Autonomic markers of extubation readiness in premature infants

Background In premature infants, extubation failure is common and difficult to predict. Heart rate variability (HRV) is a marker of autonomic tone. Our aim is to test the hypothesis that autonomic impairment is associated with extubation readiness. Methods Retrospective study of 89 infants <28 weeks. HRV metrics 24 h prior to extubation were compared for those with and without extubation success within 72 h. Receiver-operating curve analysis was conducted to determine the predictive ability of each metric, and a predictive model was created. Results Seventy-three percent were successfully extubated. The success group had significantly lower oxygen requirement, higher sympathetic HRV metrics, and a lower parasympathetic HRV metric. α 1 (measure of autocorrelation, related to sympathetic tone) was the best predictor of success—area under the curve (AUC) of .73 ( p = 0.001), and incorporated into a predictive model had an AUC of 0.81 ( p < 0.0001)—sensitivity of 81% and specificity of 78%. Conclusions Extubation success is associated with HRV. We show an autonomic imbalance with low sympathetic and elevated parasympathetic tone in those who failed. α 1 , a marker of sympathetic tone, was noted to be the best predictor of extubation success especially when incorporated into a clinical model. Impact This article depicts autonomic markers predictive of extubation success. We depict an autonomic imbalance in those who fail extubation with heightened parasympathetic and blunted sympathetic signal. We describe a predictive model for extubation success with a sensitivity of 81% and specificity of 78%.