Management and treatment of perioperative hypersensitivity.

PURPOSE OF REVIEW: Perioperative hypersensitivity reactions are rare but potentially catastrophic events. This review acts to summarize recent recommendations for both immediate and poststabilization management of suspected reactions, alongside practical advice for anaesthetists who may be faced with these events. RECENT FINDINGS: Prompt treatment is essential but may be hampered by delay in recognition. This can occur because there are multiple differential diagnoses for the observed clinical signs as well as variations in clinical presentation. Resuscitation is dependent on the use of adrenaline and fluids. Adrenaline should be administered in small, titrated intravenous boluses. Low-dose infusions should be commenced early if the response to boluses is poor. Large volume fluid resuscitation may be required to maintain adequate circulating volume. Chest compressions are recommended when there is evidence of inadequate perfusion, rather than waiting until cardiac arrest is confirmed. Antihistamines and corticosteroids are no longer recommended in the immediate management phase. Once the patient has been stabilized, it is important to obtain serial tryptase concentrations to aid the subsequent clinic investigation. The decision to proceed or abandon surgery will be based on an individual risk-benefit analysis. All cases of suspected perioperative hypersensitivity, including fatal cases, must be referred for formal investigation. SUMMARY: There have been recent updates to management guidelines in perioperative hypersensitivity. Treatment algorithms, treatment packs and referral packs can all help the anaesthetist manage these complex cases, aid the subsequent investigation and ensure patient safety in the future.

A multicentre observational study to investigate feasibility of a direct oral penicillin challenge in de-labelling 'low risk' patients with penicillin allergy by non-allergy healthcare professionals (SPACE study): Implications for healthcare systems.

OBJECTIVE: The huge burden of inaccurate penicillin allergy labels (PALs) is an important driver of antimicrobial resistance. This is magnified by insufficient allergy specialists and lack of 'point-of-care' tests. We investigated the feasibility of non-allergy healthcare professionals (HCPs) delivering direct oral penicillin challenges (DPCs) for penicillin allergy de-labelling. METHODS: This prospective observational study was conducted in three hospitals in England across three settings (acute medical, pre-surgical and haematology-oncology). Patients with a PAL were screened and stratified as low risk/high risk. Low risk patients (non-immune mediated symptoms, benign rash, tolerated amoxicillin since and family history) underwent a DPC. RESULTS: N = 2257 PALs were screened, 1054 were eligible; 643 were approached, 373 declined, 270 consented and 259 risk stratified (low risk = 155; high risk = 104). One hundred and twenty-six low risk patients underwent DPC, 122 (96.8%) were de-labelled with no serious allergic reactions. Conversion rate from screening-to-consent was 12% [3.3% and 17.9% in acute and elective settings respectively; odds ratios for consent were 3.42 (p < 0.001) and 5.53 (p < 0.001) in haematology-oncology and pre-surgical setting respectively. Common reasons for failure to progress in the study included difficulty in reaching patients, clinical instability/medical reasons, lacking capacity to consent and psychological factors. INTERPRETATION: DPCs can be delivered by non-allergy HCPs. A high proportion of patients with PALs did not progress in the study pathway. Strategies to deliver DPC at optimal points of the care pathway are needed to enhance uptake. Elective settings offer greater opportunities than acute settings for DPC. The safety and simplicity of DPCs lends itself to adoption by healthcare systems beyond the UK, including in resource-limited settings.

Pholcodine and allergy to neuromuscular blocking agents: where are we and how did we get here?

Despite the purported link between pholcodine and neuromuscular blocking agent allergy, screening for prior pholcodine use offers no practical benefit to patients, and anaesthetists should continue to use a neuromuscular blocking agent where this is clinically indicated.

Treatment of perioperative anaphylaxis: room for improvement?

Perioperative anaphylaxis is associated with significant morbidity and mortality. Prompt and appropriate treatment is required for optimal outcome. Despite general knowledge of this condition, delays occur in the administration of epinephrine and in particular the use of i.v. route of administration in the perioperative setting. Barriers should be addressed to allow prompt utilisation of i.v. epinephrine in perioperative anaphylaxis.

