Efficacy of Non-Beta-lactam Antibiotics for Prevention of Cesarean Delivery Surgical Site Infections

Beta-lactam allergy risk stratification in a maternity population in Australia: Scope for allergy de-labelling

BACKGROUND

Unconfirmed beta-lactam allergy in pregnant people has been associated with higher morbidity, unnecessary exposure to broad-spectrum antibiotics and prolonged hospitalisation. There are no published data on beta-lactam allergies in pregnant people in Australia.

AIMS

The aim was to describe patient-reported beta-lactam allergies and appropriateness for antibiotic allergy de-labelling in a maternity cohort in Australia.

METHODS

Maternity patients aged ≥18 years admitted to our institution between March 2021 and June 2021 with a beta-lactam allergy documented in their electronic medical record were interviewed for details of their allergy. The documented allergies were compared to the allergy history obtained from the interview. Severity of the allergy was rated, and appropriateness for allergy de-labelling was assessed using the Victorian Therapeutics Advisory Group beta-lactam antibiotic allergy assessment tool.

RESULTS

One hundred and fifty-three beta-lactam allergies (182 reactions) were reported by 145 patients. Penicillin class antibiotics were the most frequently implicated, including unspecified penicillins (95/153, 62%), amoxicillin (19/153, 13%) and amoxicillin-clavulanate (8/153, 5%). Allergy documentation required amending in 52 of 145 patients (36%); 85 of 153 (56%) of the beta-lactam allergies were considered low risk and potentially appropriate for direct oral re-challenge.

CONCLUSION

Beta-lactam allergies were inaccurately documented in more than one third of the maternity patients included in our study. As such, education of maternity care providers about the importance of accurate allergy history taking remains an urgent unmet need. Furthermore, allergy assessment and de-labelling during pregnancy should be considered in maternity patients to optimise antibiotic prescribing and to improve maternal and neonatal health outcomes.

Pregnant Patients with a Documented History of Penicillin Allergy and Associated Maternal and Neonatal Outcomes at a Tertiary Care Center

OBJECTIVE

Pregnant individuals are likely to need antibiotics during the peripartum period. For pregnant individuals who report a history of penicillin allergy, non-β-lactam antibiotics are often administered. Compared with first-line β-lactam antibiotics, alternative antibiotics can be less effective, more toxic, and more costly. It remains unclear if being labeled with a penicillin allergy is associated with adverse maternal and neonatal outcomes.

STUDY DESIGN

We conducted a retrospective cohort study of all pregnant patients who delivered a viable singleton between 24 and 42 weeks of gestation at a large academic hospital from 2013 to 2021. We compared patients who had a documented penicillin allergy history in their electronic medical record versus those who did not and examined whether there were significant differences in maternal outcomes and neonatal outcomes. Bivariable and multivariable analyses were performed.

RESULTS

Of 41,943 eligible deliveries included in the analysis, 4,705 (11.2%) patients had a penicillin allergy history documented in their electronic medical record and 37,238 (88.8%) did not. Even after adjusting for potential confounders, patients with a documented penicillin allergy had a higher risk of postpartum endometritis (adjusted odds ratio [aOR]: 1.46; 95% confidence interval [CI]: 1.01-2.11) and a higher risk of their neonates having a postnatal hospital stay lasting more than 72 hours (aOR: 1.10; 95% CI: 1.02-1.18). There were no significant differences seen in the other maternal and neonatal outcomes in both bivariable and multivariable analyses.

CONCLUSION

Pregnant patients who are labeled as having a penicillin allergy are more likely to have postpartum endometritis, and neonates born to mothers who are labeled as having a penicillin allergy are more likely to have a postnatal hospital stay lasting more than 72 hours. There were no other significant differences seen in pregnant patients and their newborns whether they were labeled as having a penicillin allergy history or not. However, pregnant individuals with a penicillin allergy documented in their medical record were significantly more likely to receive alternative non-β lactam antibiotics, and may have benefitted from having more details of their allergy history available as well as proper allergy verification with testing.

KEY POINTS

· It is unclear whether pregnant individuals labeled with penicillin allergies have worse obstetric outcomes.. · These individuals were significantly more likely to have endometritis and their newborns hospitalized for >72 hours.. · They were significantly more likely to receive alternative non-β lactam antibiotics than those without documented allergies..

Impact of antimicrobial stewardship interventions on peripartum antibiotic prescribing in patients with penicillin allergy

BACKGROUND

Beta-lactam antibiotics (eg, penicillins, cephalosporins, and carbapenems) are preferred for group B streptococcus prophylaxis, intra-amniotic infection, and cesarean surgical site infection prophylaxis. Non-beta-lactam alternatives are associated with inferior efficacy and contribute to higher rates of surgical site infection and longer lengths of stay. Most patients who report a penicillin allergy can tolerate penicillins without any adverse reaction. There are low rates of cross-reactivity between penicillins and other beta-lactams, including cephalosporins and carbapenems. Efforts to evaluate penicillin allergy and promote the use of beta-lactams are needed.

