Time to adapt in the pandemic era: a prospective randomized non –inferiority study comparing time to intubate with and without the barrier box

Abstract

Background The challenges posed by the spread of COVID-19 disease through aerosols have compelled anesthesiologists to modify their airway management practices. Devices such as barrier boxes are being considered as potential adjuncts to full PPE’s to limit the aerosol spread. Usage of the barrier box raises concerns of delay in time to intubate (TTI). We designed our study to determine if using a barrier box with glidescope delays TTI within acceptable parameters to make relevant clinical conclusions. Methods Seventy-eight patients were enrolled in this prospective non-inferiority controlled trial and were randomly allocated to either group C (without the barrier box) or the study group BB (using barrier box). The primary measured endpoint is time to intubate (TTI), which is defined as time taken from loss of twitches confirmed with a peripheral nerve stimulator to confirmation of end-tidal CO 2. 15 s was used as non-inferiority margin for the purpose of the study. We used an unpaired two-sample single-sided t-test to test our non- inferiority hypothesis (H 0: Mean TTI diff ≥15 s, H A: Mean TTI diff < 15 s). Secondary endpoints include the number of attempts at intubation, lowest oxygen saturation during induction, and the need for bag-mask ventilation. Results Mean TTI in group C was 42 s (CI 19.2 to 64.8) vs. 52.1 s (CI 26.1 to 78) in group BB. The difference in mean TTI was 10.1 s (CI -∞ to 14.9). We rejected the null hypothesis and concluded with 95% confidence that the difference of the mean TTI between the groups is less than < 15 s (95% CI -∞ to 14.9,p = 0.0461). Our induction times were comparable (67.7 vs. 65.9 s).100% of our patients were intubated on the first attempt in both groups. None of our patients needed rescue breaths. Conclusions We conclude that in patients with normal airway exam, scheduled for elective surgeries, our barrier box did not cause any clinically significant delay in TTI when airway manipulation is performed by well-trained providers. The study was retrospectively registered at clinicaltrials.gov (NCT04411056) on May 27, 2020.

The impact of a barrier enclosure on time to tracheal intubation: a randomized controlled trial

“… 20 Madabhushi et al also found that a barrier enclosure increased the time to intubation by an experienced anesthesiologist by a mean of 10.1 sec in adults without anticipated difficult airway; however, they used 15 sec as a non-inferiority margin and thus did not reject the null hypothesis and concluded no difference between groups. 21 Consistent with both of these studies, we found that using barrier enclosure when intubating patients with normal airways resulted in a longer mean TTI compared with control, although this effect size (mean duration of 8.6 sec) was neither statistically nor clinically significant. Our study finding was not surprising because the consultant anesthesiologists were likely able to compensate for any additional challenge posed by a physical barrier during intubation.…”

“…Two previous trials have evaluated the use of a barrier enclosure in a clinical setting. 20 , 21 Trujillo and Arango found that in children over one year of age without anticipated difficult airways, the use of the barrier enclosure increased the time to intubation by a consultant anesthesiologist by a median of five seconds. 20 Madabhushi et al also found that a barrier enclosure increased the time to intubation by an experienced anesthesiologist by a mean of 10.1 sec in adults without anticipated difficult airway; however, they used 15 sec as a non-inferiority margin and thus did not reject the null hypothesis and concluded no difference between groups.…”

Macintosh laryngoscope and i-view™ and C-MAC® video laryngoscopes for tracheal intubation with an aerosol box: a randomized crossover manikin study

“…1 ). Recently, Madabhushi et al enrolled 78 patients with normal airways who had no COVID-19 and found that by using Glidescope (Verathon, Bothell, WA, USA) with an external display, the tracheal intubation time with the aerosol box was non-inferior to that without the box [ 18 ]. Furthermore, Puthenveettil et al reported that C-MAC was easier to use than Macintosh for tracheal intubation with an aerosol box in 60 patients with normal airways without COVID-19 [ 19 ].…”

“…Furthermore, Puthenveettil et al reported that C-MAC was easier to use than Macintosh for tracheal intubation with an aerosol box in 60 patients with normal airways without COVID-19 [ 19 ]. These results may suggest the potential benefit of an external display when performing tracheal intubation with an aerosol box in real patients [ 18 , 19 ]. Although an external display might be useful in clinical settings where visual conditions are more unfavorable, such as cloudy or well-worn eye-protective PPE or aerosol boxes, we could not confirm the advantage in this simulation study using a transparent acrylic box.…”

The FEES box: A novel barrier to contain particles during aerosol-generating procedures

“…A cough was believed to be a particular concern for spreading particulate matter [ 11 , 12 , 14 , 20 , 21 ] and was of notable clinical relevance to the present study given that dysphagia evaluations may involve frequent spontaneous or cued coughing. In this study, however, no statistically significant increase in particulate matter from baseline was generated during the cough tasks, regardless of the presence of the FEES Box.…”