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CompletedNCT00851825Updated May 8, 2009

Heart Rate Variability During Weaning From Mechanical Ventilation

An observational study in Critical Care and Weaning, sponsored by Hospital de Clinicas de Porto Alegre. Completed at 1 site in Brazil. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2009-05-08.

Sponsored by Hospital de Clinicas de Porto Alegre · Observational

Study type
Observational
Time perspective
Cross-sectional
Enrollment
30
Ages
18 Years and older
Sex
All
01

Study summary

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.

Read the 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.

02

Conditions studied

  • Critical Care
  • Weaning

Keywords

  • autonomic modulation
  • heart rate
  • pressure support ventilation
  • T-tube
  • Mechanical ventilation
03

In context

Lead sponsor

Hospital de Clinicas de Porto Alegre is the lead sponsor of 450 studies on the registry; 61 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No
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.

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

Exclusion Criteria:

  • arterial hypotension (systolic blood pressure \< 100mmHg), severe brain disease, barotraumas, presence of thoracic drain or tracheostomy, using vasoactive and sedative drugs
05

Study design

Time perspective
Cross-sectional
Enrollment
30 participants (actual)
06

What researchers measure

Primary outcomes

  1. heart rate variability analysis

    Time frame: minutes

Secondary outcomes

  1. Cardiorespiratory variables

    Time frame: minutes

07

Study locations

1 site
  • Federal University of Rio Grande do Sul
    Porto Alegre, RS, Brazil
08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on May 8, 2009, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT00851825
Lead sponsor
Hospital de Clinicas de Porto Alegre
First posted
Feb 26, 2009
Start date
Mar 2003
Completion
Jun 2007
Last update
May 8, 2009

Study contacts

Silvia R Veira, PhD
principal investigator · Hospital de Clínicas de Porto Alegre

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in May 2009. You cannot join it, but the record below documents what was studied.

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