Originally published by 2 Minute Medicine® (view original article). Reused on AccessMedicine with permission.

1. In a randomized-controlled simulation trial, intubation using the VieScope in a difficult airway showed similar rates of correct tracheal tube position as the conventional and video laryngoscope.

Evidence Rating Level: 1 (Excellent)

Study Rundown:

Endotracheal intubation is a life-saving measure of securing the airway in emergency situations. Historically, intubations have been usually achieved via direct laryngoscopy. However, there is increasing use of video laryngoscopy especially with difficult intubations due to anatomical variations or other situational factors. The VieScope is a novel tool in airway management that allows a direct line of sight towards the larynx and allows intubation in a two-step process via a bougie. It is primarily used in emergency medical services and combat medicine and thus data on its effectiveness in hospital settings is limited. Thus, this study aimed to evaluate the success rates and time to intubation of the VieScope in comparison to the conventional and video laryngoscopes commonly used in practice currently.

The study participants included 35 physicians from the Department of Anesthesia in the University Hospital of Cologne. In a randomized order, each participant completed three intubation attempts: one with the conventional Macintosh (MAC) laryngoscope, one with the GlideScope, and one with the VieScope. The intubations were completed on a mannequin with an inflated tongue and a cervical spine collar to simulate a difficult airway. The primary outcome measured was the positioning of the tube (esophagus versus trachea). It was found that there was no significant difference in correct tube positioning amongst the three methods used. The secondary outcomes measured were time to intubation, time to first ventilation, handling time and best Cormack and Lehane scoring. Comparison analysis demonstrated that time to intubation with the VieScope was prolonged compared to intubation via both the MAC and GlideScope. Similarly, time to first ventilation was greater when using the VieScope versus the two other methods. Handling time was defined as the time until Bougie placement for VieScope (first step in two step intubation) and time until intubation for MAC and GlideScope. There were no significant differences found in the handling time amongst the three groups. The Cormack and Lehane score classifies views obtained by a laryngoscope based on the structures seen. It was found that the participants rated the VieScope with a better Cormack and Lehane score when compared to the MAC.

This is one of the first studies examining the VieScope’s use in a hospital setting with physicians, thus bringing to light a potential novel tool that could be integrated into clinical practice in the future. A strength of this study was that all participants completed intubation via each of the methods in a randomized order, thus acting as their own controls. However, one limitation is that the study included only 35 participants with similar characteristics, thus decreasing generalizability of the results. Additionally, given the nature of the study, the participants nor the researchers could be blinded when measuring the results. Finally, the participants had much more experience utilizing the MAC and GlideScope compared to the VieScope which could have had a major impact on their performance. Overall, although this study has introduced a novel tool for intubation in the hospital environment, additional larger-scale studies are needed to evaluate the feasibility, efficacy and safety of the VieScope.

In-Depth [randomized controlled trial]:

A total of 35 staff anesthesiologists were recruited for the study (mean age, 35 years; 18 [51%] female). Each participant completed three intubation attempts, one with each device, and thus a total of 105 intubation attempts were analyzed. For the primary outcome, 35 (100%) had correct endotracheal position with GlideScope, 32 (91%) with the MAC, and 31 (89%) with the VieScope (p=0.137). Thus, no significant difference found between the groups. The time to intubation was significantly longer using the VieScope when compared to the MAC and GlideScope (mean [SD], 36.3 [10.1] seconds versus 20.8 [8.1] seconds and 27.5 [20.3] seconds, respectively; p<0.001 both). Similarly, time until first ventilation was longer in VieScope when compared to MAC and GlideScope (mean [SD], 46.5[12.4] seconds versus 31.9 [9.5] seconds and 39.3 [21.6] seconds, respectively; p<0.001 both). There was no statistically significant difference found in the handling time amongst the three scopes. Finally, comparison of the Comrack and Lehane score given by participants after every intubation showed that MAC had a mean [SD] score of 1.6 [0.7] while the VieScope had a better score of 1.2 [0.4], p<0.001.

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