Randomised trial of estimating oral endotracheal tube insertion depth in newborns using suprasternal palpation of the tip or weight

Background: Endotracheal tube (ETT) tip position is determined on chest X-ray (CXR) and should lie between the upper border of the first thoracic vertebra (T1) and the lower border of second thoracic vertebra (T2). Infant weight is commonly used to estimate how far the ETT should be inserted but frequently results in malpositioned ETT tips. Palpation of the ETT tip at the suprasternal notch has been recommended as an alternative.

Objective: To determine whether estimating ETT insertion depth using suprasternal palpation of the ETT tip rather than weight results in more correctly positioned ETT tips.

Design: Single-centre randomised controlled trial.

Setting: Level III neonatal intensive care unit (NICU) at a university maternity hospital.

Patients: Newborn infants without congenital anomalies intubated in the NICU.

Interventions: Participants were randomised to have ETT insertion depth estimated using palpation of the ETT tip at the suprasternal notch or weight [insertion depth (cm)=6 + wt (kg)].

Main outcome measure: Correct ETT position, that is, between the upper border of T1 and lower border of T2 on CXR, determined by one consultant paediatric radiologist masked to group assignment.

Results: There was no difference in the proportion of correctly placed ETT tips between the groups (suprasternal palpation 27/58 (47%) vs weight 23/60 (38%), p=0.456). Most incorrectly positioned ETTs were too low (56/68 (82%)).

Conclusion: Estimating ETT insertion depth using suprasternal palpation did not result in more correctly positioned ETTs.

Trial registration number: ISRCTN13570106.