N. S. Assali

Measurement of uterine blood flow and uterine metabolism

Abstract In recent years valuable techniques have been devised to measure blood flow to the kidneys, brain, heart, and liver, and great progress has been made in the study of the circulation and metabolism in these organs. Surprisingly, however, such studies have not as yet been satisfactorily extended to the nonpregnant and pregnant uterus, despite the obvious value which would be derived from knowledge of uterine blood flow and uterine metabolism. These studies probably would contribute to the solution of important problems in obstetrics and gynecology, such as those related to uterine and placental ischemia, uterine inertia, effects of various hormones and other therapeutic agents on uterine and fetal circulation, and presumably also dysmenorrhea and functional uterine bleeding. The present paper reviews and evaluates the studies which heretofore have been made on the measurement of uterine blood flow in experimental animals and human subjects. It also discusses the possibilities and significance of applying the newer methods and techniques used in measuring the circulation in other organs, in the determination of uterine blood flow and uterine metabolism.

RENAL FUNCTION STUDIES IN TOXEMIA OF PREGNANCY: EXCRETION OF SOLUTES AND RENAL HEMODYNAMICS DURING OSMOTIC DIURESIS IN HYDROPENIA

The occurrence of proteinuria and the repeated demonstration of depression of filtration rate and renal plasma flow in toxemia of pregnancy are evidence that there is impairment of renal function. Structural abnormalities are not demonstrable in pre-eclampsia although when the stage of eclampsia supervenes morphologic abnormalities are occasionally detectable (1, 2). The invariable presence of edema attests to the fact that the functional lesion involves the mechanism of excretion of water and solutes. Attempts to define the mechanism of retention of fluid in toxemia of pregnancy have been directed mainly at the hormonal balance of toxemic subjects (3). Investigations focused specifically on the renal mechanism of water and electrolyte excretion and carried out under standard and reproducible conditions have not been reported. The present investigation was undertaken to apply some of the recently acquired knowledge of the relationship between excretion of water and solutes under the specific conditions of osmotic diuresis in hydropenia to patients with toxemia of pregnancy. The relationship between excreted loads of electrolytes and other urinary constituents, on the one hand, and water on the other, is predictable and reproducible in normal pregnant and non-pregnant subjects studied with this technique (4-6). It has been observed that the amount of water excreted under these conditions is determined solely by the osmotic pressure of the excreted solutes, that the concentrations of sodium and chloride in the urine are remarkably constant and independent of the rate of urine flow, and that the rates of excretion of sodium and

The formation, regression, and differential diagnosis of true infarcts of the placenta

Abstract In a series of 562 entire placentas, and other specimens of gravid uteri and contents, together with material from autopsies in cases of maternal and fetal deaths, the formation, regression, and differential diagnosis of true infarcts of the placenta were studied. Diagnostic criteria were established which are comparable to those commonly used in general pathology. Accurate diagnosis, often by means of microscopic sections, is a necessity in the determination of the etiology and clinical significance of nodular placental lesions.

STUDIES ON AUTONOMIC BLOCKADE. II. OBSERVATIONS ON THE NATURE OF BLOOD PRESSURE FALL WITH HIGH SELECTIVE SPINAL ANESTHESIA IN PREGNANT WOMEN

In the preceding report (p. 1354 of this issue) it was demonstrated that normal pregnant females at term respond with a striking fall in blood pressure to autonomic blockade with high selective spinal anesthesia or TEAC. With the former, severe side effects, such as nausea, vomiting, cyanosis, fatigue and other symptoms of imminent circulatory collapse, were present while with the latter, these symptoms were absent although the hypotensive levels were the same. This suggested to us the necessity for further investigation on the nature of blood pressure fall with high selective spinal anesthesia in pregnant women.

Measurement of uterine blood flow and uterine metabolism: II. The techniques of catheterization and cannulation of the uterine veins and sampling of arterial and venous blood in pregnant women☆

Abstract The techniques of catheterization and cannulation of the uterine veins and sampling of venous and arterial blood for measurement of uterine blood flow have been described. The advantages, disadvantages, and difficulties of each technique are discussed.