[Daytime mechanical ventilation in chronic ventilatory insufficiency].

BACKGROUND Nocturnal hypoventilation is associated with chronic ventilatory insufficiency (CVI). Noninvasive mechanical ventilation (NIV) performed overnight relieves symptoms of hypoventilation and improves daytime blood gases in CVI. In order to test whether the efficacy of NIV depends on its being applied during sleep we conducted a prospective case controlled study comparing daytime mechanical ventilation (DV) in awake patients with nocturnal mechanical ventilation (NV) given in equal quantities. PATIENTS AND METHODS We enrolled 34 clinically stable patients (age: 56.1 +/- 12.1 years, 20 female) with CVI due to both restrictive lung and chest wall disorders and neuromuscular disease. Using a prospective case-control design, matched subjects were allocated alternately to DV and NV. RESULTS AND CONCLUSIONS There were no significant differences between the groups in the improvement of the measured parameters; (e.g. PaCO2; DV: from 57.6 +/- 4.3 to 44.0 +/- 4.6 mm Hg, NV: from 55.5 +/- 3.5 to 45.0 +/- 4.1 mm Hg, p < 0.0001). We conclude that in many respects, when compared to NV, DV in awake patients is equally effective for the treatment of CVI.