key: cord-0733735-83ekbskj
authors: Cazes, Nicolas; Renard, Aurélien; Marsaa, Hélène; Menot, Pascal
title: Prehospital High-Flow Nasal Oxygen Therapy on COVID-19 Patients: An Additional Waiting Time
date: 2021-12-15
journal: J Emerg Med
DOI: 10.1016/j.jemermed.2021.07.047
sha: 19e901a591c7393fb0b7a7fb974b41a25f0a2bbf
doc_id: 733735
cord_uid: 83ekbskj

nan

We read with great interest the case report by Kedzierewicz et al. ( 1 ) about the use of high-flow nasal oxygen (HFNO) therapy in the prehospital setting and its logistical constraints. It is legitimate to want to initiate effective in-hospital therapies earlier in the patient's care; thus, the desire to use prehospital HFNO therapy on Coronavirus disease 2019 (COVID-19) patients in respiratory distress appears logical indeed. Nevertheless, an additional non-negligible constraint on the use of HFNO therapy in the prehospital setting that was not mentioned by the authors is the time needed to heat and humidify gas to the target temperature of 36 °C. This heating time varies depending on the model of HFNO device, the mode of use, and the surrounding temperature. The time varies from a low of about 10 min, when the system is autonomous (such as the AIRVO 2 system [Fisher & Paykel Healthcare, Auckland, New Zealand] used by the authors) and connected in a heated room with sterile water at room temperature-as is the case in an intrahospital setting-up to a high of 25 min if it is connected to a transport ventilator in oxygen therapy mode in a mobile intensive care unit, where the room temperature is around 15 °C (as is typical in winter) and the sterile water is initially cold. In these conditions-the initial temperature of the surface of the chamber base being very low (below 12 °C) and the sterile water cold-the heating time needed to reach the target temperature of 36 °C is systematically > 15 min. Given that the patient's travel time from home to hospital in highly urbanized areas is rarely longer than 20 min, it is legitimate to question the efficacy of initiating this method of oxygenation in view of the aforementioned technical difficulties.

Logistical challenge with prehospital use of high-flow nasal oxygen therapy in COVID-19-induced respiratory distress: a case report