A randomised comparative study on customised versus fixed sized pillow for tracheal intubation in the sniffing position by Macintosh laryngoscopy

Background and Aims: The sniffing position has been most commonly used for positioning of the head and neck to facilitate tracheal intubation. However, the optimum degree of head elevation for the optimal laryngeal view is not well studied, especially in non-Western countries. The present study was aimed to compare the use of a fixed height pillow versus a customised pillow (CP) height for head elevation, in terms of glottis visualisation and time required for tracheal intubation. Methods: With research and ethics committee approval from the institute, this randomised study was conducted among patients of both sexes aged 16 years or more and American Society of Anesthesiologists physical Status Ito IV. A total of 134 patients were randomly allocated into routinely used fixed-sized pillow (FP) and CP group (to achieve horizontal alignment of external auditory meatus [EAM] and sternal notch). Primary and secondary outcomes were Cormack-Lehane (C-L) grade of glottic visualisation and time required for tracheal intubation, respectively. They were compared using unpaired t-test and Fisher's exact test as applicable; P < 0.05 was considered statistically significant. Results: One hundred and nineteen patients completed the study. Both groups were similar in terms of demographic and external airway measurements. The mean +/- standard deviation height of pillow required in Group CP was 6.26 +/- 0.97 cm. Group FP had C L Grade 3 view more often than Group CP (28.33% vs. 13.56%). In patients with modified Mallampati (MMP) Grade >= 3, the C-L grades and time required for intubation were both significantly lower in group CP. The time required for tracheal intubation was significantly lower in group CP (P = 0.04), even though the C-L grades were similar. Conclusion: Customising pillow for head elevation to horizontally align the EAM and the sternal notch gives better glottic visualisation and intubating conditions in patients with higher MMP grades.