Helicopter Scene Response: Regional Variation in Compliance with Air Medical Triage Guidelines

Abstract

Background. Our state has consensus guides for helicopter emergency medical services (HEMS) scene dispatch, based on physiologic, anatomic, andspecial criteria (e.g., ejection from a vehicle, age < 10 or > 55 years). There has been much attention paid to improving HEMS triage criteria, but less focus on whether current HEMS uses meet existing criteria. Objectives. To assess a HEMS program's compliance with regional air medical dispatch guidelines andto identify factors associated with noncompliant flights. Methods. Using chart review anddiscussion with referring agencies, we conducted a consecutive case review of a HEMS program's initial 100 flights in one year (2005), collecting data pertinent to triage, prehospital times, andhospital course. Analysis (p = 0.05) of the outcome “met triage criteria” (MTC) used Kruskal-Wallis andFisher's exact tests. Logistic regression, reporting odds ratios (ORs) with 95% confidence intervals (CIs), was used to adjust for covariates while assessing predictors of the dichotomous outcome MTC. The predictors assessed included demographics, advanced life support (ALS) scene presence, andwhether transports occurred during rush hours (0700–1000 and1600–1900). Results. The 100 patients (98 blunt trauma; 73% male) from four Massachusetts emergency medical services (EMS) regions (n = 94) andNew Hampshire (n = 6) were classified as MTC in 73% of cases. Physiologic criteria were met in 19% of cases (they were the sole criterion met in one case), anatomic criteria in 49% (sole criterion n = 24), andspecial criteria in 67% (sole criterion n = 15). There was no association between MTC status andage (p = 0.98), gender (p = 0.39), rush-hour transport (p = 0.81), or ALS-trained ground EMS presence on scene (p = 0.98). Analysis adjusting for transport distance andinjury mechanism identified an association between EMS region andMTC transport status (p = 0.006); regions' likelihoods of MTC proportions ranged from 50% to 94%. Conclusion. Despite promulgation of consensus guidelines, nearly a fourth of HEMS transports were non-MTC. Wide interregional variation in the likelihood of MTC HEMS use provides a focus for further research/education. Regional systems should strive not only for the refinement of, but also the compliance with, HEMS triage guidelines.