Importance of Clinical Relevance in Clinical Trials

Abstract

We read with interest the article by Santoni et al. 1Maintaining manual in-line stabilization for direct laryngoscopy in patients with known or suspected cervical spine injury is a practice which would benefit from further research. However, we believe the protocol design in this study has limited the clinical relevance of the data generated.The authors designed a prototype pressure-sensing laryngoscope blade specifically for this study. The protocol for intubation in this study was regulated by limitations of these pressure sensors. The research team prohibited external laryngeal manipulation and prohibited use of a stylet. Use of bougie was not mentioned. Both external laryngeal manipulation and use of stylet/bougie are accepted techniques to assist intubation when laryngoscopy is difficult, and are part of the difficult airway algorithm.2,3Both of these techniques are commonly used in patients with suspected cervical spine injuries.4The approach used in the study, which does not represent normal clinical practice, resulted in an increased burden of risk to the patients in this study (three failed intubations and one dental trauma in ten subjects), so that the trial was abandoned. The clinical benefit of a study in humans needs to be balanced against the risk assumed by the subjects. It would be valuable to repeat the study in a more realistic clinical setting, allowing clinicians to intubate the patient in whatever manner they are used to, and using intubation aids as required. It would be interesting to see if manual in-line stabilization still resulted in a doubling of applied pressure in that scenario.*BC Women's Hospital, Vancouver, British Columbia, Canada. hloane@cw.bc.ca