[Ultrasound-Doppler analysis of arterial blood flow before and after cryotherapy]

The reduction of oxygen consumption of the synovial membrane and the decrease of juxta-articular muscular tension are amongst others the aims of cryotherapy. The local cold application is followed by a reactive change in blood flow even in distant parts of the body. The knee region of 19 persons was cooled with a cryogel -pack for 15 min and the arterial blood flow of the a. dorsalis pedis was analysed with an ultrasound-Doppler-apparatus. Already in the rest period of 30 minutes before cooling the mean flow decreases and reaches a minimum after 10 min of cryotherapy. Subsequently continuing the therapy, blood flow velocity increases. The parameter independent of the angle is given through the pulsatility index PI (= maximum amplitude/mean flow). Since the mean flow is the denominator of this index the PI-value rises during the first 10 min of cooling and then decreases. The change of flow velocity for the mean value of the group was up to 1.0 cm/sec, i.e. 31% of the initial value. The maximum change of the pulsatility index was about 1.0, i.e. 29% of the initial value. There was no increase of the flow velocity during the test period for a control group of 22 persons with no cryotherapy. The difference was statistically significant (p less than 0.01). The cryotherapy selected includes a 15 minutes application of a cryogel -pack on a cloth, which leads to an average increase in blood pressure in the malleolar region of less than 5%. In spite of cryotherapy in all groups the mean blood pressure in the arm remains constant or decreases slightly because of the position of rest.(ABSTRACT TRUNCATED AT 250 WORDS)