Changes in cerebral oxygenation and haemodynamics during postural blood pressure changes in patients with autonomic failure. Export

@article{citeulike:1649250, abstract = {Patients with autonomic failure suffer severe postural hypotension that may be associated with symptoms of cerebral hypoperfusion. This study utilized near-infrared spectroscopy (NIRS) to measure changes in cerebral oxygenation and haemodynamics during the head-up tilt table test in 18 patients with autonomic failure and 10 healthy age-matched volunteers. Heart rate, blood pressure (MAP), oxygen saturation, cerebral tissue oxygen index (TOI) and total cerebral haemoglobin concentration [HbT] were measured continuously. In patients with autonomic failure there was a mean (SD) reduction in MAP of 46.7 (26.5) mmHg (p < 0.005) associated with a reduction in TOI of 8.6 (6.2)\% (p < 0.005) during the head-up tilt table test. In healthy volunteers mean (SD) MAP rose by 12.3 (8.0) mmHg (p < 0.005) and TOI fell by 2.6 (3.2)\% (p < 0.05). There was a mean (SD) reduction in [HbT] of 3.09 (2.82) micromol l(-1) (p < 0.005) in patients, equivalent to a decrease in cerebral blood volume of 0.2 (0.18) ml/100 g. There were no changes in [HbT] in the healthy volunteers. Postural hypotension in patients with autonomic failure is associated with a substantial decrease in absolute cerebral oxygenation measured by NIRS and this might reflect a critical reduction in cerebral oxygen delivery.}, address = {Department of Neuroanaesthesia and Neurocritical Care, The National Hospital for Neurology and Neurosurgery and Institute of Neurology, Queen Square, London WC1N 3BG, UK. Centre for Anaesthesia, University College London, UK.}, author = {Hunt, K. and Tachtsidis, I. and Bleasdale-Barr, K. and Elwell, C. and Mathias, C. and Smith, M.}, citeulike-article-id = {1649250}, citeulike-linkout-0 = {http://view.ncbi.nlm.nih.gov/pubmed/16868345}, citeulike-linkout-1 = {http://www.hubmed.org/display.cgi?uids=16868345}, issn = {0967-3334}, journal = {Physiol Meas}, keywords = {autonomic, dysfunction, physiology, ttt}, month = {September}, number = {9}, pages = {777--785}, posted-at = {2007-09-12 21:37:49}, priority = {3}, title = {Changes in cerebral oxygenation and haemodynamics during postural blood pressure changes in patients with autonomic failure.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/16868345}, volume = {27}, year = {2006} }

TY - JOUR ID - citeulike:1649250 L3 - citeulike-article-id:1649250 N2 - Patients with autonomic failure suffer severe postural hypotension that may be associated with symptoms of cerebral hypoperfusion. This study utilized near-infrared spectroscopy (NIRS) to measure changes in cerebral oxygenation and haemodynamics during the head-up tilt table test in 18 patients with autonomic failure and 10 healthy age-matched volunteers. Heart rate, blood pressure (MAP), oxygen saturation, cerebral tissue oxygen index (TOI) and total cerebral haemoglobin concentration [HbT] were measured continuously. In patients with autonomic failure there was a mean (SD) reduction in MAP of 46.7 (26.5) mmHg (p < 0.005) associated with a reduction in TOI of 8.6 (6.2)% (p < 0.005) during the head-up tilt table test. In healthy volunteers mean (SD) MAP rose by 12.3 (8.0) mmHg (p < 0.005) and TOI fell by 2.6 (3.2)% (p < 0.05). There was a mean (SD) reduction in [HbT] of 3.09 (2.82) micromol l(-1) (p < 0.005) in patients, equivalent to a decrease in cerebral blood volume of 0.2 (0.18) ml/100 g. There were no changes in [HbT] in the healthy volunteers. Postural hypotension in patients with autonomic failure is associated with a substantial decrease in absolute cerebral oxygenation measured by NIRS and this might reflect a critical reduction in cerebral oxygen delivery. IS - 9 JF - Physiol Meas SN - 0967-3334 AD - Department of Neuroanaesthesia and Neurocritical Care, The National Hospital for Neurology and Neurosurgery and Institute of Neurology, Queen Square, London WC1N 3BG, UK. Centre for Anaesthesia, University College London, UK. EP - 785 TI - Changes in cerebral oxygenation and haemodynamics during postural blood pressure changes in patients with autonomic failure. VL - 27 SP - 777 KW - autonomic KW - dysfunction KW - physiology KW - ttt AU - Hunt, K AU - Tachtsidis, I AU - Bleasdale-Barr, K AU - Elwell, C AU - Mathias, C AU - Smith, M PY - 2006/09// UR - http://view.ncbi.nlm.nih.gov/pubmed/16868345 ER -