Abstract
Background
Tracheal intubation is a life-saving intervention, and optimizing the patient’s head and neck position for the best glottic view is a crucial step that accelerates the procedure. The left head rotation maneuver has been recently described as an innovative alternative to the traditional sniffing position used for tracheal intubation with marked improvement in glottic visualization.
Objective
This study compared the glottic view and intubating conditions in the sniffing position versus left head rotation during direct laryngoscopy.
Methods
This randomized, open-label clinical trial enrolled 52 adult patients admitted to Baguio General Hospital and Medical Center from September 2020 to January 2021 for an elective surgical procedure requiring tracheal intubation under general anesthesia. Intubation was done using a 45° left head rotation in the experimental group (n=26), while the control group (n=26) was intubated using the conventional sniffing position. Glottic visualization and intubation difficulty with the two procedures were assessed using the Cormack-Lehane grade and Intubation Difficulty Scale, respectively. Successful intubation is measured by observing a capnographic waveform in the end-tidal CO2 monitor after placement of the endotracheal tube.
Results
There was no statistically significant difference in the Cormack-Lehane grade, with 85% (n=44) of patients classified under grades 1 (n=11 and n=15) and 2 (n=11 and n=7) in the left head rotation and sniffing position groups, respectively. In addition, there were no statistically significant differences in the Intubation Difficulty Scale scores of patients intubated with left head rotation or sniffing position; 30.7% (n=8) of patients in both groups were easily intubated, while 53.8% (n=14) in left head rotation and 57.6% (n=15) in sniffing position groups were intubated with slight difficulty. Similarly, there were no significant differences between the 2 techniques in any of the 7 parameters of the Intubation Difficulty Scale, although numerically fewer patients required the application of additional lifting force (n=7, 26.9% vs n=11, 42.3%) or laryngeal pressure (n=3, 11.5% vs n=7, 26.9%) when intubated with left head rotation. The intubation success rate with left head rotation was 92.3% versus 100% in the sniffing position, but this difference was not statistically significant.
Conclusions
Left head rotation produces comparable laryngeal exposure and intubation ease to the conventional sniffing position. Therefore, left head rotation may be an alternative for patients who cannot be intubated in the sniffing position, especially in hospitals where advanced techniques such as video laryngoscopes and flexible bronchoscopes are unavailable, as is the case in this study. However, since our sample size was small, studies with a larger study population are warranted to establish the generalizability of our findings. In addition, we observed inadequate familiarity among anesthesiologists with the left head rotation technique, and the intubation success rate may improve as practitioners attain greater technical familiarization.
Trial Registration
International Standard Randomised Controlled Trial Number (ISRCTN)ISRCTN23442026; https://www.isrctn.com/ISRCTN23442026