Whenever I feel blue, I start breathing again. – Lyman Frank Baum
This trial attempted to test the hypothesis that pharyngeal oxygen insufflation during intubation slows desaturation. Patients aged 1yrs to 17 yrs and ASA status I-III undergoing nasal intubation for dental rehabilitation were enrolled into the trial. Patients were randomised to one of three methods of intubation: direct laryngoscopy (DL); direct laryngoscopy using a Truview PCD videolaryngoscope (VLO2); or laryngoscopy with an oxygen cannula attached to the side of a standard laryngoscope (DLO2).
457 patients were included in the trail with approximately equal sample sizes and baseline characteristics in terms of weight sex and ASA status. There were a larger proportion of
During the departmental discussion 14 September 2016 concerns were raised with the validity of the study. The authors undertook a sample size analysis and concluded that a sample of n=546 with per-group sample size of 169 was required to detect predetermined hazard ratios with 90% power. All three intervention groups had less than 160 subjects and the overall sample size was 457. It is unclear how this reduced sample size affected the study.
49% of patients in the Direcct Layngoscopy group without oxygen insufflation desaturated to <90% during the study. This appears to be a very high proportion when compared with our own experience of intubating without continuous oxygen insufflation and given that the mean time to 1% desaturation in this group was 30 seconds. It was also noted that the time to intubation was increased when using either the truview PCD videolaryngoscope or the laryngoscope with oxygen cannula attached. Time to intubation was not analysed for statistical significance.
Finally the primary outcome measure was questioned for its significance to anaesthetic practice. The authors stated that a 1% decrease in SpO2 from baseline was not clinically significant. Therefore, it does not seem plausible to recommend deep laryngeal oxygen insufflation for routine use in clinical practice.
Summary by Dr Michael Gilhooly