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The Young Everest Study: preliminary report of changes in sleep and cerebral blood flow velocity during slow ascent to altitude in unacclimatised children

Gavlak, Johanna C., Stocks, Janet, Laverty, Aidan, Fettes, Emma, Bucks, Romola, Sonnappa, Samatha, Cooper, Janine, Grocott, Michael P., Levett, Denny Z., Martin, Daniel S., Imray, Christopher H. and Kirkham, Fenella J. (2013) The Young Everest Study: preliminary report of changes in sleep and cerebral blood flow velocity during slow ascent to altitude in unacclimatised children Archives of Disease in Childhood, 98, (5), pp. 356-362. (doi:10.1136/archdischild-2012-302512). (PMID:23471157).

Record type: Article


BACKGROUND: Cerebral blood flow velocity (CBFV) and sleep physiology in healthy children exposed to hypoxia and hypocarbia are under-researched.

AIM: To investigate associations between sleep variables, daytime end-tidal carbon dioxide (EtCO2) and CBFV in children during high-altitude ascent.

METHODS: Vital signs, overnight cardiorespiratory sleep studies and transcranial Doppler were undertaken in nine children (aged 6-13 years) at low altitude (130 m), and then at moderate (1300 m) and high (3500 m) altitude during a 5-day ascent.

RESULTS: Daytime (130 m: 98%; 3500 m: 90%, p=0.004) and mean (130 m: 97%, 1300 m: 94%, 3500: 87%, p=0.0005) and minimum (130 m: 92%, 1300 m: 84%, 3500 m: 79%, p=0.0005) overnight pulse oximetry oxyhaemoglobin saturation decreased, and the number of central apnoeas increased at altitude (130 m: 0.2/h, 1300 m: 1.2/h, 3500 m: 3.5/h, p=0.2), correlating inversely with EtCO2 (R(2) 130 m: 0.78; 3500 m: 0.45). Periodic breathing occurred for median (IQR) 0.0 (0; 0.3)% (130 m) and 0.2 (0; 1.2)% (3500 m) of total sleep time. At 3500 m compared with 130 m, there were increases in middle (MCA) (mean (SD) left 29.2 (42.3)%, p=0.053; right 9.9 (12)%, p=0.037) and anterior cerebral (ACA) (left 65.2 (69)%, p=0.024; right 109 (179)%; p=0.025) but not posterior or basilar CBFV. The right MCA CBFV increase at 3500 m was predicted by baseline CBFV and change in daytime SpO2 and EtCO2 at 3500 m (R(2) 0.92); these associations were not seen on the left.

CONCLUSIONS: This preliminary report suggests that sleep physiology is disturbed in children even with slow ascent to altitude. The regional variations in CBFV and their association with hypoxia and hypocapnia require further investigation.

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e-pub ahead of print date: 7 March 2013
Published date: May 2013
Organisations: Human Development & Health


Local EPrints ID: 350227
ISSN: 0003-9888
PURE UUID: 9070fc4e-78b4-4016-ac66-f5435c34e5a9

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Date deposited: 20 Mar 2013 16:22
Last modified: 18 Jul 2017 04:36

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Author: Johanna C. Gavlak
Author: Janet Stocks
Author: Aidan Laverty
Author: Emma Fettes
Author: Romola Bucks
Author: Samatha Sonnappa
Author: Janine Cooper
Author: Denny Z. Levett
Author: Daniel S. Martin
Author: Christopher H. Imray
Author: Fenella J. Kirkham

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