Scandinavian Clinical Practice Guidelines on the diagnosis, management and follow-up of anaphylaxis during anaesthesia

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.

Occurrence of hemodynamic changes following administration of rocuronium in a dog presenting for an ophthalmic procedure

A 10-year-old, neutered male, Golden Retriever dog presented for surgical correction of a descemetocele. Acepromazine (0.02 mg/kg) and methadone (0.5 mg/kg) were administered intramuscularly for sedation, propofol (2 mg/kg) and midazolam (0.2 mg/kg) were administered intravenously for anaesthetic induction and isoflurane in oxygen was utilised for anaesthetic maintenance. Rocuronium (0.5 mg/kg), a neuromuscular blocking agent, was administered intravenously to facilitate central positioning of the eye for surgery. Within 10 min of rocuronium administration, the dog became tachycardic and hypotensive. Hemodynamic aberrations did not resolve with initial interventions but were successfully mitigated with the administration of diphenhydramine (0.8 mg/kg) intravenously. The dog remained stable throughout the remainder of the procedure and experienced a smooth and uneventful recovery. While it is difficult to confirm that the hemodynamic changes observed in this clinical case resulted solely from administration of rocuronium, the observance of the cardiovascular changes, timing of events and response to therapy suggest that rocuronium elicited a histamine response that was successfully treated with diphenhydramine.

Management of Refractory Anaphylaxis: An Overview of Current Guidelines

In this review, we compare different refractory anaphylaxis (RA) management guidelines focusing on cardiovascular involvement and best practice recommendations, discuss postulated pathogenic mechanisms underlining RA and highlight knowledge gaps and research priorities. There is a paucity of data supporting existing management guidelines. Therapeutic recommendations include the need for the timely administration of appropriate doses of aggressive fluid resuscitation and intravenous (IV) adrenaline in RA. The preferred second-line vasopressor (noradrenaline, vasopressin, metaraminol and dopamine) is unknown. Most guidelines recommend IV glucagon for patients on beta-blockers, despite a lack of evidence. The use of methylene blue or extracorporeal life support (ECLS) is also suggested as rescue therapy. Despite recent advances in understanding the pathogenesis of anaphylaxis, the factors that lead to a lack of response to the initial adrenaline and thus RA are unclear. Genetic factors, such as deficiency in platelet activating factor-acetyl hydrolase or hereditary alpha-tryptasaemia, mastocytosis may modulate reaction severity or response to treatment. Further research into the underlying pathophysiology of RA may help define potential new therapeutic approaches and reduce the morbidity and mortality of anaphylaxis.

Knowledge and attitudes toward anaphylaxis to local anesthetics in dental practice

OBJECTIVE/AIM

The absence of a comprehensive understanding of potential anaphylactic reactions to local anesthetics (LAs) and management can result in grave consequences. For this reason we aim to assess Latin American dentists' knowledge, preparedness, and competency in managing anaphylactic reactions to LAs.

MATERIALS AND METHODS

Design: A cross-sectional study was conducted from November 2021 to February 2022. Board-certified dentists answered a survey comprising 26 structured questions. Chi-square tests and logistic regression models were performed in Stata 17.0.

SETTING

Argentina, Brazil, Colombia, Costa Rica, Ecuador, Honduras, Mexico, Peru, Venezuela, and other Latin American countries.

RESULTS

Of 507 respondents, lidocaine was the most frequently used LA (88.1%). While 85.2% could identify dyspnea as a symptom of anaphylaxis, only 50.1% knew the correct route for epinephrine administration, and just 43.5% had epinephrine in their emergency kits. Confidence in managing anaphylactic reactions was low (9.6%). Older age was inversely related to both knowledge of anaphylaxis management and the possession of epinephrine (P = 0.003 and P = 0.0001, respectively).

DISCUSSION

Our study highlights a concerning discrepancy between the practical readiness of Latin American dentists in handling anaphylaxis.

CONCLUSION

The study's findings underscore the need for educational interventions to improve the readiness to identify and handle anaphylactic emergencies in dental practice.

Iopromide safety assessment in a radiology department: A seven-year retrospective characterization of adverse events

BACKGROUND

Since the mid-20th century, contrast agents have been widely used in radiology due to their ability to provide high-definition radiographic images and greater precision in diagnostic exams. Different types of contrast agents are used in image diagnosis, namely radiological media. Despite being considered safe, there are still uncertainties about their safety profile, interactions, and incidence of adverse drug reactions in real-world settings.

OBJECTIVE

To characterise the pattern of adverse events, during 7 years, in a radiology unit.

METHODS

We performed a retrospective observational and descriptive study at an Image Center in Portugal between August 2012 and October 2019. A total of 77,449 computed tomography (CT) were registered, and from those 15,640 cases of iopromide were used as a contrast agent. The authors have accessed, under the authorization, the data of adverse events and procedures after the event.

RESULTS

Most of the hypersensitivity events were immediate or with a short time of onset, with the majority of cases developing events with skin involvement and mild degree, where the most common events were papules (n = 60), pruritus (n = 42), erythema (n = 27) and urticaria (n = 14). Severe events, including hypersensitivity, were mainly represented by vomiting (n = 11), stridor (n = 8), breathing difficulties (n = 7) and syncope (n = 3). Abdominal-pelvic CT exam presented a higher frequency of adverse events.

