Background Anaphylaxis during anaesthesia is a serious complication for patients and anaesthetists. Methods The 6th National Audit Project (NAP6) on perioperative anaphylaxis collected and reviewed 266 reports of Grades 3–5 anaphylaxis over 1 yr from all NHS hospitals in the UK. Results The estimated incidence was ≈1:10 000 anaesthetics. Case exclusion because of reporting delays or incomplete data means true incidence might be ≈70% higher. The distribution of 199 identified culprit agents included antibiotics (94), neuromuscular blocking agents (65), chlorhexidine (18), and Patent Blue dye (9). Teicoplanin comprised 12% of antibiotic exposures, but caused 38% of antibiotic-induced anaphylaxis. Eighteen patients reacted to an antibiotic test dose. Succinylcholine-induced anaphylaxis, mainly presenting with bronchospasm, was two-fold more likely than other neuromuscular blocking agents. Atracurium-induced anaphylaxis mainly presented with hypotension. Non-depolarising neuromuscular blocking agents had similar incidences to each other. There were no reports of local anaesthetic or latex-induced anaphylaxis. The commonest presenting features were hypotension (46%), bronchospasm (18%), tachycardia (9.8%), oxygen desaturation (4.7%), bradycardia (3%), and reduced/absent capnography trace (2.3%). All patients were hypotensive during the episode. Onset was rapid for neuromuscular blocking agents and antibiotics, but delayed with chlorhexidine and Patent Blue dye. There were 10 deaths and 40 cardiac arrests. Pulseless electrical activity was the usual type of cardiac arrest, often with bradycardia. Poor outcomes were associated with increased ASA, obesity, beta blocker, and angiotensin-converting enzyme inhibitor medication. Seventy per cent of cases were reported to the hospital incident reporting system, and only 24% to Medicines and Healthcare products Regulatory Agency via the Yellow Card Scheme. Conclusions The overall incidence of perioperative anaphylaxis was estimated to be 1 in 10 000 anaesthetics.

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Anaesthesia, surgery, and life-threatening allergic reactions: epidemiology and clinical features of perioperative anaphylaxis in the 6th National Audit Project (NAP6)

The Standards of Care Committee of the British Society for Allergy and Clinical Immunology (BSACI) and an expert panel have prepared this guidance for the management of immediate and non-immediate allergic reactions to penicillins and other beta-lactams. The guideline is intended for UK specialists in both adult and paediatric allergy and for other clinicians practising allergy in secondary and tertiary care. The recommendations are evidence based, but where evidence is lacking, the panel reached consensus. During the development of the guideline, all BSACI members were consulted using a Web-based process and all comments carefully considered. Included in the guideline are epidemiology of allergic reactions to beta-lactams, molecular structure, formulations available in the UK and a description of known beta-lactam antigenic determinants. Sections on the value and limitations of clinical history, skin testing and laboratory investigations for both penicillins and cephalosporins are included. Cross-reactivity between penicillins and cephalosporins is discussed in detail. Recommendations on oral provocation and desensitization procedures have been made. Guidance for beta-lactam allergy in children is given in a separate section. An algorithm to help the clinician in the diagnosis of patients with a history of penicillin allergy has also been included.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/cea.12468

Management of allergy to penicillins and other beta‐lactams

Background
A documented penicillin allergy is associated with increased morbidity including length of hospital stay and an increased incidence of resistant infections attributed to use of broader-spectrum antibiotics. The aim of the systematic review was to identify whether inpatient penicillin allergy testing affected clinical outcomes during hospitalization.

Methods
We performed an electronic search of Ovid MEDLINE/PubMed, Embase, Web of Science, Scopus, and the Cochrane Library over the past 20 years. Inpatients having a documented penicillin allergy that underwent penicillin allergy testing were included.

Results
Twenty-four studies met eligibility criteria. Study sample size was between 24 and 252 patients in exclusively inpatient cohorts. Penicillin skin testing (PST) with or without oral amoxicillin challenge was the main intervention described (18 studies). The population-weighted mean for a negative PST was 95.1% [CI 93.8-96.1]. Inpatient penicillin allergy testing led to a change in antibiotic selection that was greater in the intensive care unit (77.97% [CI 72.0-83.1] vs 54.73% [CI 51.2-58.2], P<.01). An increased prescription of penicillin (range 9.9%-49%) and cephalosporin (range 10.7%-48%) antibiotics was reported. Vancomycin and fluoroquinolone use was decreased. Inpatient penicillin allergy testing was associated with decreased healthcare cost in four studies.

