Middle cerebral artery blood flow velocity in response to lower body positive pressure

• Published in: Clinical physiology and functional imaging 2013-11, Vol.33 (6), p.483-488
• Main Authors: Perry, Blake G., Schlader, Zachary J., Raman, Aaron, Cochrane, Darryl J., Lucas, Samuel J. E., Mündel, Toby
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological; Adult; Age; arterial blood pressure; Arterial Pressure; Blood Flow Velocity; cerebral autoregulation; cerebral blood flow; cerebral haemodynamics; Cerebrovascular Circulation; Female; Humans; Lower Body Negative Pressure; Male; Middle Cerebral Artery - diagnostic imaging; Middle Cerebral Artery - physiology; Supine Position; sympathetic nervous system; Time Factors; Ultrasonography, Doppler, Pulsed; Ultrasonography, Doppler, Transcranial; Vascular Resistance; Young Adult
• ISSN: 1475-0961; 1475-097X
• DOI: 10.1111/cpf.12046

Summary Lower body positive pressure (LBPP) has been used in the treatment of haemorrhagic shock and in offsetting g‐force induced fluid shifts. However, the middle cerebral artery blood flow velocity (MCAv) response to supine LBPP is unknown. Fifteen healthy volunteers (mean ± SD: age, 26 ± 5 year; body mass, 79 ± 10 kg; height, 174 ± 9 cm) completed 5 minutes of 20 and 40 mm Hg LBPP, in a randomized order, separated by 5 minutes rest (baseline). Beat‐to‐beat MCAv and blood pressure, partial pressure of end‐tidal carbon dioxide (PETCO2) and heart rate were recorded and presented as the change from the preceding baseline. All measures were similar between baseline periods (all P>0·30). Mean arterial pressure (MAP) increased by 7 ± 6 (8 ± 7%) and 13 ± 7 mm Hg (19 ± 11%) from baseline during 20 and 40 mm Hg (P