CONCLUSION

Despite all the current information about iopromide usage, the utilization of this agent is not abstent of risks and its safety profile not fully established. Most frequent symptoms were local, as skin adverse events, including papules, pruritus and erythema. Common medications used to treat or control adverse events were frequently hydrocortisone, clemastine and methylprednisolone.

Cardiac Arrest Due to Anaphylactic Shock Following Vecuronium Injection

Anaphylaxis under anesthesia is a rare but potentially severe disease. Although anaphylaxis is rare, it can be lethal if not diagnosed and treated appropriately. We present the case of a 43-year-old male with no prior allergy history who experienced a severe anaphylactic reaction that resulted in cardiac arrest after the intravenous injection of vecuronium. His surgery was postponed, and the patient required intensive care with ventilator support and other supportive measures. Post-reaction dermal sensitivity tests revealed a clear allergic reaction to vecuronium which confirmed the diagnosis retrospectively. Eventually, the patient made a full recovery and was rescheduled for surgery at a later date.

Intraoperative cardiac arrest due to allergic acute coronary syndrome (Kounis syndrome) triggered by cephalosporin

An acute coronary syndrome due to mast-cell activation in the presence of an allergen is known as Kounis Syndrome (KS). This relatively new entity of KS is being increasingly recognized among allergists, cardiologists, and emergency physicians; however, it is not well-known among anesthesiologists. We report here, a case of type 2 KS due to antibiotic administration causing sudden perioperative cardiac arrest.

Severe perioperative anaphylaxis: Incidence in a tertiary hospital in Spain over a 20-year period. A historical cohort study

OBJECTIVE

To assess the incidence of severe perioperative anaphylaxis, the mechanisms involved, the value of laboratory/skin tests, and the most effective treatments.

METHODS

A historical cohort study conducted in a tertiary public hospital in Spain. Patients that had undergone anaesthesia during the 20-year period were included. In these patients, 66 cases of severe anaphylaxis were found. In patients with suspicion of severe anaphylaxis, levels of blood histamine at less than 15min and serum tryptase at 2, 6, and 24h following the reaction were determined. Skin and specific IgE tests were performed between 4 and 8 weeks later.

RESULTS

Over the 20-year period, 288 594 anaesthetic procedures were performed. We observed cases of 66 severe anaphylaxis reaction (59% men; age, 60.8±17.3 years. Symptoms observed were cardiovascular (86%), respiratory (73%), and mucocutaneous (56%). Elevated serum tryptase levels were associated with degree of severity at 2 (P<.0001) and 6h (P=.026) and were highest in IgE-mediated reactions (P=.020). All patients required treatment, and 3 events were fatal. In 84.8% of patients, skin and/or specific IgE tests were positive for antibiotics (35.8%), non-steroidal anti-inflammatory drugs (23.1%), neuromuscular blocking agents (15.4%) and latex (15.4%).

CONCLUSIONS

The incidence of severe anaphylaxis in our hospital was 1 in 4.373 anaesthetic procedures, with a death rate of 4.5%. All cases required treatment. Serum tryptase was a good predictor of reaction severity. The most frequent causative agents were antibiotics, non-steroidal anti-inflammatory drugs, neuromuscular blocking agents and latex.

Echinococcosis in a non-endemic country - 20-years' surgical experience from a Norwegian tertiary referral Centre

BACKGROUND

In Scandinavia, the incidence of cystic echinococcosis (CE) and alveolar echinococcosis (AE) is low and almost exclusively an imported disease following the trends of immigration. The aim of the study was to review available data on clinical management and outcome for patients treated at Oslo University Hospital, a referral centre for echinococcosis in Norway, with special emphasis on surgical treatment.

METHODS

All patients admitted with echinococcosis between January 2000 and December 2020 were identified. Medical records were reviewed retrospectively concerning patient demographics, treatment strategy, surgical procedures, complications and outcomes.

RESULTS

A total of 92 patients with median age 37 years (range 4-85) were identified. Sixty-eight patients (74%) were symptomatic. All patients, except for two, were immigrants to Norway and born in endemic areas. Ninety patients were diagnosed with CE and two with AE. Location of the cysts was most commonly in the liver (86%) followed by peritoneum, lungs, and spleen. All patients with active cysts were treated with albendazole. Surgical treatment was performed in 51 (56%) patients. The most common reason for abstaining from surgical treatment was that the diagnostic work-up revealed inactive cysts or interventional radiology was performed. Of the 51 patients who underwent surgery, a radical procedure was performed in 32 (64%) cases, a conservative procedure in 12 (24%), and a combination in six (12%). Clavien Dindo grade ≥3 complications occurred in 30%, and 90-day mortality was 2%. Bile leakage occurred in seven patients and was treated successfully with endoscopic retrograde cholangiopancreatography with biliary stent placement in all patients.

CONCLUSION

In a low-endemic area like Norway, management of echinococcus includes medical therapy, surgery, and/or interventional radiology. Surgical intervention seems to be effective, and is associated with acceptable morbidity rates.

