Judy Morris

Anaphylaxis treated in a Canadian pediatric hospital: Incidence, clinical characteristics, triggers, and management

University of Medicine and Dentistry of New Jersey, Newark, NJ; and ENT and Allergy Associates, Hoboken, NJ. E-mail: ckeet1@jhmi.edu. Supported by National Institutes of Health/National Institute of Allergy and Infectious Diseases grant 1K23AI103187 (to C.A.K.) and the Eudowood fund. Disclosure of potential conflict of interest: R. A. Wood has consultancy arrangements with the Asthma and Allergy Foundation of America, is employed by Johns Hopkins University, has received one or more grants from or has one or more grants pending with the National Institutes of Health, and has received royalties from UpToDate. The rest of the authors declare that they have no relevant conflicts of interest.

Tryptase levels in children presenting with anaphylaxis: Temporal trends and associated factors

BACKGROUND The diagnosis of anaphylaxis currently relies on suggestive clinical history after exposure to a potential triggering factor because no reliable diagnostic marker is available to confirm the diagnosis. OBJECTIVES We aimed to evaluate tryptase levels in children with anaphylaxis and to examine predictors of elevated tryptase level (defined as ≥11.4 μg/L during reaction and for those with a baseline level, defined as a reaction level of at least 2 ng/mL + 1.2 × [postreaction tryptase level]). METHODS Children presenting with anaphylaxis to the Montreal Childrens Hospital were recruited over a 4-year period. Symptoms, triggers, and management of anaphylaxis were documented. Levels during the reaction and approximately 9 months after the reaction were compared on the basis of paired means using the t distribution. Multivariate linear and logistic regressions were used to evaluate the association between tryptase levels and risk factors. RESULTS Over a 4-year period, 203 children had serum tryptase levels measured. Among these, 39 children (19.2%; 95% CI, 14.1%-25.4%) had elevated levels. Only severe reactions were associated with reaction levels of 11.4 μg/L or more (odds ratio, 6.5; 95% CI, 2.2-19.0). Milk-induced anaphylaxis and severe reactions were more likely associated with increased tryptase levels (beta-adjusted, 4.0; 95% CI, 0.95-7.0, and 7.5; 95% CI, 4.8-10.3, respectively). Reaction levels exceeding the threshold level of 2 ng/mL + 1.2 × (postreaction tryptase level) detected most of the anaphylactic reactions, particularly if baseline levels were taken within 2 months of the reaction. CONCLUSIONS Tryptase levels are particularly useful for the diagnosis of severe and/or milk-induced anaphylaxis. Assessing the difference between reaction and postreaction tryptase levels may improve diagnostic sensitivity.

Rate, Triggers, Severity and Management of Anaphylaxis in Adults Treated in a Canadian Emergency Department

Background: The Cross-Canada Anaphylaxis Registry (C-CARE) assesses the triggers and management of anaphylaxis and identifies predictors of the development of severe allergic reactions and of epinephrine use. Here, we present data from an urban adult tertiary care emergency department (ED) in Montreal, Canada. Methods: Potential anaphylaxis cases were identified using ICD-10 codes related to anaphylaxis or allergic reactions. Putative cases underwent chart review to ensure they met anaphylaxis diagnostic criteria. Demographic, clinical and management data were collected. Multivariate logistic regressions were conducted to assess the effect of demographic characteristics, triggers, and comorbidities on severity and management of reactions. Results: Among 37,730 ED visits, 0.26% (95% CI 0.21, 0.32) fulfilled the definition of anaphylaxis. Food was the suspected trigger in almost 60% of cases. Epinephrine was not administered in almost half of moderate-to-severe cases, and similar numbers of individuals with moderate-to-severe reactions were not prescribed an epinephrine autoinjector. Reaction to shellfish was associated with more severe reactions (OR 13.9; 95% CI 2.2, 89.4). Older individuals and those not receiving steroids were more likely managed without epinephrine (OR 1.04; 95% CI 1.01, 1.07 and OR 2.97; 95% CI 1.05, 8.39, respectively). Conclusions: Anaphylaxis accounted for a substantial number of ED visits in adults, and the most common trigger was food. There is non-adherence to guidelines recommending epinephrine use for all cases of anaphylaxis. We postulate that this may be related to concerns regarding the side effects of epinephrine in adults.

