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Intrinsic Periodic Pattern of Breathing (PERHYP1)

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ClinicalTrials.gov Identifier: NCT02201875
Recruitment Status : Unknown
Verified July 2014 by Pr. Jean Paul RICHALET, Association pour la Recherche en Physiologie de l'Environnement.
Recruitment status was:  Not yet recruiting
First Posted : July 28, 2014
Last Update Posted : July 28, 2014
Sponsor:
Information provided by (Responsible Party):
Pr. Jean Paul RICHALET, Association pour la Recherche en Physiologie de l'Environnement

Brief Summary:

We made a fortuitous observation of periodic breathing in a healthy subject coming to our outpatient mountain medicine consultation at Avicenne hospital in Bobigny (France). During this consultation, subjects perform a hypoxia exercise test, which allows a good prediction of their risk factors for severe high altitude illnesses. Surprisingly, breath-by-breath recording of the ventilation signal showed a periodic breathing pattern, which increased when the subject started to exercise in hypoxic conditions and was maintained during normoxic exercise.

Therefore, our objective was to confirm this observation in a retrospective study led in 82 subjects who passed this test. We tested the hypothesis that subjects with a brisk ventilatory response to hypoxia might show a more pronounced periodic pattern of ventilation, due to a higher gain of the chemoreceptor feedback loop. Then, our objective is to investigate the mechanisms involved in the periodic pattern in healthy subjects, as a function of exercise intensity, altitude intensity, role of peripheral and central chemoreceptors to O2 and CO2. Finally, we want to investigate the possible role of this ventilatory instability in patients with obstructive or central apneas.


Condition or disease
Normoxia Hypoxia Hyperoxia Hypercapnia

Detailed Description:

In a preliminary study, among the population coming to the outpatient consultation of mountain medicine at Avicenne hospital in 2012, 82 subjects (38 females and 44 males) were randomly selected and separated in two groups of 41 high and 41 low responders to hypoxia according to the median value of the hypoxic ventilatory response to hypoxia at exercise (HVRe > or < 0.84 L/min/kg) derived from the hypoxic exercise test (inspired fraction of O2: 0.115, exercise intensity of 30% of maximal aerobic power), as previously described.

The hypoxic exercise test consists in 4 successive phases of 3 to 4 minutes each with the following sequence: rest in normoxia (RN), rest in hypoxia (RH), exercise in hypoxia (EH) and exercise in normoxia (EN). Minute ventilation ( E, L.min-1) is measured through a metabograph (Vmax Encore, SensorMedics, Yorba Linda, CA). Pulse O2 saturation (SpO2, %) is measured by transcutaneous oximetry (Nellcor N-595, Nellcor, Pleasanton, CA) on a pre-warmed ear lobe. End tidal PCO2 (PETCO2) is measured by infrared thermopile (Vmax Encore, SensorMedics, Yorba Linda, CA). During the whole test, VE, SpO2 and PETCO2 were recorded breath-by-breath. Continuous blood pressure is measured by a Finapres system. Data are transferred to a computer for further spectrum analysis. A Fast Fourier Transform (FFT) is then applied to the ventilation signal in sequences of 128 points in each phase of the test. This method will allow us to detect the presence of peaks in the frequency domain of the ventilation signal. Two main parameters are derived from the FFT: the frequency in hertz (or period in seconds) of the larger peak and its power estimated as the area under the peak at ± 0.02 Hz around the peak (in L2.s-2).

The main study will be designed in order to unravel the mechanisms and role of these oscillations in ventilation. An overall population of 90 healthy subjects and 30 patients will be included in the study.

Step 1. Effect of exercise intensity.

Step 2. Effect of altitude level.

Step 3. Effect of the stimulation of central chemoreceptors by acetazolamide.

Step 4. Effect of inhibiting the peripheral chemoreceptors by hyperoxia.

Step 5. Effect of inhibiting the peripheral chemoreceptors by hyperoxia and stimulating the central chemoreceptors by hypercapnia.

Step 6. Evaluating the presence of these oscillations in patients with sleep apneas.

Step 7. Evaluating the presence of these oscillations in patients with cardiac failure.


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Study Type : Observational
Estimated Enrollment : 120 participants
Observational Model: Cohort
Official Title: Study of Periodic Breathing in Healthy Humans
Study Start Date : September 2014
Estimated Primary Completion Date : June 2015
Estimated Study Completion Date : December 2015

Group/Cohort
Healthy subjects
male, aged 18-65 moderately trained healthy, no treatment
obstructive sleep apneas
patients with apnea/hypopnea index > 15 BMI < 30 Age < 50 yrs
cardiac failure
NYHA class I to III ejection fraction < 40% age < 65 yrs BMI < 30



Primary Outcome Measures :
  1. Periodic pattern of ventilation [ Time Frame: The measure is made at the end of the 6-min exercise period, only once in each condition (normoxia, hypoxia, hyperoxia, hypercapnia), ]
    Presence of oscillation in the ventilation signal


Secondary Outcome Measures :
  1. Oscillations in heart rate [ Time Frame: The measure is made at the end of the 6-min exercise period, only once in each condition (normoxia, hypoxia, hyperoxia, hypercapnia) ]
    Presence of oscillations in the beat-by-beat ECG signal with a specific peak in the frequency spectrum

  2. Oscillations in arterial blood pressure [ Time Frame: The measure is made at the end of the 6-min exercise period, only once in each condition (normoxia, hypoxia, hyperoxia, hypercapnia) ]
    Presence of oscillations in the systolic/diastolic value of instant arterial blood pressure, measured non-invasively.



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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Probability Sample
Study Population
Healthy subjects Patients with obstructive sleep apneas Patients with cardiac failure
Criteria

Inclusion Criteria:

  • depending on the group: see definition of groups

Exclusion Criteria:

  • BMI > 30
  • history of severe cardiac arrhythmia
  • pulmonary hypertension
  • history of coronary disease

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 ClinicalTrials.gov identifier (NCT number): NCT02201875


Contacts
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Contact: Jean-Paul Richalet, MD, PhD 33148387758 richalet@univ-paris13.fr

Locations
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France
Physiology Department Recruiting
Bobigny, France, 93009
Contact: Jean-Paul Richalet, MD, PhD    33148387758    richalet@univ-paris13.fr   
Principal Investigator: Jean-Paul Richalet, MD, PhD         
Sub-Investigator: François J Lhuissier, MD, PhD         
Sub-Investigator: Carole Planès, MD, PhD         
Sub-Investigator: Christophe Meune, MD, PhD         
Sponsors and Collaborators
Association pour la Recherche en Physiologie de l'Environnement

Publications:
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
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Responsible Party: Pr. Jean Paul RICHALET, Director of Department, Association pour la Recherche en Physiologie de l'Environnement
ClinicalTrials.gov Identifier: NCT02201875     History of Changes
Other Study ID Numbers: PERHYP1
First Posted: July 28, 2014    Key Record Dates
Last Update Posted: July 28, 2014
Last Verified: July 2014
Keywords provided by Pr. Jean Paul RICHALET, Association pour la Recherche en Physiologie de l'Environnement:
hypoxia
exercise
periodic breathing
hypercapnia
apneas
cardiac failure
Additional relevant MeSH terms:
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Respiratory Aspiration
Hypoxia
Hypercapnia
Hyperoxia
Respiration Disorders
Respiratory Tract Diseases
Pathologic Processes
Signs and Symptoms, Respiratory
Signs and Symptoms