Effect of Buteyko breathing retraining method on resting ventilation and asthma control in asthma patients

Asthma has been related to dysfunctional breathing and hyperventilation. The aim of the study was to evaluate the effect of Buteyko breathing retraining method (BM) on resting ventilation and asthma control in asthma patients. Methods: 18 asthma patients (45±13 years; 5 males) were evaluated 3 times with 6 months intervals. The 1st interval was a control period but BM was applied during the 2nd interval. 14 healthy controls paired for age, gender and body mass index were evaluated twice with 6 months interval. Ventilation (V9E), CO2 output (V9CO2),partial end-tidal pressure of CO2 (PETCO2) and O2 (PETO2) were measured at rest. Breath holding time (BHT), FVC and FEV1 were measured and alveolar ventilation per V9CO2 (V9A/V9CO2) was calculated. Patients filled out the Asthma Control Test (ACT) where scoring >19 indicates well controlled asthma. Results: None of the measured parameters changed during the control period in the asthma patients. After BM PETCO2 increased from 33.4±3.9 to 35.4±2.7 mmHg (p<0.01), PETO2 decreased from 107± 5 to 103± 4 mmHg (p<0.01), BHT increased from 13±7 to 25±10 seconds (p<0.0001), ACT increased from 16.5±5.0 to 21.4±3.3 points (p<0.005), FEV1/FVC remained 0.74 (NS) and V9A/VCO2 remained 38.6±7.8 (NS). At the beginning, all measured parameters were equal between the control group and the patients except for FEV1/FVC (0.81±7.4; p<0.05) and BHT (19±7 sec; p<0.05). No changes were found in the control group from first to second measurement. Conclusion: Hyperventilation was not detected in asthma patients neither pre nor post BM. The increase in PETCO2 and BHT post BM indicates reduction of the respiratory center sensitivity. BM improved asthma control.