[High-frequency ultrasonic studies of peripheral circulatory behavior during anesthesia. 1st results with a new...

A new measurement system, based on high-frequency ultrasound Doppler shift detection, was developed to yield semiquantitative information on blood flow velocity in peripheral vascular compartments during anaesthesia. In 25 patients, anaesthetized by mask or intubation techniques, by this device blood flow velocity in the finger tips was recorded simultaneously with other physiological and haemodynamic parameters. In all patients characteristic changes in blood flow velocity were shown very consistently corresponding to different phases of the anaesthetic course. The graphic display of the Doppler shift frequency as an analogue signal yielded a continuous record of pulsatile blood flow velocity, while histograms on a TV-monitor showed its spectral distribution. Medications as well as stimuli from the area of surgery could be shown to reproducibly regarding course and depth of anaesthesia. The high sensitivity of this new monitoring technique producing semiquantitative data offers to the anaesthesist a reliable interpretation of the patient's intraoperative condition.