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

摘要

Aim: 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. Methods: This observational study was performed using a NeopuffTM 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. Results: 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. Conclusion: 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.