Prediction of extubation failure in preterm neonates

The aim of this study was to compare the results of lung function measureme nts made before and after extubation and ventilator settings recorded immed iately prior to extubation with regard to their ability to predict extubati on success in mechanically ventilated, prematurely born infants. Immediatel y after extubation all infants were nursed in an appropriate amount of humi dified oxygen bled into a headbox. Functional residual capacity, spontaneou s tidal volume and compliance of the respiratory system were measured both within 4 h before and within 24 h after extubation. The peak inspiratory pr essure and inspired oxygen concentration immediately prior to extubation we re recorded. The results were related to extubation failure: requirement fo r continuous positive airways pressure or re-ventilation within 48 h of ext ubation. A total of 30 infants, median gestational age 29 weeks (range 25-3 3 weeks) were studied at a median postnatal age of 3 days (range 1-6 days). Extubation failed in ten infants, who differed significantly from the rest of the cohort with regard to their post extubation functional residual cap acity (FRC) (median 23, range 15.6-28.7 ml/kg versus 28.6, range 18.1-39.2 ml/kg, P < 0.01) and their requirement for a higher inspired oxygen concent ration post extubation (median 0.30, range 0.21-0.40 versus 0.22, range 0.2 1-0.36, P < 0.05). An FRC of less than 26 ml/kg post extubation had the hig hest positive predictive value in predicting extubation failure. Conclusion A low lung volume performed best in predicting extubation failur e when compared to the results of other lung function measurements and comm only used 'clinical' indices, i.e, ventilator settings. A low gestational a ge, however, was a better predictor of extubation failure than a low lung v olume.