The aim of this thesis was to investigate gravitational blood volume distribution and effects on regional pressure, especially intracranial pressure. Graded head-up and down tilt was used to manipulate the magnitude and direction of the hydrostatic gradients (study I and study III). However, the only way to abolish hydrostatic gradients altogether is by weightlessness. Therefore weightlessness is a unique research-tool because it provides a control-situation for the effects of gravity and this was used by study II and study IV.
The thesis was based on the following publications:
- Petersen LG, Carlsen JF, Nielsen MB, Damgaard M, Secher NH. The hydrostatic pressure indifference point underestimates or- thostatic redistribution of blood in humans. J Appl Physiol. 116: 730–735, 2014.
- Petersen LG, Damgaard M, Petersen JCG, Norsk P. Mechanisms of increase in cardiac output during acute weightlessness in hu- mans. J Appl Physiol. 111: 407–411, 2011.
- Petersen LG, Petersen JCG, Andresen M, Secher NH, Juhler M. Postural influence on intracranial and cerebral perfusion pres- sure in ambulatory neurosurgical patients. Am J Physiol Regul Integr Comp Physiol. 310: r100–104, 2016.
- Lawley JS, Petersen LG, Howden EJ, Sarma S, Cornwell WK, Zhang R, Whitworth LA, Williams M, Levine BD. Effect of grav- ity on the intracranial pressure: Implications for visual impairment in space. Unpublished, manuscript in preparation.
Supervisor and reviewers
The primary thesis supervisor was:
Professor Niels H. Secher
Department of Anaesthesia,
The Copenhagen Muscle Research Centre,
Rigshospitalet, University of Copenhagen, DK
The thesis reviewers were:
- (Chairperson) Professor Christian Aalkjær
Department of Biomedical Sciences,
University of Copenhagen, DK
- Professor Tobias Wang
Department of Bioscience,
Aarhus University, DK
- Professor Richard Hughson
Department of Kinesiology,
Faculty of Applied Health Sciences,
University of Waterloo, Canada