Tidal Volumes and Outcome of Extubation in Mechanically Ventilated Premature Infants

Abstract

Objectives: To compare the adjusted and unadjusted-for-weight tidal volume (V_T) in ventilated prematurely born infants who were successfully extubated compared with the ones who failed extubation and explore the ability of V_T to predict successful extubation.

Study design: This is a two-center, prospective, observational, cohort study of ventilated infants born <32 weeks of gestational age (GA) at King's College Hospital and St George's University Hospital, London, United Kingdom between February and September 2018. Expiratory V_T was recorded before extubation, and extubation was considered successful if the infants were not reintubated within 72 hours.

Results: Fifty-six (29 male) infants with a median (interquartile range) GA of 26 (25-29) weeks were studied. The infants who successfully extubated (N = 36) had a higher GA (27 [25-30] weeks) and V_T (7.2 [4.8-9.5] mL) compared with the GA (25 [24-26] weeks) and V_T (4.3 [4.0-5.5] mL) of the infants who failed extubation (p = 0.002 and p = 0.001, respectively). V_T/kg was not different in infants who successfully extubated compared with the ones who failed extubation (p = 0.643). Following multivariate regression, V_T was associated with extubation success (adjusted p = 0.022) and GA was not (adjusted p = 0.167). A V_T > 4.5 mL predicted successful extubation with 82% sensitivity and 58% specificity (area under the curve = 0.786).

Conclusion: Successful extubation was associated with higher unadjusted-for-weight V_Ts compared with failed extubation, and unadjusted V_T predicted extubation outcome with moderate sensitivity and specificity.