The effect of different pillow heights on direct laryngoscopic views: A prospective randomised controlled study

Abstract

PurposeThe purpose of this study was to determine the optimal pillow height for the best laryngoscopic view in adult patients scheduled for elective surgery under general anaesthesia.MethodsA total of fifty adult patients without any anticipated difficult airway and who gave proper informed consent were enrolled for the study. The preanaesthetic airway evaluations were done in all the patients and were recorded. After induction of anaesthesia, the appropriate sized Macintosh blade was used for direct laryngoscopy. The assessment of direct laryngoscopic views was done at head positions without a pillow and with non-compressible pillows of heights 4.5 cm, 9 cm and 13.5 cm, respectively. The views were simultaneously imaged with a flexible fibreoptic bronchoscope attached along the junction between the tongue and the flange of the Macintosh blade, and the position offering the best view was sought for which was graded by one anaesthesiologist.ResultsThe laryngoscopic view with the 4.5 cm pillow was significantly superior to that with other pillows and without a pillow (p < 0.01). The incidence of difficult laryngoscopy (Cormack and Lehane grade 3) was 18% without a pillow. In these cases, laryngoscopic views were improved using a 4.5 cm pillow.ConclusionThe use of a 4.5 cm pillow is recommended during direct laryngoscopy in the ‘sniff’ position for obtaining the best laryngoscopic view.