgery, prolonged antibiotic therapy, extended postoperative hospital stay, periprosthetic joint infection, and increased morbidity and mortality. This review discusses the risk factors associated with surgical site infection.

Related risk factors

The patient-related factors include sex, age, body mass index (BMI), obesity, nutritional status, comorbidities, primary diagnosis, living habits, and scores of the American Society of Anesthesiologists physical status classification system, etc. Surgery-related factors involve preoperative skin preparation, prolonged duration of surgery, one-stage bilateral joint replacement surgery, blood loss, glove changes, anti-microbial prophylaxis, topical anti-bacterial preparations, wound management, postoperative hematoma, etc. Those risk factors are detailed in the review.

Conclusion

Preventive measures must be taken from multiple perspectives to reduce the incidence of surgical site infection after joint replacement surgery.

Documented β-Lactam Allergy and Risk for Cesarean Surgical Site Infection

Objective

To examine the relationship between documented β-lactam allergy and cesarean delivery (CD) surgical site infection (SSI). Study Design. We conducted a retrospective cohort analysis of women who underwent CD at Ben Taub Hospital and Texas Children's Pavilion for Women (Houston, TX) from August 1, 2011, to December 31, 2019. The primary exposure was a documented β-lactam allergy, and the second exposure of interest was the type of perioperative antibiotic received. The primary outcome was the prevalence of SSI. Maternal characteristics were stratified by the presence or absence of a documented β-lactam allergy, and significance was evaluated using Pearson's chi-squared test for categorical variables and t-test for continuous variables. A logistic regression model estimated odds of SSI after adjusting for possible confounders.

Results

Of the 12,954 women included, 929 (7.2%) had a documented β-lactam allergy while 12,025 (92.8%) did not. Among the 929 women with a β-lactam allergy, 495 (53.3%) received non-β-lactam perioperative prophylaxis. SSI occurred in 38 (4.1%) of women who had a β-lactam allergy versus 238 (2.0%) who did not (p ≤ 0.001). β-Lactam allergy was associated with higher odds of SSI compared to no allergy (adjusted odds ratio (aOR) = 1.97; 95%confidence interval (CI) = 1.24-3.14; p = 0.004) after controlling for age, race, ethnicity, insurance status, delivery body mass index (BMI), tobacco use, intra-amniotic infection in labor, duration of membrane rupture, preterm delivery, delivery indication, diabetes, hypertension, group B Streptococcus colonization, and type of perioperative antibiotic received.

Conclusion

The presence of a β-lactam allergy is associated with increased odds of developing a CD SSI after controlling for possible confounders, including the type of perioperative antibiotic received.

Patients Who Do Not Receive Aspirin Because of Allergy Have an Increased Risk of Venous Thromboembolism Following Total Joint Arthroplasty

BACKGROUND

Patient-reported allergies to aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) may preclude certain patients from receiving aspirin as venous thromboembolism (VTE) prophylaxis after total joint arthroplasty (TJA). The purpose of the study was to (1) determine whether the use of non-aspirin agents due to a self-reported aspirin or NSAID allergy was associated with a higher incidence of VTE and (2) determine the rate of true allergic reactions in patients who reported an allergy but still received aspirin.

METHODS

Prospectively collected data from 45,171 patients who underwent primary TJA between 2000 and 2019 were reviewed. Patients who reported an allergy to aspirin or NSAIDs were identified (n = 823). Using a validated VTE risk calculator, each patient was assigned a risk score based on 26 comorbidities. Bleeding complications, VTEs that occurred within 90 days postoperatively, and allergic reactions were collected as end points. Multivariable logistic regression was performed to determine the factors associated with VTE.

RESULTS

The overall incidence of aspirin or NSAID allergy was 1.8%. Only 80 of 267 patients (30%) reported an allergy to only aspirin and still received aspirin. Compared with patients who received aspirin without a history of allergy (n = 17,648), patients who received non-aspirin thromboprophylaxis due to allergy (n = 383) had a higher incidence of VTE (2.87% versus 0.24%, p < 0.001). On multivariable regression, these patients had an 8-fold increase in VTE risk (adjusted odds ratio, 7.94; 95% confidence interval, 2.86 to 22.07; p < 0.001). The incidence of true allergic reactions to aspirin among those with a reported allergy was 1.8% (number needed to harm = 55). No patients developed anaphylaxis or severe hypersensitivity reactions.

CONCLUSIONS

Patients with a self-reported allergy to aspirin or NSAIDs were at a significantly increased risk for VTE if they received non-aspirin thromboprophylaxis agents following TJA. Future research should evaluate the usefulness of preoperative allergy testing when selecting a VTE prophylactic agent in patients with self-reported allergies.

LEVEL OF EVIDENCE

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

Are Patient-Reported Drug Allergies Associated With Prosthetic Joint Infections and Functional Outcomes Following Total Hip and Knee Arthroplasty?

BACKGROUND

The purpose of this study is to determine if the number and types of patient-reported drug allergies are associated with prosthetic joint infection (PJI) and functional outcomes following total joint arthroplasty (TJA).

METHODS

This is a retrospective review of all patients who underwent a primary, elective total hip (THA) or knee arthroplasty (TKA) over a 10-year period at a single academic institution. Demographic, clinical information, and number and type of patient-reported drug allergy was collected. Univariate and multivariate logistic regressions were performed to identify risk factors for PJI and risk of PJI based on number of allergies. Univariate analysis was also performed to identify if the number of patient-reported allergies affected functional outcome scores.

RESULTS

Of 31,109 patients analyzed, there were 941 (3%) revisions for infection (491 knees and 450 hips). At least one allergy was reported by 16,435 (52.8%) patients, with a mean of 1.2 ± 1.9. Those who underwent revision for infection had a significantly higher number of reported allergies (1.68 ± 1.9 vs 1.23 ± 1.9, P < .0005, 95% confidence interval -0.58 to 0.33). On univariate regression the number of allergies independently predicted revision TJA for infection (P < .0001) as did age, gender, body mass index, and smoking status. On multivariate regression for each additional patient-reported allergy, risk of PJI increased by 1.11 times (95% confidence interval 1.07-1.14, P < .0001). Number of patient-reported allergies did not predict 3-month or 1-year functional outcome scores.

CONCLUSION

Patients with a higher number of reported allergies may be at increased risk of PJI following TJA.

LEVEL OF EVIDENCE

Prognostic Level II.

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.

Economic Burden of Patient-Reported Penicillin Allergy on Total Hip and Total Knee Arthroplasty

INTRODUCTION

Self-reported penicillin allergies in patients undergoing total joint arthroplasty often results in the use of second-line prophylactic antibiotics. A higher risk of prosthetic joint infection (PJI) is associated with suboptimal antibiotics vs first generation cephalosporins, which have historically been grouped with other beta-lactam antibiotics such as penicillin for potential allergic reactions. This study evaluates the economic burden of self-reported penicillin allergies in total joint arthroplasty (TJA).

METHODS

Data from studies reporting true incidence of IgE-mediated penicillin allergies, infection-free survivorship of TJA, and cost of PJI attributed to use of second-line antibiotics were obtained. Projected cost of preoperative penicillin allergy testing and potentially avoidable PJI associated with second-line antibiotic usage were calculated. This was compared with projected cost of PJI in the current state to estimate cost savings.

RESULTS

Implementation of preoperative penicillin allergy testing leads to a potential savings of nearly $37 million to payors in the first year based on 1-year survivorship. This savings increases to $411.6 million over a 10-year span and $1.18 billion over a 20-year span.

CONCLUSION

Preoperative penicillin allergy testing or risk stratification via thorough history should be implemented as standard of care for patients with self-reported penicillin allergies before TJA and would result in decreased cost of PJI.

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.

A Rapid Recovery Protocol Applied to Total Joint Arthroplasty Reduced Readmissions for Surgical but Not Medical Reasons Over a 5-Year Period

Background: Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are commonly performed procedures that are expected to continue increasing in demand. Although they are proven to be safe and effective, emergency room (ER) visits or hospital readmissions within 90 days after these procedures account for more than one-third of the total cost of postacute care. Purpose: We sought to identify changes in reasons for 90-day ER visits and readmissions after total joint arthroplasty (TJA) during a 5-year period over which rapid recovery protocols evolved. Methods: We conducted a retrospective cohort study comparing 1980 patients who had undergone TJA from July 2017 to June 2018 with a previously published cohort of 7466 patients who had undergone TJA from July 2013 to June 2017. All procedures were performed at a single institution. Changes in the proportion of patients returning for medical and surgical reasons were compared using univariate analysis. Results: For patients discharged home, the 2017-2018 cohort showed a significant reduction in the proportion of ER visits due to pain and swelling and wound infection and an increase in visits for medical reasons. This cohort had a higher proportion of readmissions for medical reasons. In patients discharged to a skilled nursing facility (SNF), similar reasons for ER visits were observed across time periods, and a decrease in the proportion of readmissions for wound infections was observed in the 2017-2018 cohort. Falls and nausea, vomiting, or diarrhea increased significantly to account for 9.5% of readmissions each in 2017-2018. Conclusion: The results of a comparison of 2 cohorts demonstrate the heterogeneous and dynamic nature of unplanned return-to-hospital events and the importance of patient support throughout the surgical episode. As we strive toward minimizing ER visits and readmissions after TJA, rapid recovery protocols must continue to evolve to address the complexity of this patient population.

The impact of patient-reported penicillin or cephalosporin allergy on surgical site infections

OBJECTIVE

To determine the impact of a documented penicillin or cephalosporin allergy on the development of surgical site infections (SSIs).

BACKGROUND

Appropriate preoperative antibiotic prophylaxis reduces SSI risk, but documented antibiotic allergies influence the choice of prophylactic agents. Few studies have examined the relationship between a reported antibiotic allergy and risk of SSI and to what extent this relationship is modified by the antibiotic class given for prophylaxis.

METHODS

We conducted a retrospective cohort study of adult patients undergoing coronary artery bypass, craniotomy, spinal fusion, laminectomy, hip arthroplasty and knee arthroplasty at 3 hospitals from July 1, 2013, to December 31, 2017. We built a multivariable logistic regression model to calculate the adjusted odds ratio (aOR) of developing an SSI among patients with and without patient-reported penicillin or cephalosporin allergies. We also examined effect measure modification (EMM) to determine whether surgical prophylaxis affected the association between reported allergy and SSI.

RESULTS

We analyzed 39,972 procedures; 1,689 (4.2%) with a documented patient penicillin or cephalosporin allergy, and 374 (0.9%) resulted in an SSI. Patients with a reported penicillin or cephalosporin allergy were more likely to develop an SSI compared to patients who did not report an allergy to penicillin or cephalosporins (adjusted odds ratio, 3.26; 95% confidence interval, 2.71-3.93). Surgical prophylaxis did not have significant EMM on this association.

CONCLUSIONS

Patients who reported a penicillin or cephalosporin allergy had higher odds of developing an SSI than nonallergic patients. However, the increase in odds is not completely mediated by the type of surgical prophylaxis. Instead, a reported allergy may be a surrogate marker for a more complicated patient population.

Assessment of the Frequency of Dual Allergy to Penicillins and Cefazolin: A Systematic Review and Meta-analysis

Importance

Cefazolin is the preoperative antibiotic of choice because it is safer and more efficacious than second-line alternatives. Surgical patients labeled as having penicillin allergy are less likely to prophylactically receive cefazolin and more likely to receive clindamycin or vancomycin, which results in higher rates of surgical site infections.

Objective

To examine the incidence of dual allergy to cefazolin and natural penicillins.

Data Sources

MEDLINE/PubMed, Web of Science, and Embase were searched without language restrictions for relevant articles published from database inception until July 31, 2020.

Study Selection

In this systematic review and meta-analysis, a search of MEDLINE/PubMed, Web of Science, and Embase was performed for articles published from database inception to July 31, 2020, for studies that included patients who had index allergies to a natural penicillin and were tested for tolerability to cefazolin or that included patients who had index allergies to cefazolin and were tested for tolerability to a natural penicillin. A total of 3228 studies were identified and 2911 were screened for inclusion.

Data Extraction and Synthesis

Data were independently extracted by 2 authors. Bayesian meta-analysis was used to estimate the frequency of allergic reactions.

Main Outcomes and Measures

Dual allergy to cefazolin and a natural penicillin.

Results

Seventy-seven unique studies met the eligibility criteria, yielding 6147 patients. Cefazolin allergy was identified in 44 participants with a history of penicillin allergy, resulting in a dual allergy meta-analytical frequency of 0.7% (95% credible interval [CrI], 0.1%-1.7%; I2 = 74.9%). Such frequency was lower for participants with unconfirmed (0.6%; 95% CrI, 0.1%-1.3%; I2 = 54.3%) than for those with confirmed penicillin allergy (3.0%; 95% CrI, 0.01%-17.0%; I2 = 88.2%). Thirteen studies exclusively assessed surgical patients (n = 3884), among whom 0.7% (95% CrI, 0%-3.3%; I2 = 85.5%) had confirmed allergy to cefazolin. Low heterogeneity was observed for studies of patients with unconfirmed penicillin allergy who had been exposed to perioperative cefazolin (0.1%; 95% CrI, 0.1%-0.3%; I2 = 13.1%). Penicillin allergy was confirmed in 16 participants with a history of cefazolin allergy, resulting in a meta-analytical frequency of 3.7% (95% CrI, 0.03%-13.3%; I2 = 64.4%). The frequency of penicillin allergy was 4.4% (95% CrI, 0%-23.0%; I2 = 75%) for the 8 studies that exclusively assessed surgical patients allergic to cefazolin.

