title: A pilot study of the relationship between Doppler-estimated carotid and brachial artery flow and cardiac index.
abstract: We measured carotid and brachial artery blood flow by Doppler ultrasound in 11 human volunteers, and related these to cardiac index and to each other. The median (IQR [range]) carotid arterial blood flow was 0.334 (0.223-0.381 [0.052-0.563]) l.min(-1) on the right and 0.315 (0.223-0.369 [0.061-0.690]) l.min(-1) on the left. The brachial arterial blood flow was 0.049 (0.033-0.062 [0.015-0.204]) l.min(-1) on the right and 0.039 (0.027-0.054 [0.011-0.116]) on the left. Cardiac index was 3.2 (2.8-3.5 [1.9-5.4]) l.min(-1) .m(-2) . There was a moderate to good correlation between right-and left-sided flows (brachial: ρ = 0.45; carotid: ρ = 0.567). Brachial and carotid flow had no or a negative correlation with cardiac index (right brachial: ρ = -0.145, left brachial: ρ = -0.349; right carotid: ρ = -0.376, left carotid: ρ = -0.285). In contrast to some previous studies, we found that Doppler-estimated peripheral arterial blood flows only show a weak correlation with cardiac index and cannot be used to provide non-invasive estimates of cardiac index in man.
authors.affiliation: Department of Intensive Care, Austin Hospital, Melbourne, Victoria, Australia.
authors.forename: U
authors.initials: U
authors.lastname: Weber
authors.affiliation: Australian and New Zealand Intensive Care Research Centre and Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
authors.forename: N J
authors.initials: NJ
authors.lastname: Glassford
authors.affiliation: Australian and New Zealand Intensive Care Research Centre and Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
authors.forename: G M
authors.initials: GM
authors.lastname: Eastwood
authors.affiliation: Australian and New Zealand Intensive Care Research Centre and Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Bellomo
authors.affiliation: Department of Intensive Care, Austin Hospital, Melbourne, Victoria, Australia.
authors.forename: A K
authors.initials: AK
authors.lastname: Hilton
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000502:physiology*; D002302:Cardiac Output / Q000502:physiology*; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D012039:Regional Blood Flow / Q000502:physiology; D015203:Reproducibility of Results; D018608:Ultrasonography, Doppler / Q000379:methods