Drugs and Vaccines Hypersensitivity in Children with Mastocytosis

Mastocytosis, a heterogeneous mastcell disease, include three different entities: cutaneous mastocytosis, systemic mastocytosis (SM) and mast-cell sarcoma. Tryptase levels can differentiate cutaneous mastocytosis from SM. In mastocytosis, quick onset drug hypersensitivity reactions (DHRs) that are facilitated by mastcell mediators, are investigated in adults. Due to the limited number of children with mastcell disease and increased serum tryptase levels, the role of drugs in this age group is less studied. In this review, we critically assessed relevant papers related with immediate DHRs in children with mastocytosis and discuss practical issues of the management. In childhood mastocytosis, anaphylaxis is frequently idiopathic, and elevated level of basal tryptase, and high burden of disease may increase the risk. Among drugs, antibiotics, NSAIDs and opioids can potentially induce anaphylaxis, anyway avoidance should be recommended only in case of previous reactions. Moreover, vaccinations are not contraindicated in patients with mastocytosis. The risk of severe systemic reactions after drugs intake seems to be extremely low and in general lower in children than in adults. Anyway, studies on this topic especially focusing on children, are missing to state final recommendations.

A Clinical Practice Guideline for the Emergency Management of Anaphylaxis (2020)

Background: For anaphylaxis, a life-threatening allergic reaction, the incidence rate was presented to have increased from the beginning of the 21st century. Underdiagnosis and undertreatment of anaphylaxis are public health concerns. Objective: This guideline aimed to provide high-quality and evidence-based recommendations for the emergency management of anaphylaxis. Method: The panel of health professionals from fifteen medical areas selected twenty-five clinical questions and formulated the recommendations with the supervision of four methodologists. We collected evidence by conducting systematic literature retrieval and using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. Results: This guideline made twenty-five recommendations that covered the diagnosis, preparation, emergency treatment, and post-emergency management of anaphylaxis. We recommended the use of a set of adapted diagnostic criteria from the American National Institute of Allergy and Infectious Diseases and the Food Allergy and Anaphylaxis Network (NIAID/FAAN), and developed a severity grading system that classified anaphylaxis into four grades. We recommended epinephrine as the first-line treatment, with specific doses and routes of administration for different severity of anaphylaxis or different conditions. Proper dosage is critical in the administration of epinephrine, and the monitor is important in the IV administration. Though there was only very low or low-quality evidence supported the use of glucocorticoids and H1 antagonists, we still weakly recommended them as second-line medications. We could not make a well-directed recommendation regarding premedication for preventing anaphylaxis since it is difficult to weigh the concerns and potential effects. Conclusion: For the emergency management of anaphylaxis we conclude that: • NIAID/FAAN diagnostic criteria and the four-tier grading system should be used for the diagnosis • Prompt and proper administration of epinephrine is critical.

Incidence of intraoperative anaphylaxis caused by blood products: a 12-year single-center, retrospective study

PURPOSE

Intraoperative anaphylaxis caused by blood products is uncommon, but it is unclear whether the rarity of this reaction is attributable to the difficulty of diagnosis, underreporting, or both. We investigated the incidence of intraoperative transfusion anaphylaxis and its reporting to the hemovigilance system.

METHODS

We retrospectively reviewed cases wherein general anesthesia was used at a single hospital during a 12-year period. Cases of intraoperative anaphylaxis were extracted using an electronic search strategy and determined using the recently developed grading and clinical scoring system. The causative blood products were determined by the onset duration based on literature regarding intraoperative transfusion anaphylaxis cases.

RESULTS

Among the 62,146 general anesthesia cases, 22 cases of intraoperative anaphylaxis were identified, and 11 of the 22 cases received transfusions before the onset of anaphylaxis. Intraoperative transfusion anaphylaxis was defined as occurring within 30 min of transfusion. Finally, nine cases of intraoperative transfusion anaphylaxis were analyzed. The overall incidence of intraoperative transfusion anaphylaxis was 1/3,994, with the highest incidence noted for fresh frozen plasma (1/2146; 95% confidence interval [CI] 1/6610-1/920), platelet concentrate (1/2348; 95% CI 1/92,742-1/422), and red blood cells (1/22,867; 95% CI 1/903,199-1/4,105). No evidence indicated that these cases were reported to the Japanese hemovigilance system, although all intraoperative transfusion anaphylaxis cases were diagnosed by anesthesiologists.

CONCLUSION

The incidence of intraoperative anaphylaxis caused by blood products was higher than that reported and may be underreported to the Japanese hemovigilance system. Further research, particularly multicenter studies, is needed to confirm our results.

Risk predictive tools of perioperative drug hypersensitivity reaction: A case-control study

Objective

We aimed to determine the risk factors of perioperative drug hypersensitivity reaction (DHR) and develop a predictive score for use in clinical practice.

Methods

A case-control study was conducted in patients who underwent anesthesia at a tertiary hospital in Thailand, between 2015–2018. DHR cases were graded clinically from 1 to 4 according to the World Federation of Societies of Anesthesiologists by two anesthesiologists. Controls were randomly matched with cases (ratio 2:1) by age group and month and type of surgery. Patient and anesthesia-related factors and agents given intraoperatively were recorded. A risk score was derived from the coefficients of the significant predictors of the final multivariate logistic regression model. Risk scores, adjusted odds ratios (OR) for perioperative DHR and 95% confidence intervals (CI) were determined.

