Hypersensitivity reactions to neuromuscular blocking agents

Sustained intraoperative allergic reaction to chlorhexidine: A case report

Physicians should be prepared for the presentation and treatment of an anaphylactic reaction in a patient who has been exposed to chlorhexidine perioperatively and consider a sustained source of allergic exposure when faced with a refractory response to treatment.

Neuromuscular blocking agent re-exposure in a retrospective cohort with neuromuscular blocking agent-associated anaphylaxis

BACKGROUND

Neuromuscular blocking agents (NMBAs) are one of the most common causes of perioperative anaphylaxis. Although skin test positivity may help identify reactive NMBAs, it is unclear whether skin test negativity can guarantee the safety of systemically administered NMBAs.

OBJECTIVE

This study aimed to evaluate the real-world safety of alternative NMBAs screened using skin tests in patients with suspected NMBA-induced anaphylaxis.

METHODS

A retrospective cohort of suspected NMBA-induced anaphylaxis were recruited among patients at Seoul National University Hospital from June 2009 to May 2021, and their characteristics and outcomes were assessed.

RESULTS

A total of 47 cases (0.017%) of suspected anaphylaxis occurred in 282,707 patients who received NMBAs. Cardiovascular manifestations were observed in 95.7%, whereas cutaneous findings were observed in 59.6%. Whereas 83% had a history of undergoing general anesthesia, 17% had no history of NMBA use. In skin tests, the overall positivity to any NMBA was 94.6% (81.1% to culprit NMBAs) and the cross-reactivity was 75.7%, which is related to the chemical structural similarity among NMBAs; the cross-reactivity and chemical structure similarity of rocuronium were 85.3% and 0.814, respectively, with vecuronium; this is in contrast to 50% and 0.015 with cisatracurium and 12.5% and 0.208 with succinylcholine. There were 15 patients who underwent subsequent surgery with a skin test-negative NMBA; whereas 80.0% (12/15) safely completed surgery, 20.0% (3/15) experienced hypotension.

CONCLUSION

Similarities in chemical structure may contribute to the cross-reactivity of NMBAs in skin tests. Despite the high negative predictability of skin tests for suspected NMBA-induced anaphylaxis, the potential risk of recurrent anaphylaxis has not been eliminated.

Safety of administering cefazolin versus other antibiotics in penicillin-allergic patients for surgical prophylaxis at a major Canadian teaching hospital

BACKGROUND

Cefazolin surgical prophylaxis is associated with better patient outcomes; however, its use in penicillin-allergic patients is controversial. We evaluated the safety of cefazolin as surgical prophylaxis in penicillin-allergic patients, including those with anaphylaxis histories.

METHODS

We conducted a pre and postintervention quality improvement evaluation of an institution-wide policy change at a tertiary-care hospital, before (October 2017-January 2018), during (February 2018-September 2018), and after (October 2018-October 2019) transition to routine cefazolin prophylaxis for penicillin-allergic patients, including those with anaphylaxis histories but excluding severe delayed reactions (eg, Stevens-Johnson syndrome). Retrospective data was collected on all surgical prophylaxis patients with penicillin-anaphylactic histories between October 2017 and September 2018. From October 2018, we prospectively reviewed adverse events with cefazolin. Primary outcome was adverse events in penicillin-allergic patients receiving cefazolin perioperatively.

RESULTS

From October 2017 to October 2019, 27,467 operations were performed. Of 220 patients with penicillin-anaphylactic histories reviewed prior to the full policy change, no statistically significant differences were reported in allergic reactions (P = .70), surgical site infections (P = 1.00), or adverse events (P = .32) with cefazolin compared to other antibiotics. Postpolicy implementation, cefazolin usage increased 18.2%, while vancomycin and clindamycin decreased by 11.4% and 62.0%, respectively. No anaphylaxis was documented in penicillin-allergic patients receiving cefazolin in either the review or quality assurance follow-up after the change. Of 3 patients developing reactions to cefazolin, none had histories of penicillin allergy. Surgical site infection rates were similar between pre and postpolicy time periods (P = .842).

CONCLUSION

Administration of cefazolin in penicillin-anaphylactic patients for surgical prophylaxis appears to be safe.

Serious bronchospasm induced by cisatracurium besylate: A case report

RATIONALE

Cis-atracurium as an intermediate-acting non-depolarizing neuromuscular blocker is widely used clinically with less causing cyclic fluctuations and less histamine release. As the use rate increases, allergic reactions and anaphylactoid reactions caused by cis-atracurium increase.

PATIENT CONCERNS

A 23-year-old woman underwent laparoscopic bariatric surgery. Airway spasm occurred after anesthesia induction and the operation was suspended. After adjustment, the anesthesia was performed with the same anesthetic scheme again. After induction, skin flushing and airway resistance increased, then the symptoms were relieved. When the cis-atracurium was given again, the symptoms of airway spasm reappeared immediately, and after communicating with the family, the operation was successfully completed with rocuronium.

DIAGNOSES

Serious bronchospasm induced by cisatracurium besylate.

INTERVENTIONS

The patient was undergone assisted ventilation with continuous positive airway pressure (CPAP) and aminophylline 250 mg, methylprednisolone 80 mg were given intravenously.

OUTCOMES

There was no any obvious discomfort in the patient's self-report during the next day's visit. The patient was discharged 7 days later. No abnormalities were observed during following 4 weeks.

LESSONS

Although the anaphylactoid reactions caused by cis-atracurium are rare, the bronchospasm and anaphylactic shock caused by it greatly increase the risk of anesthesia, which should be taken seriously by clinicians. Increased vigilance in diagnosis, and treatment are essential to prevent aggravation and further complication.

Severe Bronchoconstriction Caused by Administration of Rocuronium in a 3-Month-Old Infant: Case Report

We present the case of a 3-month-old infant with severe, persistent bronchoconstriction following administration of rocuronium. This observation raises awareness of a rare but potentially life-threatening reaction to neuromuscular blocking agents.

Assessing cross-reactivity to neuromuscular blocking agents by skin and basophil activation tests in patients with neuromuscular blocking agent anaphylaxis

BACKGROUND

Following diagnosis of neuromuscular blocking agent (NMBA) anaphylaxis, identifying safe alternatives for subsequent anaesthesia is critical. A patient with anaphylaxis to one NMBA can also have an allergic reaction to other NMBAs (cross-reactivity). Whilst drug provocation testing is standard for identifying or excluding allergy, there is significant risk. In vitro, after an allergen activates basophils, basophils express surface activation markers that can be measured by basophil activation testing (BAT). We compared cross-reactivity between NMBAs assessed by BAT against that by skin testing.

METHODS

All patients attending an anaesthetic allergy clinic in Sydney, Australia between May 2017 and July 2018 diagnosed with NMBA anaphylaxis qualified for this study comparing intradermal skin tests and BAT with a panel of NMBAs (rocuronium, vecuronium, pancuronium, suxamethonium, cisatracurium).

RESULTS

Of the 61 patients participating, sensitisation on skin testing and on BAT completely matched in only nine patients (15%). Sensitisation was not in agreement for pancuronium, cisatracurium and rocuronium, but was in agreement for vecuronium and suxamethonium. Nine patients with negative skin tests subsequently tolerated cisatracurium, and one false positive on BAT to cisatracurium was detected.

CONCLUSIONS

The utility of BAT in identifying safe NMBAs for subsequent anaesthesia needs further evaluation. BAT detects a different cross-reactivity profile to skin tests. Negative skin testing and BAT might increase confidence in performing drug provocation testing, but this and follow-up of subsequent anaesthesia in our cohort is necessary to determine the clinical significance of BAT sensitisation.

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.

Pediatric drug hypersensitivity: which diagnostic tests?

Along with the anamnesis and clinical evaluation, diagnostic tests are one of the mainstream key points in the evaluation and management of drug hypersensitivity reactions (DHR). A wide knowledge gap, both in diagnosis and management of pediatric DHR, must be filled.  Only a few published studies evaluated sensitivity and specificity of skin and in vitro tests in children. However, selected case series show that diagnostic work-up for adults could be useful, with some limitations, in pediatric age. Indeed, despite improvement in in vivo and in vitro diagnosis, drug provocation test remains the gold standard in pediatric age, too. Unmet needs in children include multi-centric studies on incidence of DHR, utility and feasibility of in vivo and in vitro diagnostic tests and specifically dedicated guidelines for the diagnosis and management of DHR in children.

Intradermal skin tests for rocuronium and cisatracurium in patients with a history of allergy: a retrospective study

BACKGROUND

Neuromuscular blocking agents (NMBAs) are a leading cause of perioperative anaphylaxis. However, the performance of systematic screening skin tests to detect reactions for NMBAs prior to general anesthesia is not recommended. We retrospectively examined intradermal tests (IDTs) for rocuronium and cisatracurium in patients with a history of allergy.

METHODS

We reviewed the records of patients who underwent IDTs for NMBAs between January 1 and December 31, 2016. We analyzed the patients' allergy histories and skin test results for NMBAs.

RESULTS

The overall prevalence of positive IDTs was 5.8% (26/451), and there was no significant difference in prevalence among allergy types (P = 0.655). In logistic regression analysis, there was no allergy history that had a significant effect on positive IDT for NMBAs.

CONCLUSIONS

We found no association between allergy history and positive skin test for NMBAs. Therefore, a systematic screening test for NMBAs or other anesthetic agents before anesthesia is not considered necessary even in patients with an allergy history.

Six years without pholcodine; Norwegians are significantly less IgE-sensitized and clinically more tolerant to neuromuscular blocking agents

BACKGROUND

As a strong inducer of IgE antibodies to substituted ammonium ion epitopes (QAI), pholcodine (PHO) is a postulated cause of allergic anaphylaxis to neuromuscular blocking agents (NMBAs). Three years after withdrawal of PHO in Norway, a significant reduction in IgE sensitization and anaphylaxis reporting was seen.

OBJECTIVE

Six-year follow-up study on the effects of PHO withdrawal on IgE sensitization and anaphylaxis reporting.

METHODS

From 650 acute consecutive reports (2005-2013) to the Norwegian Network for Anaphylaxis under Anaesthesia (NARA), total number of reports on suspected anaphylactic reactions, number of reactions where NMBAs were administered, number of reactions where serum IgE antibodies (≥0.35 kU_A /l) to suxamethonium (SUX) and PHO were present at time of reaction and anaphylaxis severity grades were retrieved. In addition, NMBA sales and prevalence of IgE sensitization to PHO and SUX among 'allergics' were monitored.

RESULTS

From baseline period P0 (PHO on the market) through the first (P1) and second (P2), three-year periods after withdrawal, significant falls in total reports (P < 0.001) and reports with IgE antibodies to PHO (P = 0.008) and SUX (P = 0.001) at time of reaction were found. Total NMBA sales in P2 were 83% of P0, and SUX and rocuronium (ROC) together made up 86% of sales throughout the study. Five NMBA-related anaphylactic deaths occurred during P0 and P1 and, however, none during P2. Prevalence of IgE sensitization to SUX in 'allergics' fell to 0% at 4 and 5 years after withdrawal.

CONCLUSIONS

Six years after PHO withdrawal, the Norwegian population has become significantly less IgE-sensitized and clinically more tolerant to NMBAs.

A case of anaphylaxis apparently induced by sugammadex and rocuronium in successive surgeries

Rocuronium is the agent most frequently involved in perioperative anaphylaxis, and sugammadex has also been known to induce anaphylactic reactions. We describe a case of successive anaphylactic episodes that seemed to be induced by clinical doses of rocuronium and sugammadex. The patient was a 19-year-old woman who had a medical history of asthma, but no history of surgery. She had been injured in a fall, and several surgeries were scheduled for multiple bone fractures. At the first surgery under general anesthesia, she developed anaphylaxis 5 min after sugammadex administration. A second general anesthesia for treatment of calcaneal fracture was induced uneventfully without neuromuscular blockade after 10 days. A third general anesthesia was scheduled to reinforce the spinal column 12 days after the first surgery. She developed anaphylaxis 8 min after rocuronium administration. The level of plasma histamine was elevated, but serum tryptase level remained normal. This surgery was canceled and rescheduled without use of a neuromuscular blockade. Skin tests were performed in a later investigation. The patient showed positive results on intradermal tests for sugammadex and rocuronium, supporting a diagnosis of allergic reactions to both drugs. Clinicians must be aware that anaphylactic reactions can be induced by both sugammadex and rocuronium.

A fatal adverse effect of cefazolin administration: severe brain edema in a patient with multiple meningiomas

Cefazolin is commonly administered before surgery as a prophylactic antibiotic. Hypersensitivity to cefazolin is not uncommon, and the symptoms mostly include urticaria, skin reaction, diarrhea, vomiting, and transient neutropenia, which are rarely life threatening. We present a rare case of fatal cefazolin hypersensitivity in a female who was diagnosed with multiple meningiomas and scheduled for craniotomy and tumor removal. Immediately after cefazolin IV administration, the patient developed acute hypertensive crisis, which resolved within 10 minutes after the treatment. This was followed by unexplained metabolic acidosis. The patient then developed severe brain edema 100 minutes later. The patient had facial edema when her face was exposed for the next 30 minutes. A computed tomography scan revealed global brain edema with herniation. She was admitted to the intensive care unit for symptomatic treatment and died 10 days after surgery from multiorgan failure. The serum IgE level was very high (734 IU/mL). Single-dose administration of cefazolin for surgical prophylaxis may lead to rare, fatal adverse reaction. The warning signs are sudden, unexplained metabolic acidosis, hypertensive crisis, tachycardia, and facial angioedema predominating with or without cutaneous symptoms like urticaria.

Antibiotic-induced immediate type hypersensitivity is a risk factor for positive allergy skin tests for neuromuscular blocking agents

BACKGROUND

Skin tests for neuromuscular blocking agents (NMBAs) are not currently recommended for the general population undergoing general anaesthesia. In a previous study we have reported a high incidence of positive allergy tests for NMBAs in patients with a positive history of non-anaesthetic drug allergy, a larger prospective study being needed to confirm those preliminary results. The objective of this study was to compare the skin tests results for patients with a positive history of antibiotic-induced immediate type hypersensitivity reactions to those of controls without drug allergies.

METHODS

Ninety eight patients with previous antibiotic hypersensitivity and 72 controls were prospectively included. Skin tests were performed for atracurium, pancuronium, rocuronium, and suxamethonium.

RESULTS

We found 65 positive skin tests from the 392 tests performed in patients with a positive history of antibiotic hypersensitivity (1 6.58%) and 23 positive skin tests from the 288 performed in controls (7.98%), the two incidences showing significant statistical difference (p = 0.0011). The relative risk for having a positive skin test for NMBAs for patients versus controls was 1.77 (1.15-2.76). For atracurium, skin tests were more often positive in patients with a positive history of antibiotic hypersensitivity versus controls (p = 0.02). For pancuronium, rocuronium and suxamethonium the statistical difference was not attained (p-values 0.08 for pancuronium, 0.23 for rocuronium, and 0.26 for suxamethonium).

CONCLUSIONS

Patients with a positive history of antibiotic hypersensitivity seem to have a higher incidence of positive skin tests for NMBAs. They might represent a group at higher risk for developing intraoperative anaphylaxis compared to the general population.

Immediate-type hypersensitivity drug reactions

Hypersensitivity reactions including anaphylaxis have been reported for nearly all classes of therapeutic reagents and these reactions can occur within minutes to hours of exposure. These reactions are unpredictable, not directly related to dose or the pharmacological action of the drug and have a relatively high mortality risk. This review will focus on the clinical presentation, immune mechanisms, diagnosis and prevention of the most serious form of immediate onset drug hypersensitivity reaction, anaphylaxis. The incidence of drug-induced anaphylaxis deaths appears to be increasing and our understanding of the multiple and complex reasons for the unpredictable nature of anaphylaxis to drugs is also expanding. This review highlights the importance of enhancing our understanding of the biology of the patient (i.e. immune response, genetics) as well as the pharmacology and chemistry of the drug when investigating, diagnosing and treating drug hypersensitivity. Misdiagnosis of drug hypersensitivity leads to substantial patient risk and cost. Although oral provocation is often considered the gold standard of diagnosis, it can pose a potential risk to the patient. There is an urgent need to improve and standardize diagnostic testing and desensitization protocols as other diagnostic tests currently available for assessment of immediate drug allergy are not highly predictive.

The incidence of perioperative hypersensitivity reactions: a single-center, prospective, cohort study

BACKGROUND

The incidence of perioperative hypersensitivity reactions, which can be life-threatening, ranges from 1 in 20,000 to 1 in 1361. These reactions are usually classified as IgE or non-IgE mediated. The aim of this study was to determine the incidence of allergic reactions during general anesthesia in our hospital, to establish the incidence of the allergic reactions for each drug used, to assess the frequency of IgE-mediated reactions in even mild reactions, and to compare the degree of agreement between anesthesiologist suspicion and allergy diagnosis.

METHODS

We included patients diagnosed with a clinical hypersensitivity reaction during a procedure under general anesthesia over a 30-month period (February 2008 to August 2010). Plasma histamine and serum tryptase concentrations were determined in these patients. We performed skin tests to diagnose the causative agent. Data from the hospital electronic prescribing system were collected to determine the ratio of reactions for each drug.

RESULTS

During the study period, 16,946 anesthetic procedures were performed (53% involved males; mean age, 51.6 years). Forty-four perianesthetic reactions were recorded, and the ratio of reactions was 1 in 385 operations (95% confidence interval, 1/529-1/287). Twenty-five reactions (25/44; 57%) occurred during the induction of anesthesia. Twenty-one reactions (21/44; 48%) were mild, involving only skin, and 23 of 44 (52%) were anaphylactic reactions. Four of 10 patients who had only a rash experienced IgE-mediated reactions. Five surgeries (11%) were suspended because of the severity of the reactions. Fifteen reactions (15/30; 50%) were IgE mediated, and, in 2 of 30 (7%), a non-IgE agent was found (cold urticaria and nonsteroidal anti-inflammatory drug intolerance). The ratio of reactions for each drug was as follows: protamine, 1 in 468; cisatracurium, 1 in 1388; amoxicillin-clavulanate, 1 in 1968; atracurium, 1 in 2039; and dipyrone, 1 in 3159.

CONCLUSIONS

Perioperative reactions are more common than previously reported. Mild hypersensitivity perioperative reactions-involving only skin-should be considered in evaluating patients because a substantial number of these reactions are IgE mediated.

