Treatment of chronic respiratory failure in kyphoscoliosis: oxygen or ventilation?

Patients with kyphoscoliosis and chronic respiratory insufficiency are treated either with home oxygen therapy or ventilation. Kyphoscoliotic patients demonstrate impaired ventilatory mechanics, consequently ventilation seems to be the treatment of choice. Yet, no randomised controlled trials (CRT) exist to prove it. Most investigators find it difficult to ethically justify a CRT. Therefore, the current authors performed the following retrospective study: survival and pulmonary function were analysed in all consecutive kyphoscoliotic patients who started long-term oxygen therapy (LTO group; n=15, aged 62+/-11 yrs (mean+/-SD)) or LTO plus nocturnal nasal intermittent positive pressure ventilation (nNIPPV group; n=18, aged 61+/-7 yrs) in the Dept of Pulmonology (University Hospital Gasthuisberg, Leuven) between 1990-2002. Prior to treatment partial pressure of oxygen (PO2) was lower, partial pressure of carbon dioxide (PCO2) tended to be higher and vital capacity (VC) tended to be lower in the nNIPPV group than in the LTO group (PO2 5.9+/-1 versus 6.7+/-0.9 kPa (44+/-8 versus 50+/-7 mmHg), PCO2 8+/-1 versus 7.3+/-0.9 kPa (60+/-8 versus 55+/-7 mmHg), VC 32+/-12 versus 40+/-16% predicted, or 645+/-244 versus 970+/-387 mL). In the nNIPPV group the 1-yr survival was higher (100% versus 66%). nNIPPV patients demonstrated an improvement in PO2 (breathing air) +54%, PCO2 (breathing air) -21%, VC +47% and maximal static inspiratory mouth pressure +33%; these improvements were absent in the LTO group. In conclusion, nocturnal nasal intermittent positive pressure ventilation, plus long-term oxygen therapy results in more favourable survival and changes in blood gases and respiratory function than long-term oxygen therapy alone.