This Article Full Text Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Smielewski, P. Articles by Pickard, J. D. Search for Related Content PubMed PubMed Citation Articles by Smielewski, P. Articles by Pickard, J. D.

(Stroke. 1996;27:2197-2203.)
© 1996 American Heart Association, Inc.

Articles

Assessment of Cerebral Autoregulation Using Carotid Artery Compression

Peter Smielewski, MSc; Marek Czosnyka, PhD; Peter Kirkpatrick, FRCS (SN); Helen McEroy, BSc; Helen Rutkowska, BSc John D. Pickard, FRCS

the MRC Cambridge Centre for Brain Repair and Academic Neurosurgical Unit, Addenbrooke's Hospital, University of Cambridge (UK).

Correspondence to Peter Smielewski, Neurosurgery Unit, Level 4, A Block, Addenbrooke's Hospital, Hills Rd, Cambridge, CB2 2QQ, UK.

Background and Purpose A simple method of testing cerebral autoregulation by observing transcranial Doppler changes in middle cerebral artery flow velocity (FV) during a brief ipsilateral carotid artery compression (the transient hyperemic response test) was studied in 11 normal healthy volunteers. The aim of this study was to assess the reliability of the method and to compare derived autoregulatory indices with those of a standard noninvasive test of autoregulation, Aaslid's leg-cuff test.

Methods Volunteers were subjected to repeated carotid compressions and leg-cuff tests at different levels of CO₂. Hypercapnia was induced using inhalation of a mixture of 5% CO₂ in air. Hypocapnia was induced by moderate hyperventilation. To assess the influence of the duration of carotid compression, a series of carotid compressions lasting 3, 4, 5, 7, and 9 seconds were performed in random sequence. Monitored parameters included ipsilateral FV, end-tidal CO₂, and arterial blood pressure. The transient hyperemic response ratio (THRR), calculated as the maximum increase of FV divided by baseline values after release of the carotid compression, was taken as the autoregulation index. This index was compared with the rate of autoregulation index derived from the leg-cuff test.

Results Both tests were significantly associated with end-tidal CO₂ (ANOVA, P<.000001 for both carotid compression and cuff test). There was a linear correlation between THRR and autoregulation index (r=.86). However, the reproducibility of the THRR was more consistent than for the autoregulation index from single tests (13% versus 46%, respectively; P<.0001). Although the influence of the duration of carotid compression on THRR values was significant for carotid compressions lasting up to 5 seconds, there was no relation to the relative magnitude of FV drop during the compression.

Conclusions Brief (>5 seconds) carotid artery compression provides an index of cerebral autoregulation that is reproducible and is affected by CO₂ tension in a fashion similar to autoregulatory indices derived from a standard leg-cuff test. The simplicity of the method provides a potentially useful addition to other noninvasive autoregulation tests for clinical assessments, particularly when repeated measurements are required.

Key Words: autoregulation • blood flow velocity • carotid arteries • cerebral circulation • ultrasonics

This article has been cited by other articles:

				A. Conti, D. G. Iacopino, V. Fodale, S. Micalizzi, O. Penna, and L. B. Santamaria Cerebral haemodynamic changes during propofol-remifentanil or sevoflurane anaesthesia: transcranial Doppler study under bispectral index monitoring Br. J. Anaesth., September 1, 2006; 97(3): 333 - 339. [Abstract] [Full Text] [PDF]

				G. T. Wong, I. Luginbuehl, C. Karsli, and B. Bissonnette The effect of sevoflurane on cerebral autoregulation in young children as assessed by the transient hyperemic response. Anesth. Analg., April 1, 2006; 102(4): 1051 - 1055. [Abstract] [Full Text] [PDF]

				H. Skinner, C. Mackaness, N. Bedforth, and R. Mahajan Cerebral haemodynamics in patients with chronic renal failure: effects of haemodialysis Br. J. Anaesth., February 1, 2005; 94(2): 203 - 205. [Abstract] [Full Text] [PDF]

