[Effect of neurally adjusted ventilatory assist ventilation in severe neurological cerebrovascular diseases patients undergoing mechanical ventilation].

OBJECTIVE

To explore the prognostic effect and safety of neurally adjusted ventilatory assist (NAVA) mode on the patients with severe neurological cerebrovascular disease undergoing mechanical ventilation.

METHODS

A prospective study was conducted. Fifty-four patients with cerebrovascular disease undergoing mechanical ventilation admitted to the neurosurgery intensive care unit (NSICU) of the First Affiliated Hospital of Wannan Medical College (Yijishan Hospital) from December 2020 to May 2022 were enrolled. They were divided into NAVA group and pressure support ventilation (PSV) group by computer random number generator with 27 patients in each group. The ventilation time of the two groups was ≥ 72 hours. The general basic data of the two groups were recorded. The time without mechanical ventilation 28 days after enrollment, total length of mechanical ventilation, survival rate of 90 days after enrollment, length of NSICU stay, total length of hospital stay, NSICU mortality, in-hospital mortality, Glasgow outcome score (GOS), complications related to mechanical ventilation, and changes of respiratory mechanics indexes, arterial blood gases, vital signs, and diaphragm function indexes were observed.

RESULTS

The time without mechanical ventilation 28 days after enrollment in the NAVA group was significantly longer than that in the PSV group [days: 22 (15, 26) vs. 6 (0, 23), P < 0.05]. However, there were no significant differences in the total length of mechanical ventilation, 90-day survival rate, length of NSICU stay, total length of hospital stay, NSICU mortality, in-hospital mortality, GOS score, and incidence of mechanical ventilator-related complications between the two groups. In terms of respiratory mechanics parameters, the expiratory tidal volume (VTe) on 3 days after mechanical ventilation of patients in the NAVA group was significantly lower than that on 1 day and 2 days, and significantly lower than that in the PSV group [mL: 411.0 (385.2, 492.6) vs. 489.0 (451.8, 529.4), P < 0.01]. Minute ventilation (MV) at 2 days and 3 days in the NAVA group was significantly higher than that at 1 day, and significantly higher than that in the PSV group at 2 days [L/min: 9.8 (8.4, 10.9) vs. 7.8 (6.5, 9.8), P < 0.01], while there was no significant change of MV in the PSV group. At 1 day, peak airway pressure (Ppeak) and mean airway pressure (Pmean) in the NAVA group were significantly lower than those in the PSV group [Ppeak (cmHO, 1 cmHO ≈ 0.098 kPa): 14.0 (12.2, 17.0) vs. 16.6 (15.0, 17.4), Pmean (cmHO): 7.0 (6.2, 7.9) vs. 8.0 (7.0, 8.2), both P < 0.05]. However, there was no significant difference in the Ppeak or Pmean at 2 days and 3 days between the two groups. In terms of arterial blood gas, there was no significant difference in pH value between the two groups, but with the extension of mechanical ventilation time, the pH value at 3 days of the two groups was significantly higher than that at 1 day. Arterial partial pressure of oxygen (PaO) at 1 day in the NAVA group was significantly lower than that in the PSV group [mmHg (1 mmHg ≈ 0.133 kPa): 122.01±37.77 vs. 144.10±40.39, P < 0.05], but there was no significant difference in PaO at 2 days and 3 days between the two groups. There was no significant difference in arterial partial pressure of carbon dioxide (PaCO) or oxygenation index (PaO/FiO) between the two groups. In terms of vital signs, the respiratory rate (RR) at 1, 2, and 3 days of the NAVA group was significantly higher than that of the PSV group [times/min: 19.2 (16.0, 25.2) vs. 15.0 (14.4, 17.0) at 1 day, 21.4 (16.4, 26.0) vs. 15.8 (14.0, 18.6) at 2 days, 20.6 (17.0, 23.0) vs. 16.7 (15.0, 19.0) at 3 days, all P < 0.01]. In terms of diaphragm function, end-inspiratory diaphragm thickness (DTei) at 3 days in the NAVA group was significantly higher than that in the PSV group [cm: 0.26 (0.22, 0.29) vs. 0.22 (0.19, 0.26), P < 0.05]. There was no significant difference in end-expiratory diaphragm thickness (DTee) between the two groups. The diaphragm thickening fraction (DTF) at 2 days and 3 days in the NAVA group was significantly higher than that in the PSV group [(35.18±12.09)% vs. (26.88±8.33)% at 2 days, (35.54±13.40)% vs. (24.39±9.16)% at 3 days, both P < 0.05].

CONCLUSIONS

NAVA mode can be applied in patients with neuro-severe cerebrovascular disease, which can prolong the time without mechanical ventilation support and make patients obtain better lung protective ventilation. At the same time, it has certain advantages in avoiding ventilator-associated diaphragm dysfunction and improving diaphragm function.