Effect of magnesium, high altitude and acute mountain sickness on blood flow velocity in the middle cerebral artery.

Détails

ID Serval
serval:BIB_862470011B03
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Effect of magnesium, high altitude and acute mountain sickness on blood flow velocity in the middle cerebral artery.
Périodique
Clinical Science
Auteur(s)
Lysakowski C., Von Elm E., Dumont L., Junod J.D., Tassonyi E., Kayser B., Tramèr M.R.
ISSN
0143-5221 (Print)
ISSN-L
0143-5221
Statut éditorial
Publié
Date de publication
2004
Peer-reviewed
Oui
Volume
106
Numéro
3
Pages
279-285
Langue
anglais
Résumé
Cerebral blood flow is thought to increase at high altitude and in subjects suffering from acute mountain sickness (AMS); however, data from the literature are contentious. Blood flow velocity in the middle cerebral artery (MCAv) may be used as a proxy measure of cerebral blood flow. Using transcranial Doppler sonography, MCAv was measured during normo- and hyper-ventilation in subjects who participated in a trial that tested the effect of magnesium supplementation on the prevention of AMS. First, MCAv was recorded at 353 m (baseline). Subjects were then randomized to receive oral magnesium citrate and matching placebo. A second measurement was taken after a 24 +/- 2 h ascent from 1130 m to 4559 m (altitude I), and a third after a 20-24 h stay at 4559 m (altitude II). Using multivariate linear regression, an association was sought between MCAv and magnesium supplementation, subjects' age and gender, altitude itself, a temporary stay at altitude, and the presence of AMS (Lake Louise Score >6 with ataxia, nausea and/or headache). Subjects with AMS had additional Doppler recordings immediately before and after rescue medication (oxygen, dexamethasone and acetazolamide). Forty-seven subjects had measurements at baseline, 39 (21 receiving magnesium and 18 placebo) at altitude I and 26 (13 receiving magnesium and 13 placebo) at altitude II. During hyperventilation, MCAv decreased consistently (for each measurement, P<0.001). Magnesium significantly increased MCAv by 8.4 cm.s(-1) (95% confidence interval, 1.8-15), but did not prevent AMS. No other factors were associated with MCAv. Eleven subjects had severe AMS [median score (range), 11 (8-16)] and, after rescue medication, the median score decreased to 3 (range, 0-5; P=0.001), but MCAv remained unchanged (65 +/- 18 cm.s(-1) before compared with 67 +/- 16 cm.s(-1) after rescue medication; P=0.79). MCAv was increased in subjects who received magnesium, but was not affected by exposure to high altitude or by severe AMS.

Mots-clé
Administration, Oral, Altitude, Altitude Sickness/physiopathology, Altitude Sickness/prevention & control, Blood Flow Velocity, Citric Acid/administration & dosage, Citric Acid/therapeutic use, Gender Identity, Humans, Least-Squares Analysis, Middle Cerebral Artery/physiology, Organometallic Compounds/administration & dosage, Organometallic Compounds/therapeutic use, Time Factors, Ultrasonography, Doppler
Pubmed
Web of science
Création de la notice
30/10/2017 15:09
Dernière modification de la notice
20/08/2019 14:45
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