Results

Overall, 325 cases and 650 controls were recruited. The severity of DHR was grade 1 (72.9%), grade 2 (24%), and grade 3 (3.1%). Our risk predictive tools for perioperative DHR provided a sensitivity of 62% and specificity of 65%. Predictive scores of subgroups of moderate to severe DHR showed high specificity (80%) but low sensitivity (47%). Common predictors of overall DHR and moderate to severe DHR were history of drug allergy to 2 or more drug categories (score 2.5–3.5), being allergic to analgesics (score 2.5–4.0), and intraoperative morphine use (score of 1). The sole predictor of high-risk perioperative DHR (score ≥3.5) was airway management with an endotracheal tube intubation (OR 5.6, 95% CI 2.2–14.4) whereas history of allergic rhinitis (OR 11.7, 95% CI 1.3–105.1) was a predictor of high-risk moderate to severe DHR (score ≥2.5).

Conclusions

Our predictive tool for perioperative DHR provided a modest predictive ability. History of drug allergies, rhinitis, morphine use and endotracheal intubation were significant risk factors of DHR after adjusting for age and type of surgery.

What do we know about perioperative hypersensitivity reactions and what can we do to improve perioperative safety?

Hypersensitivity reactions are an important aspect of perioperative care and are a crucial interdisciplinary issue in anaesthesiological practice, as well as allergological and laboratory diagnostics. This phenomenon was observed as early as the 1980s and 1990s in Western European countries, and knowledge on this subject has grown significantly over time. Although hypersensitivity reactions are not frequent events (the incidence of perioperative hypersensitivity reactions ranges from 1:386 to 1:13 000 procedures, with higher frequency - 1 per 6500 general anaesthesias with neuromuscular blocking agents administrations), their courses are unfortunately serious and life-threatening. It should also be noted that there is no information regarding the occurrence of perioperative hypersensitivity reactions in many countries. Hence, global assessment of the problem is underestimated. The primary source of actual knowledge comes from epidemiological studies, which indicate an increasing frequency of hypersensitivity reaction occurrence and changes in aetiological factors. The first report from France (1984 to 1989) described two main causes - neuromuscular blocking agents and hypnotic agents. The following years confirmed an increase in perioperative hypersensitivity reactions associated with latex and antibiotics. The most recent data from the National Audit Project 6 indicated increased participation of antibiotics, chlorhexidine, and contrast agents. The results of epidemiological analyses are the basis of medical management guidelines and practice modification. Thanks to the activity of many organisations monitoring the intensity and nature of perioperative hypersensitivity reactions, guidelines for diagnostics and management have been developed. This article presents the results of numerous studies, including the first and the most recent, from various geographical regions. The clinical significance, pathogenesis mechanisms are also discussed. This publication also presents important directions for further scientific and epidemiological research on perioperative hypersensitivity reactions.Key messagesThe incidence of perioperative hypersensitivity reactions ranges from 1:386 to 1:13 000 procedures, with higher frequency - 1 per 6500 general anaesthesias with neuromuscular blocking agents administrations.Reactions may occur during the first episode of anaesthesia, most frequently in the induction of general anaesthesia, and much less frequently during postoperative follow-up.The first reports of perioperative hypersensitivity reaction come from the 1990s, and knowledge on this subject has grown significantly over time.In many countries, multidisciplinary teams and organisations have been established to identify, monitor the occurrence of this phenomenon, and have set the directions of medical activities and have changed the rules and recommendations.There is no information about the occurrence of perioperative hypersensitivity reactions in many countries, and global assessment of the problem is underestimated. Additionally, there is a great need to develop a system to monitor their occurrence in other countries.The long-term epidemiologic studies have demonstrated variability in pharmacologic triggers. However, the main pharmacological substances (antibiotics, muscle relaxants, disinfectans, contrast agents) are related to aspects of patient safety during anaesthesia.

Clinical reasoning in anaphylactic shock: addressing the challenges faced by anaesthesiologists in real time: A clinical review and management algorithms

Acute hypersensitivity reactions to drugs occur infrequently during anaesthesia and the peri-operative period. When clinical presentation includes the classical triad, erythema, cardiovascular abnormalities and increased airway pressure, the diagnosis is evident and the challenge is to prescribe a therapeutic regimen according to guidelines and to manage refractory signs in a timely manner. In many situations, however, the initial clinical signs are isolated, such as increased airway pressure or arterial hypotension. Rendering a differential diagnosis with causes and mechanisms other than acute hypersensitivity reactions (AHRs) is difficult, delaying treatment with possible worsening of the clinical signs, and even death, in previously healthy individuals. In these difficult diagnostic situations, clinical reasoning is mandatory, and guidelines do not explicitly explain the elements on which clinical reasoning can be built. In this article, based on clinical evidence whenever available, experimental data and pathophysiology, we propose algorithms that have been evaluated by experts. The goal of these algorithms is to provide explicit elements on which the differential diagnosis of AHRs can be made, accelerating the implementation of adequate therapy.

