Facial immersion in cold water enhances cerebral blood velocity during breath-hold exercise in humans

TY - JOUR

T1 - Facial immersion in cold water enhances cerebral blood velocity during breath-hold exercise in humans

AU - Kjeld, Thomas

AU - Pott, Frank C

AU - Secher, Niels H

N1 - Times Cited: 0ArticleEnglishKjeld, TRigshosp, Dept Aneasthesiol, Blegdamsvej 9, DK-2100 Copenhagen Hovedstaden, DenmarkCited References Count: 22427AWAMER PHYSIOLOGICAL SOC9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USABETHESDA

PY - 2009

Y1 - 2009

N2 - The diving response is initiated by apnea and facial immersion in cold water and includes, besides bradycardia, peripheral vasoconstriction, while cerebral perfusion may be enhanced. This study evaluated whether facial immersion in 10 degrees C water has an independent influence on cerebral perfusion evaluated as the middle cerebral artery mean flow velocity (MCA V(mean)) during exercise in nine male subjects. At rest, a breath hold of maximum duration increased the arterial carbon dioxide tension (Pa(CO(2))) from 4.2 to 6.7 kPa and MCA V(mean) from 37 to 103 cm/s (mean; approximately 178%; P <0.001). Similarly, during 100-W exercise, a breath hold increased Pa(CO(2)) from 5.9 to 8.2 kPa (P <0.001) and MCA V(mean) from 55 to 113 cm/s ( approximately 105%), and facial immersion further increased MCA V(mean) to 122 cm/s ( approximately 88%; both P <0.001). MCA V(mean) also increased during 180-W exercise (from 47 to 53 cm/s), and this increment became larger with facial immersion (76 cm/s, approximately 62%; P <0.001), although Pa(CO(2)) did not significantly change. These results indicate that a breath hold diverts blood toward the brain with a >100% increase in MCA V(mean), largely because Pa(CO(2)) increases, but the increase in MCA V(mean) becomes larger when combined with facial immersion in cold water independent of Pa(CO(2)).

AB - The diving response is initiated by apnea and facial immersion in cold water and includes, besides bradycardia, peripheral vasoconstriction, while cerebral perfusion may be enhanced. This study evaluated whether facial immersion in 10 degrees C water has an independent influence on cerebral perfusion evaluated as the middle cerebral artery mean flow velocity (MCA V(mean)) during exercise in nine male subjects. At rest, a breath hold of maximum duration increased the arterial carbon dioxide tension (Pa(CO(2))) from 4.2 to 6.7 kPa and MCA V(mean) from 37 to 103 cm/s (mean; approximately 178%; P <0.001). Similarly, during 100-W exercise, a breath hold increased Pa(CO(2)) from 5.9 to 8.2 kPa (P <0.001) and MCA V(mean) from 55 to 113 cm/s ( approximately 105%), and facial immersion further increased MCA V(mean) to 122 cm/s ( approximately 88%; both P <0.001). MCA V(mean) also increased during 180-W exercise (from 47 to 53 cm/s), and this increment became larger with facial immersion (76 cm/s, approximately 62%; P <0.001), although Pa(CO(2)) did not significantly change. These results indicate that a breath hold diverts blood toward the brain with a >100% increase in MCA V(mean), largely because Pa(CO(2)) increases, but the increase in MCA V(mean) becomes larger when combined with facial immersion in cold water independent of Pa(CO(2)).

U2 - http://dx.doi.org/10.1152/japplphysiol.90370.2008

DO - http://dx.doi.org/10.1152/japplphysiol.90370.2008

M3 - Journal article

SN - 8750-7587

VL - 106

SP - 1243

EP - 1248

JO - Journal of Applied Physiology

JF - Journal of Applied Physiology

IS - 4

ER -