RESPIRATORY CARE Paper in Press. Published on February 19, 2013 as DOI: 10.4187/respcare.02060
Comparative evaluation of two ventilator circuits during noninvasive ventilation (NIV) with Helmet: a bench study
Giuliano Ferrone, Flora Cipriani, Giorgia Spinazzola, Olimpia Festa, Andrea Arcangeli, Rodolfo Proietti, Massimo Antonelli, Giorgio Conti, Roberta Costa Dept. of Intensive Care and Anesthesia, Catholic University of Rome, Policlinico A. Gemelli, Largo F. Vito 1, 00168, Rome, Italy
Corresponding Author: G. Ferrone Dept. of Intensive Care and Anesthesia, Catholic University of Rome, Policlinico A. Gemelli .Largo F. Vito 1, 00168, Rome, Italy e-mail:
[email protected]
Copyright (C) 2013 Daedalus Enterprises Epub ahead of print papers have been peer-reviewed and accepted for publication but are posted before being copy edited and proofread, and as a result, may differ substantially when published in final version in the online and print editions of RESPIRATORY CARE.
RESPIRATORY CARE Paper in Press. Published on February 19, 2013 as DOI: 10.4187/respcare.02060
Abstract
Purpose The aim of this study was to compare helmet-NIV (non invasive ventilation), in terms of patientventilator interaction and performance, using two different circuits for connection: a double tube circuit (with one inspiratory and one expiratory line) and a standard circuit (an Y piece connected only to one side of the helmet, closing the other side). Methods A mannequin, connected to a test lung, set at two different respiratory rates (20 and 30 breaths/min), was ventilated in Pressure Support Ventilation (PSV) mode with two different settings, randomly applied: Pressurization time/Expiratory trigger (Timepress/Trexp) 50%/25%, Default setting and Timepress/Trexp 80%/60%, Fast setting, through a helmet. The helmet was connected to the ventilator randomly with the double and the standard circuit. Patient-ventilator interaction was evaluated measuring: Inspiratory trigger delay (Delaytrinsp), Expiratory trigger delay (Delaytrexp), Pressurization Time (Timepress), Time of synchrony (Timesyn). The performance was analyzed measuring: Trigger pressure drop, Inspiratory Pressure-Time Product (PTPt), Pressure Time Product at 300 ms and 500 ms (PTP 300 and PTP 500 respectively) and Pressure Time Product 500 ms expressed as percentage of an ideal PTP500 (PTP500 index). Results At both respiratory rates and ventilator settings helmet-NIV with the double tube circuit showed better interaction, with shorter Delaytrinsp, Delaytrexp and Timepress and longer Timesyn (p
