Does the Miller blade truly provide a better laryngoscopic view and intubating conditions than the Macintosh blade in small children?

Abstract

Both Miller and Macintosh blades are widely used for laryngoscopy in small children, though the Miller blade is more commonly recommended in pediatric anesthetic literature. The aim of this study was to compare laryngoscopic views and ease and success of intubation with Macintosh and Miller blades in small children under general anesthesia. One hundred and twenty children aged 1-24 months were randomized for laryngoscopy to be performed in a crossover manner with either the Miller or the Macintosh blade first, following induction of anesthesia and neuromuscular blockade. The tips of both the blades were placed at the vallecula. Intubation was performed following the second laryngoscopy. The glottic views with and without external laryngeal maneuver (ELM) and ease of intubation were observed. Similar glottic views with both blades were observed in 52/120 (43%) children, a better view observed with the Miller blade in 35/120 (29%) children, and with the Macintosh blade in 33/120 (28%). Laryngoscopy was easy in 65/120 (54%) children with both the blades. Restricted laryngoscopy was noted in 55 children: in 27 children with both the blades, 15 with Miller, and 13 with Macintosh blade. Laryngoscopic view improved following ELM with both the blades. In children aged 1-24 months, the Miller and the Macintosh blades provide similar laryngoscopic views and intubating conditions. When a restricted view is obtained, a change of blade may provide a better view. Placing the tip of the Miller blade in the vallecula provides satisfactory intubating conditions in this age group.