Prioritized Brain Circulation During Ergometer Cycling with Apnea and Face Immersion in Ice-Cold Water: A Case Report

• Main Authors: Bjertnaes LJ, Hauge A, Thoresen M, Walløe L
• Format: Article in Journal/Newspaper
• Language: English
• Published: Dove Medical Press 2021
• Subjects: apnea; breath-hold; cardiopulmonary resuscitation; diving response; hypothermia; Medicine (General); R5-920; Arctic; Norway; Tromsø; North Norway; Arctic University of Norway; UiT The Arctic University of Norway
• Online Access: https://doaj.org/article/fa767862108e40f2a8464cfa1901a192

Lars J Bjertnaes,1,2 Anton Hauge,3 Marianne Thoresen,3,4 Lars Walløe3 1Anesthesia and Critical Care Research Group, Department of Clinical Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, N-9037, Norway; 2Department of Intensive Care Medicine, University Hospital of North Norway, Tromsø, N- 9017, Norway; 3Division of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, 0317, Norway; 4Translational Health Sciences, University of Bristol, Bristol, UKCorrespondence: Lars J BjertnaesAnesthesia and Critical Care Research Group, Department of Clinical Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, N-9037, NorwayTel [phone]Fax [phone]Email [e-mail]: Successful cardiopulmonary resuscitation after drowning or avalanche is often attributed to hypothermia-induced decrease in metabolism, which adapts the oxygen demand to the amount supplied under cardiac compression. Four decades ago, we speculated if oxygen-sparing mechanisms like those found in marine mammals, may improve cerebral oxygenation during acute airway blockade in humans. We investigated hemodynamic changes during steady state ergometer cycling with intermittent periods of apnea and face immersion (AFI) in ice-cold water. During AFI, heart rate (HR) dropped by 58% whereas average blood velocity (ABV) determined by means of a Doppler ultrasound velocity meter (UNIDOP University of Oslo, Oslo, Norway) fell by 85% in the radial artery and rose by 67% in the vertebral artery. Similar changes occured in radial artery ABV, albeit more slowly, when the test subject only held his breath while cycling. When he breathed via a snorkel during face immersion, HR remained unchanged while radial artery ABV fell transiently and subsequently returned to its pre-immersion level. These findings later were confirmed by other investigators. Moreover, a recent study revealed that the seal even has a system for selective brain cooling during the dive.Conclusion: ...