Discussion
sore throat, hoarseness, trauma
SORE THROAT, SECONDARY, RECRUITMENT, BLIND
We propose here the protocol for a randomized, controlled, patient-blinded multi- centre trial on the routine use of VAL in a peri-operative anaesthesiologic setting. Although several studies in the broader research area have been conducted in the past, conclusive evidence enabling clear recommendations is still not available. As Lewis et al. pointed out in a Cochrane systematic review on the matter, there is high heterogeneity in the findings [Despite our best efforts to design this study as diligently and efficiently as possible, some points of concern still remain. For one, there will always be an issue with the inability to blind the interventionist regarding the intervention allocation. It is well conceivable that the physician performing endotracheal intubation will always be aware of the device they are using. In analogy to this, the outcome assessor cannot be blinded for similar reasons. Therefore, there will always be a risk for performance or detection bias. We will, however, have patients and statisticians blinded, thus avoiding additional potential bias where possible.With a recruitment goal of more than 2,500 patients, we needed to assure that the observation period stays as compact and short as possible. To meet a comprehensive set of outcome parameters which allows for proper comparability with previous studies, we incorporated in this trial a follow-up two hours after the end of surgery to assess additional outcomes like hoarseness and sore throat. However, we decided not to extend the follow-up period for possible endpoints like hospital length of stay or mortality. We do not foresee any fundamental issues or inconveniences in recruiting the projected number of patients. Due to the nature of the inclusion and exclusion criteria, many patients will be eligible for participation and with a sufficiently large number of additional study sites we expect to meet the recruitment goal within two years. This is needed to ensure that the accompanying circumstances remain reasonably constant during the conduct of the study.With the results from this trial, we aim to contribute a substantial foundation of evidence for the use of VAL in the routine peri-operative setting. We intentionally designed this study as a non-inferiority trial. In a mostly unselected population like this one, overall first attempt success rates for intubation are (fortunately) high to begin with. We cannot with reasonable certainty expect to see VAL superior in this regard, although with the choden statistical design this would be possible to prove as well. However, with the ORs of patient-relevant secondary outcomes like laryngeal/airway trauma, sore throat and hoarseness previously reported to tend to favour VAL (OR [95% CI] 0.68 [0.48, 0.96], 0.82[0.56, 1.19] and 0.57 [0.36, 0.88], respectively [