Practical guidelines for the response to perioperative anaphylaxis

Perioperative anaphylaxis is a severe adverse event during anesthesia that requires prompt diagnosis and treatment by physicians, including anesthesiologists. Muscle relaxants and antibiotics are the most common drugs that cause perioperative anaphylaxis in Japan, as in many countries. In addition, sugammadex appears to be a primary causative agent. Obtaining previous anesthesia records is necessary in a patient with a history of allergic reactions during anesthesia, whenever possible, to avoid recurrence of anaphylaxis. Although medical staff are likely to notice abnormal vital signs because of complete monitoring during anesthesia, surgical drapes make it difficult to notice the appearance of skin symptoms. Even if there are no skin symptoms, anaphylaxis should be suspected, especially when hypotension resistant to inotropes and vasopressors persists. For improving the diagnostic accuracy of anaphylaxis, it is helpful to collect blood samples to measure histamine/tryptase concentrations immediately after the events and at baseline. The first-line treatment for anaphylaxis is adrenaline. In the perioperative setting, adrenaline should be administered through the intravenous route, which has a faster effect onset and is secured in most cases. Adrenaline can cause serious complications including severe arrhythmias if the appropriate dose is not selected according to the severity of symptoms. The anesthesiologist should identify the causative agent after adverse events. The gold standard for identifying the causative agent is the skin test, but in vitro tests including specific IgE antibody measurements and basophil activation tests are also beneficial. The Working Group of the Japanese Society of Anesthesiologists has developed this practical guide to help appropriate prevention, early diagnosis and treatment, and postoperative diagnosis of anaphylaxis during anesthesia.Grade of recommendations and levels of evidence Anaphylaxis is a relatively rare condition with few controlled trials, and thus a so-called evidence-based scrutiny is difficult. Therefore, rather than showing evidence levels and indicating the level of recommendation, this practical guideline only describes the results of research available to date. The JSA will continue to investigate anaphylaxis during anesthesia, and the results may lead to an amendment of this practical guideline.

Hymenoptera venom-induced anaphylaxis and hereditary alpha-tryptasemia

PURPOSE OF REVIEW

To discuss the association between the common dominantly inherited genetic trait hereditary alpha-tryptasemia (HαT) and hymenoptera venom-induced anaphylaxis (HVA).

RECENT FINDINGS

Elevated BST has been correlated with more severe systemic anaphylaxis in humans in a number of settings - most notably in HVA. Clonal mast cell disease, in particular, systemic mastocytosis, is frequently associated with elevated BST, and is a major risk factor for severe HVA. However, clonal mast cell diseases are believed to be rare, whereas HVA is relatively more common. HαT affects an estimated 3-5% of Western populations and is the common cause for elevated BST in these individuals. An association between HαT and severe HVA, as well as clonal mast cell disease has recently been demonstrated wherein this trait modifies reaction severity in venom allergic individuals. A mechanism underlying this association has been proposed through the identification of naturally occurring heterotetrameric tryptases and characterization of their unique physical attributes.

SUMMARY

Here we discuss the long-standing association between elevated BST and HVA severity, how HαT fits into this landscape, and review the clinical and mechanistic evidence that supports HαT as a modifier of HVA.

Prevention of Drug Hypersensitivity Reactions: Prescreening and Premedication

Drug hypersensitivity reactions (DHR) are heterogeneous in their pathomechanisms, clinical presentation, severity, and outcomes. Novel DHR mechanisms, phenotypes, and endotypes have been described. The key to prevention from further exposure to the culprit drugs involves correct identification of the putative drug through a combination of in vitro and/or in vivo tests, accurate drug allergy labeling and reporting, and electronic decision support systems within electronic medical records to prevent future accidental prescribing. Prescreening and premedication, the focus of this review, may be a useful adjunct to preventive measures in certain situations. After an index immediate drug hypersensitivity reaction, prescreening may be useful in perioperative anaphylaxis, and iodinated (ICM) and gadolinium-based contrast media (GCM) where the culprit and potential alternative agents are skin tested. In certain nonimmediate DHR, pharmacogenomic prescreening may be used before prescribing high-risk drugs (eg, carbamazepine and allopurinol) where specific human-leukocyte antigen genotypes are associated with severe cutaneous adverse reactions. Premedication with antihistamine and systemic corticosteroids is another therapeutic strategy to prevent infusion reactions for certain biologicals and chemotherapeutic agents, in cases of perioperative anaphylaxis, ICM and GCM DHR, and clonal mast cell disorders. Rapid drug desensitization may also be used to induce temporary tolerance in situations where there are limited alternative drugs.

Evaluation of skin test indications for general anesthetics in real life: a prospective cohort study

BACKGROUND

In daily practice, atopic patients and those who have other drug allergies are referred to allergy clinics for evaluation of possible general anesthetic allergy despite the fact that it is not recommended in recent guidelines.

OBJECTIVE

The aim of this prospective study is to determine the negative predictive value of skin tests for common general anesthetic drugs prior to general anesthesia in atopic patients and in patients who had drug allergies by including the data of those who had previously tolerated or reacted to general anesthesia.

METHODS

A database program was constituted to collect the preoperative skin test data of patients referred to our clinic between 2013 and 2018. Demographic and clinical history, medications implemented during perioperative period, reactions, and results of skin tests performed with anesthetic drugs and latex were evaluated.

