Long-term nocturnal mechanical ventilation in patients with kyphoscoliosis

1) to evaluate the long-term efficacy of nocturnal IPPV either via tracheostomy (tIPPV) or a nasal mask (nIPPV) as a means to improve alveolar ventilation in patients with chronic severe hypercapnia caused by kyphoscoliosis; and 2) to assess the effect of MV on hospitalizations and life-style. Twenty six patients with kyphoscoliosis in chronic respiratory failure were enrolled in the study. Patients were divided into two groups. The first group comprised 13 subjects who had been clinically stable for at least 1 month (arterial carbon dioxide tension (Pa,CO2) 81 +/- 1.5 kPa (60.8 +/- 10.9 mmHg), arterial oxygen tension (Pa,O2) 7.3 +/- 0.8 kPa (54.6 +/- 6.1 mmHg)). The second group comprised 13 patients who were either suffering or recovering from an episode of acute respiratory insufficiency (Pa,CO2 9.0 +/- 1.8 kPa (67.8 +/- 13.3 mmHg), Pa,O2 6.8 +/- 1.1 kPa (51.2 +/- 8.2 mmHg), breathing supplemental oxygen in seven cases). Patients in the first group were treated with nocturnal IPPV via a nasal mask, whilst those in the second received nocturnal IPPV via tracheostomy. Similar improvements in arterial blood gases (ABGs) were achieved with both methods. Despite the differences in the degree of severity at baseline, after 1 month, ABG values were: Pa,CO2 6.2 +/- 0.6 kPa (46.6 +/- 4.4 mmHg), Pa,O2 9.0 +/- 1.3 kPa (67.5 +/- 9.6 mmHg) (nIPPV patients); Pa,CO2 6.1 +/- 0.9 kPa (46.1 +/- 6.8 mmHg), Pa,O2 9.8 +/- 1.3 kPa (73.6 +/- 9.8 mmHg) (tIPPV patients). After 1 yr, this improvement was still evident. Days of hospitalization were significantly reduced in both groups during the first year of MV. We conclude that both tIPPV and nIPPV are effective in the long-term treatment of respiratory failure in patients with kyphoscoliosis. It would appear from our data that if nIPPV is initiated early in the evolution of chronic respiratory failure in patients with kyphoscoliosis it will delay the necessity to use an invasive technique; however, long-term follow-up studies and larger case series are needed to demonstrate this.