Nasal Ventilation Versus Voluntary Hypoventilation in the Rehabilitation of Hyperventilation Syndrome

Nasal Ventilation Versus Voluntary Hypoventilation in the Rehabilitation of Hyperventilation Syndrome: a Randomized, Controlled Trial

The main objective of this study is to measure the effect (at 3 months) of dyspnea control rehabilitation with nasal ventilation versus standard rehabilitation, in dyspneic patients with hyperventilation syndrome.

Hyperventilation syndrome (SHV) is a complex disorder of adaptation of ventilation to exercise. This is a frequent reason for consultation because it is associated with major symptoms, which can be a source of sometimes heavy exploration and wandering. The breathless patient reduces his activity and enters the vicious circle of deconditioning. The principal clinical symptom in this pathology is the dyspnea with hypocapnia. The diagnosis is based on quality of life questionnaires and provocation tests, such as stress testing. When hypocapnia becomes chronic, a disturbance of breathing control sets in.

In SHV therapy, control of ventilation to exercise is recommended in the first line. It aims to slow the respiratory rate or tidal volume with, for example, techniques of voluntary hypoventilation and abdominal ventilation. But the evidence of literature is lacking to recommend a particular technique. Given the implication of the dysfunction of the nose, of non-unicist and often multifactorial origin in the respiratory pathologies, one of the possibilities of intervention is to reeducate the patient to the nasal ventilation.

Our rehabilitation of nasal ventilation is based on the clinical observation of hyperventilation dyspnea. During breathlessness breathing is essentially oral. It is a natural mechanism of adaptation that responds to the metabolic demand, which is far too present in the hyperventilation syndrome. From our therapeutic experience, the hypothesis is that the work on nasal ventilation can provide the necessary elements for the correction of SHV. The importance of the nasal breath in managing emotions and effort in sport is already considered.

This study will evaluate pathophysiological and clinical parameters effets of rehabilitation of nasal ventilation compared to those of the technique of voluntary hypoventilation (ThV) which is the conventional management of patients with SHV.

Inclusion Criteria:

• The patient must have given his / her free and informed consent and signed the consent
• The patient must be a member or beneficiary of a health insurance program
• The patient is available for 3 months of follow-up
• The patient has at least two of the following clinical symptoms consistent with hyperventilation sydrome: dyspnea, chest pain or pressure, visual blurring, dizziness, a sensation of abdominal swelling, tingling in the fingers, stiffness in the fingers or arms, tingling sensation around the mouth, cold or moist hands, tension or anxiety
• Resting hypocapnia defined by a PaCO2 <38 mmHg and a normal O2 alveolo-arterial gradient D (A-a) O2
• Absence of significant obstructive or restrictive pathology according to respiratory function tests
• Absence of indirect signs of pulmonary arterial hypertension according to echocardiography
• Absence of alteration of gas exchange on maximum cardiopulmonary stress test (elevation of gradient D (A-a) O2 > 35 mmHg at peak stress)
• At least 2 of the following criteria: (i) a Nijmegen questionnaire score > 23, (ii) the recurrence of at least two common symptoms during the maximum cardiopulmonary stress test, (iii) delayed return of PETCO2 (partial pressure of end-tidal carbon dioxide) to its basal value (> 5 minutes)

Exclusion Criteria:

• The subject is participating in another study
• The subject is in an exclusion period determined by a previous study
• The subject is under judicial protection, or is an adult under any kind of guardianship
• The subject refuses to sign the consent
• It is impossible to correctly inform the subject
• The subject cannot fluently read French
• The patient is pregnant
• The patient is breastfeeding
• The subject has a contra-indication (or an incompatible drug association) for a treatment required during this study (a priori, there are no contra-indicated drugs)