Effect of Different Ventilatory Strategies on Cardiac Function in Patients With Acute Respiratory Failure

Overview

Mechanical ventilation with low tidal volume (about 6 ml.kg-1) reduces mortality in ALI/ARDS patients respect to high tidal volume ventilation (about 12 ml.kg-1).

This finding is usually explained by alveolar tidal overdistension associated to high tidal volume. Stretch-induced lung injury may trigger a cytokine-mediated inflammatory response. This may contribute to the development of systemic inflammatory response and multiple system organ failure and death.

High tidal volume strategies might affect organ function by pathways not mediated by inflammatory response.

It is well recognized the inverse relationship between tidal volume and cardiac output during mechanical ventilation. Nevertheless there are no clinical studies about cardiac output changes induced by low (6 ml.kg-1) and high tidal volume (12 ml.kg-1) in ALI/ARDS patients.

The study hypothesis is that high tidal volume ventilation reduces cardiac output in ALI/ARDS patients respect to low tidal volume strategy. Thereafter reduced hemodynamic impact could explain beneficial effect of low respect to high tidal volume ventilation.

If study hypothesis is confirmed, other studies should define the main cause of mortality reduction related to low tidal volume strategies and if appropriate hemodynamic monitoring and support should be required when low tidal volume strategies are harmful (i.e. traumatic brain injury).

Full Title of Study: “Hemodynamic Impact of Low and High Tidal Volume Mechanical Ventilation in Acute Lung Injury (ALI)/Acute Respiratory Distress Syndrome (ARDS) Patients”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Crossover Assignment
    • Masking: Single (Outcomes Assessor)
  • Study Primary Completion Date: May 2009

Interventions

  • Procedure: Mechanical ventilation with low and high tidal volume
    • Tidal volume of 6 or 12 ml.kg-1, calculated on ideal body weight

Arms, Groups and Cohorts

  • Experimental: 1
    • Two different tidal volumes (6 and 12 ml.kg-1 of ideal weight) are alternatively delivered to patients 30 minutes each one. The order of the two tidal volumes is randomized. Between the two study tidal volumes, patient returns for 30 minutes to the tidal volume used before the study recruitment.

Clinical Trial Outcome Measures

Primary Measures

  • cardiac index
    • Time Frame: after 30 minutes of mechanical ventilation with tidal volume of 6 or 12 ml.kg-1

Secondary Measures

  • oxygen delivery
    • Time Frame: after 30 minutes of mechanical ventilation with tidal volume of 6 or 12 ml.kg-1
  • oxygen consumption
    • Time Frame: after 30 minutes of mechanical ventilation with tidal volume of 6 or 12 ml.kg-1
  • mixed venous saturation
    • Time Frame: after 30 minutes of mechanical ventilation with tidal volume of 6 or 12 ml.kg-1
  • relationship between partitioned elastance (lung and chest wall) and cardiac index difference between ventilation with tidal volume 6 and 12 ml.kg-1
    • Time Frame: after 30 minutes of mechanical ventilation with tidal volume of 6 or 12 ml.kg-1
  • abdominal perfusion pressure (mean arterial pressure minus abdominal pressure)
    • Time Frame: after 30 minutes of mechanical ventilation with tidal volume of 6 or 12 ml.kg-1

Participating in This Clinical Trial

Inclusion Criteria

  • diagnosis of ARDS/ALI

Exclusion Criteria

  • mean arterial pressure lower than 65 mmHg
  • beginning or change of vasoactive agents infusion rate in the last 2 hours

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Fondazione Poliambulanza Istituto Ospedaliero
  • Provider of Information About this Clinical Study
    • Natalini Giuseppe, FPoliambulanza
  • Overall Official(s)
    • Giuseppe Natalini, MD, Principal Investigator, Fondazione Poliambulanza Istituto Ospedaliero

Clinical trials entries are delivered from the US National Institutes of Health and are not reviewed separately by this site. Please see the identifier information above for retrieving further details from the government database.

At TrialBulletin.com, we keep tabs on over 200,000 clinical trials in the US and abroad, using medical data supplied directly by the US National Institutes of Health. Please see the About and Contact page for details.