Respiratory physiological changes post initiation of neurally adjusted ventilatory assist in preterm infants with evolving or established bronchopulmonary dysplasia

To assess respiratory changes after neurally adjusted ventilatory assist (NAVA) initiation in preterm infants with evolving or established bronchopulmonary dysplasia (BPD). Premature infants born less than 32 weeks gestation with evolving or established BPD initiated on invasive or non-invasive (NIV) NAVA were included. Respiratory data: PCO<INF><INF>2</INF></INF> and SpO<INF>2</INF>/FiO<INF>2</INF> (S/F) ratio before and at 4, 24, 48 h post-NAVA initiation were collected. Eighty-eight infants, median GA 25.1 (range 22.7-30.3) weeks, with 191 NAVA episodes were included. Infants born < 32 weeks with evolving and established BPD showed improvements in PCO<INF><INF>2</INF></INF> and S/F ratio 48 h post-NAVA compared to prior: 7.6 (4.5-11.8) versus 8.1 (4.7-13.1) kPa; p < 0.001 and 285 (118-471) versus 276 (103-471); p = 0.013, respectively. Improvements were observed in invasive NAVA: 7.6 (4.5-11.8) versus 8.5 (4.7-12.4) kPa; p = 0.001, 290 (148-471) versus 271 (103-467); p = 0.002, and NIV-NAVA: 7.5 (4.6-11.7) versus 7.9 (5.2-13.1) kPa; p = 0.001, 283 (128-471) versus 294 (114-471); p = 0.002. Severe BPD infants had reductions in PCO<INF><INF>2</INF></INF> 48 h post-initiation: 7.2 (5.6-9.7) versus 8.0 (5.4-11.7) kPa; p = 0.002, with lower FiO<INF>2</INF> requirements 0.37 (0.21-0.65) versus 0.43 (0.21-0.8); p = 0.011, and improved S/F ratios 263 (146-471) versus 219 (114-457); p = 0.006. On subgroup analysis, similar improvements were noted in; PCO<INF>2</INF> levels in invasive NAVA (p = 0.011) and NIV-NAVA (p = 0.002), S/F ratios in invasive NAVA (p = 0.046) and NIV-NAVA (p = 0.002) and FiO<INF>2</INF> in invasive NAVA (p = 0.034) and NIV-NAVA (p = 0.053). Conclusion: NAVA improves CO<INF><INF>2</INF></INF> clearance and oxygenation in infants with evolving or established and severe BPD at 48 h post-initiation. In severe BPD, NAVA also reduced oxygen requirements