Oxygenation during the apnoeic phase preceding intubation in adults in prehospital, emergency department, intensive care and operating theatre environments

• Published in: Cochrane database of systematic reviews 2023-08, Vol.8 (8), p.CD013558
• Main Authors: White, Leigh D, Vlok, Ruan A, Thang, Christopher Yc, Tian, David H, Melhuish, Thomas M
• Format: Article
• Language: English
• Subjects: Adult; Apnea - etiology; Critical Care; Critical Illness; Emergency Medical Services; Humans; Hypoxia - etiology; Hypoxia - prevention & control; Intubation, Intratracheal - adverse effects; Lungs & airways; Orthopaedics & trauma; Oxygen; Respiratory Management
• ISSN: 1469-493X; 1469-493X
• DOI: 10.1002/14651858.CD013558.pub2

Apnoeic oxygenation is the delivery of oxygen during the apnoeic phase preceding intubation. It is used to prevent respiratory complications of endotracheal intubation that have the potential to lead to significant adverse events including dysrhythmia, haemodynamic decompensation, hypoxic brain injury and death. Oxygen delivered by nasal cannulae during the apnoeic phase of intubation (apnoeic oxygenation) may serve as a non-invasive adjunct to endotracheal intubation to decrease the incidence of hypoxaemia, morbidity and mortality. To evaluate the benefits and harms of apnoeic oxygenation before intubation in adults in the prehospital, emergency department, intensive care unit and operating theatre environments compared to no apnoeic oxygenation during intubation. We used standard, extensive Cochrane search methods. The latest search date was 4 November 2022. We included randomized controlled trials (RCTs) and quasi-RCTs that compared the use of any form of apnoeic oxygenation including high flow and low flow nasal cannulae versus no apnoeic oxygenation during intubation. We defined quasi-randomization as participant allocation to each arm by means that were not truly random, such as alternation, case record number or date of birth. We excluded comparative prospective cohort and comparative retrospective cohort studies, physiological modelling studies and case reports. We used standard Cochrane methods. Our primary outcomes were 1. hospital stay and 2. incidence of severe hypoxaemia. Our secondary outcomes were 3. incidence of hypoxaemia, 4. lowest recorded saturation of pulse oximetry (SpO ), 5. intensive care unit (ICU) stay, 6. first pass success rate, 7. adverse events and 8. We used GRADE to assess certainty of evidence. We included 23 RCTs (2264 participants) in our analyses. Eight studies (729 participants) investigated the use of low-flow (15 L/minute or less), and 15 studies (1535 participants) investigated the use of high-flow (greater than 15 L/minute) oxygen. Settings were varied and included the emergency department (2 studies, 327 participants), ICU (7 studies, 913 participants) and operating theatre (14 studies, 1024 participants). We considered two studies to be at low risk of bias across all domains. None of the studies reported on hospital length of stay. In predominately critically ill people, there may be little to no difference in the incidence of severe hypoxaemia (SpO less than 80%) when using apnoeic oxygenation at any flow rate fr