Heart Rate Variability During Weaning From Mechanical Ventilation

May 7, 2009 updated by: Hospital de Clinicas de Porto Alegre

The Effect of T-Tube and Pressure Support on Cardiorespiratory Variables and Heart Rate Variability During Weaning From Mechanical Ventilation

The discontinuation of mechanical ventilation (MV) and the recovery of spontaneous breathing can lead to important cardiovascular alterations due to changes in the intrathoracic pressure. The autonomic modulation assessed through heart rate variability (HRV) during weaning from MV and its impact on cardiorespiratory variables has not been well elucidated yet. To evaluate the effect of T-tube (TT) and pressure support ventilation (PSV) during weaning from MV on cardiorespiratory variables and heart rate variability.

Study Overview

Status

Completed

Conditions

Detailed Description

Thirty patients who had received MV for ≥ 48 hours and who met the criteria for weaning were assessed. Two different weaning methods were used and randomization was performed to choose one of the following sequences (baseline, PSV, rest, TT; or baseline, TT, rest, PSV). HRV was assessed by heart rate spectral analysis during MV, PSV, and TT. Each intervention lasted 30 minutes and there was a 30-minute rest period between the interventions. At the end of each period of time, the following cardiorespiratory variables were analyzed: respiratory rate (f), minute ventilation (VE), tidal volume (VT), rapid shallow breathing index (f/VT), peripheral oxygen saturation (SpO2), heart rate (HR) and blood pressure. In the HRV, the total spectral power (TP), the low frequency (LF) and the high frequency (HF) components, and the ratio between the low/high frequency (LF/HF) components were calculated.

Study Type

Observational

Enrollment (Actual)

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Brazil
- RS
  - Porto Alegre, RS, Brazil
    - Federal University of Rio Grande do Sul

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Patients with respiratory failure receiving MV for more than 48 hours, who had been admitted to the Intensive Care Unit (ICU) of the Hospital de Clínicas de Porto Alegre, and who met the criteria for weaning from MV according to the parameters previously defined were selected to participate in this study.

Description

Inclusion Criteria:

Patients with respiratory failure receiving MV for more than 48 hours
for weaning from MV according to the parameters previously defined were selected to participate in this study

Exclusion Criteria:

arterial hypotension (systolic blood pressure < 100mmHg), severe brain disease, barotraumas, presence of thoracic drain or tracheostomy, using vasoactive and sedative drugs

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
heart rate variability analysis Time Frame: minutes	minutes

Secondary Outcome Measures

Outcome Measure	Time Frame
Cardiorespiratory variables Time Frame: minutes	minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hospital de Clinicas de Porto Alegre

Investigators

Principal Investigator: Silvia R Veira, PhD, Hospital de Clinicas de Porto Alegre

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

March 1, 2003

Study Completion (Actual)

June 1, 2007

Study Registration Dates

First Submitted

February 25, 2009

First Submitted That Met QC Criteria