Neurally adjusted ventilatory assist vs. pressure support to deliver protective mechanical ventilation in patients with acute respiratory distress syndrome: a randomized crossover trial

Author(s)

Diniz-Silva, Fabia ^[1] ; Moriya, Henrique T. ^[2] ; Alencar, Adriano M. ^[3] ; Amato, Marcelo B. P. ^[1] ; Carvalho, Carlos R. R. ^[1] ; Ferreira, Juliana C. ^[1]

Affiliation

^[1] Univ Sao Paulo, Div Pneumol, Inst Coracao, Hosp Clin HCF MUSP, Fac Med, Ave Dr Eneas de Carvalho Aguiar 44, 5 Andar, BR-05403900 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Biomed Engn Lab, Escola Politecn, Ave Prof Luciano Gualberto, Trav 3, 158, Cidade Univ, BR-05586060 Sao Paulo, SP - Brazil

^[3] Univ Sao Paulo, Inst Fis, Caixa Postal 66318, BR-05314970 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: ANNALS OF INTENSIVE CARE; v. 10, n. 1 FEB 10 2020.
• Web of Science Citations: 0

Abstract

Background Protective mechanical ventilation is recommended for patients with acute respiratory distress syndrome (ARDS), but it usually requires controlled ventilation and sedation. Using neurally adjusted ventilatory assist (NAVA) or pressure support ventilation (PSV) could have additional benefits, including the use of lower sedative doses, improved patient-ventilator interaction and shortened duration of mechanical ventilation. We designed a pilot study to assess the feasibility of keeping tidal volume (V-T) at protective levels with NAVA and PSV in patients with ARDS. Methods We conducted a prospective randomized crossover trial in five ICUs from a university hospital in Brazil and included patients with ARDS transitioning from controlled ventilation to partial ventilatory support. NAVA and PSV were applied in random order, for 15 min each, followed by 3 h in NAVA. Flow, peak airway pressure (Paw) and electrical activity of the diaphragm (EAdi) were captured from the ventilator, and a software (Matlab, Mathworks, USA), automatically detected inspiratory efforts and calculated respiratory rate (RR) and V-T. Asynchrony events detection was based on waveform analysis. Results We randomized 20 patients, but the protocol was interrupted for five (25%) patients for whom we were unable to maintain V-T below 6.5 mL/kg in PSV due to strong inspiratory efforts and for one patient for whom we could not detect EAdi signal. For the 14 patients who completed the protocol, V-T was 5.8 +/- 1.1 mL/kg for NAVA and 5.6 +/- 1.0 mL/kg for PSV (p = 0.455) and there were no differences in RR (24 +/- 7 for NAVA and 23 +/- 7 for PSV, p = 0.661). Paw was greater in NAVA (21 +/- 3 cmH(2)O) than in PSV (19 +/- 3 cmH(2)O, p = 0.001). Most patients were under continuous sedation during the study. NAVA reduced triggering delay compared to PSV (p = 0.020) and the median asynchrony Index was 0.7% (0-2.7) in PSV and 0% (0-2.2) in NAVA (p = 0.6835). Conclusions It was feasible to keep V-T in protective levels with NAVA and PSV for 75% of the patients. NAVA resulted in similar V-T, RR and Paw compared to PSV. Our findings suggest that partial ventilatory assistance with NAVA and PSV is feasible as a protective ventilation strategy in selected ARDS patients under continuous sedation. Trial registration ClinicalTrials.gov (NCT01519258). Registered 26 January 2012, https://clinicaltrials.gov/ct2/show/NCT01519258 (AU)

• FAPESP's process: 11/20225-1 - Performance of NAVA as lung protective mechanical ventilation in patients with acute respiratory distress syndrome
• Grantee: Juliana Carvalho Ferreira
• Support Opportunities: Regular Research Grants