462: Air Medical Providers Accurately Prospectively Assess Airway Difficulty

Abstract

Invasive airway management by endotracheal intubation (ETI) is frequently performed by air medical providers. Accurately predicting the difficulty of the procedure allows providers to have appropriate equipment available, and may improve patients' subsequent clinical course. Accurately estimating difficulty is especially important for air medical providers, as they perform ETI under less than ideal conditions, and have fewer resources available than in the hospital setting. The objective of this study is to determine how accurately air medical providers assess airway difficulty and to explore factors associated with under- and over-estimates of difficulty. Patients with advanced airway management performed by an air medical provider were enrolled in the Air Care Airway Registry from April 2004 to May 2007. The providers were flight registered nurses and flight physicians. Flight physicians were emergency medicine resident post-graduate year (PGY) 2-4, and attending emergency physicians. A PGY-1 emergency physician was present on some training flights. Prospective and retrospective airway difficulty was assessed by the air medical provider completing airway management. Difficulty was estimated on a 1 to 10 point scale, with 1 being easiest and 10 being most difficult. The difference between prospective and retrospective difficulty scores was calculated. Differences between means were assessed using student's t-test or analysis of variance (ANOVA). Pearson's correlation was used to assess the relationship between continuous variables. There were 179 patients in the registry; 3 did not have airway difficulty assessments recorded. The mean age of the 176 included patients was 38 (SD 22); 70% were male and mean weight was 81 kg (SD 28). The first medical provider attempting ETI was most commonly a PGY-2 physician (46%) or a flight nurse (30%), and ETI most often occurred in an ambulance (60%) prior to transport. Mean prospective difficulty was 5.0 (SD 2.5) and mean retrospective difficulty was 4.6 (SD 2.9). The majority of airways (73%) had an absolute difference between prospective and retrospective difficulty assessment ≤2. Factors associated with increasing difficulty were use of straight blade and decreased glottic exposure. Factors associated with decreasing difficulty were no suction needed, no backward upward rightward pressure (BURP) needed, and increased mouth opening (all p < 0.05). Air medical providers in this single center registry were accurate in the assessment of prospective airway difficulty: one quarter of cases examined had no change between prospective and retrospective assessments, and nearly three quarters had absolute difference between prospective and retrospective difficulty <2. Airways with a difficulty estimate that changed significantly from pre- to post-procedure shared characteristics that may not be readily apparent on initial visual assessment. While these factors were statistically associated with changes in airway difficulty assessments, the changes were small (<1.2 points) so effect on clinical course is unclear.