Emergency scalpel cricothyroidotomy use in a prehospital trauma service: a 20-year review

Abstract
Background This study aimed to determine the rate of scalpel cricothyroidotomy conducted by a physician–paramedic prehospital trauma service over 20 years and to identify indications for, and factors associated with the intervention. Methods A retrospective observational study was conducted from 1 January 2000 to 31 December 2019 using clinical database records. This study was conducted in a physician–paramedic prehospital trauma service, serving a predominantly urban population of approximately 10 million in an area of approximately 2500 km2. Results Over 20 years, 37 725 patients were attended by the service, and 72 patients received a scalpel cricothyroidotomy. An immediate ‘primary’ cricothyroidotomy was performed in 17 patients (23.6%), and ‘rescue’ cricothyroidotomies were performed in 55 patients (76.4%). Forty-one patients (56.9%) were already in traumatic cardiac arrest during cricothyroidotomy. Thirty-two patients (44.4%) died on scene, and 32 (44.4%) subsequently died in hospital. Five patients (6.9%) survived to hospital discharge, and three patients (4.2%) were lost to follow-up. The most common indication for primary cricothyroidotomy was mechanical entrapment of patients (n=5, 29.4%). Difficult laryngoscopy, predominantly due to airway soiling with blood (n=15, 27.3%) was the most common indication for rescue cricothyroidotomy. The procedure was successful in 97% of cases. During the study period, 6570 prehospital emergency anaesthetics were conducted, of which 30 underwent rescue cricothyroidotomy after failed tracheal intubation (0.46%, 95% CI 0.31% to 0.65%). Conclusions This study identifies a number of indications leading to scalpel cricothyroidotomy both as a primary procedure or after failed intubation. The main indication for scalpel cricothyroidotomy in our service was as a rescue airway for failed laryngoscopy due to a large volume of blood in the airway. Despite high levels of procedural success, 56.9% of patients were already in traumatic cardiac arrest during cricothyroidotomy, and overall mortality in patients with trauma receiving this procedure was 88.9% in our service.