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NCT Number: NCT02892981

Dead Space Evaluation in 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.

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Key information

Conditions

Pulmonary Hypertension Cardiovascular Diseases Hypertension Hypertension, Pulmonary Lung Diseases Respiratory Tract Diseases Vascular Diseases

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

cardiopulmonary exercise test,hypoxia and hypercapnia test

Other

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

Primary outcomes

  1. 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.

Secondary outcomes

  1. 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.

  2. 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

  3. 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

Sponsors and collaborators

Lead sponsor

Centro Cardiologico Monzino

Other

Registry information

Official study title

Dead Space Evaluation During Exercise in Patients With Pulmonary Hypertension

Important dates

Study start
2015
Primary completion
2016
Study completion
2016
First posted
Sep 8, 2016
Registry last updated
Sep 8, 2016

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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