Anaesthesia-associated hypersensitivity reactions: seven years' data from a British bi-specialty clinic

Relationship between perioperative anaphylaxis and history of allergies or allergic diseases: A systematic review and meta-analysis with meta-regression

STUDY OBJECTIVE

We conducted this meta-analysis to summarize the available evidence and evaluate the relationship between a history of allergies/allergic diseases and perioperative anaphylaxis to offer preventive decision support.

DESIGN

Systematic review and meta-analysis of observational studies.

SETTING

We searched the MEDLINE (OVID), EMBASE, and the Cochrane Central Register of Controlled Trials databases for observational studies. Two investigators independently performed the search, screened the articles, and collected the study details.

MEASUREMENTS

Several databases were systematically searched to evaluate the relationship between a history of allergies/allergic diseases and perioperative anaphylaxis using subgroup analysis, sensitivity analysis and meta-regression.

MAIN RESULTS

A total of 19 studies involving 672 anaphylaxis episodes, 5608 immune-mediated reactions, and 1126 severe episodes met the eligibility criteria and were included in this meta-analysis. Drug allergies, food allergies, a history of allergies, and atopy increased the incidence of perioperative anaphylaxis (Drug allergies, odds ratio [OR] 3.54, 95% confidence interval [CI] 1.07-11.69; Food allergies, OR 2.29, 95% CI 1.23-4.26; A history of allergies, OR 4.86, 95% CI 3.65-6.49; Atopy, OR 3.58, 95% CI 1.47-8.71), but not the presence of immune-mediated reactions and the severity of perioperative anaphylaxis.

CONCLUSIONS

Patients with previous drug allergies, food allergies, a history of allergies, or atopy are more likely to develop anaphylaxis during the perioperative period. Additional studies should be carried out to determine whether a history of allergies/allergic diseases is a major factor for perioperative anaphylaxis when confounders are controlled.

The Normal Range of Baseline Tryptase Should Be 1 to 15 ng/mL and Covers Healthy Individuals With HαT

Physiological levels of basal serum tryptase vary among healthy individuals, depending on the numbers of mast cells, basal secretion rate, copy numbers of the TPSAB1 gene encoding alpha tryptase, and renal function. Recently, there has been a growing debate about the normal range of tryptase because individuals with the hereditary alpha tryptasemia (HαT) trait may or may not be symptomatic, and if symptomatic, uncertainty exists as to whether this trait directly causes clinical phenotypes or aggravates certain conditions. In fact, most HαT-positive cases are regarded as asymptomatic concerning mast cell activation. To address this point, experts of the European Competence Network on Mastocytosis (ECNM) and the American Initiative in Mast Cell Diseases met at the 2022 Annual ECNM meeting and discussed the physiological tryptase range. Based on this discussion, our faculty concluded that the normal serum tryptase range should be defined in asymptomatic controls, inclusive of individuals with HαT, and based on 2 SDs covering the 95% confidence interval. By applying this definition in a literature screen, the normal basal tryptase in asymptomatic controls (HαT-positive persons included) ranges between 1 and 15 ng/mL. This definition should avoid overinterpretation, unnecessary referrals, and unnecessary anxiety or anticipatory fear of illness in healthy individuals.

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.

Perioperative Allergic Reactions: Allergy Assessment and Subsequent Anesthesia

BACKGROUND

Evidence-based guidelines are needed in the United States to improve evaluation of perioperative allergic reactions including recommendations for subsequent anesthesia.

OBJECTIVE

To identify causative agent(s) and evaluate patients' tolerability of subsequent anesthesia in patients evaluated by Allergy/Immunology (A/I) at Massachusetts General Hospital.

METHODS

We performed a retrospective review of patients referred to the outpatient A/I clinic for perioperative allergic reactions between October 2003 and May 2017. Patient demographics, atopic history, and prior adverse drug reactions were reviewed. Patients underwent a comprehensive evaluation with testing including skin testing (ST), drug challenges (when appropriate), tryptase level measurement, and specific IgE to latex measurement. Tolerance of subsequent procedures requiring anesthesia was assessed.

RESULTS

Of 123 patients referred, 74 (60%) were female and the mean age was 46 (±18) years. At least 1 causative agent was identified in 28 patients (24%, n = 28 of 118). Seventeen of 28 (61%) patients were ST positive to an antibiotic, including 13 (46%) positive to cefazolin; 3 patients (11%) had a positive latex specific IgE. Of 85 patients who had subsequent anesthesia with a known outcome, 78 (91%) did not have another perioperative allergic reaction. Two of 5 patients with an elevated baseline tryptase level did not tolerate subsequent anesthesia.

