Neurally adjusted ventilatory assisted ventilation compared to pressure support during post-operative weaning of hepatic patients undergoing major abdominal surgeries: a randomized control trial

Abstract

Objective: Patient-ventilator asynchrony (PVA) is a discrepancy between the patient’s demands and the ventilator. Pressure support ventilation (PSV) is the most popular mode of partial ventilation. Neurally adjusted ventilatory assist (NAVA) tailors the level of assistance to the diaphragm’s electromyographic activity. We aimed to evaluate the PVA during NAVA versus PSV in hepatic patients undergoing Whipple operation.

Methods: This study was a prospective, randomized, controlled double-blind trial. 120 adult Child-Pugh A and B hepatic patients of both sexes aged 18 to 65 years, undergoing Whipple operation, completed the study. We excluded severely debilitated patients and contraindications to the placement of the NAVA probe. 60 patients in the PSV (group) received PSV weaning mode, and 60 in the NAVA (group) received NAVA weaning mode. Outcome measures were asynchrony index, duration of mechanical ventilation MV, application and duration of post-extubation non-invasive CPAP, total sedating drug doses used, and ICU stay.

Results: The total asynchrony index was lower in the NAVA group than the PSV group, 6.12 ± 1.51 and 7.06 ± 1.25%, respectively, P < 0.001(95%CI 0.43 to 1.44). Cases with total ASI ≥ 10% were lower in the NAVA group than the PSV group, 6 and 16, respectively, P 0.02.The NAVA group had better oxygenation than PSV group, PaO₂ and PaO₂/FiO₂ ratio_s were 208.53 ± 14.61 vs. 188.8 ± 25.55 mmHg, p < 0.001(95%CI -27.25 to -12.20) and 521.32 ± 36.52 vs. 472.01 ± 63.88, p < 0.001 (95%CI -68.12 to -30.50) respectively. The NAVA group had a lower duration of MV (4.05 ± 0.29 vs. 4.62 ± 0.52 h; P < 0.001(95%CI 0.41 to 0.72), auto-PEEP occurrence, and total doses of fentanyl and propofol than the PSV group.

Conclusions: NAVA serves better patient-ventilator interaction and synchronization than PSV, as indicated by a lower total asynchrony index, a reduced number of patients with total ASI ≥ 10%, the total doses of sedation used, the duration of MV needed, minimized need for post-extubation CPAP, and better oxygenation.

Trial registration: Menoufia University Faculty of Medicine research ethics committee IRB (N. and date 3/2020/ANET9), and National Liver Institute Menoufia University Institutional Review Board (NLI IRB 000140140). The study was retrospectively registered at the Pan African Clinical Trial with identification number PACTR202401894086611 on 26 January 2024.

Clinical registration: The study was registered at the Pan African Clinical Trial with identification number PACTR202401894086611.

Supplementary Information: The online version contains supplementary material available at 10.1186/s12871-025-03159-y.

Keywords: Neurally adjusted ventilatory assist; Patient-ventilator asynchrony; Pressure support ventilation.

Fig. 1

CONSORT flow chart. NAVA: Neurally Adjusted Ventilatory Assisted, PSV: Pressure Support Ventilation

Fig. 2

The number of cases with severe asynchrony (total ASI ≥ 10%) in group 1 PSV group (Pressure Support Ventilation) and group 2 NAVA group (Neurally Adjusted Ventilatory Assisted)

Fig. 3

The total asynchrony index, ineffective trigger index, auto trigger index, long cycle index, double trigger index and short cycle index in group 1 PSV group and group 2 NAVA group

Fig. 4

The ROC curve for the total asynchrony index ASI for prediction of the need for postoperative CPAP in PSV group (A) and in NAVA group (B)