Abstract
Objective To systematically review the methods for estimating endotracheal tube (ETT) insertion
depth in neonates.
Study Design Medline, Embase, Cochrane Central, and Cumulative Index to Nursing and Allied Health
Literature databases searched for randomized clinical trials (RCTs). RCTs comparing
two or more different methods to estimate ETT insertion depth were included. Two co-authors
independently extracted the data and assessed the risk of bias. The primary outcome
includes the proportion of optimally placed ETT tips identified on chest X-ray.
Results Eight RCTs evaluating seven different estimation methods were included. Trials varied
defining the optimal position of the ETT tip. Overall, the percentage of optimal position
ranged from 8.8 to 93%. The weight, gestation nomogram, and vocal cord estimation
methods resulted in malpositioning of ETT tips in more than half of infants ≤30 weeks'
gestational age. The rates of optimal ETT tip placement with the digital palpation
method differ between moderately (83–93%; two RCTs) and extremely (47%; one RCT) preterm
infants. Meta-analysis showed no difference between weight-based and digital palpation
methods (relative risk = 0.88; 95% confidence interval = 0.75–1.04; three RCTs; participants = 205;
I
2 = 0%; quality of evidence, low).
Conclusion Commonly used estimation methods for ETT tip placement are inaccurate and unreliable.
Further research is required to improve the accuracy of estimation methods and also
to identify the usefulness of the digital palpation method in large clinical trials.
Keywords
infants - neonates - endotracheal tube - ventilation - ETT
