Noninvasive ventilation reduces energy expenditure in amyotrophic lateral sclerosis

BMC Pulmonary Medicine

Table 2 Evaluation of ventilatory variables on noninvasive ventilation

	Spontaneous breathing in room air	Noninvasive ventilation median [1^st-3^rdquartiles]	p-value
Vt (ml)	406.8 [289.5-486.8]	535.7 [450.8-578.4]	0.003
RF (/min)	17.6 [14.7-23.9]	15.4 [14.5-18.4]	0.02
Ventilation (l/min)	7.1 [6.5-7.9]	8.3 [7.5-9.9]	<0.001
PaCO2 (mmHg) (n = 12)*	47 [43-48]	41.5 [38-44]	0.002
PaO2 (mmHg) (n = 12)*	69 [65.7-75.2]	88.5 [70-97.5]	0.005
A-a gradient (mmHg) (n = 12)*	23.1 [16.6-27.6]	9.2 [3.9-29.3]	0.03
Vd (ml) (n = 12)*	117.7 [78.2-141.6]	178.9 [152.6-211.8]	0.01
Time spent with SpO₂ < 90% (% of recording time)	30 [6.2-72]	1 [1-3]	<0.001

Abbreviations: A-a gradient for Alveolar-arterial gradient, PaO ₂ arterial oxygen tension, PaCO ₂ arterial carbon dioxide tension, RF Respiratory Frequency, SpO ₂ transcutaneous pulsed oxygen saturation, V t for tidal volume, V d dead space volume (calculated using Bohr formula, note that non invasive ventilation efficiently corrects PaCO2 in spite of an increased Vd -expected-).

ISSN: 1471-2466