We appreciate the letter to the editor by Mendelson et al (1) regarding our recent randomized trial of video laryngoscopy (VL) versus direct laryngoscopy (DL) for endotracheal intubation of critically ill adults (2).
Mendelson et al cite a recent study by Silverberg et al comparing VL and DL for intubation of critically ill adults using a Glidescope®(3) rather than the McGrath® MAC VL which was used in 98.6% of the intubations in the FELLOW trial (2). This is an important difference between the Silverberg study and the FELLOW trial suggesting the data on the McGrath® MAC may not be generalizable to patient care scenarios where the Glidescope® is being used for intubation. Although certainly possible, we would argue that our data remain generalizable to video laryngoscopes as both studies demonstrated improved glottic view with VL, these two devices are not functionally different (both aim a camera at the glottis), and an effect size of 34% seen in the Silverberg study (3) is likely overestimated (4) and not likely to carry over to clinical practice. The large effect size seen in the Silverberg study may be due to a number of factors pointed out by Mendelson et al. In addition, unlike the FELLOW trial, the Silverberg study (3) was not a randomized trial which further biases towards an overestimation of an effect size (5) (device assignment was not random, but uniformly alternated between even and odd numbers of intubations for each operator in which the operator knew which would be the next device assignment).
Mendelson et al also inquire as to the definition of aspiration in the FELLOW trial (2). After completion of the procedure, the operator was asked if peri-procedural aspiration had occurred based on their own subjective definition of aspiration. Given the unreliable nature of self-reported data during airway management (6) and the lack of a uniformly accepted objective definition, we urge caution in comparing the aspiration event rate in our trial to other trials. Self-reporting of data is a common limitation of intubation studies, which is why the FELLOW trial used independent observers not participating in the procedure or the trial to record the majority of the trial outcomes.
Acknowledgments
Source of Funding: Investigators were supported by a National Heart, Lung, and Blood Institute (NHLBI) T32 award (HL087738 09).
Copyright form disclosure: Dr. Janz's institution received funding from the National Institutes of Health (NIH). He received support for article research from the NIH. Dr. Semler received support for article research from the NIH. Dr. Rice received support for article research from the NIH. He received funding from GlaxoSmithKline, Avisa Pharma, and Cumberland Pharmaceuticals.
Footnotes
Authors contributions: Drafting and revision of the manuscript: D.R.J., M.W.S., and T.W.R.
Conflicts of Interest: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors declare no potential conflicts of interest. T.W.R. reported serving on an advisory board for Avisa Pharma, LLC, as a DSMB member for GlaxoSmithKline PLC, and as Director of Medical Affairs for Cumberland Pharmaceuticals, Inc.
References
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