Objective: To assess the efficacy of noninvasive ventilatory support and intermittent positive pressure ventilation via uncuffed tracheostomy tubes (uTIPPV) to prolong survival in amyotrophic lateral sclerosis.
Design: Survival was prolonged by continuous noninvasive ventilatory support or TIPPV dependence. Once noninvasive ventilatory support was no longer adequate for six noninvasive ventilatory support users, they and 22 others underwent tracheotomy within 1 mo of measurement of spirometry (forced vital capacity and forced volume expired in 1 sec), peak cough flows, maximum insufflation capacity, manually assisted peak cough flows, and mechanically assisted peak cough flows. Glottic function was estimated by maximum insufflation capacity, FVC difference, and bulbar-innervated muscle function by Norris scale bulbar-innervated muscle subscore. Cuffless tubes were replaced by cuffed ones when hypoventilation developed despite increasing uTIPPV volumes.
Results: The survival of 22 patients was prolonged by continuous noninvasive ventilatory support dependence for 7.8 +/- 8.1 mos (range, 1-36 mos; median, 5 mos) after 13.9 +/- 11.2 mos (range, 2-36 mos) of part-time noninvasive ventilatory support. Six of these and 22 others underwent tracheotomy and initially used uTIPPV effectively. For ten of the 28 (35.7%) patients, the tubes had to be replaced by cuffed ones after 5.7 +/- 7.8 mos with the other 18 still using tracheostomy intermittent positive pressure ventilation volumes via uncuffed tubes for 20.2 +/- 17.6 mos at data collection. Pretracheotomy FVC was significantly lower in the ten patients who eventually required cuffed tubes (0.70 +/- 0.44 vs. 1.06 +/- 0.43 L, P < 0.05). The bulbar-innervated muscle was significantly lower when the uTIPPV users required cuffed TIPPV than when beginning uTIPPV (Norris scale bulbar-innervated muscle subscore, 3.20 +/- 1.30 vs. 8.00 +/- 3.20, P < 0.05), respectively.
Conclusions: Noninvasive and tracheostomy IPPV via cuffless tubes can prolong survival for patients with amyotrophic lateral sclerosis until excessive air leak and hypoventilation necessitate a cuffed tube.