CONCLUSION

The majority of patients safely received subsequent anesthesia after comprehensive A/I evaluation for their perioperative allergic reactions; however, improved algorithmic care is needed in the United States. Among ST-positive patients (24%), antibiotics (especially cefazolin) were the most common culprits. An elevated baseline tryptase level was associated with an increased risk of recurrent perioperative allergic reactions.

Using Baseline and Peak Serum Tryptase Levels to Diagnose Anaphylaxis: a Review

The diagnosis of anaphylaxis relies on a suggestive clinical history after exposure to a potential triggering factor. Serum tryptase concentrations increase on degranulation of mast cells and therefore serum tryptase levels are measured to diagnose anaphylaxis. There is no standardized method for assessing total serum mast cell tryptase (MCT) in anaphylaxis. The Working Conference in 2010 proposed a consensus equation (peak MCT should be > 1.2x baseline tryptase + 2 ng/L) to diagnose acute mast cell activation (aMCA). Our objective was to narratively review the literature since the Working Conference in 2010, examining the use of the consensus equation and other equations comparing baseline and peak serum tryptase during anaphylaxis. Computerized bibliographic searches of PUBMED and EMBASE were supplemented with a manual search of reference lists. English-language studies were included. Eleven studies met our inclusion criteria with a total of 4551 participants. However, only four studies with 653 participants used the consensus equation. The other seven studies used other methods to compare peak and baseline serum tryptase concentrations. Measuring serum tryptase levels is valuable in the diagnosis of anaphylaxis but is unable to detect all anaphylactic reactions. Based on our current literature review, the consensus equation is underused in the diagnosis of anaphylaxis. There is also a need for exploration of other biomarkers which could be used in parallel to peak and baseline serum tryptase measurements for further diagnostic certainty. Serum tryptase is the most studied biomarker in anaphylaxis but is still far from being the ideal biomarker for this. There is a need to identify new potential useful biomarkers. Serum tryptase levels are valuable in the diagnosis of anaphylaxis, but are unable to detect all anaphylactic reactions. Additionally serial tryptase measurements are laborious in daily clinical practice.

A Well-Trained Team During Anaphylactic Shock After Rocuronium in a Patient With Aortic Stenosis: A Case Report

A 66-year-old patient with aortic stenosis was scheduled for an aortic valve replacement and coronary artery bypass surgery. Anesthesia was induced by intravenous injection of midazolam, fentanyl, and propofol. After administration of rocuronium, he developed anaphylactic shock, which was diagnosed by clinical signs, vital parameters, and unresponsiveness to the usual vasopressors. After 30 min of cardiopulmonary resuscitation, the patient survived without any neurological deficits. This case is a reminder that early recognition and treatment of intraoperative hypersensitivity reactions are imperative. Anesthetists should also receive simulation training to achieve an adequate experience in a safe environment. With a well-trained team, it is possible to save the life of patients with aortic stenosis.

Anaphylaxis in Pregnancy in the United States: Risk Factors and Temporal Trends Using National Routinely Collected Data

BACKGROUND

Anaphylaxis in pregnancy is an understudied, rare, and severe complication of pregnancy.

OBJECTIVE

To describe the incidence and temporal trends, and to identify potential risk factors for anaphylaxis-related hospitalizations while pregnant in the United States.

METHODS

All hospitalizations while pregnant and any anaphylactic reactions were identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes from the National Inpatient Sample, United States, over the period 2004 to 2014. Annual incidence rates of anaphylaxis during pregnancy were calculated. Logistic regression models assessed risk factors for anaphylaxis during pregnancy, presented as odds ratios (ORs) and 95% CIs.

RESULTS

During the period 2004 to 2014, the incidence of anaphylaxis during pregnancy was 3.8 (95% CI, 3.4-4.2) per 100,000 hospitalizations while pregnant. The incidence did not statistically differ during the period 2004 to 2014. After adjustment, there were 3 factors that increased the odds of anaphylaxis during pregnancy: cesarean delivery (adjusted OR [aOR], 4.19; 95% CI, 3.28-5.35) compared with noncesarean delivery; history of an allergic reaction (aOR, 4.05; 95% CI, 2.64-6.23) compared with no history; and a black race (aOR, 1.57; 95% CI, 1.15-2.15) and other race (aOR, 1.69; 95% CI, 1.08-2.63) compared with white race.

