Total airway resistance and respiratory muscle activity during sleep

Effect of Ventilatory Variability on Occurrence of Central Apneas

“…54 In our study, subjects receiving PSV exhibited increased peak EAdi variability during non-REM sleep and a concomitant V T increase, with little V T variability. This pattern increases the risk of central apnea, especially as the apneic threshold is lower in REM sleep than in non-REM sleep.…”

Pathophysiology of obstructive sleep apnoea

“…Factors that reduce upper airway calibre lead to increased upper airway resistance, with the generation of a more negative pharyngeal pressure during inspiration [38], and thereby predispose to upper airway occlusion during sleep. There are a number of recognized anatomical abnormalities that are associated with narrowing of the upper airway and predispose to OSA.…”

“…The onset of sleep leads to an increase in respiratory system resistance in healthy humans [38,[89][90][91][92][93], the increase being located almost entirely in the upper airway above the larynx [89], primarily at either the level of the palate or hypopharynx [94]. Although the nose can contribute significantly to upper airway resistance on assuming the supine posture, due to increased nasal mucosal congestion [61], there is little further increase in nasal resistance with the change from wakefulness to sleep [4].…”

“…The mechanism underlying these reductions is not thought to be due exclusively to decreased central respiratory drive [171], and may relate, at least in part, to mechanical changes, such as reduced upper airway patency during sleep [38,89,95]. Support for this possibility comes from the observation that mouth occlusion pressure (P0.1), which is a better index of respiratory drive than the ventilatory response [172], increases from wakefulness to NREM and REM sleep in men, with little change in women; and the P0.1 response to hypercapnia is generally maintained during NREM sleep in comparison to wakefulness [171].…”

Ventilation during sleep onset

“…Minute ventilation has been consistently found to decrease with sleep (Birchfield, Sieker & Heyman, 1959;Bulow, 1963;Bulow & Ingvar, 1961;Douglas White, Pickett, Weil & Zwillich, 1982a;Douglas, White, Weil, Pickett, Martin, Hudgel & Zwillich, 1982b;Gleeson, Zwillich, Braier & White, 1986;Gothe, Altose, Goldman & Cherniack, 1981;Gothe, Cherniack & Williams, 1986;Lopes, Tabachnik, Muller & Levison, 1983;Lugaresi, Coccagna, Cirignotta, Farneti, Gallasi, Di Donato & Verucchi, 1978;Magnussen, 1944;Reed & Kellogg, 1958;1960a;1960b;Rist, Daubenspeck & McGovern, 1986;Robin, Whaley, Crump & Travis, 1958;Skatrud & Berssenbrugge, 1983;Skatrud & Dempsey, 1983;Tabachnik et al, 1981;White, 1986;White, Douglas, Pickett, Weil & Zwillich, 1982;White, Weil & Zwillich, 1985b;Yamashiro et al, 1987). In addition, Gothe, Goldman, Cherniack & Mantey (1982), reported a non-significant decrease.…”