Due to the short airways in premature children, an accurate position of the endotracheal tube (ETT) is crucial for adequate mechanical ventilation. Verification of ETT-position is done in chest radiographs. However, ETT-position varies substantially with head movement. When the head is flexed, the tube might appear too deeply inserted, and inadvertent extubation may occur in cases of retraction of ETT after radiography. Extension of the cervical spine will suggest an inappropriately high ETT-position, so that intended corrections can lead to main-stem intubation. Radiographic visible skeletal structures could serve as reference points to allow the detection of head declination and imperfect positioning of ETT. Ratios of anatomical landmarks were used to estimate head position. In this study, 111 radiographs of 24 preterm neonates with a gestational age of 24-29 weeks and weights of 500-1,000 g were analyzed. A mathematical algorithm for the detection and correction of ETT-positions, based on common chest radiographs, was developed. In 108 cases (97.3%), ETT-distance from the midtracheal level was less than 2 mm after use of the proposed correction.Thus, the suggested correction equation for head position enables verification of the actual ETT-position without requiring a defined placement of the head during radiography. Moreover, it can be helpful for estimating the depth of ETT-insertion in conditions when radiography is not available.
Copyright 2002 Wiley-Liss, Inc.