Hemodynamic assessment of local anesthetic administration by laser Doppler flowmetry.

OBJECTIVE: The hemodynamic effects of local anesthetic administration with and without a vasoconstrictor were compared by using laser Doppler flowmetry. STUDY DESIGN: Seventeen people participated in a single study session in which they were given 2 intraoral injections. The injections, which were administered in random order, consisted of 1.8 mL lidocaine (2%) with epinephrine (1:100,000) and mepivacaine (3%). Hemodynamic parameters consisting of blood pressure, heart rate, and laser Doppler flowmetry were reordered at regular intervals. RESULTS: The laser Doppler flowmeter detected changes in the peripheral perfusion of the finger that were not detected by changes in blood pressure and heart rate. The greatest change was associated with anxiety and occurred just before the injection. The inclusion of epinephrine in the local anesthetic resulted in a persistence of these changes. CONCLUSION: This investigation has confirmed the sensitivity of laser Doppler flowmetry as an investigational tool for assessing hemodynamic changes associated with anxiety and the administration of local anesthesia.

CT assessment of cerebral perfusion: experimental validation and initial clinical experience.

PURPOSE: To validate a dynamic single-section computed tomographic (CT) method to measure cerebral blood volume (CBV) and cerebral blood flow (CBF) by using a noncarotid artery as the input and to demonstrate the feasibility of this method in a pilot series of patients. MATERIALS AND METHODS: Twelve dynamic contrast material-enhanced CT studies were performed in beagles. CBV, CBF, and mean transit time (MTT) values were calculated by using an internal carotid artery (ICA) and a noncarotid artery as the input artery to the brain. Patient studies with use of the radial artery as the input were performed (a) repetitively in two patients after subarachnoid hemorrhage, (b) in a patient with a symptomatic ICA occlusion before and after the intravenous injection of 1 g of acetazolamide, and (c) in a patient with a malignant brain tumor. RESULTS: Linear regression analyses revealed highly significant correlations (P < .001) between CBV (r, 0.98; slope, 0.96), CBF (r, 0.89; slope, 0.87), and MTT (r, 0.80; slope, 0.76) values calculated with the ICA and the noncarotid inputs. The CT-derived patient data correlated well with ancillary clinical and neuroradiologic findings. CONCLUSION: Dynamic single-section CT scanning to measure CBV and CBF on the basis of a noncarotid input is a highly accessible and cost-effective blood flow measurement technique.