CONCLUSIONS

Despite increased rates of cesarean delivery in the United States and consequent drug administration, there was no evidence of an increasing trend in anaphylaxis. Cesarean delivery and history of an allergic reaction allow the identification of women at risk of anaphylaxis. Not all women had clear risk factors, and preparations should always be in place to ensure timely management if this uncommon event occurs.

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.

Improvement of the Elevated Tryptase Criterion to Discriminate IgE- From Non-IgE-Mediated Allergic Reactions

BACKGROUND

Differentiating between immunoglobulin E (IgE)-dependent and IgE-independent hypersensitivity reactions may improve the etiologic orientation and clinical management of patients with allergic reactions in the anesthesia setting. Serum tryptase levels may be useful to discriminate the immune mechanism of allergic reactions, but the diagnostic accuracy and optimal cutpoint remain unclear.We aimed to compare the diagnostic accuracy of tryptase during reaction (TDR) alone and the TDR/basal tryptase (TDR/BT) ratio for discriminating IgE- from non-IgE-mediated allergic reactions, and to estimate the best cut point for these indicators.

METHODS

We included 111 patients (45% men; aged 3-99 years) who had experienced an allergic reaction, even though the allergic reaction could be nonanaphylactic. Allergy tests were performed to classify the reaction as an IgE- or non-IgE-mediated one. The area under the curve (AUC) of the receiver operating characteristic analysis was performed to estimate the discriminative ability of TDR and TDR/BT ratio.

RESULTS

An IgE-mediated reaction was diagnosed in 49.5% of patients, and 56% of patients met anaphylaxis criteria. The median (quartiles) TDR for the IgE-mediated reactions was 8.0 (4.9-19.6) and 5.1 (3.5-8.1) for the non-IgE-mediated (P = .022). The median (quartiles) TDR/BT ratio was 2.7 (1.7-4.5) in IgE-mediated and 1.1 (1.0-1.6) in non-IgE-mediated reactions (P < .001). The TDR/BT ratio showed the greatest ability to discriminate IgE- from non-IgE-mediated reactions compared to TDR (AUC TDR/BT = 0.79 [95% confidence interval (CI), 0.70-0.88] and AUC TDR = 0.66 [95% CI, 0.56-0.76]; P = .001). The optimal cut point for TDR/BT (maximization of the sum of the sensitivity and specificity) was 1.66 (95% CI, 1.1-2.2).

CONCLUSIONS

The TDR/BT ratio showed a significantly better discriminative ability than TDR to discriminate IgE- from non-IgE-mediated allergic reactions. An optimal TDR/BT ratio threshold of approximately 1.66 may be useful in clinical practice to classify allergic reactions as IgE- or non-IgE-mediated.

Preventing iatrogenic gelatin anaphylaxis

OBJECTIVE

To assess the iatrogenic risks of gelatin allergy and identify resources for patient management.

DATA SOURCES

A literature review was performed using PubMed and public databases provided by the National Library of Medicine.

STUDY SELECTIONS

Reports of iatrogenic gelatin allergy associated with vaccines, hemostatic agents, intravenous colloids, medicinal capsules, and intraoperative surgical supplies.

RESULTS

Gelatin ingredients may not be identified by electronic medical record safeguards, and an exhaustive listing of potential iatrogenic exposures is elusive. The National Library of Medicine AccessGUDID (https://accessgudid.nlm.nih.gov/) can be a useful resource in evaluating medical devices for gelatin content. Unexpected sources of iatrogenic gelatin exposure include hemostatic agents, vascular grafts, intravascular cannulas, bone replacement implants, and emergency resuscitation fluids.

CONCLUSION

Vigilance is important within medical systems to avoid inadvertent gelatin exposure when caring for patients with gelatin allergy. Additional safeguards are needed to remove latent health care system errors that fail to prevent gelatin administration in this at-risk population.

