Neuromuscular blocking agents induced anaphylaxis: Results and trends of a French pharmacovigilance survey from 2000 to 2012

Neuromuscular blocking agent drug challenge: a literature review and protocol proposal with biological evaluation

BACKGROUND

Drug challenge is the gold standard for identifying causative agents of drug allergies. Although clinical guidelines have recently been published, they do not recommend neuromuscular blocking agent (NMBA) drug challenges. NMBA challenges are rendered difficult by the lack of homogeneity of routine allergy work-ups and the necessity of a specialised setting. Several scenarios support NMBA challenges, such as an ambiguous allergy work-up, a high suspicion of a false-positive skin test or identification of a well tolerated alternative NMBA strategy. Furthermore, routine allergy work-ups may not recognise non-IgE mechanisms, such as IgG or MRGPRX2, whereas drug challenges may reveal them. Finally, if the culprit NMBA is not identified, subsequent anaesthesia regimens will be challenging to implement, resulting in increased risk.

OBJECTIVES

This literature review discusses the indications, strategies, doses, monitoring methods, limitations, and unresolved issues related to drug challenges for NMBAs.

DESIGN

The literature review included randomised controlled trials, observational studies, reviews, case reports, series, and comments on humans.

DATA SOURCES

Studies were retrieved from databases (PubMed) and electronic libraries (OVID, EMBASE, Scopus, etc.).

ELIGIBILITY CRITERIA

All studies that referred to the NMBA challenge were included without publication date limitations.

RESULTS

NMBA challenge may be considered in NMBA anaphylaxis patients with inconclusive or ambivalent IgE diagnostic work-up under controlled conditions (presence of anaesthetists and allergists with continuous monitoring in a secured environment). To illustrate its utility, a case report of a double NMBA challenge in a patient with NMBA cross-reactivity is presented, along with biological explorations to detect subclinical cellular activation, a novel aspect of this procedure.

CONCLUSION

Drug challenges could be implemented during the NMBA allergy work-up under strict safety conditions at specialised centres with close collaboration between anaesthetists and allergists. This could decrease uncertainty and contribute to defining a safer strategy for subsequent anaesthetic drug regimens.

Drug-Induced Anaphylaxis: National Database Analysis

(1) Background: National health system databases represent an important source of information about the epidemiology of adverse drug reactions including drug-induced allergy and anaphylaxis. Analysis of such databases may enhance the knowledge of healthcare professionals regarding the problem of drug-induced anaphylaxis. (2) Methods: A retrospective descriptive analysis was carried out of spontaneous reports (SRs) with data on drug-induced anaphylaxis (SRsAs) extracted from the Russian National Pharmacovigilance database (analyzed period 2 April 2019-21 June 2023). The percentage of SRsAs among SRs of drug-induced allergy (SRsDIAs) was calculated, as well as of pediatric, elderly, and fatal SrsAs. Drugs involved in anaphylaxis were assessed among total SRsAs, pediatric, and elderly SRsAs, and among fatal SRsAs. Demographic parameters of patients were assessed. (3) Results: SRsAs were reported in 8.3% of SRsDIAs (2304/27,727), the mean age of patients was 48.2 ± 15.8 years, and females accounted for 53.2% of cases. The main causative groups of drugs were antibacterials (ABs) for systemic use (44.6%), local anesthetics (20.0%), and cyclooxygenase (COX) inhibitors (10.1%). Fatal SRsAs were reported in 9.5% (218/2304) of cases, the mean age of patients was 48.0 ± 16.7 years, and females accounted for 56.4% of cases. Pediatric SRsAs accounted for 3.9% of pediatric SRsDIAs and 5.8% of all SRsAs, with a mean age of 11.8 ± 4.5 years, and females acccounted for 51.9% of cases. Elderly SRsAs accounted for 2% of elderly SRsDIAs and 2.8% of all SRsAs, and the mean age was 73.0 ± 5.3 years, and females accounted for 43.5% of cases. ABs caused 40% of SRsAs in the elderly, 42.9% in children, and 50% of fatal SRsAs. (4) Conclusions: Our study revealed a relatively high proportion of anaphylaxis among SRs of drug-induced allergy. ABs were the most prevalent causative agents, especially in fatal SRsAs.

