ABSTRACT
INTRODUCTION: An emergent front of neck airway (FONA) is needed when a 'can't intubate, can't oxygenate' crisis occurs. A FONA may also in specific cases be the primary choice of airway management. Two techniques exist for FONA, with literature favouring the surgical technique over the percutaneous. The reported need for a prehospital FONA is fortunately rare as the mortality has been shown to be high. Due to the low incidence, literature on FONA is limited with regards to different settings, techniques and operators. As a foundation for future research and improvement of patient care, we aim to describe the frequency, indications, technique, success, and outcomes of FONA in the Finnish helicopter emergency medical services (HEMS). MATERIALS AND METHODS: This retrospective descriptive study reviews FONA performed at the Finnish HEMS during 1.1.2012 to 8.9.2019. The Finnish HEMS consists of six units, staffed mainly by anaesthesiologists. Clinical data was gathered from a national HEMS database and trough chart reviews. Data on mortality was obtained from a population registry. Only descriptive statistics were performed. RESULTS: A total of 22 FONA were performed during the study period, 7 were primary and 14 performed after failure to intubate (missing data regarding indication for one attempt). This equals a 0.13 % (14/10,813) need for a rescue FONA and a rate of 0.20 % (22/10,813) FONA out of all advanced airway management. All but one FONA was performed using a surgical approach (20/21, 95 %, missing data = 1) and all were successful (22/22, 100 %). Indications were mainly cardiac arrest (10/22, 45 %) and trauma (6/22, 27 %), and the most common reason for a need for a secondary FONA was obstruction of airway by food or fluids (7/14, 50 %). On-scene mortality was 36 % (8/22) and 30-day mortality 90 % (19/21, missing data = 1). CONCLUSION: The need for FONA is scarce in a HEMS system with experienced airway providers. Even though the procedure is successfully performed, the mortality is markedly high.
ABSTRACT
BACKGROUND: Severity of illness scoring systems are used in intensive care units to enable the calculation of adjusted outcomes for audit and benchmarking purposes. Similar tools are lacking for pre-hospital emergency medicine. Therefore, using a national helicopter emergency medical services database, we developed and internally validated a mortality prediction algorithm. METHODS: We conducted a multicentre retrospective observational register-based cohort study based on the patients treated by five physician-staffed Finnish helicopter emergency medical service units between 2012 and 2019. Only patients aged 16 and over treated by physician-staffed units were included. We analysed the relationship between 30-day mortality and physiological, patient-related and circumstantial variables. The data were imputed using multiple imputations employing chained equations. We used multivariate logistic regression to estimate the variable effects and performed derivation of multiple multivariable models with different combinations of variables. The models were combined into an algorithm to allow a risk estimation tool that accounts for missing variables. Internal validation was assessed by calculating the optimism of each performance estimate using the von Hippel method with four imputed sets. RESULTS: After exclusions, 30 186 patients were included in the analysis. 8611 (29%) patients died within the first 30 days after the incident. Eleven predictor variables (systolic blood pressure, heart rate, oxygen saturation, Glasgow Coma Scale, sex, age, emergency medical services vehicle type [helicopter vs ground unit], whether the mission was located in a medical facility or nursing home, cardiac rhythm [asystole, pulseless electrical activity, ventricular fibrillation, ventricular tachycardia vs others], time from emergency call to physician arrival and patient category) were included. Adjusted for optimism after internal validation, the algorithm had an area under the receiver operating characteristic curve of 0.921 (95% CI 0.918 to 0.924), Brier score of 0.097, calibration intercept of 0.000 (95% CI -0.040 to 0.040) and slope of 1.000 (95% CI 0.977 to 1.023). CONCLUSIONS: Based on 11 demographic, mission-specific, and physiologic variables, we developed and internally validated a novel severity of illness algorithm for use with patients encountered by physician-staffed helicopter emergency medical services, which may help in future quality improvement.
