Pumphrey et al, 1999, UK | 164 cases of fatality with anaphylaxis recorded as the cause of death between 1992 and 1998 (148 had records available for further analysis) | Analysis of registry data | Median time to respiratory or cardiac arrest. | 30 min for foods (range 6–360), 15 min for venom (range 4–120) and 5 min for iatrogenic reactions (range 1–80) | Registry data, not specifically designed to answer this question.Only fatal cases included. Cases where epinephrine self-treatment prevented death therefore not included. Adults and children included |
Details of patients who had been given repinephrine self-treatment kits | 5 did not use the kit (not with patient in 2 cases, out of date in 1 case, may have collapsed too quickly in 1 case, found dead holding unused kit in 1 case (could not assemble it?) |
Gold et al, 2000, Australia | 68 children with a history of anaphylaxis who were prescribed EpiPens by the paediatric allergy service.Data collected by telephone interview with parents | Retrospective telephone survey | Parental recall of method of administration with Epipen | Only 16 (24%) of parents were able to recall all 4 steps required for the correct use of Epipens; 5% could not recall any steps. | Suboptimal study design to answer this question. A prospective observational cohort would be more informative (randomised controlled trial would be ideal but probably unethical).Possible selection bias—the parents of only 80% of the patients identified were interviewed. 19% could not be contacted—their outcome is unknown.No standard criteria for initial prescription of Epipen.Time since index reaction not standardised.In-hospital epinephrine use apparently assessed by parental interview.Severity of episodes not objectively measured |
Epipen use in anaphylaxis | Epipen given in 13 (29%) of 45 anaphylactic reactions. Of those not given Epipen, 15 (45%) were later given epinephrine in hospital. Of those given Epipen, 2 of 13 (15%) later received epinephrine in hospital (p<0.05) |
Hospital admission | Epipen not given: 15 of 32 (47%) admitted; Epipen given: 2 of 13 (15%) admitted (p<0.05) |
Colver et al, 2005, UK | 229 cases of children (aged under 16 years) admitted to hospital with food allergic reactions between 1998 and 2000 | Prospective survey | Death | 3 children died. One received epinephrine via auto-injector at home | Patients only included after reported hospital admission. Emergency department attendances without admission not included |
Near fatal anaphylaxis | Occurred in 6 children. In 3 children excess epinephrine administration (in hospital) was implicated in clinical deterioration. |
Potential reduction in severity by use of epinephrine auto-injectors | 6 severe cases and 7 non-severe cases received epinephrine via auto-injector before arriving at hospital. Auto-injectors could therefore have reduced the severity of a maximum of 13/229 reactions |
Potential benefits if epinephrine auto-injectors had been more widely available | Of the 58 severe cases, a maximum of 6 could have benefited had auto-injectors been available to them (the remainder either did not have epinephrine at any point, already had an auto-injector but did not use it, had epinephrine administered by primary care or ambulance staff within 10 min, had not had a previous allergic reaction to food or were over 12 years old and their only previous reaction had been to allergens as babies) |