Time to achieve desired fraction of inspired oxygen using a T-piece ventilator during resuscitation of preterm infants at birth.

Abstract

To determine the time between adjustment of FiO₂ at the oxygen blender and the desired FiO₂ reaching the preterm infant during respiratory support at birth. This observational study was performed using a Neopuff^™ T-piece Resuscitator attached to either a test lung (during initial bench tests) or a face mask during the stabilization of infants at birth. FiO₂ was titrated following resuscitation guidelines. The duration for the desired FiO₂ to reach either the test lung or face mask was recorded, both with and without leakage. A respiratory function monitor was used to record FiO₂ and amount of leak. In bench tests, the median (IQR) time taken to achieve a desired FiO₂ was 34.2 (21.8-69.1) s. This duration was positively associated with the desired FiO₂ difference, the direction of titration (upwards) and the occurrence of no leak (R² 0.863, F 65.016, p < 0.001). During stabilization of infants (median (IQR) gestational age 29⁺⁰ (28⁺²-30⁺⁰) weeks, birthweight 1290 (1240-1488) g), the duration (19.0 (0.0-57.0) s) required to reach a desired FiO₂ was less, but still evident. In 27/55 (49%) titrations, the desired FiO₂ was not achieved before the FiO₂ levels were again changed. There is a clear delay before a desired FiO₂ is achieved at the distal end of the T-piece resuscitator. This delay is clinically relevant as this delay could easily lead to over- and under titration of oxygen, which might result in an increased risk for both hypoxia and hyperoxia.