[Effects of intermittent self-ventilation on ventilatory drive and respiratory pump function].

BACKGROUND

A chronic hypercapnic ventilatory failure appears in patients with restrictive chest wall disorders, chronic obstructive pulmonary disease (COPD) or obstructive sleep apnea (OSA), but it can also appear in patients with a disorder of the central respiratory drive.

PATIENTS AND METHOD: We studied the lung function, the respiratory muscle function and the PCO2 recruitment threshold (pCO2RT) during nasal intermittent positive pressure ventilation (IPPV) in 16 chronic hypercapnic patients (scoliosis = 8, COPD = 4, OSA = 4).

RESULTS

The pCO2RT decreased from 61 +/- 6 mm Hg to 48 +/- 4 mm Hg (p < 0.0001) during intermittent IPPV, while spontaneous pCO2 decreased from 55 +/- 6 mm Hg to 42 +/- 5 mm Hg (p < 0.0001). The load of the respiratory pump decreased (P0.1/P0.1 max:0.27 +/- 0.18 before, 0.15 +/- 0.08 after intermittent IPPV; p < 0.04).

CONCLUSION

We conclude, that the pCO2RT can be normalized by intermittent nasal IPPV as well as the pCO2 under spontaneous breathing. The load of the respiratory pump decreases due to an increase of the inspiratory muscle strength.