Methods of pre oxygenation in ICU

Abstract

Endotracheal intubation is a daily performed procedure in Intensive Care Unit (ICU), but providing frequent complications. The most severe and frequent complication is deep oxygen desaturation, favored by apnea related to anaesthesia. Pre-oxygenation of patients is one of the key elements to reduce the incidence of these desaturations. 

The objective of this pre-oxygenation phase is to saturate the pulmonary functional residual capacity with pure oxygen to make it a reservoir. In addition, the apneic oxygenation can be used to maintain oxygen supply throughout the apnea phase.

Preoxygenation is more difficult and of limited efficacy in ICU than in the operating room. Its duration is recommended to 3 or 4 minutes. During these past years, several studies have been conduct, including non-invasive ventilation (NIV) and high-flow oxygen therapy by nasal cannulae (HFNC). According to these studies, today, it is probably necessary to have strategies that are adapted to the patients, notably to their pathology and their severity. The conventional strategy (bag valve mask or non-rebreathing mask) possibly keeps a place for the less severe patients. For the more severe patients, although the incidence of desaturations remains high, HFNC and NIV appear to have close results to prevent desaturations. It seems that NIV should be considered first in the most severely hypoxemic patients.