Hugh Montgomery

Oxygen Tension of Tissues by the Polarographic Method III. The Effect of Local Heat on the Oxygen Tension of the Skin of Extremities

Simultaneous measurements of skin oxygen tension by polarography and skin temperature by thermocouple were made in patients with peripheral arterial disease and in individuals with normal extremities over a range of skin temperature of 10 to 50 C. The oxygen tension of the skin was found to increase as the skin temperature was raised to about normal body temperature in the ischemic extremity and to significantly higher temperature in the normal extremity. Possible reasons for these changes are discussed.

George E. Brown Memorial Lecture Oxygen Tension of Tissues in Vivo

It seems fair to say that prior to the use of the oxygen electrode there was a static concept of the oxygen tension of tissues. This was true in spite of the fact that Bazett and Sribyatta, with the gas bubble technic, had demonstrated one example of a labile oxygen tension, in the subcutaneous space of man.17 They of course could not show the rapidity with which the changes take place. Experiments with the polarographic technic have shown that profound changes in oxygen tension can take place very rapidly, all the way from values approaching that of arterial blood down to zero. In vasodilated skin oxygen tension approaches that of arterial blood. When different concentrations of oxygen are breathed, the changes in oxygen tension in such skin closely follow those of the arterial blood. When the circulation to skin is limited by peripheral arterial occlusion, oxygen is reduced and does not increase on vasodilatation as much as does that of normal skin. When a normal person breathes oxygen, the oxygen in the tissues that use little oxygen quickly reaches a pressure 4 or 5 times that produced when he breathes air. In the case of tissues that use greater amounts of oxygen this relationship is not so close. The higher tensions have not been found in the tissues that use the most oxygen. The transfer of oxygen from the capillaries to the tissue is rapid but not instantaneous. The usual ranges of oxygen tension of various tissues such as skeletal muscle, heart muscle, brain, etc., are not yet known in terms of millimeters of mercury, but this should now be possible. It is hoped that local metabolisms will be measured reasonably accurately in intact tissues within the body. Perhaps the storage of oxygen by myoglobin and cytochromes can be derived, again in situ, from the metabolism and the rate of change of oxygen tension when the circulation is arrested. The potentialities of the oxygen electrode are great, but limitations of the method should be respected. Further development of the method may free it of some of its defects. Other methods may supplant it, but if so they will need to be equally rapid and more capable of exact calibration. In closing this presentation I want to thank our chairman, my friend Dr. Arthur Merrill, for allowing me to speak to you. I want also to thank Dr. George Brown, in memoriam, for his pioneering in the paths of study of the interrelations of circulatory and tissue physiology and medicine.

Glutamic oxalacetic transaminase, lactic dehydrogenase and creatine changes with local cold injury of the rabbit limb.

Abstract Some biochemical effects of local cold injury were studied by immersing the hind leg of the rabbit in 2°C. water for 24 hours and then analyzing creatine, glutamic oxalacetic transaminase and lactic dehydrogenase of the muscle and of systemic serum 24 hours later. There was a decrease in muscle creatine but no change in theserum. There was a decrease in muscle GOT in both the chilled and contralateral legs and a rise in serum, while LDH showed no change in muscle nut did increase in the serum. Some possible mechanisms responsible for these changes are discussed briefly.

Influence of an Oscillating Bed on Cutaneous Temperature and Oxygen Tension of Ischemic Toes

Measurements of temperature and oxygen tension of the skin demonstrated that treatment with an oscillating bed increases the circulation to ischemic toes. When the angle and duration of the dependent position of the foot of the bed were increased, further increments in circulation resulted.

OXYGEN TENSION OF TISSUES BY THE POLAROGRAPHIC METHOD. VI. EFFECT OF CHANGES IN POSITION ON OXYGEN TENSION OF THE SKIN OF TOES

peripheral arterial occlusion is aggravated by raising the limb and relieved somewhat by lowering the limb. Patients with this condition often complain of foot pain while in bed. This is relieved by getting out of bed. If the head of the bed is raised or special devices are used to lower the leg (1) the pain of the foot is often relieved and the color of the foot improved. Conversely, a case recently came to our attention in which the foot of a patient, who had been confined to bed for a year because of a cerebrovascular accident, became gangrenous only two days after being elevated on two pillows. Elevation of a normal limb decreases the arterial pressure within it, whereas dependency increases the pressure. Measurements of intra-arterial pressure show that the pressure varies directly with the vertical distance from the right atrium to the point of measurement (2). Such changes might be ex

Clinical study and treatment of varicose veins.

The widely different kinds of varices are easy to differentiate if the underlying anatomy and physiology are understood. Appropriate therapy is wholly dependent upon this understanding. Surgery is a reasonably definitive therapy of primary varices, but secondary varices usually require rest, elevation and elastic support.

Oxygen Tension of Tissues by the Polarographic Method II. Detection of Right to Left Shunts by Changes in Skin Oxygen Tension Resulting from Inhalation of Oxygen

Normal individuals breathing pure oxygen obtain full saturation of their hemoglobin, whereas those with right to left shunts do not. Oxygen hemoglobin dissociation curves indicate that increases to full oxygen saturation of hemoglobin are accompanied by marked increases of the oxygen tension. When breathing oxygen fails to produce full saturation, relatively little change in oxygen tension occurs. When the cutaneous circulation is rapid, changes in skin oxygen tension have been shown to vary directly with changes in blood oxygen tension. Taking advantage of these facts the authors have described a method of detecting significant right to left shunts by polarographic measurements of skin oxygen tension.