RESULTS

Four hundred fifty-nine out of the total 1167 patients referred fulfilled the inclusion criteria for further evaluation. Nearly 75% of the patients were female and mean age was 46.3 ± 14.3 years. History of hypersensitivity reactions (HRs) due to NSAIDs and/or antibiotics, radiocontrast agents, local anesthetics, and food were present in the 53.1%, 4.1%, 1.5%, and 2.0%, respectively. The negative predictive values of skin tests for general anesthetics were in the range of 80-100%. Only 4 patients (0,87%) experienced HRs during operation.

CONCLUSION

These real-life data reveal high rates of negative predictive value of skin tests with general anesthetic drugs and a low reaction rate in atopic patients and in patients with allergy to other drugs.

Sugammadex and anaphylaxis: An analysis of 33 published cases

In this study, the published sugammadex-induced anaphylaxis reports were reviewed to determine similarities in their presentation during anesthesia. PubMed was searched for sugammadex-induced anaphylaxis without time limitation. Reports were evaluated if they were in English and met the criteria of anaphylaxis determined by the World Allergy Organization. Two independent reviewers extracted and assessed the data using predesigned data collection forms. In total, 23 suitable articles were found and 33 sugammadex-induced anaphylaxis cases were included in the study. The mean age was 43.09 years (from 3–89 years) and 17 (51.5%) of the patients were female. Considering all reported cases, the average onset time of anaphylaxis was 3.08 min, with a median of 3 min (range 1–8 min). The most common signs and symptoms were hypotension, tachycardia, erythema, and desaturation. Of the 20 patients who underwent confirmatory skin testing, 15 had a positive skin reaction for sugammadex. Epinephrine was not given when indicated in about 25% of cases. Sugammadex-induced anaphylaxis onset time was less than 5 min in 92.3% of all the reported cases. Rapid diagnosis and early recognition of signs and symptoms of anaphylaxis are essential for a favorable prognosis. Treatment needs to be started as soon as possible to ensure the best outcome for the patient.

Perioperative Anaphylaxis: Evaluation and Management

Perioperative anaphylaxis (PA) is a rare but life-threatening condition that poses diagnostic and management challenges in the operating room. The incidence of severe perioperative reactions is estimated to be approximately 1:7000-10,000. Management involves both immediate stabilization of the patient and identifying the culprit agent. Identification is essential to prevent recurrence of the event in subsequent surgeries and to avoid unnecessary labeling of drug allergy. Identifying all possible exposures including medications, disinfectants, latex, and dyes and choosing the appropriate tests are essential for proper evaluation. To identify the culprit, primary testing modalities include tryptase at the time of the reaction with subsequent levels and skin testing with nonirritating concentrations to the medications and substances utilized during the procedure and those potentially used as alternates. This strategy provides guidance for future surgeries and procedures. Close collaboration between the allergy, anesthesiology, and surgery teams is essential for appropriate management of these patients at the time of the reaction, during the post event evaluation and in preparation for subsequent surgeries.

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.

Anaphylaxis after rabies vaccination for dogs in Japan

Severe adverse reactions after rabies vaccination in dogs were examined from 317 cases reported to the Ministry of Agriculture, Forestry and Fisheries (MAFF) in Japan during 15-year period from April 2004 to March 2019. We found that 109 of the 317 dogs showed anaphylaxis (0.15/100,000 vaccinated dogs), and 71 of the 109 cases of anaphylaxis resulted in death (0.10/100,000 vaccinated dogs). We measured bovine serum albumin (BSA) in four commercially available rabies vaccines and found the levels ranged from 0.1 to 16.6 µg/dose. Our survey showed that the rate of anaphylaxis to rabies vaccines in dogs is rare, although some cases of anaphylaxis resulted in death. Veterinarians should be well prepared to deal with vaccine-associated anaphylaxis.

Remimazolam anaphylaxis during anesthesia induction

Anaphylactic shock is a potentially lethal complication during anesthesia and requires appropriate management to save the patient's life. We report a 32-year-old man who developed anaphylaxis during induction of general anesthesia with remimazolam for hand surgery. He received general anesthesia with midazolam 4 weeks before. This time facial flushing followed by a decrease of peripheral oxygen saturation (SpO₂) and blood pressure occurred 2 min after starting continuous remimazolam infusion at 6 mg/kg/h. Hypotension and SpO₂ were recovered by repeated administration of adrenaline. Despite no increase of serum tryptase levels, intradermal allergy tests 4 weeks postoperatively revealed that remimazolam and midazolam were positive, suggesting remimazolam as a causative agent for anaphylaxis. In the previous surgery, midazolam, which has a similar structure to remimazolam, may have caused sensitization. This is probably the first case report of anaphylaxis caused by remimazolam.

Mast Cell Activation During Suspected Perioperative Hypersensitivity: A Need for Paired Samples Analysis

BACKGROUND

Perioperative hypersensitivity (POH) reactions constitute a significant clinical and diagnostic challenge. A transient increase in serum tryptase during POH reflects mast cell activation (MCA) and helps to recognize an underlying hypersensitivity mechanism.