OBJECTIVE

This study aimed to evaluate whether an antimicrobial stewardship intervention improved the use of first-line antibiotics for peripartum indications in patients with a reported penicillin allergy, following updates to institutional guidelines.

STUDY DESIGN

This was a retrospective study of adult patients presenting for vaginal or cesarean delivery at 2 hospitals within a healthcare system. Patients received at least 1 dose of antibiotics for a peripartum indication between May 1, 2018, and October 31, 2018 (preintervention group) and May 1, 2020, to October 31, 2020 (postintervention group). The stewardship intervention bundle, which was implemented between March 2019 and April 2020, included updates to institutional antibiotic guidelines, reclassification of severe penicillin allergy, development of obstetrical prophylaxis and treatment order sets, promotion of allergy referral services, and establishment of a physician champion. The primary outcome was the composite rates of patients with reported penicillin allergy who received a preferred antibiotic for a peripartum indication. The secondary measures included maternal and neonatal outcomes.

RESULTS

A total of 192 patients with a history of documented penicillin allergy were evaluated (96 patients in the preintervention group and 96 patients in the postintervention group). Hives were the most commonly reported index symptom in both groups (40/96 [41.7%] vs 39/96 [40.6%]; P=.883). After stewardship interventions, there was a significant increase in the rate of preferred antibiotic use (33/96 [34.3%] vs 81/96 [84.3%]; P<.001). The effect was the greatest in patients with nonsevere allergy (14/76 [18.4%] vs 68/82 [82.9%]; P<.001). There was no difference in the rates of postpartum endometritis, 30-day readmission, 90-day surgical site infection, or neonatal early-onset sepsis between the pre- and postintervention groups. Of note, 1 patient in the postintervention group experienced itching, and another patient developed a rash, both of which resolved with medical management.

CONCLUSION

A comprehensive antibiotic stewardship intervention was associated with a 50% increase in the use of preferred antibiotics for peripartum indications in patients with penicillin allergy. Allergic reactions with first-line beta-lactams were minimal and manageable.

Optimizing Cefazolin Prophylaxis in Obstetrical Patients with Reported Beta-Lactam Allergy Undergoing Cesarean Delivery

OBJECTIVE

Evaluate the impact of an allergy history guided algorithm for optimizing peri-operative cefazolin use in patients with reported beta-lactam allergy undergoing cesarean delivery.

METHODS

The Allergy Clarification for Cefazolin Evidence-based Prescribing Tool (ACCEPT) was developed through consensus by allergists, anesthesiologists and infectious diseases specialists, and implemented over a two-month period (December 1, 2018 to January 31, 2019). A segmented regression on monthly cefazolin use was conducted during the baseline (January 1 to November 30, 2018) and intervention (February 1 to December 31, 2019) periods to evaluate the impact of ACCEPT on the monthly use of peri-operative cefazolin in patients with reported beta-lactam allergy undergoing cesarean delivery. The frequency of peri-operative allergic reactions and surgical site infections were collected during both periods.

RESULTS

Of the 3128 eligible women who underwent a cesarean delivery, 282 (9%) reported a beta-lactam allergy. The most common beta-lactam allergens were penicillin (64.3%), amoxicillin (16.0%), and cefaclor (6.0%). The most frequently reported allergic reactions were rash (38.1%), hives (21.4%), and unknown (11.6%). Use of cefazolin increased from 52% (baseline) to 87% during the intervention period. Segmented regression analysis confirmed a statistically significant increase following implementation (incidence rate ratio 1.62, 95% CI 1.19 - 2.21, p=0.002). There was one perioperative allergic reaction in the baseline period and two during the intervention period. Cefazolin use remained high (92%) two years after algorithm implementation.

CONCLUSIONS

Implementation of a simple allergy history guided algorithm in obstetrical patients with reported beta-lactam allergy resulted in a sustained increase in peri-operative cefazolin prophylaxis.

Evidence-based guideline for the prevention and management of perioperative infection

BACKGROUND

We have updated the guideline for preventing and managing perioperative infection in China, given the global issues with antimicrobial resistance and the need to optimize antimicrobial usage and improve hospital infection control levels.

METHODS

We conducted a comprehensive evaluation of the evidence for prevention and management of perioperative infection, based on the concepts of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The strength of recommendations was graded and voted using the Delphi method and the nominal group technique. Revisions were made to the guidelines in response to feedback from the experts.

