Research
Optimization of ventilator setting by flow and pressure waveforms analysis during noninvasive ventilation for acute exacerbations of COPD: a multicentric randomized controlled trial
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* Corresponding author: Fabiano Di Marco fabiano.dimarco@unimi.it
1 Pneumologia Ospedale San Paolo, Università degli Studi di Milano, via A. di Rudinì 8, Milano, 20142, Italy
2 Emergency Department, Valduce Hospital, via Dante Alighieri 11, Como, 22100, Italy
3 U. O. Clinica Pneumologica, Università degli Studi di Milano-Bicocca, Azienda Ospedaliera S. Gerardo, via Pergolesi 33, Monza, 20900, Italy
4 Pneumologia e UTSIR, Ospedale Campo di Marte, via dell'Ospedale 1, Lucca, 55100, Italy
5 ICU, Ospedale Regionale Bellinzona e Valli, viale Officina 3, Bellinzona 6500, Switzerland
6 Respiratory and Critical Care Unit, Sant'Orsola Malpighi Hospital, via Albertoni 15, Bologna, 40138, Italy
Critical Care 2011, 15:R283 doi:10.1186/cc10567
Published: 24 November 2011Abstract
Introduction
The analysis of flow and pressure waveforms generated by ventilators can be useful in the optimization of patient-ventilator interactions, notably in chronic obstructive pulmonary disease (COPD) patients. To date, however, a real clinical benefit of this approach has not been proven.
Methods
The aim of the present randomized, multi-centric, controlled study was to compare optimized ventilation, driven by the analysis of flow and pressure waveforms, to standard ventilation (same physician, same initial ventilator setting, same time spent at the bedside while the ventilator screen was obscured with numerical data always available). The primary aim was the rate of pH normalization at two hours, while secondary aims were changes in PaCO2, respiratory rate and the patient's tolerance to ventilation (all parameters evaluated at baseline, 30, 120, 360 minutes and 24 hours after the beginning of ventilation). Seventy patients (35 for each group) with acute exacerbation of COPD were enrolled.
Results
Optimized ventilation led to a more rapid normalization of pH at two hours (51 vs. 26% of patients), to a significant improvement of the patient's tolerance to ventilation at two hours, and to a higher decrease of PaCO2 at two and six hours. Optimized ventilation induced physicians to use higher levels of external positive end-expiratory pressure, more sensitive inspiratory triggers and a faster speed of pressurization.
Conclusions
The analysis of the waveforms generated by ventilators has a significant positive effect on physiological and patient-centered outcomes during acute exacerbation of COPD. The acquisition of specific skills in this field should be encouraged.
Trial registration
ClinicalTrials.gov NCT01291303.