Changes In Peripheral Blood Flow Research Articles

HEAT CLEARANCE A CONVENIENT METHOD OF ESTIMATING PERIPHERAL BLOOD FLOW?

SUMMARY A heat clearance technique using heated thermocouples for the measurement of peripheral blood flow has been examined. It is concluded that the technique is a convenient and accurate method of estimating rapid changes in peripheral blood flow.

Effect of gallamine triethiodide and pentobarbital on certain cardiovascular and respiratory events.

In dogs peripheral blood flow and blood pressure were not significantly altered during a period of 2 hours following the administration of Flaxedil. Heart rate increased significantly. Rectal temperature, hematocrit, O2 consumption and CO2 production were not altered. The changes in peripheral blood flow and heart rate which occur following an anesthetic dose of pentobarbital sodium were not influenced by the administration of combinations of pentobarbital and Flaxedil. Flaxedil appears to be a desirable agent to employ for controlling the muscular activity in experiments concerned with the measure of peripheral blood flow and blood pressure since this drug per se has little or no effect on these variables and thus would permit establishment of their control values. The use of this drug alone would not be permissible in painful experimental procedures.

Quantitative and qualitative evaluation of skin erythema I. Technic of measurement and description of the reaction.

It is usually agreed that the visual measurement of x-ray skin reaction is hampered by many psychological and physical difficulties that render quantitative description precarious if not impossible. Three main categories of difficulties can be described: 1. Variation in the chromatic acuity of the observers. 2. Variations in the ambient light in the examining suite, which influence the judgment of the observers. 3. Lack of quantitative means to evalu- ate the intensity of response. To keep these factors at a minimum, it seemed desirable to develop an objective method for studying the skin changes produced by ionizing radiation. In an effort to eliminate such variables as visual acuity and quality of the incident light, Sheard and his co-workers (1–3) developed a spectrophotometric method for analyzing skin color in normal and pathologic states. Edwards and Duntley (4) refined these technics and made an extensive study of the types and distribution of pigments in normal skin, showing that oxyhemoglobin, reduced hemoglobin, and melanin are the primary factors in determining skin color. Estimation of the amount of oxyhemoglobin and reduced hemoglobin may be made by reflectance measurements at 574 and 556 millimicrons, respectively. Since these two compounds contribute very little to the intensity of reflected light at the long wave lengths, the melanin content may be determined by measurement of the intensity of the reflectance spectrum between 660 and 680 millimicrons (Fig. 1). The absorption spectrum of normal skin is essentially the sum of these curves. In 1932 Harris and co-workers (5) employed the reflectance spectrophotometer for the study of x-ray-induced skin erythema. Their results were expressed in terms of relative luminosity, hue, and saturation. They measured only the irradiated areas, however, and did not compensate for normal variations of skin color due to changes in peripheral blood flow or variations in skin pigmentation. Their data, therefore, may be considered as a measurement of both the x-ray reaction and normal variations. Jansen (6) in his investigations of ultraviolet erythema and pigmentation was able to eliminate the normal variations due to alterations in peripheral blood flow, width of the vessels, and seasonal changes, by the rather simple method of expressing data in terms of the per cent of normal skin color. This was accomplished by taking readings of the adjacent normal skin on both sides of the irradiated area and obtaining a ratio of irradiated skin to nonirradiated skin × 100 for each important absorption band. A modification of Jansen's technic has been used for quantitative determination of the x-ray-induced skin reaction. Materials and Methods For this study the Photovolt Model 610 Reflectance Meter, a filter spectrophotometer, was used for a quantitative determination of the x-ray skin reaction.

Polarographic determination of intravascular oxygen tensions in vivo.

Abstract.The peripheral circulation in the duck during diving has been studied. Changes in peripheral blood flow were indicated by measuring the venous pressure‐rise in a branch of the femoral vein, when the main venous return was occluded. Electrocardiograms and arterial pressures were recorded simultaneously. Upon diving of the animals an extreme bradycardia was observed while the arterial pressure underwent only small changes. The slow drop in the arterial diastolic pressure during diving indicated a great reduction in the rate of emptying from the larger arteries. The peripheral blood flow determined from the degree of venous return was likewise found to be markedly reduced. It is concluded that diving induces an adjustatory shut down of the circulation through the whole limb. This explains the animals' ability to compensate for the extreme bradycardia in the maintenance of high systemic blood pressure, thus securing an ample circulation to the brain during asphyxia.

A Photometric Technique for the Quantitative Measurement of Changes in Peripheral Blood Flow

A technique is described which utilizes a multiplier photometer, Model 520-M, equipped with photo-multiplier tube No. 21-C and an argon light source to measure quantitatively and record the circulatory changes in the skin and striated muscles of anesthetized and unanesthetized laboratory animals. With this technique drug-produced changes in blood flow through the peripheral vascular system may be compared with simultaneously acquired manometric recordings of carotid blood pressure. The method yields information which is subject to statistical analysis.

The effect of smoking cigarettes on the peripheral blood flow in subjects in the older age group with coronary arteriosclerosis and hypertension

The effect of smoking standard cigarettes on the peripheral blood flow was studied by means of a method with which the average amount of blood allotted to the periphery can be measured in cubic centimeters per square meter of body surface per minute. The peripheral blood flow was measured in seventeen patients who exhibited evidences of hypertension and coronary arteriosclerosis and who were in the older age group ranging from 38 to 81 years of age. Effects on the basal metabolic rate, blood pressure, and pulse rate were also recorded. Studies were made before, during, and after the smoking of one brand of regular commercial cigarettes. All observations were made with patients in a basal metabolic state at a room temperature of 27° C. and 45 to 50 per cent humidity. 1. 1. As a result of smoking, the peripheral blood flow decreased in thirteen subjects and increased in four subjects. In the four showing increases, the peripheral blood flow decreased for single observations either during or after smoking but not sufficiently to counterbalance the average trend of increase in peripheral blood flow for the whole period of the observations. After cessation of smoking the peripheral blood flow continued to decrease in some and began to return toward the control levels in others. 2. 2. The blood pressure rose and the pulse rate increased in the group in which smoking decreased the peripheral blood flow, but it was essentially unchanged in the group in which smoking increased the peripheral blood flow. 3. 3. The rectal temperature rose as a result of smoking. 4. 4. The average skin temperature decreased as a result of smoking. 5. 5. These changes resulting from smoking are similar to those occurring in normal subjects. 6. 6. The changes in peripheral blood flow, blood pressure, heart rate, rectal temperature, and average skin temperature (especially the temperature of the hands and feet) were, however, less marked in these patients in the later decades of life than in normal young subjects.

Peripheral Vascular Responses to General Anoxia.

SummaryInhalation of a mixture of 10% oxygen and 90% nitrogen produced a moderate increase in blood flow through the leg and forearm and a decrease through the hand. These changes in peripheral blood flow were associated with a significant augmentation in pulse rate, a slight increase in the amplitude or number of respirations and no definite change in blood pressure.