RESULTS

There were 17 questions prepared, for which 37 recommendations were made. According to the GRADE system, we evaluated the body of evidence for each clinical question. Based on the meta-analysis results, recommendations were graded using the Delphi method to generate useful information.

CONCLUSIONS

This guideline provides evidence to perioperative antimicrobial prophylaxis that increased the rational use of prophylactic antimicrobial use, with substantial improvement in the risk-benefit trade-off.

Management of the Pregnant Patient with Beta-Lactam Allergy

PURPOSE OF REVIEW

We review the literature and discuss the logistics of testing pregnant patients for penicillin allergy.

RECENT FINDINGS

As in the general population, pregnant patients commonly report a penicillin allergy, but most patients are able to tolerate penicillin. Avoidance of beta-lactams in pregnancy is associated with increased morbidity: longer hospitalizations, more frequent infections, and more complications. Penicillin allergy testing is safe in pregnant patients, and obstetricians are eager for allergists to offer this procedure to their patients. As allergists, we can improve our patients' health outcomes by offering penicillin allergy testing in our practices. The protocols for testing both with and without skin testing in pregnant patients have been studied, and future studies will continue to clarify the safety and efficacy of penicillin allergy delabeling in pregnant patients.

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.

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.

Penicillin Allergy Assessment in Pregnancy: Safety and Impact on Antibiotic Use

BACKGROUND

Penicillin and other beta-lactam antibiotics are recommended for group B Streptococcus and cesarean section prophylaxis, but approximately 10% of pregnant patients report a penicillin allergy.

OBJECTIVE

To assess the safety and impact of penicillin allergy evaluation in pregnant patients.

METHODS

In this retrospective study of obstetrician-ordered Allergy/Immunology (AI) electronic consultations (e-consults) from September 20, 2017 through December 31, 2019, we reviewed the electronic health record for e-consult recommendation; patient demographic, obstetric, and allergy histories; and peripartum antibiotic utilization with indication. For patients whose electronic consultation recommended an in-person AI evaluation, testing outcomes were determined, and multivariable logistic regression models were used to compare antibiotic use between patients who did and did not receive an in-person AI evaluation.

RESULTS

Of 389 obstetrician-ordered e-consults, 363 (93%) recommended an in-person AI evaluation; of these, 222 (61%) patients received an in-person AI evaluation. Of 220 (99%) patients skin tested, 209 (95%) had their penicillin allergy label safely removed. Compared with patients who did not receive an in-person AI evaluation despite it being recommended (n = 141), patients with in-person AI evaluation (n = 222) had reduced peripartum vancomycin (adjusted odds ratio [aOR], 0.07; 95% CI, 0.01-0.33), clindamycin (aOR, 0.17; 95% CI, 0.08-0.34), and gentamicin (aOR, 0.39; 95% CI, 0.19-0.78) use and increased penicillin (aOR, 18.0; 95% CI, 6.30-51.2) use. The fully AI evaluated patients had increased first-line antibiotic prophylaxis for group B Streptococcus (aOR, 26.9; 95% CI, 6.32-114) and cesarean section (aOR, 1.94; 95% CI, 1.06-3.52).

CONCLUSIONS

In a sample of 220 pregnant patients with penicillin allergy histories and in-person AI evaluation, penicillin allergy testing was safe and associated with significantly reduced broad-spectrum antibiotic use and increased first-line beta-lactam antibiotic use.

Skin testing and oral amoxicillin challenge in the outpatient allergy and clinical immunology clinic in pregnant women with penicillin allergy

BACKGROUND

Penicillin allergy is frequently reported. In pregnant women, reported penicillin allergy is associated with negative health outcomes and suboptimal group B streptococcal prophylaxis. For individuals having penicillin allergy, skin testing followed by an observed oral challenge is recommended. Previous data indicate a low risk of adverse reaction with skin testing in pregnant women, but the subsequent oral challenge was not routinely pursued.

OBJECTIVE

To determine whether skin testing followed by the outpatient oral challenge is tolerated by pregnant women.

METHODS

We conducted a retrospective review of all pregnant women who underwent penicillin allergy evaluation at an outpatient allergy and clinical immunology clinic. The patients underwent oral amoxicillin challenges based on the discretion of the allergy provider. We evaluated the index reaction history, skin test results, oral challenge results, and subsequent antibiotic exposure.

RESULTS

A total of 46 pregnant women underwent skin testing without adverse reactions, of whom 44 patients (95.6%) received negative results. A total of 18 women (39%) completed an oral challenge without adverse reactions. Patients challenged vs not challenged did not differ in patient age, gestational age, latency since index reaction, or reaction history risk level. Notably, 28 women received intrapartum antibiotics. There was no difference in intrapartum antibiotic administration between those who did or who did not complete an in-office oral challenge (P = .90).

