Dependence of high altitude sleep apnea on ventilatory sensitivty to hypoxia

Lahiri, S.; Maret, K. H.; Sherpa, Mingma G.

doi:10.1016/0034-5687(83)90086-5

Cited by 167 publications

(110 citation statements)

References 22 publications

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“…is lower than those reported previously in a hypoxic chamber (WAGGENER et al, 1984) and at altitudes higher than 5,300 m (LAHIRI et al, 1983;SUTTON et al, 1979;WEST et al, 1986) but is similar to that in the studies of WELL et al(1978) and HACKETT et al (1987). Figure 2 shows the relationship between ventilatory chemosensitivities and PB index.…”

Section: Disordered Breathing At Altitudesupporting

confidence: 85%

“…Some (BERSSENBRUGE et al, 1983;LAHIRI et al, 1983;WHITE et al, 1987;GLEESON et al, 1988) insist that high peripheral chemosensitivity is an important determinant for PB at high altitude; others (PowLEs et al, 1978;WEST et al, 1986) conclude that there is no positive relationship between them. Some (CHERNIACK and LONGOBARDO,1973;KHoo et al, 1982;PRYOR,1951) propose a hypothesis that circulation delay is one of the important factors for PB, but others (WAGGENER et al, 1984;WEST et al, 1986) show that circulation time at high altitude is shorter than that at sea level.…”

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confidence: 99%

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Periodic breathing at high altitude and ventilatory responses to O2 and CO2.

et al. 1989

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To determine the relationship between periodic breathing (PB) during sleep at high altitude and ventilatory chemosensitivities, we studied nine Japanese climbers who participated in the expedition to the Kunlun Mountains (7,167m) in China in 1986. At sea level, ventilatory response to hypoxia (HVR) by isocapnic progressive hypoxia test and to hypercapnia (HCVR) by Read's method were examined. At altitude 5,360 m, respiratory movements of the chest and abdominal wall, Saoz, ECG, and HR were monitored. Seven climbers manifested PB during sleep. There was a significant correlation between PB during sleep and HVR and HCVR (p <0.05). All the climbers showed severe desaturation during sleep. There was a significant negative correlation between degree of desaturation during sleep and HVR (p <0.05). A negative correlation was also detected between PB and the degree of desaturation during sleep. We concluded that ventilatory chemosensitivities play an important role in eliciting PB and that climbers with high HVR can maintain their arterial oxygenation during sleep, due to hyperventilation induced by PB, which is considered an advantageous adaptation for lowland sojourners.

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Section: Disordered Breathing At Altitudesupporting

confidence: 85%

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confidence: 99%

Periodic breathing at high altitude and ventilatory responses to O2 and CO2.

et al. 1989

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“…A further important difference is that the human controller apparently has a relatively fixed apneic threshold for CO 2 (19,30), whereas the lamb and several other species do not (12,28). It seems likely that these fundamental differences are the reason hypoxia normally precipitates PB in sleeping humans (6,27), whereas it has never been reported to do so in the lamb.…”

Section: Discussionmentioning

confidence: 99%

“…It is particularly prevalent during sleep, occurring at sea level in apparently normal-term and preterm infants (22,43), at high altitude in normal adults (27), and after hypoxic exposure in experimental animals (11,21). It also occurs in patients with congestive heart failure (36), with idiopathic central sleep apnea (52), with bilateral brain stem lesions (40), and in periodic obstructive sleep apnea (41).…”

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confidence: 99%

“…For example, in preterm infants, the waxing and waning pattern of PB that is characteristic of the adult is replaced by a more or less abrupt on-off pattern that shows little change in tidal volume during the breathing phase (42); this pattern resembles that seen in hibernating animals (34). Furthermore, although the response to hyperoxic inspired gas applied during PB is generally similar in adults and infants (17,27,51) in that the instability is transiently enhanced as evidenced by the immediate increase in the duration of the apneic pause, incidental observations show that the response to hypoxia applied during PB in preterm infants (44) is apparently opposite to that of adults (48). In the preterm infant, PB is suppressed by hypoxic inspired gas, whereas it is enhanced in adults.…”

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Impact of changes in inspired oxygen and carbon dioxide on respiratory instability in the lamb

Wilkinson¹,

Sia²,

Skuza³

et al. 2005

Journal of Applied Physiology

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. Impact of changes in inspired oxygen and carbon dioxide on respiratory instability in the lamb. J Appl Physiol 98: 437-446, 2005. First published October 8, 2004 doi:10.1152/japplphysiol.00532.2004We examined the effect of hypoxia and hypercapnia administered during deliberately induced periodic breathing (PB) in seven lambs following posthyperventilation apnea. Based on our theoretical analysis, the sensitivity or loop gain (LG) of the respiratory control system of the lamb is directly proportional to the difference between alveolar PO2 and inspired PO2. This analysis indicates that during PB, when by necessity LG is Ͼ1, replacement of the inspired gas with one of reduced PO2 lowers LG; if we made inspired PO2 approximate alveolar PO2, we predict that LG would be approximately zero and breathing would promptly stabilize. In six lambs, we switched the inspired gas from an inspiratory oxygen fraction of 0.4 to one of 0.12 during an epoch of PB; PB was immediately suppressed, supporting the view that the peripheral chemoreceptors play a pivotal role in the genesis and control of unstable breathing in the lamb. In the six lambs in which we administered hypercapnic gas during PB, breathing instability was also suppressed, but only after a considerable time lag, indicating the CO2 effect is likely to have been mediated through the central chemoreceptors. When we simulated both interventions in a published model of the adult respiratory controller, PB was immediately suppressed by CO2 inhalation and exacerbated by inhalation of hypoxic gas. These fundamentally different responses in lambs and adult humans demonstrate that PB has differing underlying mechanisms in the two species.Cheyne-Stokes respiration; hypoxia; hypercapnia; sleep apnea syndromes; control of breathing; periodic breathing PERIODIC BREATHING (PB), or Cheyne-Stokes respiration, appears under a wide range of physiological and clinical conditions. It is particularly prevalent during sleep, occurring at sea level in apparently normal-term and preterm infants (22,43), at high altitude in normal adults (27), and after hypoxic exposure in experimental animals (11,21). It also occurs in patients with congestive heart failure (36), with idiopathic central sleep apnea (52), with bilateral brain stem lesions (40), and in periodic obstructive sleep apnea (41). A form of PB can also be found in hibernating animals (7,34).Although it is often assumed that the underlying mechanisms causing PB in infants and adults are similar, in each case involving instability of the chemical control system that regulates breathing, there are some marked differences in the pattern of PB and its responses to changes in inspired gas that remain largely unexplained. For example, in preterm infants, the waxing and waning pattern of PB that is characteristic of the adult is replaced by a more or less abrupt on-off pattern that shows little change in tidal volume during the breathing phase (42); this pattern resembles that seen in hibernating animals (34). Furthermore, although the re...

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The Safety of Trekking at High Altitude After Coronary Bypass Surgery-Reply

West¹

1988

JAMA

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Dependence of high altitude sleep apnea on ventilatory sensitivty to hypoxia

Cited by 167 publications

References 22 publications

Periodic breathing at high altitude and ventilatory responses to O2 and CO2.

Periodic breathing at high altitude and ventilatory responses to O2 and CO2.

Impact of changes in inspired oxygen and carbon dioxide on respiratory instability in the lamb

The Safety of Trekking at High Altitude After Coronary Bypass Surgery-Reply

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