				K. Lu, J. W. Clark Jr., F. H. Ghorbel, C. S. Robertson, D. L. Ware, J. B. Zwischenberger, and A. Bidani Cerebral autoregulation and gas exchange studied using a human cardiopulmonary model Am J Physiol Heart Circ Physiol, February 1, 2004; 286(2): H584 - H601. [Abstract] [Full Text] [PDF]

				S. M. Hancock, R. P. Mahajan, and L. Athanassiou Noninvasive Estimation of Cerebral Perfusion Pressure and Zero Flow Pressure in Healthy Volunteers: The Effects of Changes in End-Tidal Carbon Dioxide Anesth. Analg., March 1, 2003; 96(3): 847 - 851. [Abstract] [Full Text] [PDF]

				C. W. Park, M. Sturzenegger, C. M. Douville, R. Aaslid, and D. W. Newell Autoregulatory Response and CO2 Reactivity of the Basilar Artery Stroke, January 1, 2003; 34(1): 34 - 39. [Abstract] [Full Text] [PDF]

				R. W. Sherman, R. A. Bowie, M. M. E. Henfrey, R. P. Mahajan, and D. Bogod Cerebral haemodynamics in pregnancy and pre-eclampsia as assessed by transcranial Doppler ultrasonography Br. J. Anaesth., November 1, 2002; 89(5): 687 - 692. [Abstract] [Full Text] [PDF]

				R. Schondorf, R. Stein, R. Roberts, J. Benoit, and W. Cupples Dynamic cerebral autoregulation is preserved in neurally mediated syncope J Appl Physiol, December 1, 2001; 91(6): 2493 - 2502. [Abstract] [Full Text] [PDF]

				N. M. Bedforth, K. J. Girling, H. J. Skinner, and R. P. Mahajan Effects of desflurane on cerebral autoregulation Br. J. Anaesth., August 1, 2001; 87(2): 193 - 197. [Abstract] [Full Text] [PDF]

				R. K. Tibble, K. J. Girling, and R. P. Mahajan A Comparison of the Transient Hyperemic Response Test and the Static Autoregulation Test to Assess Graded Impairment in Cerebral Autoregulation During Propofol, Desflurane, and Nitrous Oxide Anesthesia Anesth. Analg., July 1, 2001; 93(1): 171 - 176. [Abstract] [Full Text] [PDF]

				C.-L. Chao and Y.-T. Lee Impairment of Cerebrovascular Reactivity by Methionine-Induced Hyperhomocysteinemia and Amelioration by Quinapril Treatment Stroke, December 1, 2000; 31(12): 2907 - 2911. [Abstract] [Full Text] [PDF]

				N. M. Bedforth, K. J. Girling, J. M. Harrison, and R. P. Mahajan The Effects of Sevoflurane and Nitrous Oxide on Middle Cerebral Artery Blood Flow Velocity and Transient Hyperemic Response Anesth. Analg., July 1, 1999; 89(1): 170 - 170. [Abstract] [Full Text] [PDF]

				K. J. Girling, G. Cavill, and R. P. Mahajan The Effects of Nitrous Oxide and Oxygen on Transient Hyperemic Response in Human Volunteers Anesth. Analg., July 1, 1999; 89(1): 175 - 175. [Abstract] [Full Text] [PDF]

				R. B. Panerai, R. P. White, H. S. Markus, and D. H. Evans Grading of Cerebral Dynamic Autoregulation From Spontaneous Fluctuations in Arterial Blood Pressure Stroke, November 1, 1998; 29(11): 2341 - 2346. [Abstract] [Full Text] [PDF]

				V. Novak, P. Novak, J. M. Spies, and P. A. Low Autoregulation of Cerebral Blood Flow in Orthostatic Hypotension Stroke, January 1, 1998; 29(1): 104 - 111. [Abstract] [Full Text] [PDF]