Intensive Care Medicine

, Volume 33, Issue 8, pp 1444–1451

Performance of noninvasive ventilation modes on ICU ventilators during pressure support: a bench model study

  • Laurence Vignaux
  • Didier Tassaux
  • Philippe Jolliet
Experimental

DOI: 10.1007/s00134-007-0713-0

Cite this article as:
Vignaux, L., Tassaux, D. & Jolliet, P. Intensive Care Med (2007) 33: 1444. doi:10.1007/s00134-007-0713-0

Abstract

Objective

Noninvasive ventilation (NIV) is often applied with ICU ventilators. However, leaks at the patient-ventilator interface interfere with several key ventilator functions. Many ICU ventilators feature an NIV-specific mode dedicated to preventing these problems. The present bench model study aimed to evaluate the performance of these modes.

Design and setting

Bench model study in an intensive care research laboratory of a university hospital.

Methods

Eight ICU ventilators, widely available in Europe and featuring an NIV mode, were connected by an NIV mask to a lung model featuring a plastic head to mimic NIV conditions, driven by an ICU ventilator imitating patient effort. Tests were conducted in the absence and presence of leaks, the latter condition with and without activation of the NIV mode. Trigger delay, trigger-associated inspiratory workload, and pressurization were tested in conditions of normal respiratory mechanics, and cycling was also assessed in obstructive and restrictive conditions.

Results

On most ventilators leaks led to an increase in trigger delay and workload, a decrease in pressurization, and delayed cycling. On most ventilators the NIV mode partly or totally corrected these problems, but with large variations between machines. Furthermore, on some ventilators the NIV mode worsened the leak-induced dysfunction.

Conclusions

The results of this bench-model NIV study confirm that leaks interfere with several key functions of ICU ventilators. Overall, NIV modes can correct part or all of this interference, but with wide variations between machines in terms of efficiency. Clinicians should be aware of these differences when applying NIV with an ICU ventilator.

Keywords

Noninvasive ventilationMechanical ventilationMechanical ventilators

Supplementary material

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Laurence Vignaux
    • 1
  • Didier Tassaux
    • 1
    • 2
  • Philippe Jolliet
    • 1
  1. 1.Intensive CareUniversity HospitalGeneva 14Switzerland
  2. 2.AnesthesiologyUniversity HospitalGeneva 14Switzerland