Effect of high‐flow nasal oxygen on hypoxaemia during procedural sedation: a systematic review and meta‐analysis

We conducted a systematic review to evaluate the effect of high‐flow nasal oxygen and conventional oxygen therapy during procedural sedation amongst adults and children. We searched MEDLINE, EMBASE and CINAHL for randomised controlled trials that reported the effects of high‐flow nasal oxygen during procedural sedation. The primary outcome measure was hypoxaemia and the secondary outcomes were minimum oxygen saturation; hypercarbia; requirement for airway manoeuvres; and procedure interruptions. The quality of evidence was assessed using the revised Cochrane risk‐of bias tool and grading of recommendations, assessment, development and evaluation (GRADE). Nineteen randomised controlled trials (4121 patients) including three in children were included. Administration of high‐flow nasal oxygen reduced hypoxaemia, risk ratio (95%CI) 0.37 (0.24–0.56), p < 0.001; minor airway manoeuvre requirements, risk ratio (95%CI) 0.26 (0.11–0.59), p < 0.001; procedural interruptions, risk ratio (95%CI) 0.17 (0.05–0.53), p = 0.002; and increased minimum oxygen saturation, mean difference (95%CI) 4.1 (2.70–5.50), p < 0.001; as compared with the control group. High‐flow nasal oxygen had no impact on hypercarbia, risk ratio (95%CI) 1.24 (0.97–1.58), p = 0.09, I(2) = 0%. High‐flow nasal oxygen reduced the incidence of hypoxaemia regardless of the procedure involved, degree of fractional inspired oxygen, risk‐profile of patients and mode of propofol administration. The evidence was ascertained as moderate for all outcomes except for procedure interruptions. In summary, high‐flow nasal oxygen compared with conventional oxygenation techniques reduced the risk of hypoxaemia, increased minimum oxygen saturation and reduced the requirement for airway manoeuvres. High‐flow nasal oxygen should be considered in patients at risk of hypoxaemia during procedural sedation.