Ventilator-assisted preoxygenation: Protocol for combining non-invasive ventilation and apnoeic oxygenation using a portable ventilator

Abstract

Objective: To describe a simple protocol for ventilator-assisted preoxygenation (VAPOX) prior to rapid sequence intubation in the ED using a Hamilton T1 ventilator in an effort to further reduce the incidence of transient and critical hypoxaemia. Methods: Ventilator-assisted preoxygenation includes the following steps; preparation for rapid sequence intubation as per institutional protocols, including departmental checklists. Hamilton T1 ventilator is setup in non-invasive spontaneous/timed mode with settings as described. The patient is optimally positioned and nasal cannula applied with an oxygen flow rate of 15 L/min. A face mask is applied with the jaw pulled forward using a two-handed thenar eminence grip and the ventilator is started. Preoxygenation occurs for 3min. Drugs including neuromuscular blockers are administered, while the operator ensures the airway remains patent. The ventilator transitions into Pressure Controlled Ventilation once apnoea ensues. Nasal oxygen continues until endotracheal tube is successfully secured. Results: We describe a case series of the first eight consecutive adult patients on who VAPOX was applied. All eight patients were clinically deemed at high risk of oxygen desaturation. No clinically significant hypoxia occurred, and the lowest oxyhaemoglobin desaturation was 92%. Conclusion: Preoxygenation using a ventilator with an open valve system may allow safe combination of noninvasive ventilation, pressure controlled ventilation and apnoeic oxygenation using nasal cannula. VAPOX may be the technique of choice to preoxygenate and apnoeic oxygenate many patients who undergo rapid sequence intubation in the ED equipped with these ventilators.