The accuracy of anaesthetists in the depth of oral endotracheal tube placement in an academic hospital

Abstract

Background: Endotracheal intubation is currently the proverbial “gold standard” for securing and protecting a patient’s airway. However, endotracheal tube (ETT) misplacement is a recognised complication of intubation and can result in significant patient morbidity and mortality. The aims of this study were to describe anaesthetists accuracy at placing oral ETTs to the correct depth, factors which influenced this accuracy and the methods used by anaesthetists to confirm correct ETT placement. Methods: A prospective, contextual, descriptive research design was used. The sample included 138 adult patients presenting for elective surgery requiring oral ETT insertion, and the anaesthetists intubating these patients. Recorded variables included patient age, gender, height, ETT position at the front upper incisors, ETT tip to carina distance and the methods used by anaesthetists to confirm correct ETT placement. Results: Only 45.7% of ETTs were accurately placed with 34.8% being too deep. There were significantly more deep ETT misplacements in females (p=0.0231), and patients with deep ETT placement were significantly shorter than those with accurate ETT placement (p<0.05). The number of methods used by anaesthetists to confirm correct ETT placement did not influence accuracy (p=0.4014). Neither the 21/23 cm nor the 20/22 cm methods were shown to improve the accuracy of ETT placements. Endotracheal tube distance measured at the front upper incisors was weakly correlated to the ETT distance measured above the carina in female patients but not in males. Conclusion: Endotracheal tube misplacement is a frequent event in the intraoperative period, and potential risk factors identified included female gender and extremes of height. Endotracheal tube placement should be individualized. Airway ultrasound is a point of care test that could potentially help confirm correct ETT placement.