Morphine and pholcodine-specific IgE have limited utility in the diagnosis of anaphylaxis to benzylisoquinolines

BACKGROUND

Investigation of immediate hypersensitivity reactions in the perioperative setting involves skin testing and measurement of specific IgE (sIgE) as standard practice. In the case of the neuromuscular blocking agents (NMBAs), the main allergenic epitopes have been shown to be substituted ammonium groups. Commercial assays are available for detection of sIgE to these epitopes using morphine and pholcodine substrates but questions have been raised about the effectiveness of these assays in the diagnosis of benzylisoquinoline anaphylaxis. This study was therefore undertaken to assess the effectiveness of these assays in the diagnosis of hypersensitivity reactions to this group of NMBAs.

METHODS

Analysis was carried out on all available results for patients assessed at the Royal North Shore Hospital Anaesthetic Allergy Clinic during the period June 2009 to June 2016. Standardised intradermal skin tests were performed with a panel of NMBAs. Measurement of sIgE to morphine and pholcodine was performed via the Phadia ImmunoCAP^® system.

RESULTS

For all patients with positive skin test results to NMBAs which included a benzylisoquinoline NMBA (n = 24), 75% exhibited negative sIgE to both morphine and pholcodine. Where patients were reactive to benzylisoquinoline NMBAs alone (n = 12), 100% exhibited negative sIgE results, indicating 0% sensitivity of the assays relative to skin testing, in this subgroup.

CONCLUSION

Use of sIgE testing to morphine and pholcodine in the assessment of NMBA immediate hypersensitivity is a valuable tool particularly in the case of reactions to the aminosteroid NMBAs. However, these assays are unreliable in detecting sensitisation to benzylisoquinoline NMBAs.

In Vitro Diagnosis of Immediate Drug Hypersensitivity Anno 2017: Potentials and Limitations

Background

For most physicians, quantification of drug-specific immunoglobulin E (drug-sIgE) antibodies constitutes the primary in vitro measure to document immediate drug hypersensitivity reactions (IDHR). Unfortunately, this is often insufficient to correctly identify patients with IgE-mediated IDHR and impossible for non-IgE-mediated IDHR that result from alternative routes of basophil and mast cell activation. In these difficult cases, diagnosis might benefit from cellular tests such as basophil activation tests (BAT).

Aim

The aim was to review the potential and limitations of quantification of sIgE and BAT in diagnosing IDHR. The utility of quantification of serum tryptase is discussed.

Methods

A literature search was conducted using the key words allergy, basophil activation, CD63, CD203c, diagnosis, drugs, hypersensitivity, flow cytometry, specific IgE antibodies; this was complemented by the authors’ own experience.

Results

The drugs that have been most studied with both techniques are β-lactam antibiotics and curarizing neuromuscular blocking agents (NMBA). For sIgE morphine, data are available on the value of this test as a biomarker for sensitization to substituted ammonium structures that constitute the major epitope of NMBA, especially rocuronium and suxamethonium. For the BAT, there are also data on non-steroidal anti-inflammatory drugs (NSAIDs) and iodinated radiocontrast media. For β-lactam antibiotics, sensitivity and specificity of sIgE varies between 0 and 85% and 52 and 100%, respectively. For NMBA, sensitivity and specificity varies between 38.5 and 92% and 85.7 and 100%, respectively. Specific IgE to morphine should not be used in isolation to diagnose IDHR to NMBA nor opiates. For the BAT, sensitivity generally varies between 50 and 60%, whereas specificity attains 80%, except for quinolones and NSAIDs.

Conclusions

Although drug-sIgE assays and BAT can provide useful information in the diagnosis of IDHR, their predictive value is not absolute. Large-scale collaborative studies are mandatory to harmonize and optimize test protocols and to establish drug-specific decision thresholds.

Anaphylaxis after disinfection with 2% chlorhexidine wand applicator

A 54-year-old man with end-stage renal failure attended for dialysis. Within seconds of applying 2% w/v chlorhexidine (ChloraPrep 3 mL Wand Applicator) to the skin surrounding the insertion point of his dialysis catheter (Tesio catheter), he developed pruritus, urticaria, shortness of breath, hypotension and reduced responsiveness. Treatment for anaphylaxis was initiated with rapid improvement of his symptoms, and he made a full recovery. Allergy to chlorhexidine was confirmed with skin testing, and the patient was warned against all future exposure to chlorhexidine. Subsequent dialysis without chlorhexidine was uneventful.

