Normalizing CO2 in Chronic Hyperventilation by a Novel Breathing Mask: A Pilot Study

CO2 Rebreathing by a Partial Rebreathing Mask as a Treatment of Chronic Idiopathic Hyperventilation - a Pilot Study

Background: Chronic Idiopathic Hyperventilation (CIH) is a form of dysfunctional breathing which has proven hard to treat effectively. The investigators hypothesised that by periodically inducing normocapnia over several weeks, it would be possible to raise the normal resting level/set point of CO2 and achieve a reduction of symptoms.

Methods: Six CIH patients were treated two hours a day for four weeks with a novel breathing mask. The mask was used to induce normocapnia in these chronically hypocapnic patients.

Capillary blood gases (PcCO2, pH, Standard Base Excess (SBE) etc.) were measured at baseline and once each week at least three hours after mask use, as well as spirometric values, breath holding tolerance and hyperventilation symptoms as per the Nijmegen Questionnaire (NQ),.

Inclusion Criteria:

Chronic idiopathic hyperventilation, i.e.:

• PCO2 level below 4.7 kPa AND
• SBE value more negative than -1.0

Exclusion Criteria:

• Oxygen saturation of 95% or lower at rest