@article{ref1,
title="Effects of inspiratory support upon breathing in humans during wakefulness and sleep",
journal="Respiration physiology",
year="1993",
author="Morrell, M. J. and Shea, S. A. and Adams, L. and Guz, A.",
volume="93",
number="1",
pages="57-70",
abstract="We have compared the effects on breathing of inspiratory mechanical support during wakefulness and sleep in healthy subjects. Nine awake volunteers breathed through a nose mask connected to a machine supplying variable levels of inspiratory positive airway pressure (IPAP). Tidal volume (VT), breath duration (TTOT) and end-tidal PCO2 (PETCO2) were measured over 1 min steady state periods with IPAP set at a minimal level (approx. 2 cmH2O) and at approx. 10 cmH2O. This protocol was repeated in 6 of the subjects during non-REM sleep. When awake, &quot;10 cmH2O IPAP&quot; caused a significant increase in mean VT from 513 to 842 ml and a significant fall in PETCO2 from 39.7 to 32.7 mmHg. During sleep, &quot;10 cmH2O IPAP&quot; caused no significant changes in VT (388 to 390 ml) or PETCO2 (41.8 to 39.8 mmHg). In each state, &quot;10 cmH2O IPAP&quot; had no significant effect on TTOT. Three subjects repeated the protocol with diaphragmatic surface EMG recorded as an index of efferent inspiratory activity. &quot;10 cmH2O IPAP&quot; had no consistent effect on EMG when awake but caused a reduction in each subject during sleep. We conclude that during non-REM sleep, inspiratory mechanical support is associated with a compensatory decrease in efferent inspiratory activity to achieve a similar tidal volume with maintenance of arterial PCO2. When awake, a &quot;wakefulness drive to breathe&quot; may be associated with maintained inspiratory activity such that mechanical support results in an increased tidal volume despite a fall in arterial PCO2.<p /><p>Language: en</p>",
language="en",
issn="0034-5687",
doi="",
url="http://dx.doi.org/"
}