Retention of En Route Cricothyroidotomy Skills in Novice Providers Following a Simulation-Based Mastery Learning Curriculum

Document Type

Journal Article

Publication Date



Military medicine




INTRODUCTION: Surgical cricothyroidotomy (SC) is a vital skill that combat first responders must master as airway obstruction is the third most preventable cause of death on the battlefield. Degradation of skills over time is a known problem, and there is inadequate knowledge regarding the rate of SC skill retention. Our prior study showed that simulation-based mastery learning was effective in training 89 novices how to reliably perform an en route SC to mastery performance standards. This study aims to assess the durability of this skill by bringing participants back in 3 separate cohorts at 6, 12, or 24 months following the initial training to perform SC in the same test environment. MATERIALS AND METHODS: This was a randomized prospective trial. Random cohorts of equal subjects who previously underwent SC simulation-based mastery learning training were selected to return at 6, 12, and 24 months to retest in the same en route medical evacuation (MEDEVAC) helicopter scenario. A total of 22, 14, and 10 subjects returned at 6, 12, and 24 months, respectively, due to Coronavirus-19 impacts and travel limitations. Participants in the 24-month cohort received a refresher training prior to retesting. All attempts were recorded and blindly graded using the same 10 item standardized SC checklist used in initial training. Our previous work found that mastery criteria for performing a SC were ≤40 seconds and completion of 9/10 items on the checklist. Outcome measures in this study were time to complete the procedure and percent of subjects who completed at least 9/10 items on the SC checklist. RESULTS: There was an increase in time required to complete the procedure compared to initial training in all three retesting cohorts (initial: median 27.50, interquartile range 25.38-31.07 seconds; 6 months: median 36.33, interquartile range 31.59-55.22 seconds; 12 months: median 49.50, interquartile range 41.75-60.75 seconds; 24 months: median 38.79, interquartile range 30.20-53.08 seconds; P < .0001, P < .0001, P = .0039). There was a decline in median value checklist scores compared to initial training in the 6- and 12-month retesting cohorts (initial: median 10.00/10, interquartile range 9.50-10.00; 6 months: median 8.00/10, interquartile range 6.75-9.00; 12 months: median 8.00/10, interquartile range 6.75-9.25; P < .0001, P < .001). There was no difference in median checklist scores between the initial and 24-month retesting scenario (initial: median 10.00/10, interquartile range 9.50-10.00; 24 months: 10.00/10, interquartile range 9.00-10.00; P= .125). There was a decrease in retention of skills as only 31.82% of subjects at 6 months and 14.29% at 12 months met the defined passing criteria of time to completion of ≤40 seconds and checklist score of ≥9/10. A brief refresher course several months prior to the 24-month cohort retesting greatly increased the retention of SC procedural skills, with 60% of subjects meeting the time and checklist criteria. CONCLUSIONS: This study showed that the skill required to perform a SC after initial mastery training does decay significantly. A brief refresher course can help increase retention of skills. Based on our findings SC skills should be refreshed at a minimum of every 6 months to assure optimal proficiency.


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