Objective: The aim of the study was to evaluate the efficacy of noninvasive ventilatory assistance/support via mouthpiece to improve performance in 6-min walk tests for individuals with severe restrictive ventilatory disorders.
Design: Each subject performed the 6-min walk test breathing spontaneously and again while using mouthpiece noninvasive ventilatory assistance/support at full ventilatory support. Oxyhemoglobin saturation (O2 sat), heart rate, Borg scale, distance walked, and ambulation duration were recorded.
Results: Eighteen patients using nocturnal nasal noninvasive ventilatory assistance/support, median (interquartile range) age of 58.5 (20) yrs, were studied. Their median baseline forced vital capacity and PaCO2 were 940 (385) ml and 54.1 (6) mm Hg, respectively. All used noninvasive ventilatory assistance/support for at least overnight hours for 36 (111) mos. Because of the progression of ventilatory impairment and hypercapnia, daytime mouthpiece noninvasive ventilatory assistance/support was initiated. All the 6-min walk test parameters improved significantly by using noninvasive ventilatory assistance/support. Both initial and final values of O2 saturation significantly increased (92% [6] vs 96% [2], P < 0.001) and (80% [19] vs 85.50% [13], P = 0.001), respectively. The median distance walked increased by 43% with noninvasive ventilatory assistance/support (175 [218] m vs 250 [113] m, P = 0.017), and the total ambulation time also increased with noninvasive ventilatory assistance/support (5.45 [3] mins vs. 6 [0] mins, P = 0.008).
Conclusions: The exercise tolerance of patients with severe ventilatory impairment can improve by using noninvasive ventilatory support.