Use of simulation to improve management of perioperative anaphylaxis: a narrative review.

Simulation-based education is often highlighted as a method to prepare health personnel to handle clinical emergencies through repeated training and the design of supports. As one of the most common clinical emergencies in anaesthesia, anaphylaxis is often included in simulation scenarios at both graduate and postgraduate levels. Case reviews of anaphylaxis management continue to identify deficiencies in clinical responses. We evaluated the evidence to support the use of simulation to address these deficiencies. We undertook a comprehensive review of the MEDLINE and Embase databases with MESH terms 'Anaphylaxis', 'Anaesthesia', 'Simulation training', and variations of these terms. Articles were also searched from reference lists in the identified papers. A total of 39 articles on perioperative anaphylaxis simulation were identified, with most focusing on the clinical skills of individuals. However, anaphylaxis scenarios are also being used in assessment of teams and in the evaluation of broader system performance. Many countries mandate simulation training and competency assessment at graduate and postgraduate levels: despite this, none of the articles linked simulation training or assessment with improved patient management or outcomes. We found evidence that in situ simulation and use of cognitive aids lead to improved teamwork and task performace. Quantitative and qualitative evidence for simulation-based perioperative training is limited. Future studies should investigate whether simulation training in perioperative anaphylaxis, particularly in situ simulation, translates into improved patient management and outcomes.

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

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

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

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

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.

Safety Aspects of Postanesthesia Care Unit Discharge without Motor Function Assessment after Spinal Anesthesia: A Randomized, Multicenter, Semiblinded, Noninferiority, Controlled Trial.

BACKGROUND: Postanesthesia care unit (PACU) discharge without observation of lower limb motor function after spinal anesthesia has been suggested to significantly reduce PACU stay and enhance resource optimization and early rehabilitation but without enough data to allow clinical recommendations. METHODS: A multicenter, semiblinded, noninferiority randomized controlled trial of discharge from the PACU with or without assessment of lower limb motor function after elective total hip or knee arthroplasty under spinal anesthesia was undertaken. The primary outcome was frequency of a successful fast-track course (length of stay 4 days or less and no 30-day readmission). Noninferiority would be declared if the odds ratio (OR) for a successful fast-track course was no worse for those patients receiving no motor function assessment versus those patients receiving motor function assessment by OR = 0.68. RESULTS: A total of 1,359 patients (98.8% follow-up) were available for analysis (93% American Society of Anesthesiologists class 1 to 2). The primary outcome occurred in 92.2% and 92.0%, corresponding to no motor function assessment being noninferior to motor function assessment with OR 0.97 (95% CI, 0.70 to 1.35). Adverse events in the ward during the first 24 h occurred in 5.8% versus 7.4% with or without motor function assessment, respectively (OR, 0.77; 95% CI, 0.5 to 1.19, P = 0.24). CONCLUSIONS: PACU discharge without assessment of lower limb motor function after spinal anesthesia for total hip or knee arthroplasty was noninferior to motor function assessment in achieving length of stay 4 days or less or 30-day readmissions. Because a nonsignificant tendency toward increased adverse events during the first 24 h in the ward was discovered, further safety data are needed in patients without assessment of lower limb motor function before PACU discharge.

Treatment with epinephrine (adrenaline) in suspected anaphylaxis during anesthesia in Denmark.

BACKGROUND: Literature on the use of epinephrine in the treatment of anaphylaxis during anesthesia is very limited. The objective of this study was to investigate how often epinephrine is used in the treatment of suspected anaphylaxis during anesthesia in Denmark and whether timing of treatment is important. METHODS: A retrospective study of 270 patients investigated at the Danish Anaesthesia Allergy Centre after referral due to suspected anaphylaxis during anesthesia was performed. Reactions had been graded by severity: C1, mild reactions; C2, moderate reactions; C3, anaphylactic shock with circulatory instability; C4, cardiac arrest. Use of epinephrine, dosage, route of administration, and time between onset of circulatory instability and epinephrine administration were noted. RESULTS: A total of 122 (45.2%) of referred patients had C3 or C4 reactions; of those, 101 (82.8%) received epinephrine. Route of administration was intravenous in 95 (94%) patients. Median time from onset of reported hypotension to treatment with epinephrine was 10 min (range, 1-70 min). Defining epinephrine treatment less than or equal to 10 min after onset of hypotension as early, and more than 10 min as late, infusion was needed in 12 of 60 patients (20%) treated early versus 12 of 35 patients (34%) treated late (odds ratio, 2.09) (95% confidence interval, 0.81-5.35). CONCLUSION: Anaphylaxis may be difficult to diagnose during anesthesia, and treatment with epinephrine can be delayed as a consequence. Anaphylaxis should be considered and treated in patients with circulatory instability during anesthesia of no apparent cause who do not respond to the usual treatments.

Effect of general anesthesia and orthopedic surgery on serum tryptase.

