Endotracheal tube displacement during cervical manipulation in the dog

A retrospective study was performed to identify positional changes of endotracheal tubes (ETT) during cervical spine radiography in 153 dogs. Three neck positions were identified: traction, hyperextension, and flexion. A properly placed ETT was defined as having the caudal tip of the tube located between the caudal half of the fourth cervical (C) vertebra (C4) and the caudal half of C7. In the traction position, before neck flexion and extension, the caudal tip of 13% of ETT were located caudal to C7, and one tube was in the endobronchial position at the seventh thoracic (T) vertebra (T7). In the hyperextended position, 60% of ETT moved cranially. The average distance moved was 0.6 vertebral spaces. In the flexed position, all ETT moved caudally. The average distance moved was 3.5 vertebral spaces, with 81.8% of ETT located caudal to C7 and seven tubes in endobronchial positions. Endotracheal tube occlusion caused by kinking at the atlanto-occipital joint was seen in four dogs during flexion of the neck. Based on this study, ETT position should be monitored during cervical manipulation.