Influences of Duration of Inspiratory Effort, Respiratory Mechanics, and Ventilator Type on Asynchrony With Pressure Support and Proportional Assist Ventilation.

Autor: Vasconcelos RS; Federal University of Ceará, Fortaleza, Brazil. renatavasconcelos23@gmail.com., Sales RP; Federal University of Ceará, Fortaleza, Brazil., Melo LHP; Federal University of Ceará, Fortaleza, Brazil., Marinho LS; Federal University of Ceará, Fortaleza, Brazil., Bastos VP; Federal University of Ceará, Fortaleza, Brazil., Nogueira ADN; Federal University of Ceará, Fortaleza, Brazil., Ferreira JC; University of São Paulo School of Medicine, São Paulo, Brazil., Holanda MA; Federal University of Ceará, Fortaleza, Brazil.
Jazyk: angličtina
Zdroj: Respiratory care [Respir Care] 2017 May; Vol. 62 (5), pp. 550-557. Date of Electronic Publication: 2017 Feb 14.
DOI: 10.4187/respcare.05025
Abstrakt: Background: Pressure support ventilation (PSV) is often associated with patient-ventilator asynchrony. Proportional assist ventilation (PAV) offers inspiratory assistance proportional to patient effort, minimizing patient-ventilator asynchrony. The objective of this study was to evaluate the influence of respiratory mechanics and patient effort on patient-ventilator asynchrony during PSV and PAV plus (PAV+).
Methods: We used a mechanical lung simulator and studied 3 respiratory mechanics profiles (normal, obstructive, and restrictive), with variations in the duration of inspiratory effort: 0.5, 1.0, 1.5, and 2.0 s. The Auto-Trak system was studied in ventilators when available. Outcome measures included inspiratory trigger delay, expiratory trigger asynchrony, and tidal volume (V T ).
Results: Inspiratory trigger delay was greater in the obstructive respiratory mechanics profile and greatest with a effort of 2.0 s (160 ms); cycling asynchrony, particularly delayed cycling, was common in the obstructive profile, whereas the restrictive profile was associated with premature cycling. In comparison with PSV, PAV+ improved patient-ventilator synchrony, with a shorter triggering delay (28 ms vs 116 ms) and no cycling asynchrony in the restrictive profile. V T was lower with PAV+ than with PSV (630 mL vs 837 mL), as it was with the single-limb circuit ventilator (570 mL vs 837 mL). PAV+ mode was associated with longer cycling delays than were the other ventilation modes, especially for the obstructive profile and higher effort values. Auto-Trak eliminated automatic triggering.
Conclusions: Mechanical ventilation asynchrony was influenced by effort, respiratory mechanics, ventilator type, and ventilation mode. In PSV mode, delayed cycling was associated with shorter effort in obstructive respiratory mechanics profiles, whereas premature cycling was more common with longer effort and a restrictive profile. PAV+ prevented premature cycling but not delayed cycling, especially in obstructive respiratory mechanics profiles, and it was associated with a lower V T .
Competing Interests: The authors have disclosed no conflicts of interest.
(Copyright © 2017 by Daedalus Enterprises.)
Databáze: MEDLINE
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