Comparison of the Onset of Action, Maintenance, and Recovery of Three Weight-based Dosing of Cisatracurium in Patients with Morbid Obesity in Laparoscopic Bariatric Surgery: A Randomized Clinical Trial

Background

For patients with morbid obesity, different cisatracurium dosage regimens are recommended. This study aimed to compare the onset of action, the sufficiency of neuromuscular blockade during infusion, and the recovery of the three distinct cisatracurium dosage scalars in patients with morbid obesity undergoing laparoscopic bariatric surgery.

Methods

In this randomized clinical trial, 55 patients were scheduled for bariatric surgery at Firoozgar Hospital from March 2020 to August 2021. Using a block randomization method, they were randomly divided into three groups, based on total body weight (TBW group), fat-free mass (FFM group), or ideal body weight (IBW group), to receive a bolus of cisatracurium 0.2 mg/Kg, followed by an infusion of 2 µg/Kg, to maintain a train-of-four (TOF) count≤2. Data were analyzed using SPSS software. P<0.05 was considered statistically significant.

Results

The mean time (seconds) to reach TOF0 in the TBW group was significantly shorter (201.89, 95%CI=192.99-210.79; P=0.004) than the IBW group (233.53, 95%CI=218.71-248.34; P=0.01). However, this difference was not statistically significant between TBW and FFM groups (220.83, 95%CI=199.73-241.94; P=0.81) or between FFM and the IBW groups (P=0.23). The rescue dose and increments of cisatracurium infusion were not required in the TBW group, whereas their probability was 4.81 times higher in the IBW group than the FFM group. Furthermore, the TBW and FFM groups had higher mean surgical condition scores than the IBW group (P<0.001, and P=0.006, respectively).

Conclusion

Cisatracurium loading and infusion dosing based on FFM provide a comparable onset of action and surgical field condition to the TBW-based dosing with a shorter recovery time. However, IBW-based dosing of cisatracurium was insufficient for laparoscopic bariatric surgery.Trial Registration Number: IRCT20151107024909N9.A preprint of this study was published at . doi: .

MRGPRX2, drug pseudoallergies, inflammatory diseases, mechanisms and distinguishing MRGPRX2- and IgE/FcεRI-mediated events

MRGPRX2, a novel Gaq -coupled human mast cell receptor, mediates non-immune adverse reactions without the involvement of antibody priming. Constitutively expressed by human skin mast cells, MRGPRX2 modulates cell degranulation producing pseudoallergies manifesting as itch, inflammation and pain. The term pseudoallergy is defined in relation to adverse drug reactions in general and immune/non-immune-mediated reactions in particular. A list of drugs with MRGPRX2 activity is presented, including a detailed examination of three important and widely used approved therapies: neuromuscular blockers, quinolones and opioids. For the clinician, the significance of MRGPRX2 is considered as an aid in distinguishing and ultimately identifying specific immune and non-immune inflammatory reactions. Anaphylactoid/anaphylactic reactions, neurogenic inflammation and inflammatory diseases with a clear or strongly suspected association with MRGPRX2 activation are examined. Inflammatory diseases include chronic urticaria, rosacea, atopic dermatitis, allergic contact dermatitis, mastocytosis, allergic asthma, ulcerative colitis and rheumatoid arthritis. MRGPRX2- and allergic IgE/FcεRI-mediated reactions may be clinically similar. Importantly, the usual testing procedures do not distinguish the two mechanisms. Currently, identification of MRGPRX2 activation and diagnosis of pseudoallergic reactions is generally viewed as a process of exclusion once other non-immune and immune processes, particularly IgE/FcεRI-mediated degranulation of mast cells, are ruled out. This does not take into account that MRGPRX2 signals via β-arrestin, which can be utilized to detect MRGPRX2 activation by employing MRGPRX2 transfected cells to assess MRGPRX2 activation via two pathways, the G-protein-independent β-arrestin pathway and the G-protein-dependent Ca2+ pathway. Testing procedures, interpretations for distinguishing mechanisms, patient diagnosis, agonist identification and drug safety evaluations are addressed.

The Japanese Epidemiologic Study for Perioperative Anaphylaxis, a prospective nationwide study: allergen exposure, epidemiology, and diagnosis of anaphylaxis during general anaesthesia

BACKGROUND

Diagnosis of perioperative anaphylaxis is often challenging. This study describes the utility of a newly developed tool for identifying patients with a high possibility of anaphylaxis, and aimed to investigate the frequency of anaphylaxis with each drug during the perioperative period in Japan.

