Integrated respiratory chemoreflex‐mediated regulation of cerebral blood flow in hypoxia: Implications for oxygen delivery and acute mountain sickness

2021 ◽  
Author(s):  
Shigehiko Ogoh ◽  
Takuro Washio ◽  
Benjamin S. Stacey ◽  
Hayato Tsukamoto ◽  
Angelo Iannetelli ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Oxygen Delivery ◽  
Acute Mountain Sickness ◽  
Respiratory Chemoreflex ◽  
Mountain Sickness

Relationship of cerebral blood flow regulation to acute mountain sickness.

1989 ◽  
Vol 8 (3) ◽  
pp. 143-148 ◽  
Author(s):  
S M Otis ◽  
M E Rossman ◽  
P A Schneider ◽  
M P Rush ◽  
E B Ringelstein
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Acute Mountain Sickness ◽  
Flow Regulation ◽  
Blood Flow Regulation ◽  
Mountain Sickness ◽  
Relationship Of

Cerebral Blood Flow in Acute Mountain Sickness and Treatment with Acetazolamide

1988 ◽  
Vol 74 (s18) ◽  
pp. 1P-1P ◽  
Author(s):  
AD Wright ◽  
AR Bradwell ◽  
J Jensen ◽  
N Lassen
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Acute Mountain Sickness ◽  
Mountain Sickness

scholarly journals Regional cerebral blood flow during acute hypoxia in individuals susceptible to acute mountain sickness

2008 ◽  
Vol 160 (3) ◽  
pp. 267-276 ◽  
Author(s):  
Edward A.W. Dyer ◽  
Susan R. Hopkins ◽  
Joanna E. Perthen ◽  
Richard B. Buxton ◽  
David J. Dubowitz
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Acute Hypoxia ◽  
Acute Mountain Sickness ◽  
Regional Cerebral Blood ◽  
Mountain Sickness

Acute mountain sickness is not related to cerebral blood flow: a decompression chamber study

1999 ◽  
Vol 86 (5) ◽  
pp. 1578-1582 ◽  
Author(s):  
Ralf W. Baumgartner ◽  
Ioakim Spyridopoulos ◽  
Peter Bärtsch ◽  
Marco Maggiorini ◽  
Oswald Oelz
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Acute Mountain Sickness ◽  
Transcranial Doppler Sonography ◽  
Simulated Altitude ◽  
Chamber Study ◽  
Mountain Sickness ◽  
Low Altitude ◽  
Artery Flow

To evaluate the pathogenetic role of cerebral blood flow (CBF) changes occurring before and during the development of acute mountain sickness (AMS), peak mean middle cerebral artery flow velocities ([Formula: see text]) were assessed by transcranial Doppler sonography in 10 subjects at 490-m altitude, and during three 12-min periods immediately (SA1), 3 (SA2), and 6 (SA3) h after decompression to a simulated altitude of 4,559 m. AMS cerebral scores increased from 0.16 ± 0.14 at baseline to 0.44 ± 0.31 at SA1, 1.11 ± 0.88 at SA2( P < 0.05), and 1.43 ± 1.03 at SA3( P < 0.01); correspondingly, three, seven, and eight subjects had AMS. Absolute and relative[Formula: see text] at simulated altitude, expressed as percentages of low-altitude values (%[Formula: see text]), did not correlate with AMS cerebral scores. Average %[Formula: see text] remained unchanged, because %[Formula: see text]increased in three and remained unchanged or decreased in seven subjects at SA2 and SA3. These results suggest that CBF is not important in the pathogenesis of AMS and shows substantial interindividual differences during the first hours at simulated altitude.

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

2004 ◽  
Vol 106 (3) ◽  
pp. 279-285 ◽  
Author(s):  
Christopher LYSAKOWSKI ◽  
Erik VON ELM ◽  
Lionel DUMONT ◽  
Jean-Daniel JUNOD ◽  
Edömer TASSONYI ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Middle Cerebral Artery ◽  
High Altitude ◽  
Blood Flow Velocity ◽  
Rescue Medication ◽  
Acute Mountain Sickness ◽  
Median Score ◽  
Magnesium Supplementation ◽  
Mountain Sickness

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.

Cerebral blood flow in acute mountain sickness

1990 ◽  
Vol 69 (2) ◽  
pp. 430-433 ◽  
Author(s):  
J. B. Jensen ◽  
A. D. Wright ◽  
N. A. Lassen ◽  
T. C. Harvey ◽  
M. H. Winterborn ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Sea Level ◽  
Therapeutic Intervention ◽  
Acute Mountain Sickness ◽  
Initial Slope ◽  
Acute Change ◽  
Before And After ◽  
Radioactive Xenon ◽  
Mountain Sickness

Changes in cerebral blood flow (CBF) were measured using the radioactive xenon technique and were related to the development of acute mountain sickness (AMS). In 12 subjects, ascending from 150 to 3,475 m, CBF was 24% increased at 24 h [45.1 to 55.9 initial slope index (ISI) units] and 4% increased at 6 days (47.1 ISI units). Four subjects had similar increases of CBF when ascending to 3,200 m 3 mo later, indicating the reproducibility of the measurements. In nine subjects, ascending from 3,200 to 4,785-5,430 m, CBF increased to 76.4 ISI units, 53% above estimated sea-level values. CBF and increases in CBF were similar in subjects with or without AMS. In six subjects, CBF was measured before and after therapeutic intervention. At 2 h CBF increased 22% (71.3 to 87.3 ISI units) above pretreatment values in three subjects given 1.5 g acetazolamide, while three subjects given placebo showed no change. Symptoms remained unaltered in all subjects during the 2 h of the study. Overall, the results indicated that increases in CBF were similar in subjects with or without AMS while acetazolamide-provoked increases of CBF in AMS subjects caused no acute change in symptoms. Alterations in CBF cannot be directly implicated in the pathogenesis of AMS.

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