Intensive Care Medicine

, Volume 37, Issue 12, pp 1943–1950

Noninvasive ventilation through a helmet in postextubation hypoxemic patients: physiologic comparison between neurally adjusted ventilatory assist and pressure support ventilation

  • Gianmaria Cammarota
  • Carlo Olivieri
  • Roberta Costa
  • Rosanna Vaschetto
  • Davide Colombo
  • Emilia Turucz
  • Federico Longhini
  • Francesco Della Corte
  • Giorgio Conti
  • Paolo Navalesi
Original

DOI: 10.1007/s00134-011-2382-2

Cite this article as:
Cammarota, G., Olivieri, C., Costa, R. et al. Intensive Care Med (2011) 37: 1943. doi:10.1007/s00134-011-2382-2

Abstract

Purpose

Neurally adjusted ventilatory assist (NAVA) has been shown to improve patient–ventilator interaction and reduce asynchronies in intubated patients, as opposed to pressure support ventilation (PSV). This is a short-term head-to-head physiologic comparison between PSV and NAVA in delivering noninvasive ventilation through a helmet (h-NIV), in patients with postextubation hypoxemic acute respiratory failure.

Methods

Ten patients underwent three 20-min trials of h-NIV in PSV, NAVA, and PSV again. Arterial blood gases (ABGs) were assessed at the end of each trial. Diaphragm electrical activity (EAdi) and airway pressure (Paw) were recorded to derive neural and mechanical respiratory rate and timing, inspiratory (delayTR-insp) and expiratory trigger delays (delayTR-exp), time of synchrony between diaphragm contraction and ventilator assistance (timesynch), and the asynchrony index (AI).

Results

ABGs, peak EAdi, peak Paw, respiratory rate, either neural or mechanical, neural timing, and delayTR-exp were not different between trials. Compared with PSV, with NAVA the mechanical expiratory time was significantly shorter, while the inspiratory time and duty cycle were greater. Timesynch was 0.79 ± 0.35 s in NAVA versus 0.60 ± 0.30 s and 0.55 ± 0.29 s during the PSV trials (p < 0.01 for both). AI exceeded 10% during both PSV trials, while not in NAVA (p < 0.001).

Conclusions

Compared with PSV, NAVA improves patient–ventilator interaction and synchrony, with no difference in gas exchange, respiratory rate, and neural drive and timing.

Keywords

Noninvasive ventilationHelmetPatient–ventilator interactionPatient–ventilator asynchronyNeurally adjusted ventilatory assist (NAVA)Pressure support ventilation (PSV)

Supplementary material

134_2011_2382_MOESM1_ESM.doc (54 kb)
Supplementary material 1 (DOC 53 kb)

Copyright information

© Copyright jointly held by Springer and ESICM 2011

Authors and Affiliations

  • Gianmaria Cammarota
    • 1
  • Carlo Olivieri
    • 1
  • Roberta Costa
    • 2
  • Rosanna Vaschetto
    • 1
  • Davide Colombo
    • 1
  • Emilia Turucz
    • 3
  • Federico Longhini
    • 3
  • Francesco Della Corte
    • 1
    • 3
  • Giorgio Conti
    • 2
  • Paolo Navalesi
    • 3
    • 4
  1. 1.Anesthesia and Intensive CareMaggiore della Carità University HospitalNovaraItaly
  2. 2.Department of Anesthesiology and Intensive CareUniversità Cattolica del Sacro Cuore, A. Gemelli University HospitalRomeItaly
  3. 3.Department of Clinical and Experimental MedicineUniversità del Piemonte Orientale “Amedeo Avogadro” Alessandria-Novara-VercelliNovaraItaly
  4. 4.Anesthesia and Intensive CareSant’Andrea HospitalVercelliItaly