CONCLUSION

Penicillin skin testing and oral challenge in pregnant women can safely be performed in the outpatient setting. There was no difference in the intrapartum antibiotic use between women who were and those who were not challenged. Further research is needed to determine the utility of oral challenge in pregnant patients.

Reducing Cesarean Delivery Surgical Site Complications

Cesarean delivery (CD) wound complications disrupt the time a mother spends with her newborn. Surgical site infections (SSI) may result in unplanned office visits, emergency room visits, and hospital readmissions. Despite increasing attention to preoperative preparation, the CD SSI rate remains high. Local practices must be evaluated, and new methods to reduce CD SSI must be used.

Time Has Come for Routine Penicillin Allergy Testing in Obstetrics

Objective  This study evaluates penicillin allergy during pregnancy to estimate the proportion that could benefit from penicillin allergy testing. Study Design  Retrospective cohort study of women with penicillin allergy that delivered from January 1, 2018 to December 31, 2018. Results  Among 6,321 deliveries, 446 (7%) were identified with penicillin allergy. Nine percent (41/446) had no documentation of allergy severity. Allergies associated with intolerance, low, moderate, or high risk of anaphylaxis were reported in 6% (25/446), 40% (177/446), 32% (142/446), and 14% (61/446), respectively. Nearly 74% (330/446) received an antibiotic either antepartum, at delivery, or within 6 weeks of postpartum. The majority of women, 81% (360/446) (i.e., undocumented reactions, low, or moderate risk of anaphylaxis) would have been eligible for penicillin allergy testing. Greater appropriate utilization of antibiotics occurred in women with a high 80% (39/49) or moderate risk of anaphylaxis 70% (79/112) versus low risk of anaphylaxis 55% (64/117), history of intolerance 40% (8/20), or undocumented reaction 19% (6/32), p  ≤ 0.01. Conclusion  Most women who report a penicillin allergy during pregnancy would be candidates for penicillin allergy testing. With the high rate of antibiotic interventions in pregnant women who report a penicillin allergy, consideration should be given for penicillin allergy assessment.

Preoperative cefazolin rather than clindamycin or metronidazole is associated with lower postpartum infection among women with chorioamnionitis delivering by cesarean delivery

BACKGROUND

The optimal antibiotic regimen to prevent maternal postpartum infection among high-risk women treated for chorioamnionitis delivering by cesarean delivery remains to be defined. Emerging data suggest that cefazolin decreases the risk of cesarean surgical site infection.

OBJECTIVE

To investigate whether intrapartum antibiotic therapy with cefazolin versus the current standard clindamycin or metronidazole decreases the risk of postpartum infectious morbidity among women delivering by cesarean delivery who were receiving a base regimen of ampicillin or penicillin with gentamicin for chorioamnionitis.

MATERIALS AND METHODS

A secondary analysis from the Maternal-Fetal Medicine Units Network (MFMU) Cesarean Registry. We included women who delivered by cesarean delivery with presumptive chorioamnionitis (intrapartum fever >100.4°F and receipt of intrapartum antibiotics). All women received a base regimen of penicillin or ampicillin with gentamicin. We compared antibiotic therapy with cefazolin versus clindamycin or metronidazole. The primary outcome was a composite of postpartum maternal infection, including endometritis and surgical site infection. Multivariable logistic regression was used, adjusting for age, parity, race/ethnicity, insurance, body mass index at delivery, tobacco use, pregestational diabetes, American Society of Anesthesiologists classification, trial of labor prior to cesarean delivery, and postpartum antibiotics.

RESULTS

Among 1105 women with presumptive chorioamnionitis who delivered by cesarean delivery, 22.0% (n = 244) received cefazolin and 77.9% (n = 861) received clindamycin or metronidazole. Most women were in labor prior to cesarean delivery (93.8%) and received postpartum antibiotics (88.4%). Almost one-tenth (9.5%) were diagnosed with a postpartum infection, most commonly endometritis (80.9%), followed by surgical site infection (20.9%) (not mutually exclusive). Women treated with cefazolin rather than clindamycin or metronidazole had lower odds of postpartum infectious morbidity (adjusted odds ratio, 0.49; 95% confidence interval, 0.26-0.90). This association held when the outcome was restricted to surgical site infection (adjusted odds ratio, 0.11; 95% confidence interval, 0.01-0.92) but not endometritis. Similar results were observed with propensity score analysis.

CONCLUSION

Among women delivering by cesarean delivery who were treated for chorioamnionitis, additional antibiotic therapy with cefazolin decreased the risk of postpartum infection, primarily surgical site infection, compared to the current standard clindamycin or metronidazole.