The Risk of Recurrent Anaphylaxis

Objectives To determine the recurrence rate of anaphylaxis in children medically attended in an emergency department (ED), we performed a prospective cohort study to evaluate prehospital and ED management of children with recurrent anaphylaxis and to assess factors associated with recurrent anaphylaxis. Study design As part of the Cross‐Canada Anaphylaxis Registry, parents of children with anaphylaxis identified prospectively in 3 EDs and through an emergency medical response service were contacted annually after presentation and queried on subsequent reactions. Cox regression analysis determined factors associated with recurrence. Results Among 292 children who were registered as having had medical attended anaphylaxis, 68.5% completed annual follow‐up questionnaires. Forty‐seven patients experienced 65 episodes of anaphylaxis during 369 patient‐years of follow‐up. Food was the trigger in 84.6% of cases, and epinephrine was used in 66.2%. In 50.8%, epinephrine was used outside the health care facility, and 81.7% were brought to a health care facility for treatment. Asthma, reaction triggered by food, and use of epinephrine during the index episode increased the odds of recurrent reaction. Patients whose initial reaction was triggered by peanut were less likely to have a recurrent reaction. Conclusions We report a yearly anaphylaxis recurrence rate of 17.6% in children. There is substantial underuse of epinephrine in cases of anaphylaxis. Educational programs that promote effective avoidance strategies and prompt use of epinephrine are required.

Food-induced anaphylaxis to a known food allergen in children often occurs despite adult supervision

8. Fiocchi A, Dionisi-Vici C, Cotugno G, Koch P, Dahdah L. Fruit induced FPIES masquerading as hereditary fructose intolerance. Pediatrics. 2014;134:e602-e605. 9. Morita H, Nomura I, Orihara K, et al. Antigenspecific Tcell responses in patients with nonIgEmediated gastrointestinal food allergy are predominantly skewed to T(H)2. J Allergy Clin Immunol. 2013;131:590-592. 10. Wada T, Matsuda Y, Toma T, Koizumi E, Okamoto H, Yachie A. Increased CD69 expression on peripheral eosinophils from patients with food proteininduced enterocolitis syndrome. Int Arch Allergy Immunol. 2016;170:201-205. 11. Goswami R, Blazquez AB, Kosoy R, Rahman A, Nowak-Węgrzyn A, Berin MC. Systemic innate immune activation in food proteininduced enterocolitis syndrome. J Allergy Clin Immunol. 2017;139:1885-1896.

Prehospital Advanced Cardiac Life Support for Out‐of‐hospital Cardiac Arrest: A Cohort Study

OBJECTIVES Out-of-hospital advanced cardiac life support (ACLS) has not consistently shown a positive impact on survival. Extracorporeal cardiopulmonary resuscitation (E-CPR) could render prolonged on-site resuscitation (ACLS or basic cardiac life support [BCLS]) undesirable in selected cases. The objectives of this study were to evaluate, in patients suffering from out-of-hospital cardiac arrest (OHCA) and in a subgroup of potential E-CPR candidates, the association between the addition of prehospital ACLS to BCLS and survival to hospital discharge, prehospital return of spontaneous circulation (ROSC), and delay from call to hospital arrival. METHODS This cohort study targets adult patients treated for OHCA between April 2010 and December 2015 in the city of Montreal, Canada. We defined potential E-CPR candidates using clinical criteria previously described in the literature (65 years of age or younger, initial shockable rhythm, absence of ROSC after 15 minutes of prehospital resuscitation, and emergency medical services-witnessed collapse or witnessed collapse with bystander cardiopulmonary resuscitation). Associations were evaluated using multivariate regression models. RESULTS A total of 7,134 patients with OHCA were included, 761 (10.7%) of whom survived to discharge. No independent association between survival to hospital discharge and the addition of prehospital ACLS to BCLS was found in either the entire cohort (adjusted odds ratio [AOR] = 1.05 [95% confidence interval {CI} = 0.84-1.32], p = 0.68) or among the 246 potential E-CPR candidates (AOR = 0.82 [95% CI = 0.36-1.84], p = 0.63). The addition of prehospital ACLS to BCLS was associated with a significant increase in the rate of prehospital ROSC in all patients experiencing OHCA (AOR = 3.92 [95% CI = 3.38-4.55], p < 0.001) and in potential E-CPR candidates (AOR = 3.48 [95% CI = 1. 76-6.88], p < 0.001) compared to isolated prehospital BCLS. Delay from call to hospital arrival was longer in the ACLS group than in the BCLS group (difference = 16 minutes [95% CI = 15-16 minutes], p < 0.001). CONCLUSIONS In a tiered-response urban emergency medical service setting, prehospital ACLS is not associated with an improvement in survival to hospital discharge in patients suffering from OHCA and in potential E-CPR candidates, but with an improvement in prehospital ROSC and with longer delay to hospital arrival.

