[Evaluation of increasing digital blood flow during early period of air-cooled cold test]

The present study was performed to elucidate peripheral hemodynamic changes, especially, digital blood flow, caused by an air-cooled cold test. Experiments were carried out by placing the subject's left hand in a box that was kept at a temperature of about 18 degrees C by air-cooling. At the same time, the digital blood flow, digital blood pressure, compliances of the peripheral resistance and capacitance vessels were measured. These parameters were measured on the left forefinger of the cooled side, and also on the opposite side according to Kato's method at 3 points, 1) at normal condition (before cooling stated). 2) 30 seconds after the cooling began and 3) 10 minutes after the cooling began. The following results were obtained; 1) The systemic blood pressure, digital blood pressure and heart rate showed no statistically significant differences in measurements taken at the above three stages. 2) The mean value of the digital blood flow was found to have increased after 30 seconds, and to have decreased after 10 minutes of cooling. Statistically, significant differences were noted at the above three stages. 3) The mean value of the peripheral vascular resistance was found to have increased after 30 seconds, and to have decreased after 10 minutes. 4) Compliances of the peripheral resistance vessel and capacitance vessel showed no significant changes on either side except between normal condition and after 10 minutes of cooling.