METHODS

This study included patients with anaphylaxis of Grade 2 or higher severity during general anaesthesia at 42 facilities across Japan in 2019 and 2020. We developed and adopted a unique objective evaluation tool yielding a composite score for diagnosing anaphylaxis, which includes the results of skin tests and basophil activation tests, and clinical scores for perioperative anaphylaxis. The number of cases using each drug and the total number of anaphylaxis cases were investigated to calculate the frequency of anaphylaxis.

RESULTS

General anaesthesia was performed in 218 936 cases, which included 55 patients with suspected perioperative anaphylaxis. The developed composite score diagnosed 43 of them with a high probability of anaphylaxis. The causative agent was identified in 32 cases. Plasma histamine levels showed high diagnostic accuracy for anaphylaxis. The top causative agents were rocuronium (10 cases in 210 852 patients, 0.005%), sugammadex (7 cases in 150 629 patients, 0.005%), and cefazolin (7 cases in 106 005 patients, 0.007%).

CONCLUSIONS

We developed a composite tool to diagnose anaphylaxis, and found that the combination of tryptase levels, skin testing, and basophil activation testing results and clinical score improved the certainty of anaphylaxis diagnosis. The incidence of perioperative anaphylaxis in our study was 1 in about 5000 general anaesthesia cases.

CLINICAL TRIAL REGISTRATION

UMIN000035350.

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.

Could Artificial Intelligence Prevent Intraoperative Anaphylaxis? Reference Review and Proof of Concept

Drugs and various medical substances have been used for many decades to diagnose or treat diseases. Procedures like surgery and anesthesia (either local or general) use different pharmacological products during these events. In most of the cases, the procedure is safe and the physician performs the technique without incidents. Although they are safe for use, these substances (including drugs) may have adverse effects, varying from mild ones to life-threatening reactions in a minority of patients. Artificial intelligence may be a useful tool in approximating the risk of anaphylaxis before undertaking a medical procedure. This material presents these undesirable responses produced by medical products from a multidisciplinary point of view. Moreover, we present a proof of concept for using artificial intelligence as a possible guardship against intraoperative anaphylaxis.

Mas-Related G Protein–Coupled Receptor-X2 and Its Role in Non-immunoglobulin E–Mediated Drug Hypersensitivity

A diverse group of Food and Drug Administration-approved cationic drugs including antibiotics, neuromuscular blocking drugs, opioids, antidepressants, and radiocontrast media activate mast cells and cause hypersensitivity reactions by both an immunoglobulin E IgE-dependent and independent manner. The recent discovery that these drugs activate mast cells via the G protein-coupled receptor known as Mas-related GPCR-X2 (MRGPRX2) has represented a paradigm shift of how drug hypersensitivity reactions are viewed. This article provides an overview of the current status of the role of MRGPRX2 on non-IgE-mediated drug hypersensitivity. Potential risk factors and evaluation for suspected MRGPRX2-mediated drug reactions are also discussed.

Clinical characteristics and allergen detection of perioperative anaphylaxis: a 12-year retrospective analysis from an anesthesia clinic in China

Abstract

Background

Anaphylaxis during anesthesia is a rare but often a potentially life-threatening event for patients. Identifying culprit agents responsible for anaphylaxis is of great important for avoiding potential re-exposure to allergens, but it poses great challenge for anesthetists. This retrospective study aimed to analyze the culprits of patients with a history of perioperative anaphylaxis referred to an anesthesia allergy clinic in China, and to evaluate the role of allergy diagnostic tests in clinical practice.

Methods

A total of 145 patients (102 female/43 male) who attended the Anesthesia Allergy Clinic for allergen detection between 1 January 2009 and 31 December 2020 were reviewed retrospectively. Clinical characteristics, results of allergy diagnostic tests including skin, and/or basophil activation tests, and the incidence of repeat anaphylaxis after use of recommended alternative anesthetics were obtained.

Results

Of these 145 patients, 109 patients (75.2%, 74 females/35 males) were determined to experience perioperative anaphylaxis. The most common presenting clinical feature was cardiovascular manifestations (n = 63, 57.8%). According to diagnostic work up, the most common causative agents for perioperative anaphylaxis were neuromuscular blocking agents (n = 35, 32.1%). After diagnostic work up, 52 patients underwent repeat anesthesia. None of these patients experienced recurrent anaphylaxis.

