Tidal Volumes and Outcome of Extubation in Mechanically Ventilated Premature Infants

Abstract

Objectives To compare the adjusted and unadjusted-for-weight tidal volume (VT) in ventilated prematurely born infants who were successfully extubated compared with the ones who failed extubation and explore the ability of VT 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 VT 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 VT (7.2 [4.8–9.5] mL) compared with the GA (25 [24–26] weeks) and VT (4.3 [4.0–5.5] mL) of the infants who failed extubation (p = 0.002 and p = 0.001, respectively). VT/kg was not different in infants who successfully extubated compared with the ones who failed extubation (p = 0.643). Following multivariate regression, VT was associated with extubation success (adjusted p = 0.022) and GA was not (adjusted p = 0.167). A VT > 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 VTs compared with failed extubation, and unadjusted VT predicted extubation outcome with moderate sensitivity and specificity.

Prediction of extubation success using the diaphragmatic electromyograph results in ventilated neonates

“…Others have shown demographic data such as the gestational age and body weight were better predictors of successful extubation than assessment of physiological variables [9,10,[13][14][15]. In a recent study, however, we demonstrated that a higher tidal volume in prematurely born infants better predicted extubation success than gestational age after adjustment for confounders [16]. In the study currently reported, we also found that the tidal volume and neuroventilatory efficiency differed significantly between those who were and were not successfully extubated.…”

Pathophysiology of gas exchange impairment in extreme prematurity: Insights from combining volumetric capnography and measurements of ventilation/perfusion ratio

“…It is interesting to note that the debate on whether efficient ventilation can occur with tidal volumes that are lower than the dead space refers predominantly to the extremely preterm infants as the contribution of the fixed amount of the instrumental dead space is relatively higher in the smallest infants, which are the ones that would benefit more from lung-protective ventilation strategies. A very low targeted tidal volume though, is not always lung protective, as too small volumes have been associated with an increased work of breathing ( 35 ), a higher incidence of extubation failure ( 36 ) and a pro-inflammatory state ( 8 ). A potential practical recommendation that emerges from our results is that the targeted tidal volume in ventilated preterm infants should not be lower than the total anatomical, alveolar and instrumental dead space and very low targeted tidal volumes (below 5 ml/kg) should be avoided.…”

Implementation of an Extubation Readiness Guideline for Preterm Infants

“…Dassios et al5 conducted an adequately powered cohort study, which found pulling tidal volumes more than 4.5 mL/kg as statistically significant for predicting successful extubation of ventilated infants less than 32 weeks of gestational age. Dassios et al5 also utilized guidelines for considering extubation as well as specific reintubation criteria for consideration.…”