BACKGROUND: Mast cell tryptase is used clinically in the evaluation of anaphylaxis during anesthesia, because symptoms and signs of anaphylaxis are often masked by the effect of anesthesia. No larger studies have examined whether surgery and anesthesia affect serum tryptase. The aim of this study was to investigate the effect of anesthesia and surgery on serum tryptase in the absence of anaphylaxis. METHODS: The study included 120 patients (median age, 54 yr; range, 19-94 yr) undergoing elective orthopedic surgery in general anesthesia. Exclusion criteria were allergic reactions during this or previous anesthesia, hematologic disease, or high-dose corticosteroid treatment. Blood samples for tryptase analysis (ImmunoCAP; Phadia, Uppsala, Sweden) were drawn shortly before anesthesia and after anesthesia and surgery. RESULTS: Median duration of anesthesia was 105 min (range, 44-263 min). Median interval between blood samples was 139 min (range, 39-370 min). Mean tryptase before surgery was 5.01 microg/l, with a mean decrease of 0.55 microg/l (P < 0.0001; 95% CI, 0.3-0.8) postoperatively. All patients received intravenous fluid (median value 750 ml; range, 200-2000 ml) perioperatively. There was no significant effect of gender, age, American Society of Anesthesiologist's physical status classification, or self-reported allergy on serum tryptase. CONCLUSIONS: Serum tryptase shows small intraindividual variation in the absence of anaphylaxis. A small decrease was observed postoperatively, likely due to dilution by intravenous fluid. On suspected anaphylaxis during anesthesia, tryptase values, even within the normal reference interval, should, when possible, be compared with the patient's own basal level taken more than 24 h after the reaction.

Lidocaine as a Rare and Hidden Allergen in the Perioperative Setting: A Case Report.

Local anesthetics are used throughout the health care system. In the perioperative setting and in other settings of exposure to local anesthetics, true allergy is reported very rarely. We present an unusual case of immediate-type perioperative hypersensitivity to lidocaine with cross-reaction to mepivacaine, which was missed on initial investigation. This case illustrates that lidocaine may be a "hidden allergen" in the perioperative setting and should always be considered a potential culprit in cases of suspected perioperative hypersensitivity. The case also demonstrates that suspected perioperative hypersensitivity requires highly specialized investigation and close collaboration between allergists and anesthesiologists.

Polyethylene glycols (PEG) and related structures: overlooked allergens in the perioperative setting.

We describe hypersensitivity to polyethylene glycols (PEGs), with cross-reactivity to a structural analog, polysorbate 80, in a 69-year-old patient with perioperative anaphylaxis and subsequent, severe anaphylactic reactions to unrelated medical products. PEGs and PEG analogs are prevalent in the perioperative setting, contained in a wide range of products seldom suspected of causing hypersensitivity reactions and thus rarely documented in surgical/anesthetic records. We suggest routine testing for PEGs after perioperative anaphylaxis because exposure to these polymers often is significant. Comprehensive brand name documentation on the anesthetic chart of all product exposures is central to identifying the responsible allergen.

[Suspected allergic reaction during anesthesia requires thorough postoperative investigation]. / Allergisk reaktion i forbindelse med anæstesi kræver grundig postoperativ udredning.

Allergic reactions during anaesthesia are rare and the cause is seldom immediately obvious. Incorrect guesses for the offending substance can lead to suboptimal management. Furthermore there is a risk of a serious reaction on subsequent exposure to the real allergen. We present a case of suspected allergy to fentanyl investigated at the Danish Anaesthesia Allergy Centre. Allergy to this drug could not be demonstrated by skin tests or challenge. The reaction was due to unspecific histamine release induced by several opioids given at the same time. Future pretreatment with antihistamine was recommended.

IgE-mediated allergy to chlorhexidine.

BACKGROUND: Investigations at the Danish Anesthesia Allergy Centre have included testing for allergy to chlorhexidine since 1999. OBJECTIVE: To investigate whether measurement of IgE and histamine release confirm an IgE-mediated mechanism for chlorhexidine allergy. METHODS: Twenty-two patients with clinical history suggestive of chlorhexidine allergy were included. Skin tests with chlorhexidine and tryptase measurements were performed during initial investigations. Sera were analyzed retrospectively for IgE and histamine release (passive sensitization) to chlorhexidine. RESULTS: Twelve patients were skin test positive and 10 were skin test negative. Of the skin test-positive patients, 11 of 12 had IgE to chlorhexidine and 7 of 11 had a positive histamine release test. None of the skin test-negative patients had specific IgE or positive histamine release to chlorhexidine. Skin test-positive patients had higher median age (64 vs 49 y) and were mainly male (11/12 vs 6/10). In both groups, 8 patients had hypotension, but bronchospasm mainly appeared in skin test-negative patients (1/12 vs 6/10). Reactions occurred more often during urologic surgery in skin test-positive patients (5/12 vs 0/10). Baseline tryptase was higher in skin test-positive patients (median, 11.5 vs 3.7 microg/L), and 6 of 7 patients had elevated IgE to chlorhexidine in serum at the time of reaction. CONCLUSION: This study confirms that chlorhexidine allergy is IgE-mediated and that measurement of specific IgE and histamine release are good adjuncts to skin testing in patients with clinical history suggesting chlorhexidine allergy. CLINICAL IMPLICATIONS: IgE and histamine release can be used to support the diagnosis of allergy to chlorhexidine.