Multifaceted bench comparative evaluation of latest intensive care unit ventilators

Background Independent bench studies using specific ventilation scenarios allow testing of the performance of ventilators in conditions similar to clinical settings. The aims of this study were to determine the accuracy of the latest generation ventilators to deliver chosen parameters in various typical conditions and to provide clinicians with a comprehensive report on their performance. Methods Thirteen modern intensive care unit ventilators were evaluated on the ASL5000 test lung with and without leakage for: (i) accuracy to deliver exact tidal volume ( V t) and PEEP in assist-control ventilation (ACV); (ii) performance of trigger and pressurization in pressure support ventilation (PSV); and (iii) quality of non-invasive ventilation algorithms. Results In ACV, only six ventilators delivered an accurate V t and nine an accurate PEEP. Eleven devices failed to compensate V t and four the PEEP in leakage conditions. Inspiratory delays differed significantly among ventilators in invasive PSV (range 75–149 ms, P =0.03) and non-invasive PSV (range 78–165 ms, P P =0.04; and 60–90% for non-invasive PSV, P Conclusions We observed real heterogeneity of performance amongst the latest generation of intensive care unit ventilators. Although non-invasive ventilation algorithms appear to maintain adequate pressurization efficiently in the case of leakage, basic functions, such as delivered V t in ACV and pressurization in PSV, are often less reliable than the values displayed by the device suggest.