Left head rotation manoeuvre to improve laryngoscopic view in elective surgery

BACKGROUND: The left head rotation (LeHeR) manoeuvre has been proposed to improve the laryngoscopic view based on case reports of unexpectedly difficult intubation under emergency conditions. OBJECTIVES: To evaluate the potential of the LeHeR manoeuvre to improve the direct laryngoscopic view under elective surgical conditions and to investigate the dependence on patient- and examiner-dependent factors. DESIGN: Single-centre prospective cohort study. SETTING: This study was conducted at the Department of Anesthesiology of Saarland University Hospital between November 2022 and March 2023. Laryngoscopy findings in the Jackson position and after the application of the LeHeR manoeuvre were recorded during the routine surgical program by the responsible anaesthetists in the presence of a study physician. PATIENTS: One hundred and two adult patients scheduled for elective surgery, general anaesthesia with endotracheal intubation, and without a particular risk of aspiration. MAIN OUTCOME MEASURES: primary outcome was the laryngoscopic view graded according to the modified Cormack and Lehane classification score (CLS) and subsequently in the percentage of glottic opening (POGO) score before and after application of the LeHeR manoeuvre. The secondary outcomes were the differences in laryngoscopic views according to both scores (ΔCLS, ΔPOGO). RESULTS: With the improved Jackson-position, the median laryngoscopic view was CLS grade 2a [1 to 2a], with a POGO score of 80 [42.5 to 100]. With LeHeR, the median laryngoscopic view was CLS grade 2a [1 to 2b], with a POGO score of 70 [42.5 to 90], indicating a reduced laryngoscopic view (CLS, P < 0.001; POGO, P = 0.041). While patient characteristics had no influence on the difference in laryngoscopic views, longer professional experience correlated significantly with an improvement in the laryngoscopic view according to the POGO ( r = 0.242, P = 0.018), but not the Cormack and Lehane scores ( r = -0.29, P = 0.004). CONCLUSIONS: The LeHeR manoeuvre failed to significantly improve the direct laryngoscopic view compared to the improved Jackson-position under standard conditions for elective surgery. However, experienced anaesthetists achieved better results with this manoeuvre than novice anaesthetists. TRIAL REGISTRATION: This study was prospectively registered in the German Clinical Trials Register (DRKS00029944).