[Peripheral circulatory responses during dental treatment under local anesthesia. Comparison between plethysmogram and ultrasonic Doppler blood flow].

In this study, peripheral circulatory responses during dental treatment under local anesthesia were observed. Changes in hemodynamics data, ECG, systolic blood pressure (SBP), diastolic blood pressure (DBP), digital and ear-lobe plethysmogram (PT), and radials and external carotid artery ultrasonic doppler blood flow (FW) were recorded by means of a multipurpose monitoring system. An improved fixed probe was devised for the purpose of stabilizing the external carotid artery FW record, and the ear-piece facebow system (Hanau, No. 153) was remodeled. Radial FW index D/S1 and external carotid FW index d/S1 were analyzed to determine systolic velocity S1 and diastolic velocity D or d. Pressure tests and cold stimulation tests were performed as fundamental research. Comparative investigations were made of changes in PT and FW in the light of SBP, DBP and heart rate (HR). A total of 71 instances of dental treatment was performed on 25 non-hypertensive patients (N-HT) and 25 patients with essential hypertension (HT). The patients were divided into 2 groups according to the local anesthetic employed: the E group, to whom 1:80,000 epinephrine with an addition of 2% lidocaine was administered, and the NE group, to whom 1:25,000 norepinephrine was administered. Results and conclusions 1. When peripheral blood flow was interrupted during the pressure test, digital PT and radial FW were disappeared. 2. Digital PT, radial diastolic FW D, and index D/S1 decreased greatly as a result of the cold stimulation test. It was suggested that changes in digital PT accord with the diastolic velocity D of radial FW. 3. At the stage of local anesthesia, SBP rose most in the HT-NE group. There was a tendency for digital PT and radial FW D either to decrease or to increase. It was assumed that cardio-stroke volume increased when PT and FW increased. Decreases in digital PT and radial FW apparently indicate increased capillary resistance. 4. Greatest increases in HR at the stage of local anesthesia occurred in the N-HT-E group. Digital PT and radial FW D tended to decrease. In cases of increased HR, PT and FW tended to decrease. In comparison with conditions immediately before treatment, digital PT and radial FW D decreased more in the N-HT group than in the HT group.