Accuracy and Precision of an Optoacoustic Prototype in Determining Endotracheal Tube Position in Children

Confirmation of endotracheal tube (ETT) tip position and timely identification and correction of malposition is an essential component of care for endotracheally intubated and mechanically ventilated children. We evaluated the ability of a prototype optoacoustic medical device to determine ETT tip position. We hypothesized that the precision of optoacoustic assessment of ETT tip position would be comparable to chest radiography.

We recruited children aged newborn to 16 y who were admitted to the pediatric ICU requiring tracheal intubation and undergoing a chest radiograph for clinical purposes. After positioning each child on a chest radiograph plate, a sterile optical fiber, temporarily inserted through the ETT, emitted laser pulses perpendicular to the fiber and to the ETT, generating acoustic (ultrasound) waves in overlying tissue when the tip of the fiber passed beneath an acoustic sensor in the sternal notch. The distance from the ETT tip to the peak acoustic signal was used to calculate the distance from the ETT tip to the carina, which was compared with the same distance calculated by the radiologist reading the chest radiograph. Pearson's correlation coefficient, paired t tests, a Bland-Altman plot were used to compare the measures (P < .05 was considered statistically significant).

Twenty-six subjects were enrolled: 15 (57.7%) were male, median (interquartile range) age, weight, and height were 9 months (4-24), 9.6 kg (5.7-13.0), and 75 cm (62-90), respectively. All ETTs were cuffed (internal diameter range 3.0-5.0 mm). The relationship between optoacoustic and chest radiograph measurements was strong (r = 0.91, P < .001). Bias was 0.1 cm with narrow limits of agreement between measures (0.58 cm and 0.76 cm).

The optoacoustic prototype accurately determined ETT tip position and was comparable in precision to chest radiograph.