Conclusions

This study suggests that neuromuscular blocking agents are the main cause of perioperative anaphylaxis. For patients with perioperative anaphylaxis, allergy diagnostic tests are essential to identify causative agents, and to find suitable alternative drugs for the future planning of subsequent anesthetics.

MRGPRX2 and Adverse Drug Reactions

Many adverse reactions to therapeutic drugs appear to be allergic in nature, and are thought to be triggered by patient-specific Immunoglobulin E (IgE) antibodies that recognize the drug molecules and form complexes with them that activate mast cells. However, in recent years another mechanism has been proposed, in which some drugs closely associated with allergic-type events can bypass the antibody-mediated pathway and trigger mast cell degranulation directly by activating a mast cell-specific receptor called Mas-related G protein-coupled receptor X2 (MRGPRX2). This would result in symptoms similar to IgE-mediated events, but would not require immune priming. This review will cover the frequency, severity, and dose-responsiveness of allergic-type events for several drugs shown to have MRGPRX2 agonist activity. Surprisingly, the analysis shows that mild-to-moderate events are far more common than currently appreciated. A comparison with plasma drug levels suggests that MRGPRX2 mediates many of these mild-to-moderate events. For some of these drugs, then, MRGPRX2 activation may be considered a regular and predictable feature after administration of high doses.

The nature and reported incidence of suspected perioperative allergic reactions: A cross-sectional survey

STUDY OBJECTIVE

Perioperative allergic reactions (POHs) are common and can lead to severe intraoperative instability and even mortality. In contrast to the situation in developed countries, where databases of perioperative anaphylaxis are well documented and analyzed, relevant data are lacking in China. Therefore, we aimed to conduct a national survey to explore the characteristics of perioperative allergic reactions, as well as the knowledge and attitudes toward management and reporting among anesthesiologists.

DESIGN

Cross-sectional survey.

SETTING

Anesthesia department.

PATIENTS

A nationally representative sample comprising anesthesiologists from 12 province-level regions was selected.

MEASUREMENTS

A 20-item questionnaire was designed and validated using the Delphi method. Survey distribution was performed between June 2019 and January 2020 by the Chinese Society of Anesthesiology (CSA), which is the official academic society of Chinese anesthesiologists. Responses were compiled and analyzed.

MAIN RESULTS

We received responses from 4389 anesthesiologists across China. The estimated rate of suspected POH was 2/1000 patients (0.2%). On average, an anesthesiologist encountered 2.1 suspected POH cases per year. Neuromuscular blocking agents (NMBAs) were perceived as the most common causative agents, followed by antibiotics and succinylated gelatin. The rates of referral and allergy consultations were very low. Institutional support, including protocol development, cognitive aids, and tool kits, was not ideal. Additionally, the management of POH varied substantially. Most anesthesiologists believed that reporting and documenting POH was necessary.

CONCLUSIONS

Our survey revealed that POH is commonly encountered by Chinese anesthesiologists, but few patients are referred to allergy specialists or clinics for further investigation. A standardized recommendation based on research and data derived from Chinese patients is required.

Revisiting the role of MRGPRX2 on hypersensitivity reactions to neuromuscular blocking drugs

Anaphylaxis is caused by a variety of triggers including Food and Drug Administration (FDA)-approved antibiotics, contrast media and neuromuscular blocking drugs (NMBDs). Traditionally, drug-induced anaphylaxis was thought to result mainly from IgE-mediated histamine release from mast cells. Recently, a G protein-coupled receptor known as MRGPRX2 has been identified and shown to be highly expressed on human skin but not lung mast cells. The demonstration that many NMBDs induce degranulation in human mast cells via MRGPRX2 led to the idea that this receptor contributes to NMBD-induced hypersensitivity reactions. However, other studies have raised doubts regarding its role in drug-induced hypersensitivity. This review discusses the current status and controversy on MRGPRX2's role on NMBD-induced hypersensitivity.

