Continuous Exhaled Breath Condensate pH in Mechanically Ventilated Patients
Recruitment status was Recruiting
|First Received Date ICMJE||January 30, 2007|
|Last Updated Date||August 6, 2008|
|Start Date ICMJE||December 2004|
|Primary Completion Date||Not Provided|
|Current Primary Outcome Measures ICMJE||Not Provided|
|Original Primary Outcome Measures ICMJE||Not Provided|
|Change History||Complete list of historical versions of study NCT00429637 on ClinicalTrials.gov Archive Site|
|Current Secondary Outcome Measures ICMJE||Not Provided|
|Original Secondary Outcome Measures ICMJE||Not Provided|
|Current Other Outcome Measures ICMJE||Not Provided|
|Original Other Outcome Measures ICMJE||Not Provided|
|Brief Title ICMJE||Continuous Exhaled Breath Condensate pH in Mechanically Ventilated Patients|
|Official Title ICMJE||Phase 2 Continuous Exhaled Breath Condensate pH in Mechanically Ventilated Patients|
Given the possible prognostic relationship between exhaled breath condensate pH and clinical symptoms, it is quite plausible that exhaled breath condensate pH can prove useful in the intensive care unit. For example, if exhaled breath condensate pH falls prior to the onset of clinical symptoms, it is likely that it can be useful as an early marker, heralding the onset of various inflammatory lung diseases. Specifically, exhaled breath condensate pH could be used as a safe, non-invasive screening tool for Ventilator Associated Pneumonia. Similarly, just as changes in exhaled breath condensate pH might predict the onset of disease, exhaled breath condensate pH changes might also mark the progression or resolution of disease (e.g. alerting clinicians to possible readiness for extubation). Although such notions are hypothetical, they are beginning to be supported by anecdotal evidence.
The investigators have developed a method of collecting exhaled breath condensate pH continually from ventilated patients, which (1) takes samples from an exhaust port on the outside of the ventilator circuit, and (2) possesses no measurable resistance to the ventilator circuit (and, therefore the sampling procedure in no way affects the patient).
Now, additionally, we have performed the continuous collection process on 10 patients in the intensive care units, none of whom have had any ill effects from the collection process.
The placement of the exhaled breath condensate collection device on the ventilator exhaust port offers a simplified, accurate, and safe method of investigating the relationships between airway pH and various pulmonary inflammatory disease processes in intubated patients of all ages.
In order to further extend our study of airway pH in intubated subjects, we believe it is necessary to obtain more frequent exhaled breath condensate pH measurements from intubated subjects. To that end, we have developed a collection system that will also measure the pH of the collected exhaled breath condensate in a fashion similar to the methodology used for thousands of assays in our laboratory and other laboratories globally. This involves deaeration of the sample to remove carbon dioxide. In the lab environment, this is performed with Argon. In the ICU setting, we will accomplish the same effect by using wall oxygen.
The continuous exhaled breath condensate pH collection and assay system consists of a condenser attached to the exhaust port of the ventilator. The condenser is kept chilled to slightly above freezing temperature by a refrigeration system commonly employed in ICU settings. The collection device stays attached to the exhalation port of the ventilator continuously, for hours to days.
Collected exhaled breath condensate is channeled into two deaeration chambers, through which wall oxygen is bubbled (total flow of 1 liter/min). In the second deaeration chamber, a micro pH electrode is inserted. This pH electrode is attached to a pH recorder that has internal memory that can record essentially an infinite number of measurements, allowing for any length duration of monitoring. This recorder has been evaluated by clinical engineering for radio frequency and other interference and is cleared for hospital use.
After measurement of pH, exhaled breath condensate is channeled into a waste chamber.
The breath condensate collection system is maintained chilled by a "hospital grade" Electri-Cool II model 767 refrigerated cooling system (or near-equivalent) that is clinically approved for use in the intensive care units. This device is approximately 30 cm on a side, and is kept on a wheeled cart out of the way of any clinical activity.
Hypothesis to be Tested: Clearly state the objectives and hypotheses and clearly define the primary and any secondary outcome measures.
|Study Type ICMJE||Observational|
|Study Design ICMJE||Not Provided|
|Target Follow-Up Duration||Not Provided|
|Sampling Method||Not Provided|
|Study Population||Not Provided|
|Intervention ICMJE||Not Provided|
|Study Group/Cohort (s)||Not Provided|
|Publications *||Not Provided|
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
|Recruitment Status ICMJE||Recruiting|
|Estimated Enrollment ICMJE||120|
|Estimated Completion Date||January 2009|
|Primary Completion Date||Not Provided|
|Eligibility Criteria ICMJE||
|Accepts Healthy Volunteers||No|
|Location Countries ICMJE||United States|
|NCT Number ICMJE||NCT00429637|
|Other Study ID Numbers ICMJE||11618|
|Has Data Monitoring Committee||Not Provided|
|Responsible Party||Not Provided|
|Study Sponsor ICMJE||University of Virginia|
|Collaborators ICMJE||Not Provided|
|Information Provided By||University of Virginia|
|Verification Date||August 2008|
ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP