Transpulmonary Pressure Gradients in High Frequency Oscillation

NCT ID: NCT01321398

Last Updated: 2014-03-17

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 7 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2010-10-31
• Study Completion Date: 2013-03-31

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.

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.

Conditions

Acute Lung Injury

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

Critically Ill patients receiving HFO

Esophageal Pressure Monitoring

Intervention Type: OTHER

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.

Interventions

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.

Intervention Type: OTHER

Eligibility Criteria

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

• Minimum Eligible Age: 19 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of British Columbia

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

William R Henderson, FRCPC

Role: PRINCIPAL_INVESTIGATOR

Universtiy of British Columbia

Locations

Vancouver General Hospital

Vancouver, British Columbia, Canada

Countries

Canada

Other Identifiers

H10-02087

Identifier Type: -

Identifier Source: org_study_id