Advances and novel developments in drug hypersensitivity diagnosis

A correct diagnosis of drug hypersensitivity reactions (DHRs) is very important for both the patient and health system. However, DHRs diagnosis is complex, time consuming, requires trained personnel, is not standardized for many drugs, involves procedures not exempt of risk, and in most cases lacks standardized in vivo and in vitro tests. Thus, there is an urgent need for improving the different approaches to diagnose patients with suspected DHRs. In this review, we have analyzed the advances performed in immediate and nonimmediate DHRs diagnosis during the last two years and obtained several conclusions: the significant heterogeneity in current practice among centers illustrates the need to re-evaluate, update, and standardize in vivo tests and protocols for the diagnosis and management of patients with suspected drug allergy. Regarding in vitro tests, the latest studies have focused on increasing their sensitivity or on establishing the sensitivity and specificity for the tests performed with new drugs. There seems to be a consensus about combining in vivo and in vitro tests as the best way to increase the diagnostic accuracy.

Epidemiology and outcome of patients admitted to intensive care after anaphylaxis in France: a retrospective multicentre study

BACKGROUND

Few data are available on patients who have experienced anaphylaxis and were admitted to ICUs. The purpose of this observational study was to describe the epidemiology and management of these patients.

METHODS

This was a multicentre retrospective study carried out in 23 French ICUs between 2012 and 2017. All patients who suffered anaphylaxis and were transferred to an ICU were included. Data were collected using an electronic database after approval by an ethics committee.

RESULTS

A total of 339 patients were included, and 17 (5%) died secondary to anaphylaxis. The main triggers were drugs (77%), contrast media (11%), and food (7%). Epinephrine was administered before ICU admission in 88% of patients with Grade III anaphylaxis and 100% of patients with Grade IV anaphylaxis. Most patients with Grades III and IV anaphylaxes did not receive the recommended dose of i.v. fluid of 30 ml kg^-1 within the first 4 h of ICU admission. The time to epinephrine administration was not statistically different between survivors and non-survivors, but non-survivors received a higher dose of epinephrine (median: 5 [3-10] vs 3 [2-7] mg; P<0.0001), which suggests that some forms of anaphylactic shock may be resistant to epinephrine. In multivariate analysis, only lactate concentration at ICU admission was a predictor of death (odds ratio: 1.47 [1.15-1.88]; P=0.002).

CONCLUSIONS

Lactate concentration at ICU admission appeared to be the most reliable criterion for assessing prognosis. Epinephrine is widely used during anaphylaxis, but the volume of fluid resuscitation was consistently lower than recommended.

CLINICAL TRIAL REGISTRATION

NCT04290507.

Postanesthetic skin erythema due to succinylcholine versus atracurium

Intraoperative anaphylactic reactions may range from mild, erythema-like to anaphylactic shock, with tension crash and bronchospasm. The substances considered to be most responsible for the occurrence of intraoperative allergic reactions are neuromuscular blocking agents, antibiotics and latex. Recent studies have identified a new receptor, Mas-Related G-Protein-coupled Receptor X2 (MRGPRX2), considered as a target for some neuromuscular blockers such as atracurium, rocuronium or fluoroquinolone, resulting in pseudoallergic or anaphylactoid reactions. Induction of anesthesia can use both depolarizing myorelaxants, useful especially in emergency situations, in the patient with gastric plenitude or at high risk of intubation, and non-depolarizing myorelaxants such as atracurium, cisatracurium and rocuronium. Succinylcholine has a short time of action and it is rapidly metabolized. Atracurium, although having a slightly longer time to action, has the benefit of a low risk of increased levels of potassium in blood, which is extremely important in patients with cardiac pathology or associated kidney diseases. The present study compared the side effects of systemic anesthesia with succinylcholine vs. atracurium.

History of the development of antagonists for neuromuscular blocking agents

Muscle relaxation induced by neuromuscular blocking agents (NMBAs) is necessary for tracheal intubation and immobilization during surgery. Although acetylcholinesterase inhibitors have been successfully used as antagonists for NMBAs, they have their limitations; their effects are transient and ineffective against profound neuromuscular blockade. In the past, alternative antagonists were developed, such as germine and 4-aminopyridine, which are effective for the treatment of diseases causing muscle weakness and could potentially be used as antagonists for NMBAs. Unfortunately, these drugs did not come into practical use due to unwanted side-effects. Sugammadex is an almost ideal antagonist because it rapidly forms a rigid complex with rocuronium and produces less adverse effects. The development of novel NMBAs and antagonists, especially sugammadex, has revolutionized anesthesia practice. Recently, novel short-acting NMBAs, such as gantacurium and CW002 have been developed. Their effects can be reversed by the amino-acid L-cysteine. More recently, calabadions have been developed, which can form complexes with both steroidal and bisbenzyl-isoquinolinium NMBAs, in a similar fashion as sugammadex. Understanding the history of the NMBA antagonist's development is interesting and useful for modern anesthesiologists since it enhances their knowledge about the mechanisms involved in neuromuscular transmission and might lead to the development of ideal NMBA antagonists.

