Transpulmonary Pressure Gradients in High Frequency Oscillation (TPG in HFO)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01321398
Recruitment Status : Completed
First Posted : March 23, 2011
Last Update Posted : March 17, 2014
Information provided by (Responsible Party):
University of British Columbia

Brief Summary:
Patients with severe lung conditions occasionally require support with a special ventilator (breathing machine) called the High Frequency Oscillator (HFO). Effective ventilation requires that the pressure generated by the ventilator be as high as possible but not too high as this can damage the lungs. In patients on HFO, there is not a well defined way to measure this pressure. We will insert a small probe into the esophagus of patients on HFO to see if this is an accurate way to measure lung pressures for these patients. A better understanding of these pressures could lead to improved patient care.

Condition or disease Intervention/treatment
Acute Lung Injury Other: Esophageal Pressure Monitoring

Detailed Description:

Trials have found that the use of lower tidal volumes (6 ml/kg) during conventional mechanical ventilation decreases morbidity and mortality. Compared to conventional ventilation, high frequency oscillation (HFO) is able to provide much smaller tidal volumes (1.1 - 2.5 ml/kg) and thus theoretically may provide additional lung protection. At this time, while trials of HFO in adults have been inconclusive, the use of HFO for the management of ALI/ARDS has become widespread

Patients with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) are critically ill and have a high mortality associated with their illness (approximately 50%). Currently, esophageal pressure monitors are used to optimize inflation pressures and improve oxygenation in conventional mechanical ventilation in patients with ALI/ARDS. With this in mind, the purpose of this study is twofold: (1) demonstrate that esophageal pressure monitors can easily be inserted in patients undergoing HFO and (2) report the transpulmonary pressures in these patients.

Study Type : Observational
Actual Enrollment : 7 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Transpulmonary Pressure Gradients in High Frequency Oscillation Study
Study Start Date : October 2010
Actual Primary Completion Date : July 2011
Actual Study Completion Date : March 2013

Group/Cohort Intervention/treatment
Critically Ill patients receiving HFO Other: Esophageal Pressure Monitoring
An esophageal pressure monitor will be placed through the mouth into the esophagus by a study physician. Placement will be confirmed by a bedside chest X-ray. Once placement has been confirmed all air will be evacuated from the balloon by syringe. One ml of air will then be injected to partially inflate the esophageal balloon. Pleural pressure measurements will be recorded after 1 minute without spontaneous breathing or patient care related movement. This measurement will be repeated at 30 minutes and at 60 minutes after the first measurement. Trans-pulmonary pressure is calculated as the difference between esophageal pressure and mouth pressure. Once the measurements have been recorded, the catheter will be removed.

Primary Outcome Measures :
  1. To demonstrate the proof of concept that esophageal pressures can easily be obtained in patients undergoing HFO. [ Time Frame: 60 minutes ]

Secondary Outcome Measures :
  1. To determine the transpulmonary pressure gradient in critically ill patients receiving HFO [ Time Frame: 60 minutes ]

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Ages Eligible for Study:   19 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Critically Ill

Inclusion Criteria:

  • 19 years of age or older
  • Receiving HFO
  • Informed Consent Obtained

Exclusion Criteria:

  • Esophageal lesions or esophageal surgery within the last 6 months
  • Morbid obesity - defined as a Body Mass Index (BMI) > 40
  • Unstable cervical spine injury or cervical spinal cord injury

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01321398

Canada, British Columbia
Vancouver General Hospital
Vancouver, British Columbia, Canada, V5Z1M9
Sponsors and Collaborators
University of British Columbia
Principal Investigator: William R Henderson, FRCPC Universtiy of British Columbia

Responsible Party: University of British Columbia Identifier: NCT01321398     History of Changes
Other Study ID Numbers: H10-02087
First Posted: March 23, 2011    Key Record Dates
Last Update Posted: March 17, 2014
Last Verified: March 2014

Keywords provided by University of British Columbia:
High Frequency Oscillation
Transpulmonary pressure

Additional relevant MeSH terms:
Lung Injury
Acute Lung Injury
Respiratory Distress Syndrome, Adult
Lung Diseases
Respiratory Tract Diseases
Thoracic Injuries
Wounds and Injuries
Respiration Disorders