Dead Space Evaluation in Pulmonary Hypertension
September 2, 2016 updated by: Piergiuseppe Agostoni, Centro Cardiologico Monzino
Dead Space Evaluation During Exercise in Patients With Pulmonary Hypertension
Aim of the study is to evaluate the role of chemoreceptor activity and ventilation perfusion mismatch on the genesis of exercise induced hyperventilation in Pulmonary hypertension patients.
So the investigators tested the chemoreceptor response at rest, both with hypoxic and hypercapnic stimuli, and the ventilatory response during exercise analyzing its two components, alveolar and dead space ventilation.
Study Overview
Status
Completed
Conditions
Intervention / Treatment
Study Type
Interventional
Enrollment (Actual)
18
Phase
- Not Applicable
Participation Criteria
Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.
Eligibility Criteria
Ages Eligible for Study
18 years to 80 years (ADULT, OLDER_ADULT)
Accepts Healthy Volunteers
No
Genders Eligible for Study
All
Description
Inclusion Criteria:
- age ≥18 and ≤ 80 years
- ability to understand the research protocol and willing to sign the study informed consent
- diagnosis of pulmonary arterial hypertension belonging to Class I and IV
- stable haemodynamic status and optimized medical treatment since at least 2 months
- ability to perform maximal cardiopulmonary exercise test and pulmonary diffusing capacity for carbon monoxide evaluation
Exclusion Criteria:
- relevant comorbidities
- usual contraindications for cardiopulmonary exercise test
- pulmonary hypertension associated to left heart and pulmonary disease, congenital heart diseases with evident cardiac shunts.
Study Plan
This section provides details of the study plan, including how the study is designed and what the study is measuring.
How is the study designed?
Design Details
- Primary Purpose: DIAGNOSTIC
- Allocation: NA
- Interventional Model: SINGLE_GROUP
- Masking: NONE
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
|
Other: Pulmonary hypertension patients
All Pulmonary hypertension patients enrolled in the study underwent a cardiopulmonary exercise test and hypoxia and hypercapnia tests
|
class I and IV Pulmonary hypertension patients in stable haemodynamic status and optimized medical therapy underwent cardiopulmonary test and hypoxia and hypercapnia tests to evaluate the chemoreceptor sensitivity
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
dead space ventilation (measured in L/min)
Time Frame: 1 week
|
Dead space ventilation is calculated through the equation: VT* [1- (863*VCO2)/(VE*PaCO2)], where VT = tidal volume, VCO2= CO2 output, VE= pulmonary ventilation,PaCO2 is the arterial partial pressure of CO2 and 863 is a constant.
|
1 week
|
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
peripheral response to hypoxia (measured in L/min/O2)
Time Frame: 1 week
|
the hypoxic test is based on the transient hypoxia (the patient inhales a mixture of nitrogen for 2-8 breaths, for 10-15 times); pulmonary ventilation (VE) and arterial oxygen saturation (O2 Saturation) by peripheral pulse oximetry is measured.
The chemoreceptor sensitivity value is calculated as the slope of the trend line built on the two maximum consecutive VE and minimum O2 Saturation of each test.
|
1 week
|
|
peripheral response to hypercapnia (measured in L/min/mmHg)
Time Frame: 1 week
|
the peripheral response to hypercapnia is evaluated through the single-breath technique (the patient inhales a mixture of 13% CO2 in air for a single breath); pulmonary ventilation (VE) and end-expiratory CO2 fraction (FetCO2) are measured and then they will be used to calculate the peripheral chemoreceptor sensitivity.In fact, the sensitivity of the chemoreceptor is calculated using the following formula VEs-VEc / (FetCO2s-FetCO2c) * (PB-47), where s and c indicate the data collected after hypercapnic stimulus and those collected during control air breathing ,respectively; PB is the atmospheric pressure in mmHg
|
1 week
|
|
central hypercapnic chemosensitivity (measured in L/min/mmHg)
Time Frame: 1 week
|
the evaluation of the central response to hypercapnia is made through the re-breathing technique (the patient breathes through a reservoir containing 7% CO2 and 93% O2 for 4 minutes); pulmonary ventilation (VE) and partial pressure of end-tidal carbon dioxide (PetCO2) are evaluated.
The slope of the curve describing the relationship between VE and PetCO2 identifies the central chemoreceptor sensitivity
|
1 week
|
Collaborators and Investigators
This is where you will find people and organizations involved with this study.
Sponsor
Publications and helpful links
The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.
Study record dates
These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.
Study Major Dates
Study Start
January 1, 2015
Primary Completion (Actual)
January 1, 2016
Study Completion (Actual)
April 1, 2016
Study Registration Dates
First Submitted
June 10, 2016
First Submitted That Met QC Criteria
September 2, 2016
First Posted (Estimate)
September 8, 2016
Study Record Updates
Last Update Posted (Estimate)
September 8, 2016
Last Update Submitted That Met QC Criteria
September 2, 2016
Last Verified
September 1, 2016
More Information
Terms related to this study
Additional Relevant MeSH Terms
Other Study ID Numbers
- ccm257
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