Anaphylaxis is more common with rocuronium and succinylcholine than with atracurium

BACKGROUND

Intraoperative anaphylaxis is a rare but serious occurrence, often triggered by neuromuscular-blocking drugs (NMBDs). Previous reports suggest that the rates of anaphylaxis may be greater for rocuronium than for other NMBDs, but imprecise surrogate metrics for new patient exposures to NMBDs complicate interpretation.

METHODS

This was a retrospective, observational cohort study of intraoperative anaphylaxis to NMBDs at two hospitals between 2006 and 2012. Expert anesthetic and immunologist collaborators investigated all referred cases of intraoperative anaphylaxis where NMBDs were administered and identified those where a NMBD was considered responsible. New patient exposures for each NMBD were extracted from electronic anesthetic records compiled during the same period. Anaphylaxis rates were calculated for each NMBD using diagnosed anaphylaxis cases as the numerator and the number of new patient exposures as the denominator.

RESULTS

Twenty-one patients were diagnosed with anaphylaxis to an NMBD. The incidence of anaphylaxis was 1 in 22,451 new patient exposures for atracurium, 1 in 2,080 for succinylcholine, and 1 in 2,499 for rocuronium (P < 0.001).

CONCLUSIONS

In Auckland, the rate of anaphylaxis to succinylcholine and rocuronium is approximately 10-fold higher than to atracurium. Previous estimates of NMBD anaphylaxis rates are potentially confounded by inaccurate proxies of new patient exposures. This is the first study to report anaphylaxis rates using a hard denominator of new patient exposures obtained directly from anesthetic records.

Sudden cardiovascular collapse caused by severe anaphylaxis after cisatracurium use: a case report

Kounis syndrome is an acute coronary syndrome concurrently occurs with allergic or hypersensitivity reactions. In patient with this syndrome, inflammatory mediators released due to an allergic reaction implicate to induce coronary artery spasm and atheromatous plaque rupture. We describe a patient with coronary artery disease who developed acute perioperative myocardial infarction leading to cardiac arrest after the anaphylactic reaction to cisatracurium, which led to a suspicion of Kounis syndrome. Anesthesiologists should be aware that anaphylaxis or allergic reactions can progress to acute coronary syndrome, thereby significantly change the course of the disease.

Anaphylaxis from atracurium without skin manifestation

Anaphylaxis is an acute, potentially fatal allergic reaction involving multi organ system that is triggered by a wide range of antigens with a subsequent release of chemical mediators from mast cells and basophils. Diagnosis is primarily clinical though laboratory studies are helpful in further confirmation. Anaphylactic reactions during anesthesia are rare, but can be fatal if not promptly recognized and treated. Among all drugs commonly used in anesthesia, muscle relaxants are the most notorious to trigger anaphylactic reactions and benzylisoquinolinium group of drugs are known to be less common an offender than the steroidal compounds. We report severe anaphylactic reaction after administration of atracurium that was promptly diagnosed and managed without any further morbidity.

Anaphylactic reactions after cisatracurium administration in two patients -a report of two cases-

Cisatracurium was initially characterized to have no evident histamine-releasing potential with excellent cardiovascular stability. However, severe anaphylactic reactions to cisatracurium that resulted in bronchospasms and cardiovascular collapse have been reported worldwide. Two cases of severe anaphylactic reactions after the administration of cisatracurium are presented. The anesthetics used in both cases were lidocaine, midazolam, propofol (microemulsion propofol in the second case), remifentanil and cisatracurium. After the administration of these drugs, bronchospasm and hypotension manifested, leading to the diagnosis of anaphylaxis and appropriate treatment. Skin intradermal testing confirmed that both cases were due to immune-mediated anaphylaxis to cisatracurium, despite the fact that neither of the patients had been exposed to the allergen previously. The anaphylaxis may be due to cross-reactivity between neuromuscular blocking agents and substances with quaternary ammonium ions. Anesthesiologists should be aware that cisatracurium has the potential to trigger severe anaphylactic reactions via an immune-mediated mechanism.

Anaphylaxis to neuromuscular blocking drugs: incidence and cross-reactivity in Western Australia from 2002 to 2011

BACKGROUND

Neuromuscular blocking drugs (NMBDs) are the most common cause of intraoperative anaphylaxis in Western Australia. Differences in the rates of anaphylaxis between individual agents have been surmised in the past, but not proven, and are an important consideration if agents are otherwise equivalent.

METHODS

We estimated a rate of anaphylaxis to NMBDs by analysing cases of NMBD anaphylaxis referred to the only specialized diagnostic centre in Western Australia over a 10 yr period. Exposure was approximated by analysing a 5 yr period of NMBD ampoule sales data. Agents were also ranked according to the prevalence of cross-reactivity in patients with previous NMBD anaphylaxis.

