Short-term monitoring of the vascular resistance of the human skin microvasculature
Török, T.; Bari, F.; Paprika, D.; Rudas, L.; Kardos, A.; Gingl, Z.
Acta Physiologica Hungarica 85(2): 153-162
1997
ISSN/ISBN: 0231-424X PMID: 9706310 Document Number: 471854
Laser Doppler flowmetry is a non-invasive tool in assessing the temporary changes of skin microcirculation. Another non-invasive equipment the Finapres 2300 finger blood pressure monitor provides a continuous blood pressure signal. The combination of the two devices allows short-term monitoring of the changes in the resistance of skin microvasculature. In order to assess the role of skin blood vessels in physiological responses to complex reflex tests Valsalva manoeuvre was performed by 12 healthy volunteers. For comparison a thermal stimulation (cold pressor) test was also done. The two tests resulted in skin blood flow responses of similar magnitude. The changes in calculated regional peripheral resistance (dRPR) indicated that both responses involved active vasoconstrictor mechanisms. It is of importance that the active vasoconstriction could be documented only at the late strain phase (V2) but not in the early strain phase (V1) of the Valsalva manoeuvre (%dRPR in V1 = 0.14 vs. V2 = 0.96, p < 0.05). In conclusion our findings support the theory that changes in the tone of the skin blood vessels parallel the changes in systemic vasculature in response to complex reflex tests. This is the first report which documents the feasibility of the continuous monitoring of the regional peripheral resistance.