Perioperative Hypersensitivity Evaluation and Management: A Practical Approach.

Perioperative hypersensitivity (POH) is an uncommon, potentially life-threatening event. Identification of POH can be difficult given the lack of familiarity, physiological effects of anesthesia, draping of the patient during surgery, and potential nonimmunological factors contributing to signs and symptoms. Given the unique nature and large number of medications administered in the perioperative setting, evaluation of POH can be challenging. In this paper, we present a practical approach to management with an emphasis on understanding what happens in the operating room, the overlap of signs and symptoms between nonimmunological and immunological reactions, acute management, and subsequent evaluation. In addition, we provide a strategy for further review of an initially negative evaluation and emphasize the importance of establishing management plans for the patient as well as providing recommendations to the medical, anesthesia, and surgical teams for future surgeries. A critical factor for successful management at all points in the process is a close collaboration between the anesthesia and the allergy teams.

BSACI guideline for the set-up of penicillin allergy de-labelling services by non-allergists working in a hospital setting.

The Standards of Care Committee of the British Society for Allergy and Clinical Immunology (BSACI) and a committee of experts and key stakeholders have developed this guideline for the evaluation and testing of patients with an unsubstantiated label of penicillin allergy. The guideline is intended for UK clinicians who are not trained in allergy or immunology, but who wish to develop a penicillin allergy de-labelling service for their patients. It is intended to supplement the BSACI 2015 guideline "Management of allergy to penicillin and other beta-lactams" and therefore does not detail the epidemiology or aetiology of penicillin allergy, as this is covered extensively in the 2015 guideline (1). The guideline is intended for use only in patients with a label of penicillin allergy and does not apply to other beta-lactam allergies. The recommendations include a checklist to identify patients at low risk of allergy and a framework for the conduct of drug provocation testing by non-allergists. There are separate sections for adults and paediatrics within the guideline, in recognition of the common differences in reported allergy history and likelihood of true allergy.

Mandatory vaccination of National Health Service staff against COVID-19: more harm than good?

Despite the clear benefits of vaccination against COVID-19, there was significant unease relating to the government policy of mandatory vaccination of health and care staff in England and the potential inequities this may lead to. Healthcare staff, and in particular doctors, speaking out on this issue may have inadvertently provided a narrative, which undermined the objective of achieving widespread vaccination of populations against this serious disease. The recent reversal of this policy may not mark the end of this debate amongst health and social care staff.

Mixed-methods evaluation of a behavioural intervention package to identify and amend incorrect penicillin allergy records in UK general practice.

OBJECTIVES: About 6% of the UK general practice population has a record of a penicillin allergy but fewer than 10% of these are likely to be truly allergic. In the ALABAMA (Allergy Antibiotics and Microbial resistance) feasibility trial, primary care patients with penicillin allergy were randomised to penicillin allergy assessment pathway or usual care to assess the effect on health outcomes. A behavioural intervention package was developed to aid delabelling. This study aimed to investigate patients' and clinicians' views of penicillin allergy testing (PAT). DESIGN: We conducted a mixed-methods process evaluation embedded within the ALABAMA trial, which included a clinician survey, a patient survey (at baseline and follow-up) and semistructured interviews with patients and clinicians. SETTINGS: The study was conducted in primary care, as part of the feasibility stage of the ALABAMA trial. PARTICIPANTS: Patients and primary care clinicians. RESULTS: Clinicians (N=53; 52.2%) were positive about PAT and its potential value but did not have previous experience of referring patients for a PAT and were unsure whether patients would take penicillin after a negative allergy test. Patients (N=36; 46%) were unsure whether they were severely allergic to penicillin and did not fear a severe allergic reaction to penicillin. Clinician interviews showed that they were already aware of the benefit of PAT. Interviews with patients suggested the importance of safety as patients valued having numerous opportunities to address their concerns about safety of the test. CONCLUSIONS: This study highlights the positive effects of the ALABAMA behavioural intervention for both patients and clinicians. TRIAL REGISTRATION NUMBER: NCT04108637; ISRCTN20579216; Pre-results.

