Effects of Short Versus Prolonged Inspiratory Times on Oxygen Saturation Targeting in Very Low Birth Weight Infants...

Effects of different inspiratory times during synchronized NIPPV on oxygen saturation targeting, intermittent SpO₂-fluctuations and cerebral tissue oxygen saturation (SctO₂) are unknown.

To assess effects of different inspiratory times during NIPPV on SpO₂ and SctO₂ parameters in very low birth weight infants with frequent fluctuations in SpO₂.

Twenty-four infants (gestational age: 25 [22-28] weeks; postnatal age: 27 [12-85] days) were randomly exposed in a cross-over-design to NIPPV with prolonged (NIPPV_Tilong; 0.6 s) and short inspiratory time (NIPPV_Tishort; 0.3 s) over 8 h each. Primary outcome was the percentage of time spent within the SpO₂ target range (88%-95% and ≥ 88% with FiO₂ 0.21). Secondary oxygenation outcomes included area under the curve (AUC) above and below a predefined SctO₂-range and number of SpO₂-desaturation events.

Percentage of time within SpO₂ target range significantly increased during NIPPV_Tilong (66.41% ± 12.76 vs. 60.33% ± 15.28, p = 0.02). Episodes with SpO₂ < 88%, duration > 180 s (0.1/h [0.0-0.9] vs. 0.2/h [0.0-1.3], p = 0.04) and episodes with SpO₂ < 80%, duration > 180 s (0.0/h [0.0-0.1] vs. 0.2/h [0.0-0.4], p = 0.03) significantly decreased during NIPPV_Tilong. The AUC with SctO₂-desaturations below the cerebral SctO₂-threshold was reduced during NIPPV_Tilong (29.75 (%*s)/h [0.0-1283.44] vs. 71.08 (%*s)/h [0.0-1474.96], p = 0.03).

NIPPV_Tilong increased the time within an SpO₂ target range, reduced the incidence of prolonged hypoxemic events and cerebral hypoxia burden. Extending the inspiratory time during synchronized NIPPV may have short-term benefits in unstable infants with SpO₂ fluctuations.