Nighttime ventilation improves respiratory failure in secondary kyphoscoliosis

Four patients with cardiorespiratory failure caused by secondary kyphoscoliosis were studied. Polycythemia, cor pulmonale, restrictive lung pattern (functional residual capacity (FRC), 17 to 27% predicted; vital capacity (VC), 11 to 23% predicted), and abnormal arterial blood gases, primarily hypoventilation (PaO2, 31 to 44 mm Hg; PaCO2, 52 to 73 mm Hg), were seen in all. Supplementary oxygen, digoxin, diuretics, 15 min of intermittent positive-pressure breathing with inspired pressure (PI) 25 cm H2O 4 times daily, and tracheostomy failed to produce improvement. However, 12 h of nighttime ventilation (NTV) with PI 28 to 35 cm H2O through a permanent tracheostomy proved effective. Within 72 h, dyspnea at rest, restless sleep, and frequent waking resolved. Within 8 to 22 days, the PaO2 was approximately 58 mmHg and the PaCO2 was approximately 41 mm Hg while breathing 21% oxygen spontaneously during the day. The right heart failure resolved within 2 to 7 wk, and the hemoglobin count decreased to approximately 165 g/L within 2 to 6 months. There was a mean increase of 700 ml (72%) in functional residual capacity and 430 ml (49%) in vital capacity. The patients were discharged 2 days to 5 wk after NTV commenced. Daytime activity increased, approaching a normal life style. The improvement was sustained over a mean follow-up period of 3.4 yr. Problems included recurrent episodes of tracheobronchitis, mild self-limiting hemoptysis, and speech modification. Nighttime ventilation may be an effective alternative for long-term treatment of cardiorespiratory failure caused by secondary kyphoscoliosis.