DALES, Drug Allergy Labels in Elective Surgical patients: a prospective, multicentre cross-sectional study of prevalence, nature and anaesthetists' approach to management.

BACKGROUND: We sought to define the prevalence and nature of patient-reported drug allergies, determine their impact on prescribing, and explore drug allergy knowledge and attitudes amongst anaesthetists. METHODS: We performed a prospective cross-sectional study in 213 UK hospitals in 2018. Elective surgical patients were interviewed, with a detailed allergy history taken in those self-reporting drug allergy. Anaesthetists completed a questionnaire concerning perioperative drug allergy. RESULTS: Of 21 219 patients included, 6214 (29.3 %) (95% confidence interval [CI]: 28.7-29.9) reported drug allergy. Antibiotics, NSAIDs, and opioids were the most frequently implicated agents. Of a total of 8755 reactions, 2462 (28.1%) (95% CI: 29.2-31.1) were categorised as high risk for representing genuine allergy after risk stratification. A history suggestive of chronic spontaneous urticaria significantly increased the risk of reporting drug allergy (odds ratio 2.68; 95% CI: 2.4-3; P<0.01). Of 4756 anaesthetists completing the questionnaire, 1473 (31%) (95% CI: 29.7-32.3) routinely discuss perioperative allergy risk with patients. Prescribing habits in the presence of drug allergy labels differ depending on the implicated agent. Most anaesthetists (4678/4697; 99.6%) (95% CI: 99.4-99.8) prescribe opioids when reactions are consistent with side-effects, although 2269/4697 (48%) (95% CI: 46.9-49.7) would avoid the specific opioid reported. CONCLUSIONS: Almost 30% of UK elective surgical patients report a history of drug allergies, but the majority of reported reactions are likely to be non-allergic reactions. Allergy labels can impact on perioperative prescribing through avoidance of important drugs and use of less effective alternatives. We highlight important knowledge gaps about drug allergy amongst anaesthetists, and the need for improved education around allergy.

Management of penicillin allergy in primary care: a qualitative study with patients and primary care physicians.

BACKGROUND: Six percent of patients are allergic to penicillin according to their medical records. While this designation protects a small number of truly allergic patients from serious reactions, those who are incorrectly labelled may be denied access to recommended first line treatment for many infections. Removal of incorrect penicillin allergy may have positive health consequences for the individual and the general population. We aimed to explore primary care physicians' (PCPs) and patients' views and understanding of penicillin allergy with a focus on clinical management of infections in the face of a penicillin allergy record. METHODS: We conducted an interview study with 31 patients with a penicillin allergy record, and 19 PCPs in the North of England. Data were analysed thematically. RESULTS: Patients made sense of their allergy status by considering the timing and severity of symptoms. Diagnosis of penicillin allergy was reported to be 'imperfect' with PCPs relying on patient reports and incomplete medical records. PCPs and patients often suspected that an allergy record was incorrect, but PCPs were reluctant to change records. PCPs had limited knowledge of allergy services. PCPs often prescribed alternative antibiotics which were easy to identify. Both patients and PCPs differed in the extent to which they were aware of the negative consequences of incorrect penicillin allergy records, their relevance and importance to their lives, and management of penicillin allergy. CONCLUSIONS: PCPs and patients appear insufficiently aware of potential harms associated with incorrect penicillin allergy records. Some of the problems experienced by PCPs could be reduced by ensuring the details of newly diagnosed reactions to antibiotics are clearly documented. In order for PCPs to overturn more incorrect penicillin records through appropriate use of allergy services, more information and training about these services will be needed.

Developing a behavioural intervention package to identify and amend incorrect penicillin allergy records in UK general practice and subsequently change antibiotic use.

