(772) Extubation Readiness Ultrasound and NIRS Association in Postoperative Cardiac Neonates

Introduction: In post-operative cardiac surgery neonates who are mechanically ventilated, diaphragmatic atrophy and reduced diaphragmatic excursion (DE) has been associated with poor extubation outcomes. We sought to explore the feasibility and utility of using DE, obtained during a spontaneous breathing trial (SBT) in predicting weaning outcomes. Near-infrared spectroscopy (NIRS) is a noninvasive comparative measure of tissue oxygenation. The sensor is placed on the flank and takes the difference of two optical pickups to determine real-time saturations of deep tissues; these readings can be used as an indicator of global perfusion. Studies have shown there may be value in NIRS as an adjunct in assessing extubation readiness. We hypothesize that successfully extubated infants will have higher NIRS reading during SBT and have a greater DE compared to failed extubation patients.

Methods: Oxygen saturation and DE is recorded using NIRS and ultrasound respectively at the beginning, mid and end of a 30-minute SBT. Ultrasound recordings will be compared to measurements established for infants and averaged. Extubation failure is defined as reintubation < 72-hours of extubation. Additional information regarding patient demographics, primary diagnosis, the reason for intubation, days intubated, and any previous intubations is also obtained.

Results: Extubation failure occurred in 1/10 (10%) instances requiring reintubation within 12 hours and 1/10 (10%) failed their SBT. Sensitivity, specificity, positive predictive value, negative predictive value, and odds ratio (OR) for failing an SBT were calculated for DE < 25%. Median DE was 1.6% [0.59-2.94]. The OR of SBT failure is 0.012 (CI: 0.0007 to 0.2293, Z-score: 2.94, P = 0.0032). No significant associations have been found between decline in cerebral or somatic NIRS and extubation outcome.

Conclusions: Our initial study suggests that ultrasound measurements of DE during spontaneous breaths in mechanically ventilated pediatric patients may be a useful addition in predicting weaning readiness. The addition of somatic regional oxygen saturation measurements to an extubation readiness trial may improve our ability to predict extubation outcome. We continue to obtain more participants in our study.