RESUMO
BACKGROUND: To compare invasive (iNAVA) and non-invasive (nivNAVA) neurally adjusted ventilatory assist in infants, respect to gas exchange, breathing pattern, respiratory drive, infant-ventilator interaction and synchrony, vital parameters and required sedation. METHODS: Ten consecutive intubated term infants admitted for respiratory failure of different etiology underwent to 2-hour not-randomized trials of iNAVA and, after extubation, nivNAVA, the latter with unchanged ventilator settings and with air-leaks compensating software. Arterialized capillary blood was sampled at the end of each trial. We computed: 1) the minimum (EAdimin) and peak (EAdipeak) values of the diaphragm electrical activity; 2) ventilator (RRmec) and own patients' (RRneu) respiratory rates; 3) inspiratory (delayTR-insp) and expiratory trigger delays (delayTR-exp) and the time of synchrony between patient's effort and ventilator assistance (Timesynch/Tineu); 4) the asynchrony index. Vital parameters and required sedation were also recorded. RESULTS: iNAVA and nivNAVA did not differ between in terms of gas exchange (pH (7.35 [7.31-7.41] vs. 7.36 [7.30-7.40], P=0.745), PcCO2 (38.4 [34.8-42.6] vs. 36.9 [33.9-41.6] mmHg, P=0.469) and PcO2/FiO2 (211 [168-323] vs. 214 [189-282], P=0.195), respectively). EAdimin, EAdipeak, RRmec and RRneu were similar before and after extubation. Both modes confirmed an optimal infant-ventilator interaction (i.e. delayTR-insp, delayTR-exp and Timesynch/Tineu), irrespective of the interface, and no patients showed clinical relevant asynchronies. A low requirement of sedation with fentanyl was recorded during both trials, without differences between. CONCLUSIONS: We found iNAVA and nivNAVA to be characterized by similar gas exchange, breathing pattern, respiratory drive, infant-ventilator interaction and synchrony, vital parameters and required sedation.