OBJECTIVES: To develop a behavioural intervention package to support clinicians and patients to amend incorrect penicillin allergy records in general practice. The intervention aimed to: (1) support clinicians to refer patients for penicillin allergy testing (PAT), (2) support patients to attend for PAT and (3) support clinicians and patients to prescribe or consume penicillin, when indicated, following a negative PAT result. METHODS: Theory-based, evidence-based and person-based approaches were used in the intervention development. We used evidence from a rapid review, two qualitative studies, and expert consultations with the clinical research team to identify the intervention 'guiding principles' and develop an intervention plan. Barriers and facilitators to the target behaviours were mapped to behaviour change theory in order to describe the proposed mechanisms of change. In the final stage, think-aloud interviews were conducted to optimise intervention materials. RESULTS: The collated evidence showed that the key barriers to referral of patients by clinicians were limited experience of referral and limited knowledge of referral criteria and PAT. Barriers for patients attending PAT were lack of knowledge of the benefits of testing and lack of motivation to get tested. The key barriers to the prescription and consumption of first-line penicillin following a negative test result were patient and clinician beliefs about the accuracy of PAT and whether taking penicillin was safe. Intervention materials were designed and developed to address these barriers. CONCLUSIONS: We present a novel behavioural intervention package designed to address the multiple barriers to uptake of PAT in general practice by clinicians and patients. The intervention development details how behaviour change techniques have been incorporated to hypothesise how the intervention is likely to work to help amend incorrect penicillin allergy records. The intervention will go on to be tested in a feasibility trial and randomised controlled trial in England.

DALES, Drug Allergy Labels in Elective Surgical patients: a prospective multicentre cross-sectional study of incidence, risks, and attitudes in penicillin de-labelling strategies.

BACKGROUND: Penicillin allergy is associated with a range of poor health outcomes. Allergy testing can be made simpler by using a direct drug provocation test in patients at low risk of genuine allergy. This approach could allow population-level 'de-labelling'. We sought to determine the incidence and nature of penicillin allergy labels in UK surgical patients and define patient and anaesthetist attitudes towards penicillin allergy testing. METHODS: A prospective cross-sectional questionnaire study was performed in 213 UK hospitals. 'Penicillin allergic' patients were interviewed and risk-stratified. Knowledge and attitudes around penicillin allergy were defined in patients and anaesthetists. RESULTS: Of 21 219 patients, 12% (n=2626) self-reported penicillin allergy; 27% reported low-risk histories potentially suitable for a direct drug provocation test; an additional 40% reported symptoms potentially suitable for a direct drug provocation test after more detailed assessment. Of 4798 anaesthetists, 40% claimed to administer penicillin routinely when they judged the label low risk. Only 47% of anaesthetists would be happy to administer penicillin to a patient previously de-labelled by an allergy specialist using a direct drug provocation test; perceived lack of support was the most common reason for not doing so. CONCLUSIONS: At least 27% of patients with a penicillin allergy label may be suitable for a direct drug provocation test. Anaesthetists demonstrated potentially unsafe prescribing in patients with penicillin allergy labels. More than half of anaesthetists lack confidence in the results of a direct drug provocation tests undertaken by a specialist. Our findings highlight significant barriers to the effective implementation of widespread de-labelling in surgical patients.

Perioperative anaphylaxis: diagnostic challenges and management.

PURPOSE OF REVIEW: Perioperative hypersensitivity reactions can pose diagnostic and management challenges for the anaesthetist. Difficulties in diagnosing hypersensitivity reactions in the perioperative setting are highlighted and recommendations from recent guidelines on the acute management of life-threatening anaphylaxis are presented. RECENT FINDINGS: Anaesthetists play a key role in investigating perioperative hypersensitivity reactions. During a suspected perioperative hypersensitivity event, a serum tryptase level should be measured to help with subsequent allergy investigation. Moreover, anaesthetists can ensure that a high-quality referral is made to allergy clinics by providing thorough documentation of the events, detailing symptoms, treatments, and the chronology of drug administrations. SUMMARY: Perioperative hypersensitivity reactions are rare but can be life-threatening. A high index of suspicion should be maintained for their successful management. Whenever a perioperative hypersensitivity reaction is suspected, close collaboration between anaesthetist and the allergy team investigating the patient is paramount, in order for the patient to be appropriately investigated and have an uneventful anaesthetic in the future.