Conclusions
Inpatient penicillin allergy testing is safe and effective in ruling out penicillin allergy. The rate of negative tests is comparable to outpatient and perioperative data. Patients with a documented penicillin allergy who require penicillin should be tested during hospitalization given its benefit for individual patient outcomes and antibiotic stewardship.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/all.13168

Clinical outcomes following inpatient penicillin allergy testing: A systematic review and meta-analysis.

https://www.jaci-inpractice.org/article/S2213-2198(13)00082-2/pdf

Treatment of patients with a history of penicillin allergy in a large tertiary-care academic hospital

Study Objective. To determine the impact of having an antimicrobial allergy label in the medical record on clinical outcomes in hospitalized patients.

Design. Retrospective cohort study.

Setting. Urban academic teaching hospital.

Patients. A total of 11,872 adults admitted to nonsurgical patient care wards who received at least one antimicrobial between August 1, 2007, and July 31, 2008; of these patients, 1324 (11.2%) had an antimicrobial allergy label and 10,548 (88.8%) did not have an allergy label documented in the medical record.

Measurements and Main Results. The following clinical outcomes were compared in patients with allergy labels versus patients without allergy labels: length of stay, admission to the intensive care unit (ICU), number of antimicrobials received during hospitalization, readmission within 4 weeks of hospital discharge, and death during hospitalization. Presence of an allergy label in the medical record was associated with increased length of stay, a higher ICU admission rate, receipt of more than one antimicrobial, and a higher mortality rate during the hospitalization. Logistic regression models were used to assess the association of allergy label with these outcomes while adjusting for covariates (age group, sex, surgery during hospitalization, and season of admission); multiple regression was used to model the association of allergy label with length of stay. On average, length of stay was 1.21 days (unadjusted) and 1.16 days (adjusted for covariates) longer in patients with allergy labels. The likelihood of an ICU admission were 1.4 times (adjusted odds ratio [OR 1.42, 95% confidence interval [CI 1.21–1.67) higher in patients with allergy labels. Presence of an allergy label was also associated with receipt of more than one antibiotic during the hospitalization (crude OR 1.61, 95% CI 1.43–1.81) and a 1.6fold higher risk of dying during the hospitalization (crude OR 1.56, 95% CI 1.20–2.04). Presence of an allergy label was not associated with an increased risk of readmission within 4 weeks of discharge (adjusted OR 0.71, 95% CI 0.63–0.80).

Conclusion. Presence of an allergy label in the medical record was associated with increased length of hospital stay and worse clinical outcomes compared with no allergy label in hospitalized patients treated with antimicrobials.

Impact of an antimicrobial allergy label in the medical record on clinical outcomes in hospitalized patients.

Summary
Background Penicillin allergy poses a major problem in the management of infectious diseases.

Objective We estimated the costs and usage of antibiotic treatment of ‘penicillin-allergic’ patients in comparison to non-allergic patients in a tertiary care hospital.

Materials and methods The study was based on the records of 118 randomly chosen in-hospital patients labelled as being ‘allergic to penicillin’ and who were treated with antibiotics. The antibiotic selection and cost of the patients with alleged penicillin allergy were compared to 118 matched patients without an antibiotic allergy (controls).

Results During in-hospital treatment, the mean antibiotic cost for penicillin-allergic patients was 63% higher than the cost for the controls. In addition, there was a 38% higher cost of the recommended anti-microbial treatment regimen to be followed upon discharge by the former compared to the latter.

Conclusions Penicillin-allergic patients were more likely to receive broader spectrum antibiotics compared to the non-allergic ones. Since many of the patients who are labelled as being ‘allergic to penicillin’ are, in fact, not allergic to it, inaccurate reporting of penicillin allergies may have costly economic and epidemiologic repercussions in addition to more toxic effects which can occur when choosing alternative drugs in case of penicillin allergy.

I. Holtzer

Papers

The economic burden of antibiotic treatment of penicillin-allergic patients in internal medicine wards of a general tertiary care hospital.