OBJECTIVE

To determine the diagnostic performance of different tryptase decision thresholds based on single and paired measurements to document MCA in suspected POH.

METHODS

Acute serum tryptase (aST) and baseline serum tryptase (bST) samples were obtained from patients referred to our outpatients clinic because of clinical POH. Tryptase samples from controls were obtained before induction (Tt₀) and 1.5 hours after induction (Tt₁) in uneventful anesthesia. Different cutoff points for tryptase increase over bST and the percentage increase in tryptase (%T) were calculated and compared with existing thresholds: aST > [1.2 × (bST) + 2] (consensus formula), aST higher than 11.4 ng/mL, and aST higher than 14 ng/mL.

RESULTS

Patients with POH had higher bST and aST levels compared with controls (respectively 5.15 vs 2.28 ng/mL for bST and 20.30 vs 1.92 ng/mL for aST). The consensus formula and a tryptase increase over bST of greater than or equal to 3.2 ng/mL held the highest accuracies to document MCA in POH (respectively 81% and 82%). A bST of higher than 8 ng/mL was present in 4% of controls, 5% of patients with grade 1 POH, 24% of patients with grade 2 POH, 15% of patients with grade 3 POH, and 17% of patients with grade 4 POH.

CONCLUSIONS

Our data endorse the consensus formula for detection of MCA in POH. Furthermore, it shows that a bST of higher than 8 ng/mL was associated with occurrence of anaphylaxis.

[Update on perioperative hypersensitivity reactions: joint document of the Brazilian Society of Anesthesiology (SBA) and Brazilian Association of Allergy and Immunology (ASBAI) - Part I: post-crisis guidelines and treatment]

Experts from the Brazilian Association of Allergy and Immunology (ASBAI) and the Brazilian Society of Anesthesiology (SBA) interested in the issue of perioperative anaphylaxis, and aiming to strengthen the collaboration between the two societies, combined efforts to study the topic and to prepare a joint document to guide specialists in both areas. The purpose of the present series of two articles was to report the most recent evidence based on the collaborative assessment between both societies. This first article will consider the updated definitions, treatment and guidelines after a perioperative crisis. The following article will discuss the major etiologic agents, how to proceed with the investigation, and the appropriate tests.

Severe Intraoperative Anaphylaxis Related to Thymoglobulin during Living Donor Kidney Transplantation

Anaphylaxis secondary to thymoglobulin (anti-thymocyte globulin) is a rare condition that can be life threatening. Thymoglobulin is a rabbit-derived T-cell depleting polyclonal immunoglobulin. It is commonly used for induction immunosuppression and/or for treatment of acute rejection in renal transplantation. We report a case of a living kidney transplant recipient who developed intraoperative anaphylactic shock secondary to thymoglobulin. The patient had a history of pet rabbit exposure. This case report highlights the importance of prompt identification and management of intraoperative anaphylaxis, which is key to a successful outcome. Induction immunosuppression selection based on patient characteristics is important. Communication between the anesthesia team and surgeons played a key role in stopping the donor surgery.

Multiple drug allergies: Recommendations for perioperative management

Life-threatening hypersensitivity reactions are more likely to occur in patients with a history of allergy, atopy, or asthma. Hence, in a patient who presented with a history of multiple drug allergies (MDA), an allergological assessment should be performed prior to surgical procedure. Drug allergies, being one of the causes of catastrophic events occurring in the perioperative period, are of major concern to anesthesiologists. Neuromuscular blocking agents are regularly used during anesthesia and are one of the most common causes of perioperative anaphylaxis. They are estimated to be responsible for 50%-70% of perioperative hypersensitivity reactions. Antibiotics and latex represent the next two groups of drug allergy. Allergic reactions to propofol are rare with an incidence of 1:60,000 exposures. Although intraoperative drug anaphylaxis is rare, it contributes to 4.3% of deaths occurring during general anesthesia. These recommendations discuss pathophysiology of MDA, preoperative evaluation, and anesthesia considerations as well as the prevention and management of allergic reactions in anesthetized patients with a history of MDA.

Pediatric Patients with Previous Anaphylactic Reactions to General Anesthesia: a Review of Literature, Case Report, and Anesthetic Considerations

PURPOSE OF REVIEW

It is rare to see pediatric patients with previous perioperative anaphylaxis receiving future anesthesia, but it is critical to understand how to choose assessments, interpret the results, and develop a future anesthetic plan.

RECENT FINDINGS

Analysis of the results revealed that patients, at any age, regardless of sex and nationality, and the number of surgeries, have the risk of perioperative anaphylaxis while the risk of allergy increases as patients present multiple surgical events or have a previous history of atopy. 94.7% of pediatric patients with allergy testing after perioperative anaphylaxis tolerated subsequent general anesthesia without complications. Specific IgE tests, basophil activation tests, and skin tests are not available and suitable for all culprits. The early skin test could be considered a supplement for later testing. Drug challenge test is the golden standard but can only be used as the last resort. If general anesthesia is inevitable, avoidance of the culprit and use of alternative agents can help the patients prevent another potential recurrence. Full use of inhalation anesthesia without unnecessary neuromuscular blockade agents and avoidance of latex is recommended when the surgery is urgent or skin tests for children cannot be performed in time. This review summarizes characteristics of perioperative pediatric anaphylaxis, main tests for various drugs, and their sensitivities and specificities as well as recommendations as to how to implement safe anesthesia in the future.