Drug provocation testing: risk stratification is key.

PURPOSE OF REVIEW: This review aims to describe current best practice and recent advances in the use of risk stratification as a tool for drug provocation testing (DPT). In particular, we focus on the testing of unsubstantiated penicillin allergy labels. RECENT FINDINGS: The inherent risks of DPT are mitigated through careful selection of patients. A detailed history will elicit features of a potentially severe index reaction, as well as significant patient comorbidities which may increase the risks associated with DPT. Such patients require skin testing and/or in vitro testing prior to consideration for a DPT. However, there is increasing evidence that patients without these features may be able to proceed directly to DPT. This has been demonstrated extensively with unsubstantiated penicillin allergy labels, and a variety of risk stratification models have been employed to identify the 'low-risk' patient. Improved outcomes and reduced cost have been demonstrated with such models without compromising patient safety. SUMMARY: Risk stratification tools may enable well-tolerated and effective 'delabelling' of low-risk patients, with less demand on already scarce resources.

Management of suspected immediate perioperative allergic reactions: an international overview and consensus recommendations.

Suspected perioperative allergic reactions are rare but can be life-threatening. The diagnosis is difficult to make in the perioperative setting, but prompt recognition and correct treatment is necessary to ensure a good outcome. A group of 26 international experts in perioperative allergy (anaesthesiologists, allergists, and immunologists) contributed to a modified Delphi consensus process, which covered areas such as differential diagnosis, management during and after anaphylaxis, allergy investigations, and plans for a subsequent anaesthetic. They were asked to rank the appropriateness of statements related to the immediate management of suspected perioperative allergic reactions. Statements were selected to represent areas where there is a lack of consensus in existing guidelines, such as dosing of epinephrine and fluids, the management of impending cardiac arrest, and reactions refractory to standard treatment. The results of the modified Delphi consensus process have been included in the recommendations on the management of suspected perioperative allergic reactions. This paper provides anaesthetists with an overview of relevant knowledge on the immediate and postoperative management of suspected perioperative allergic reactions based on current literature and expert opinion. In addition, it provides practical advice and recommendations in areas where consensus has been lacking in existing guidelines.

The use of drug provocation testing in the investigation of suspected immediate perioperative allergic reactions: current status.

Suspected perioperative allergic reactions are often severe. To avoid potentially life-threatening re-exposure to the culprit drug, establishing a firm diagnosis and identifying the culprit is crucial. Drug provocation tests are considered the gold standard in drug allergy investigation but have not been recommended in the investigation of perioperative allergy, mainly because of the pharmacological effects of drugs such as induction agents and neuromuscular blocking agents. Some specialised centres have reported benefits of provocation testing in perioperative allergy investigation, but the literature on the subject is limited. Here we provide a status update on the use of drug provocation testing in perioperative allergy, including its use in specific drug groups. This review is based on a literature search and experiences of the authors comprising anaesthesiologists and allergists with experience in perioperative allergy investigation. In addition, 19 participating centres in the International Suspected Perioperative Allergic Reaction Group were surveyed on the use of provocation testing in perioperative allergy investigation. A response was received from 13 centres in eight European countries, New Zealand, and the USA. Also, 21 centres from the Australian and New Zealand Anaesthetic Allergy Group were surveyed. Two centres performed provocation routinely and seven centres performed no provocations at all. Nearly half of the centres reported performing provocations with induction agents and neuromuscular blocking agents. Drug provocation testing is being used in perioperative allergy investigation in specialised centres, but collaborations between relevant specialties and multicentre studies are necessary to determine indications and establish common testing protocols.