RESULTS

Rocuronium was responsible for 56% of cases of NMBD anaphylaxis, succinylcholine 21%, and vecuronium 11%. There was no difference in the severity of reactions for different NMBDs. Rocuronium had a higher rate of IgE-mediated anaphylaxis compared with vecuronium (8.0 vs 2.8 per 100,000 exposures; P=0.0013). The prevalence of cross-reactivity after NMBD anaphylaxis suggested that succinylcholine also has a high risk of triggering anaphylaxis. Cisatracurium had the lowest prevalence of cross-reactivity in patients with known anaphylaxis to rocuronium or vecuronium.

CONCLUSIONS

Rocuronium has a higher rate of IgE-mediated anaphylaxis compared with vecuronium, a result that is statistically significant and clinically important. Cisatracurium had the lowest rate of cross-reactivity in patients who had previously suffered anaphylaxis to rocuronium or vecuronium.

Definitions and mechanisms of drug hypersensitivity

Adverse drug reactions are a difficult problem faced by clinicians in everyday practice. The mechanisms of drug hypersensitivity are not well understood. This is reflected by difficulties in their classification, which is mainly based upon the current knowledge of immunologic and nonimmunologic mechanisms, onset of symptoms (immediate or nonimmediate) and morphology. For the individual patient, the correct diagnosis and classification is important because strict avoidance of the offending drug might be of vital importance. Considerable experience is required to guide management, to interpret results of investigations and to undertake drug challenges. This article summarizes the current knowledge regarding definitions and mechanisms. However, the field of drug hypersensitivity is rapidly expanding. Modern drugs such as biological agents bare hypersensitivity risks that are potentially mediated by, so far, unknown mechanisms.

IgE and chemotherapy

The nexus of chemotherapeutic intervention and the immunomodulation of IgE-related phenomena are not well understood. The relationship bears importance in better understanding the causal and/or resultant effects of one on the other and their collective role in the management and sequelae of the cancer patient. This review discusses the relationship of chemotherapy on immunoglobulins with a focus on IgE and other related biological processes including hypersensitivity reactions and proposes models toward effective management of the cancer patient in this regard.

Effects of sugammadex and rocuronium mast cell number and degranulation in rat liver

We investigated the effect of rocuronium- and sugammadex-induced mast cell increase and degranulation in rat portal triads. Forty-two rats, in six groups, received either rocuronium 1 mg.kg(-1); sugammadex 15 mg.kg(-1); sugammadex 100 mg.kg(-1); rocuronium 1 mg.kg(-1) and 5 min later, sugammadex 15 mg.kg(-1); rocuronium 1 mg.kg(-1) and 5 min later, sugammadex 100 mg.kg(-1); or isotonic saline. Total mast cell numbers were significantly higher with rocuronium only, than in all other groups (p<0.003), although in all active groups, the number was greater than the control. Total mast cell number was significantly higher with rocuronium and low-dose sugammadex compared with low-dose sugammadex only. The number of tryptase-positive mast cells with rocuronium only was significantly higher than in all other groups (p<0.003). Tryptase-positive mast cell numbers in both groups receiving both rocuronium and sugammadex were significantly higher compared with both groups receiving sugammadex only. Rocuronium increased mast cell numbers, and degranulation was mitigated by sugammadex. These results suggest that sugammadex may be beneficial in treatment of rocuronium-induced anaphylaxis.

Is a positive history of non-anaesthetic drug allergy a predictive factor for positive allergy tests to anaesthetics?

AIMS

International recommendations stipulate not performing screening skin tests to a drug in the absence of a clinical history consistent with that specific drug allergy. Nevertheless, two publications showed that a positive history of non-anaesthetic drug allergy was the only predictive factor for a positive skin test when screening for allergy to anaesthetic drugs was done. We selected from a surgical population 40 volunteers with a prior history of allergy to non-anaesthetic drugs in order to analyse the prevalence of positive allergy tests to anaesthetics.

METHODS

The selected adult patients were tested for 11 anaesthetic drugs using in vivo tests: skin prick (SPT) and intradermal (IDT) tests and in vitro tests: the basophil activation test (BAT) and detection of drug-specific immunoglobulin E (IgE).

RESULTS

The prevalence for the positive SPT and IDT was 1.6% and 5.8% respectively. The result of flow cytometry agreed with the SPT in five out of seven positive SPT (71%). IgEs confirmed two positive SPT with corresponding positive BAT. Ten per cent of the patients had a positive prick test to neuromuscular blocking agents (NMBA). For midazolam none of the SPT was positive, but 11 patients had positive IDT nonconfirmed by BAT.

CONCLUSION

The prevalence of positive in vivo and in vitro allergy tests to NMBAs is higher in our study population. This could be an argument for pre-operative SPT to NMBAs for the surgical population with reported non-anaesthetic drug allergies. A larger prospective study is needed to validate changes in clinical practice.

Immunologic evaluation of drug allergy

Hypersensitivity drug reactions (HDR) consist of an individual abnormal response with the involvement of the immunological system. In addition to specific immunological mechanisms where specific antibodies or sensitised T cells participate, release of inflammatory mediators by non-specific immunological recognition may also occur. Within this category are one of the most common groups of drugs, the non-steroidal anti-inflammatory drugs. In addition to chemical drugs new emerging ones with an increasing protagonism are biological agents like humanised antibodies and others. For IgE dependent reactions both in vivo and in vitro tests can be used for the immunological evaluation. Sensitivity of these is not optimal and very often a drug provocation test must be considered for knowing the mechanism involved and/or establishing the diagnosis. For non-immediate reactions also both in vivo and in vitro tests can be used. Sensitivity for in vivo tests is generally low and in vitro tests may be needed for the immunological evaluation. Immunohistochemical studies of the affected tissue enable a more precise classification of non-immediate reactions. The monitorization of the acute response of the reactions has given clues for understanding these reactions and has promising results for the future of the immunological evaluation of HDR.

Does topical lidocaine before tracheal intubation attenuate airway responses in children? An observational audit

BACKGROUND

The use of topical lidocaine, applied to the airways with various administration techniques, is common practice in pediatric anesthesia in many institutions. However, it remains unclear whether these practices achieve their intended goal of reducing the risk of perioperative respiratory adverse events (PRAE) in children undergoing elective endotracheal intubation without neuromuscular blockade (NMB). The relative frequency of PRAE (laryngospasm, coughing, desaturation <95%) associated with no use of topical airway lidocaine (TAL), with TAL sprayed directly onto the vocal cords, and TAL administered blindly into the pharynx was assessed.

METHODS

This prospective audit involved 1000 patients undergoing general anesthesia with elective endotracheal intubation without NMB. Patients with suspected difficult airways or undergoing airway surgery were excluded. The use of TAL and the mode of administration were recorded. Respiratory adverse events were recorded in the perioperative period.

RESULTS

Two hundred and fifty-four patients had the vocal cords sprayed under direct vision, 236 had lidocaine blindly dripped into the pharynx, and 510 received no TAL. The mean age and known risk factors for PRAE (asthma, recent upper respiratory tract infection (≤2 weeks), passive smoking, hayfever, past or present eczema, nocturnal dry cough) were similar among the groups. The proportion of patients with desaturation (<95%) between induction of anesthesia and discharge from the recovery room was higher in the two groups who received TAL (data combined for all patients receiving lidocaine regardless of administration method, P = 0.01) compared to those who received no TAL. No difference in the rates of laryngospasm (P = 0.13) or cough (P = 0.07) was observed among the groups. There was no difference in the rates of PRAE between the groups given TAL directly onto the vocal cords and in those whom received TAL blindly.

CONCLUSIONS

The incidence of desaturation was higher in patients receiving TAL compared with children who did not. This association should perhaps be considered when contemplating the use of this technique.

The role of sugammadex in the development and modification of an allergic response to rocuronium: evidence from a cutaneous model

The availability of sugammadex as a selective encapsulating agent for rocuronium has led to speculation that it may be useful in mitigating rocuronium-induced anaphylaxis. Off-label use of sugammadex for this indication has already been documented in case reports although there are theoretical objections to the likelihood of an allergen-binding agent's being able to attenuate the immunological cascade of anaphylaxis. Using a cutaneous model of anaphylaxis in rocuronium-sensitised patients, we were unable to demonstrate that sugammadex was effective in attenuating the type-1 hypersensitivity reaction after it has been triggered by rocuronium, but we were able to demonstrate that these patients are anergic to sugammadex-bound rocuronium. These findings demonstrate that a cyclodextrin can bind an allergen and exclude it from interacting with the immune system, and may potentially lead to novel applications in other allergic diseases. However, there is no evidence that sugammadex should be used for the treatment of rocuronium-induced anaphylaxis, and clinical management should follow established protocols.