Perioperative anaphylaxis in children: Etiology, time sequence, and patterns of clinical reactivity

BACKGROUND

Perioperative anaphylaxis (PA) in children is an uncommon but potentially life-threatening complication associated with anesthesia. Early identification and management of PA is essential to optimize clinical outcomes.

METHODS

We performed a retrospective study of anesthesia records from pediatric patients with PA from centers in the United Kingdom, France, and the United States over a period of 10 years. Time sequence of clinical signs and physiological variables during PA were collected, along with results of allergy testing.

RESULTS

Twenty-nine children with PA were included. Median age was 11 years. Based on the modified Ring and Messmer Grading Scale, severe reactions were seen in 25 (86%) members of this cohort, with 4 (14%) experiencing cardiac arrest. Life-threatening hypotension was the first clinical sign of PA in 59% of cases, followed by tachycardia and bronchospasm. In 16 (55%) cases, the initial signs of PA involved multiple organ systems. When the initial signs of PA were cardiovascular and/or respiratory, more epinephrine doses were administered. Average time from initial sign of PA to treatment with epinephrine was 6 minutes (SD: 6, range: 1-25). The causative allergen was identified in 15 patients.

CONCLUSION

Severe hypotension is the most common presenting sign of PA in children. Initial cardiovascular and/or respiratory signs are associated with the need for increased epinephrine doses. Further studies should optimize the prediction, identification, and early management of PA in children.

Empty mast cell syndrome: fallacy or fact?

Post-anaphylaxis mast cell anergy (PAMA), commonly referred to as 'empty mast cell (MC) syndrome', is a state of temporary loss of cutaneous MC reactivity in the immediate aftermath of anaphylaxis. Data relating to this condition are sparse and the incidence rate is currently unknown. PAMA has been described only in a few published case reports in the context of hymenoptera venom allergy and perioperative anaphylaxis. Best practice guidelines regarding optimal timing for performing skin tests postanaphylaxis are largely based on expert opinion, and allergy work-up has been recommended after 4-6 weeks postanaphylaxis to avoid false-negative results.This article provides a review of clinical literature surrounding PAMA, critically evaluates intracellular events in MCs from in vitro data and hypothesises regarding plausible immune mechanisms. There are no published data to directly explain molecular mechanisms underlying this phenomenon. Although not evidence based, PAMA has been attributed to depletion of MC granules following anaphylaxis. It is also plausible that exposure to high allergen concentrations in anaphylaxis can induce a temporary shift in MCs towards dominance of inhibitory signalling pathways, thus contributing to a state of transient hyporesponsiveness observed in some patients. Other potential contributory factors for reduced MC reactivity include downregulation of FcεRI expression, cross-linking of FcεRI to the inhibitory, low-affinity IgG receptors and administration of pharmacotherapeutic agents for anaphylaxis treatment. It is likely that this interesting phenomenon can be explained by a combination of these proposed mechanisms in addition to other genetic/host factors that have not yet been identified.

Suspected Anaphylactic Reaction to Ketamine in 3 Yucatan Swine (Sus scrofa)

This case series describes the clinical courses of 3 juvenile Yucatan miniature swine (Sus scrofa) that experienced a suspected anaphylactic reaction to ketamine hydrochloride during premedication for protocol-related surgery. All 3 swine rapidly developed diffuse erythema shortly after injection with ketamine-containing drug combinations. Clinical signs ranged from tachycardia and erythema alone to tachycardia and erythema followed by respiratory and cardiac arrest. Ketamine was considered the most likely cause of these reactions because it was the only agent in the premedication sedation combination that was used in all 3 swine. Subsequent intradermal skin testing confirmed this suspicion. With supportive care measures and standard medical interventions for anaphylaxis, all 3 animals recovered well and went on to be successful experimental subjects when an alternative anesthetic regimen that did not contain ketamine was used. To our knowledge, this report is the first description of a suspected adverse ketamine reaction of this type in swine despite the widespread use of the drug in this species. Ketamine anaphylaxis is rare in people, but the few cases described presented with symptoms similar to the clinical signs seen in the pigs in this report. In addition to highlighting a potential adverse drug reaction to ketamine in swine, this case series demonstrates the value of emergency preparedness for even the most routine of procedures.

An EAACI position paper on the investigation of perioperative immediate hypersensitivity reactions

Perioperative immediate hypersensitivity reactions are rare. Subsequent allergy investigation is complicated by multiple simultaneous drug exposures, the use of drugs with potent effects and the many differential diagnoses to hypersensitivity in the perioperative setting. The approach to the investigation of these complex reactions is not standardized, and it is becoming increasingly apparent that collaboration between experts in the field of allergy/immunology/dermatology and anaesthesiology is needed to provide the best possible care for these patients. The EAACI task force behind this position paper has therefore combined the expertise of allergists, immunologists and anaesthesiologists. The aims of this position paper were to provide recommendations for the investigation of immediate-type perioperative hypersensitivity reactions and to provide practical information that can assist clinicians in planning and carrying out investigations.