Posture comparison between supine and sternal recumbency for endotracheal intubation in dogs undergoing surgery

Abstract

Endotracheal intubation is an important procedure performed prior to almost all surgeries. It is mandatory for anesthetists to use a laryngoscope during intubation. A general laryngoscope is designed to be inserted into oral space with the left hand and the endotracheal tube is managed with the right hand, while the patient lies in the supine position. Veterinarians are ac-customed to laryngoscopes used in humans that have a curve or a straight blade with a wall on the right side. A veterinarian does a similar procedure with the laryngoscope, but animal posture is sternal or ventrolateral. It was thought that the right hand and endotracheal tube itself might hinder the laryngeal view during intubation. We studied positions of dogs during the endotracheal intubation including 11 short skull (brachycephalic) and 32 medium and long skull (normocephalic) breeds. This study showed that veterinarians could perform intubation very well in all sternal-postured anesthetized dogs but not so efficiently in dogs postured in a supine recumbent manner (Wilcoxon rank test, P=0.0007). Within the brachycephalic group of dogs, intubation times on both postures were not significantly different (Wilcoxon rank test, P=0.130). The current study thus implies that supine recumbency may be appropriate for brachycephalic dogs in general, while sternal posture is more appropriate for intubation in normocephalic dogs.