EPISYNC study: predictors of patient-ventilator asynchrony in a prospective cohort of patients under invasive mechanical ventilation - study protocol

Abstract

Introduction: Patient-ventilator asynchrony is common during the entire period of invasive mechanical ventilation (MV) and is associated with worse clinical outcomes. However, risk factors associated with asynchrony are not completely understood. The main objectives of this study are to estimate the incidence of asynchrony during invasive MV and its association with respiratory mechanics and other baseline patient characteristics.

Methods and analysis: We designed a prospective cohort study of patients admitted to the intensive care unit (ICU) of a university hospital. Inclusion criteria are adult patients under invasive MV initiated for less than 72 hours, and with expectation of remaining under MV for more than 24 hours. Exclusion criteria are high flow bronchopleural fistula, inability to measure respiratory mechanics and previous tracheostomy. Baseline assessment includes clinical characteristics of patients at ICU admission, including severity of illness, reason for initiation of MV, and measurement of static mechanics of the respiratory system. We will capture ventilator waveforms during the entire MV period that will be analysed with dedicated software (Better Care, Barcelona, Spain), which automatically identifies several types of asynchrony and calculates the asynchrony index (AI). We will use a linear regression model to identify risk factors associated with AI. To assess the relationship between survival and AI we will use Kaplan-Meier curves, log rank tests and Cox regression. The calculated sample size is 103 patients. The statistical analysis will be performed by the software R Programming (www.R-project.org) and will be considered statistically significant if the p value is less than 0.05.

Ethics and dissemination: The study was approved by the Ethics Committee of Instituto do Coração, School of Medicine, University of São Paulo, Brazil, and informed consent was waived due to the observational nature of the study. We aim to disseminate the study findings through peer-reviewed publications and national and international conference presentations.

Trial registration number: NCT02687802; Pre-results.

Keywords: automatic algorithms; mechanical ventilation; patient-ventilator asynchrony; respiratory mechanics.

Conflict of interest statement

Competing interests: RMK reports grants and personal fees from Medtronic, personal fees from Orange Medical, grants from Venner Medical, outside the submitted work. LB is inventor of one Corporació Sanitaria Parc Taulí owned US patent: ‘Method and system for managed related patient parameters provided by a monitoring device,’ US Patent No. 12/538,940, founder of BetterCare S.L. which is a research and development company, start up of Corporació Sanitària Parc Taulí. JCF reports grants from FAPESP (Brazilian funding agency), during the conduct of the study; personal fees from Medtronic, outside the submitted work.

© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

Figures

Figure 1

Overview of EPISYNC protocol. ICU, intensive care unit.

Figure 2

Examples of asynchrony events detected by Better Care. INSP, inspiratory; PAW, airway pressure; RESP, respiratory; VT, tidal volume.