Food and drug allergy, and anaphylaxis in EAACI journals (2018)

The European Academy of Allergy and Clinical Immunology (EAACI) supports three journals: "Allergy," "Pediatric Allergy and Immunology (PAI)," and "Clinical and Translational Allergy (CTA)." One of the major goals of EAACI is to support health promotion in which prevention of allergy and asthma plays a critical role and to disseminate the knowledge of allergy to all stakeholders including the EAACI junior members. This paper summarizes the achievements of 2018 in anaphylaxis, and food and drug allergy. Main topics that have been focused are anaphylaxis, mechanisms of food allergy (FA), epidemiology of FA, food allergens, diagnosis of FA, prevention and control of FA, FA immunotherapy, drug allergy, and political agenda.

Peri-Operative Anaphylaxis-An Investigational Challenge

Patients with suspected peri-operative anaphylaxis (POP) require thorough investigation to identify underlying trigger(s) and enable safe anesthesia for subsequent surgery. The changing epidemiology of POP has been striking. Previous estimates of the incidence of POP have ranged between 1:6,000 and1:20,000 anesthetics, but more recent data from France and the United Kingdom suggest an estimated incidence of 1:10,000. Other important changes include a change in the hierarchy of well-recognized triggers, with antibiotics (beta-lactams) supplanting neuromuscular blockers (NMB) as the leading cause of POP. The emergence of chlorhexidine, patent blue dye, and teicoplanin as important triggers have also been noteworthy findings. The mainstay of investigation revolves around critical analysis of the time-line of events leading up to anaphylaxis coupled with judicious skin testing. Skin tests have limitations with respect to unknown predictive values for most drugs/agents and therefore, knowledge of background positivity in healthy controls, test characteristics of individual drugs and the use of non-irritant concentrations is essential to avoid both false-positive and false-negative results. Specific IgE assays for individual drugs are available only for a limited number of agents and are not a substitute for skin testing. Acute serum total tryptase has a high specificity and positive predictive value in IgE-mediated POP anaphylaxis but is limited by its moderate sensitivity and negative predictive value. Planning for safe anesthesia in this group of patients is particularly challenging and consequently anesthetists need to be alert to the possibility of repeat episodes of anaphylaxis. Because of the limitations of current investigations for POP, collecting systematic data on the outcome of repeat anesthesia is valuable in validating current investigatory approaches. This paper reviews the changing epidemiology of POP with reference to the main triggers, and the investigation and outcome of subsequent anesthesia.

Extracorporeal membrane oxygenation support in refractory perioperative anaphylactic shock to rocuronium: a report of two cases

In recent years, extracorporeal membrane oxygenation has become increasingly common in the treatment of in-hospital cardiac arrest in non-cardiac surgery patients. This includes cardiac arrest secondary to perioperative anaphylactic shock refractory to standard advanced life support protocols, which is a rare but catastrophic event associated with significant mortality. Neuromuscular blocking drugs are most commonly implicated in perioperative anaphylaxis, with rocuronium playing a major role. In this article, we report two cases of young and otherwise fit and well patients who experienced a perioperative arrest secondary to rocuronium anaphylaxis before elective surgery; both patients did not respond to conventional advanced life support, but survived neurologically intact after institution of urgent veno-arterial extracorporeal membrane oxygenation.

Comparative epidemiology of suspected perioperative hypersensitivity reactions

Suspected perioperative hypersensitivity reactions are rare but contribute significantly to the morbidity and mortality of surgical procedures. Recent publications have highlighted the differences between countries concerning the respective risk of different drugs, and changes in patterns of causal agents and the emergence of new allergens. This review summarises recent information on the epidemiology of perioperative hypersensitivity reactions, with specific consideration of differences between geographic areas for the most frequently involved offending agents.