Conclusions and Relevance

These findings suggest that most patients with a penicillin allergy history may safely receive cefazolin. The exception is patients with confirmed penicillin allergy in whom additional care is warranted.

Is Patient-reported Penicillin Allergy Independently Associated with Increased Risk of Prosthetic Joint Infection After Total Joint Arthroplasty of the Hip, Knee, and Shoulder?

BACKGROUND

Patients with a patient-reported penicillin allergy may be at greater risk for postoperative prosthetic joint infection (PJI) after total joint arthroplasty of the hip, knee, or shoulder. The increased risk of PJI in these patients has been attributed to these patients receiving a less-effective perioperative antibiotic. However, prior reports did not fully address the clinical characteristics of these unique patients, who may inherently be at greater risk of having a PJI, which may confound prior findings.

QUESTIONS/PURPOSES

After controlling for risk factors for PJI such as BMI, anxiety, depression, and other comorbidities, we asked: Are patients with a patient-reported penicillin allergy more likely to have a PJI after THA, TKA, or total shoulder arthroplasty than patients without such a reported allergy?

METHODS

We queried patient records from 2010 to 2017 from a nationwide administrative claims database of 122 million patients to adequately power an investigation comparing the 1-year incidence of PJI after TKA, total shoulder arthroplasty, and THA in patients with patient-reported penicillin allergy versus patients without a patient-reported penicillin allergy. Operative treatments for deep joint infection, identified by Current Procedural Terminology and ICD-9 and ICD-10 codes were used as a surrogate for PJI. Clinical characteristics such as age, sex, BMI, length of stay, and Charlson comorbidity index and specific comorbidities including alcohol abuse, anemia, anxiety, cardiac disease, diabetes, immunocompromised status, rheumatoid arthritis, depression, liver disease, chronic kidney disease, tobacco use, and peripheral vascular disease were queried for each study group. The odds of PJI within 1 year of THA, TKA, or total shoulder arthroplasty were compared using multiple logistic regression after adjusting for potential confounders.

RESULTS

After adjusting for potential confounding factors such as BMI, anxiety, depression and other comorbidities, we found that patient-reported penicillin allergy was independently associated with an increased odds of PJI after TKA (odds ratio 1.3 [95% confidence interval 1.1 to 1.4]; p < 0.01) and total shoulder arthroplasty (OR 3.9 [95% CI 2.7 to 5.4]; p < 0.01). However, patient-reported penicillin allergy was not independently associated with an increased odds of PJI after THA (OR 1.1 [95% CI 0.9 to 1.3]; p = 0.36) after controlling for the same risk factors.

CONCLUSIONS

In this study, we found that patients with patient-reported penicillin allergy were at an increased risk for PJI after TKA and total shoulder arthroplasty, which we suspect-but cannot prove-is likely a function of those patients receiving a second-line antibiotic for presurgical prophylaxis. Since prior research has found that many patients listed in medical records as having a penicillin allergy are in fact not allergic to penicillin, we suggest that surgeons consider preoperative allergy testing, such as using an intraoperative test dose, to aid in choosing the most appropriate antibiotic choice before knee or shoulder arthroplasty and to amend patient medical records based on testing results. Future studies should determine whether this additional diagnostic maneuver is cost-effective.

LEVEL OF EVIDENCE

Level III, therapeutic study.

β-Lactam allergy and risk of multidrug-resistant bacteria in the intensive care unit: A cohort study

Patients identified as allergic to β-lactams are frequently exposed to treatment with broad-spectrum antibiotics. However, the risk of carriage of extended-spectrum β-lactamase (ESBL)-producing isolates in this population has been poorly investigated. The aim of this study was to evaluate the characteristics and clinical outcomes of patients admitted to the intensive care unit (ICU) with and without declared β-lactam allergy at admission. A retrospective monocentric study was performed including adult patients admitted to the ICU between 2007 and 2012. The presence of multidrug-resistant bacteria was documented in rectal and nasal swabs at admission and discharge. Patients labelled allergic to β-lactams and unlabelled patients were compared. Patients labelled allergic had significantly higher rates of ESBL at admission (13.3% vs. 4.3%; P = 0.0220) and discharge (20.0% vs. 9.0%; P = 0.0460) compared with unlabelled patients, but no significant difference in rates of ESBL acquisition in the ICU was detected. No differences in mortality, duration of hospitalisation or typical risk factors for ESBL acquisition (intubation, central venous catheter and duration of hospitalisation) were reported. No differences in carriage of methicillin-resistant Staphylococcus aureus were detected. This study showed that patients with declared β-lactam allergy had a higher risk of ESBL carriage at ICU admission and discharge.