Impact of the direct transfer to percutaneous coronary intervention-capable hospitals on survival to hospital discharge for patients with out-of-hospital cardiac arrest

AIMS Patients suffering from out-of-hospital cardiac arrest (OHCA) are frequently transported to the closest hospital. Percutaneous coronary intervention (PCI) is often indicated following OHCA. This studys primary objective was to determine the association between being transported to a PCI-capable hospital and survival to discharge for patients with OHCA. The additional delay to hospital arrival which could offset a potential increase in survival associated with being transported to a PCI-capable center was also evaluated. METHODS This study used a registry of OHCA in Montreal, Canada. Adult patients transported to a hospital following a non-traumatic OHCA were included. Hospitals were dichotomized based on whether PCI was available on-site or not. The effect of hospital type on survival to discharge was assessed using a multivariable logistic regression. The added prehospital delay which could offset the increase in survival associated with being transported to a PCI-capable center was calculated using that regression. RESULTS A total of 4922 patients were included, of whom 2389 (48%) were transported to a PCI-capable hospital and 2533 (52%) to a non-PCI-capable hospital. There was an association between being transported to a PCI-capable center and survival to discharge (adjusted odds ratio = 1.60 [95% confidence interval 1.25-2.05], p < .001). Increasing the delay from call to hospital arrival by 14.0 min would offset the potential benefit of being transported to a PCI-capable center. CONCLUSIONS It could be advantageous to redirect patients suffering from OHCA patients to PCI-capable centers if the resulting expected delay is of less than 14 min.

Disparities in rate, triggers, and management in pediatric and adult cases of suspected drug‐induced anaphylaxis in Canada

Data is sparse on drug‐induced anaphylaxis (DIA) and there have not been studies assessing the differences in clinical characteristics and management of DIA between adults and children.

Short- and long-term management of cases of venom-induced anaphylaxis is suboptimal

BACKGROUND Venom-induced anaphylaxis (VIA) accounts for severe reactions. However, little is known about the short- and long-term management of VIA patients. OBJECTIVE To assess the short- and long-term management of VIA. METHODS Using a national anaphylaxis registry (C-CARE), we identified VIA cases presenting to emergency departments in Montreal and to emergency medical services (EMSs) in western Quebec over a 4-year period. Data were collected on clinical characteristics, triggers, and management. Consenting patients were contacted annually regarding long-term management. Univariate and multivariate logistic regressions were used to identify factors associated with epinephrine use, allergist assessment, and administration of immunotherapy. RESULTS Between June 2013 and May 2017, 115 VIA cases were identified. Epinephrine was administered to 63.5% (95% confidence interval [CI], 53.9%-72.1%) of all VIA cases by a health care professional. Treatment of reactions without epinephrine was more likely in reactions occurring at home and in nonsevere cases (no hypotension, hypoxia, or loss of consciousness). Among 48 patients who responded to a follow-up questionnaire, 95.8% (95% CI, 84.6%-99.3%) were prescribed epinephrine auto-injector, 68.8% (95% CI, 53.6%-80.9%) saw an allergist who confirmed the allergy in 63.6% of cases, and 81.0% of those with positive testing were administered immunotherapy. Among cases with follow-up, seeing an allergist was less likely in patients with known ischemic heart disease. CONCLUSION Almost 30% of patients with suspected VIA did not see an allergist, only two thirds of those seeing an allergist had allergy confirmation, and almost one fifth of those with confirmed allergy did not receive immunotherapy. Educational programs are needed to bridge this knowledge-to-action gap.

Potential impact of a prehospital redirection system for refractory cardiac arrest

AIM A change in prehospital redirection practice could potentially increase the proportion of E-CPR eligible patients with out-of-hospital cardiac arrest (OHCA) transported to extracorporeal cardiopulmonary resuscitation (E-CPR) capable centers. The objective of this study was to quantify this potential increase of E-CPR candidates transported to E-CPR capable centers. METHODS Adults with non-traumatic OHCA refractory to 15min of resuscitation were selected from a registry of adult OHCA collected between 2010 and 2015 in Montreal, Canada. Using this cohort, three simulation scenarios allowing prehospital redirection to E-CPR centers were created. Stringent eligibility criteria for E-CPR and redirection for E-CPR (e.g. age <60years old, initial shockable rhythm) were used in the first scenario, intermediate eligibility criteria (e.g. age <65years old, at least one shock given) in the second scenario and inclusive eligibility criteria (e.g. age <70years old, initial rhythm ≠ asystole) in the third scenario. All three scenarios were contrasted with equivalent scenarios in which patients were transported to the closest hospital. Proportions were compared using McNemars test. RESULTS The proportion of E-CPR eligible patients transported to E-CPR capable centers increased in each scenario (stringent criteria: 48 [24.5%] vs 155 patients [79.1%], p<0.001; intermediate criteria: 81 [29.6%] vs 262 patients [95.6%], p<0.001; inclusive criteria: 238 [23.9%] vs 981 patients [98.5%], p<0.001). CONCLUSIONS A prehospital redirection system could significantly increase the number of patients with refractory OHCA transported to E-CPR capable centers, thus increasing their access to this potentially life-saving procedure, provided allocated resources are planned accordingly.