Design of a heterobivalent ligand to inhibit IgE clustering on mast cells

We describe the design, synthesis, and characterization of a heterobivalent ligand (HBL) system that competitively inhibits allergen binding to mast cell bound IgE antibody, thereby inhibiting mast cell degranulation. HBLs are composed of a hapten conjugated to a nucleotide analog allowing simultaneous targeting of the antigen-binding site as well the "unconventional nucleotide binding site" on IgE Fab domains. Simultaneous bivalent binding to both sites provides HBLs with over 100-fold enhancement both in avidity for IgE(DNP) (K(d) = 0.33 μM) and in inhibition of allergen binding to IgE(DNP) (IC(50) = 0.45 μM) than the monovalent hapten (K(d)(mono) = 41 μM; IC(50)(mono) = 55.4 μM, respectively). In cellular assays, HBL2 effectively inhibits mast cell degranulation (IC(50) = 15 μM), whereas no inhibition is detected by the monovalent hapten. In conclusion, this study establishes the use of multivalency in a novel HBL design to inhibit mast cell degranulation.

Muscle relaxants allergy

The most common agents that are responsible for intraoperative anaphylaxis are muscle relaxants. In fact, neuromuscular blocking agents (NMBAs) contribute to 50-70 percent of allergic reactions during anaesthesia. The main mechanism of hypersensitivity reactions to NMBAs is represented by acute type I allergic reactions and the most severe form is anaphylaxis. The rate of non IgE mediated immediate hypersensitivity reactions usually varies between 20 percent and 35 percent of the reported cases in most large series. In a recent report, non allergic suspected reactions to NMBAs occurred with almost the same frequency as did those with an allergic component. Although the precise mechanisms of these reactions remain difficult to ascertain, they usually result from direct non specific mast cell and basophil activation. After diagnostic procedures, regardless of the specific IgE results, NMBAs are contraindicated if the skin tests were positive. In view of the constantly evolving anesthesiologic practices, and of the complexity of allergy investigation, an active policy to identify patients at risk and to provide any necessary support to anaesthetists and allergologists should be promoted. The high frequency of IgE anaphylactic reactions and the feasibility of skin tests in children justify systematic allergy testing whenever hypersensitivity reaction occurs during general anaesthesia.

IgE-sensitization to the cough suppressant pholcodine and the effects of its withdrawal from the Norwegian market

BACKGROUND

IgE-mediated anaphylaxis to neuromuscular blocking agents (NMBA), frequent in Norway, was proposed to be caused by exposure to pholcodine (PHO) carrying the allergenic quarternary ammonium ion epitope. Consequently, the PHO-containing drug was withdrawn from the market in March 2007.

OBJECTIVE

Describe the effects of withdrawal of PHO on IgE, IgE-antibodies and reported frequencies of anaphylaxis to NMBAs.

METHODS

Three hundred sera from supposedly allergic patients sampled yearly through 2006 to 2010 were analysed for IgE antibodies to PHO, suxamethonium (SUX) and morphine (MOR). Furthermore, IgE and preliminary reports from the Norwegian Network for Anaphylaxis under Anaesthesia (NARA) were monitored.

RESULTS

PHO exposure was associated with IgE sensitization to PHO, MOR and SUX. However, after withdrawal, within 1 year, antibody prevalences to PHO and SUX fell significantly from 11.0% to 5.0% and from 3.7% to 0.7%, respectively. At 3 years, SUX had fallen to 0.3%, PHO to 2.7% and MOR to 1.3%. By 2 years, the prevalence of elevated IgE was significantly reduced. After 3 years, the incidence of reported suspected anaesthetic anaphylaxis fell significantly, both the total number, the reactions related to NMBAs and those with IgE antibodies to SUX.

CONCLUSIONS

Withdrawing of PHO lowered significantly within 1-2 years levels of IgE and IgE antibodies to PHO, MOR and SUX, and, within 3 years, the frequency of NMBA suspected anaphylaxis. The results strengthen the PHO hypothesis considerably and equally the need to question the existence of cough depressants containing PHO.

Perioperative Allergy: Clinical Manifestations

Adverse drug reactions or side effects are usually expected, dose dependent, and occur at therapeutic doses. Anaphylactic and anaphylactoid reactions are unexpected and dose independent and can occur at the first exposure to drugs used during anesthesia. Perioperative anaphylaxis is a severe and rapid clinical condition that can be lethal even in previously healthy patients. The initial diagnosis of anaphylaxis is presumptive. A precise identification of the drug responsible for the adverse reaction is more difficult to establish in the case of anaphylactoid reaction because the adverse reaction could result from additive side effects of different drugs injected simultaneously. The timing of the reaction in relation to events, e.g. induction, start of surgery, administration of other drugs, i.v. fluids, is essential for the diagnosis. Generally, reactions are predominant in the induction and recovery phases, and manifested mainly as cutaneous symptoms. Reactions to drugs coincide with the phases when they are administered. Reactions to antibiotics are more frequent in the induction phase, to neuromuscular agents in the initiation and maintenance phases and to non-steroidal anti-inflammatory agents in the recovery phase. The differential diagnosis of any adverse reaction during or following anesthesia should include the possibility of anaphylaxis.