Chlorhexidine allergy in four specialist allergy centres in the United Kingdom, 2009-13: clinical features and diagnostic tests

We describe an observational survey of diagnostic pathways in 104 patients attending four specialist allergy clinics in the United Kingdom following perioperative hypersensitivity reactions to chlorhexidine reactions. The majority were life-threatening. Men undergoing urological or cardiothoracic surgery predominated. Skin prick testing and specific immunoglobulin (sIg)E testing were the most common tests used for diagnosis. Fifty-three per cent of diagnoses were made on the basis of a single positive test. Where multiple tests were performed the sensitivity of intradermal, basophil activation and skin prick testing was 68% (50-86%), 50% (10-90%) and 35% (17-55%), respectively. Seven per cent were negative on screening tests initially, and 12 cases were only positive for a single test despite multiple testing. Intradermal tests appeared most sensitive in this context. Additional sensitization to other substances used perioperatively, particularly neuromuscular blocking agents (NMBA), was found in 28 patients, emphasizing the need to test for possible allergy to all drugs to which the patient was exposed even where chlorhexidine is positive.

Quantification of specific IgE antibodies in immediate drug hypersensitivity: More shortcomings than potentials?

BACKGROUND

For many physicians, quantification of serum drug-specific IgE (sIgE) antibodies constitutes the first measure in the diagnostic approach of immediate drug hypersensitivity reactions (IDHR).

AIM

To review the accuracy and limitations of the main drug-sIgE tests, especially those that are commercially available.

METHODS

A literature search was conducted, using the key-words allergy, diagnosis, drugs, hypersensitivity, specific IgE antibodies; this was complemented by the authors' own experience.

RESULTS

The drugs that have mostly been studied appeared to be β-lactam antibiotics, neuromuscular blocking agents (NMBA) and morphine, the latter as a biomarker for sensitisation to substituted ammonium structures that constitute the major epitope of NMBA. For β-lactams sensitivity and specificity varied between 0-85% and 52-100%, respectively. For NMBA, sensitivity and specificity varied between 38.5-92% and 92-100%, respectively. With respect to sIgE to morphine it appears this drug to be a sensitive biomarker for sensitisation to rocuronium and suxamethonium but not for atracurium. However, sIgE morphine should not be applied in isolation to diagnose IDHR to NMBA nor opiates.

CONCLUSIONS

Although drug-sIgE assay can provide valuable information they should not be performed in isolation to establish correct diagnosis, as their predictive value is not per se absolute. Larger comprehensive studies are urgently required to determine the accuracy of drug-sIgE assays.

Dynamics of plasma levels of specific IgE in chlorhexidine allergic patients with and without accidental re-exposure

BACKGROUND

Chlorhexidine is an effective disinfectant, which may cause severe allergic reactions. Plasma level of specific IgE to chlorhexidine (ImmunoCAP(®) ) has high estimated sensitivity and specificity when measured within 6 months of allergic reaction, but knowledge of the dynamics over longer time periods is lacking and it is unknown whether levels fall below <0.35 kUA/L in patients with previously elevated levels. It is also unclear whether re-exposure influences levels of specific IgE.

OBJECTIVE

To investigate the dynamics of specific IgE in chlorhexidine allergic patients with and without re-exposure.

METHODS

All patients diagnosed with chlorhexidine allergy in the Danish Anaesthesia Allergy Centre January 1999 to March 2015 were invited to participate. The study included blood samples from the time of reaction and time of investigation and blood samples drawn prospectively over several years.

RESULTS

Overall, 23 patients were included. Specific IgE within hours of reaction was available in eight patients and was >0.35 kUA/L in six of these. During allergy investigations, usually 2-4 months later, specific IgE was >0.35 kUA/L in 22 of 23 patients. In the following months/years specific IgE declined <0.35 kUA/L in 17 of 23 patients (most rapidly within 4 months). Nine re-exposures in the healthcare setting were reported by seven patients (35%). Most re-exposures caused symptoms and were followed by an increase in specific IgE. Two patients with specific IgE <0.35 kUA/L reacted upon re-exposure.

CONCLUSIONS & CLINICAL RELEVANCE

Time from reaction should be considered when interpreting specific IgE results. Specific IgE is >0.35 kUA/L in most patients at time of reaction but should be repeated after a few weeks/months if negative. The optimal sampling time seems to be >1 month and <4 months. A value <0.35 kUA/L neither excludes allergy nor implies loss of reactivity in previously sensitized patients. Re-exposures are common, often iatrogenic, and can cause a rebound in specific IgE.