189 - Continuous Monitoring of Hemodynamic Responses to Extubation in Very Low Birth Weight Infants: A Pilot Feasibility Study

Poster Number: 189
Publication Number: 189.219

Nina DeBenedictis, Maria Fareri Children's Hospital at Westchester Medical Center, Scarsdale, NY, United States; Gad Alpan, NY Medical College, New York, NY, United States; Edmund F. LaGamma, New York Medical College, Valhalla, NY, United States

Background: Chronic lung disease involves alveolar simplification, small airway malacia, and pulmonary vascular distortion each contributing to respiratory vulnerability well into adulthood (AJP 321(5):L974,2021). Improvement in post-extubation cardiac output (CO) in adults is associated with extubation success (AJRCCM 158:1763, 1998); a paucity of data exists for VLBWs (Int Care Med 26(9):1164,2000). We hypothesized that continuous assessment of CO responses in VLBWs would help predict short-term extubation success and provide early evidence of alterations in pulmonary vasculature.

Objective: We sought to determine whether perturbations in cardiac function may predict extubation success and would identify critical time points in post-extubation cardiac function.

Design/Methods: Five infants with birth at GA 22-30w were evaluated with electrical velocimetry via the ICONTM system (Osypka Medical, Cardiotronic) during elective extubation to non-invasive ventilation (NIMV). Heart rate (HR), stroke volume (SV), and CO were continuously monitored, during the 1h prior (Pre-Ext), 1sth after (Ext+1hr), & 2ndh after (Ext+2h) extubation. ANOVA with repeated measures evaluated the effect of extubation over time. Post hoc Bonferroni assessed pairwise differences after t-tests when comparing subjects needing escalation in respiratory support vs successful patients.

Results: Baseline characteristics were similar for all patients (Table). Three were successfully extubated to non-invasive BiPAP, and 2 required escalation of respiratory support within 24h. For those successfully extubated, mean CO & SV were observed to increase between Pre-Ext and Ext+1hr (Fig). ANOVA revealed a statistically significant higher CO at Ext+1hr vs Pre-Ext. SV displayed a non-statistically significant increase at Ext+1hr. No difference was found in HR vs time. Subjects successfully extubated showed a significantly higher SV at Ext+1h vs those who required escalation in support. The successfully extubated group also had a significantly higher CO at Ext+1hr than those subjects who required escalation. Conclusion(s): Electrical velocimetry may aid in predicting successful extubation as early as 1 hr after removal of tube. We speculate that improved CO in this initial hour is a marker of reserve capacity to increase cardiac work-demand from spontaneous breathing and/or it is representative of lower pulmonary vascular resistance, which may be a marker for less severe vascular disease in the future. Further work is in progress to establish a consistent correlation in a larger population of neonates.
Table: Baseline Characteristics
Figure: Cardiac Parameters Pre and Post Extubation