Normal Blood Pressure Values Research Articles

Hypokalemia, normal blood pressure, andhyperreninemia with hypoaldosteronism

The etiology of persistent hypokalemia and renal potassium loss was investigated in three children. Each had normal blood pressure but low plasma aldosterone values in relation to elevated plasma renin activity. None had a history of licorice abuse, laxative or diuretic use, persistent vomiting or diarrhea, pyelonephritis, or diabetes insipidus. Additional studies in one patient showed low prostaglandin E excretion and a normal platelet aggregation response to epinephrine and ADP. Although certain aspects of this condition resemble Bartter syndrome, the low concentrations of aldosterone and the absence of evidence for mineralocorticoid excess suggest a previously undescribed syndrome.

Hypertension and Sports

The article "Response of Hypertensive Adolescents to Dynamic and Isometric Exercise Stress" which appears in this issue of Pediatrics (p 579) raises a number of interesting and practical questions for pediatricians. For example, What is hypertension? What does hypertension mean to the child or youth? Should the youth with hypertension be allowed to participate in competitive athletics? What is the role of exercise testing in the evaluation of hypertension? What additional information does it provide? WHAT IS HYPERTENSION? Blood pressure (BP) is the resultant of cardiac output (CO), and systemic vascular resistance (SVR). Because CO and SVR vary from one person to another, it is not surprising that there is a wide range of normal BP values.

Epidemiology of Essential Hypertension in Youth—Implications for Clinical Practice

Essential hypertension, a highly prevalent and devastating disease, likely begins in childhood, and presumably might respond at this stage to general preventive measures. The problems encountered in the recording of reproducible blood pressure levels are largely of a quantitative nature, and involve instrument validity, observer (examiner) training, and the interaction between the child and the physician's office environment. The problems of early diagnosis of hypertension are related to the lack of long-term observations of children. Population percentiles of normal blood pressure values could aid in the early diagnosis of hypertension. For this purpose the method of blood pressure measurement in the physician's office has to be strictly comparable to methods employed in accumulating the percentile or reference observations. Repeated measurements under basal-like conditions are advised, and the weight or height of the child is more important for standardization than is age.

Some aspects of the physiology of the anaesthetised marmoset

Some normal values of blood pressure, heart rate, and respiration rate obtained from 37 anaesthetised marmosets, are reported together with results of the electrocardiograms of 6 marmosets. The effects of a variety of pharmacological agents are also reported. The suitability of the anaesthetised marmoset as a representative of the primate order for the pharmacological evaluation of drugs that affect the cardiovascular and respiratory systems is discussed.

Research and Nursing Care in the Premature Nursery

THE TRADITION OF clinical investigation combined with optimal nursing care in the premature nursery has been a long one here in Chicago. As early as 1933, for instance, Hess, Mohr, and Barthelme reported on the physical and emotional development of the infant born prematurely. At the same time, they reported the findings from other investigative studies concerned with immaturity, including normal values for blood pressure and electrocardiograms, and the techniques for determining them; cerebrospinal fluid findings and the procedure for lumbar puncture; and the incidence of inguinal hernia. Over the decades, this approach, which combines maximum nursing care with research investigation, has resulted in reducing the neonatal mortality at the Michael Reese Hospital and Medical Center. Statistics have been collected on the 11,269 premature infants admitted to the hospital in the last 30 years: 2826 admitted between 1931 through 1940; 4385, 1941 through 1950; and 4058, 1951 through 1960. The data demonstrate a statistically significant (p = <.01) fall in mortality in all weight groups under 1500 grams, when one compares the decade 1951-1960 with that of 19411950. The mortality rate in infants over 1500 grams birth weight has remained less than 15 percent during the past 20 years (see p. 95). Despite the reduction in mortality, too many babies under 1500 grams still die, and too many who survive do not attain optimal physical, intellectual, or emotional development. Thus the need for continued research is obvious, but with a change in emphasis. The little babies-those under 1250 to 1500 grams-as well as the sick babies must be studied if we are to define and understand

Research and Nursing Care in the Premature Nursery

THE TRADITION OF clinical investigation combined with optimal nursing care in the premature nursery has been a long one here in Chicago. As early as 1933, for instance, Hess, Mohr, and Barthelme reported on the physical and emotional development of the infant born prematurely. At the same time, they reported the findings from other investigative studies concerned with immaturity, including normal values for blood pressure and electrocardiograms, and the techniques for determining them; cerebrospinal fluid findings and the procedure for lumbar puncture; and the incidence of inguinal hernia. Over the decades, this approach, which combines maximum nursing care with research investigation, has resulted in reducing the neonatal mortality at the Michael Reese Hospital and Medical Center. Statistics have been collected on the 11,269 premature infants admitted to the hospital in the last 30 years: 2826 admitted between 1931 through 1940; 4385, 1941 through 1950; and 4058, 1951 through 1960. The data demonstrate a statistically significant (p = <.01) fall in mortality in all weight groups under 1500 grams, when one compares the decade 1951-1960 with that of 19411950. The mortality rate in infants over 1500 grams birth weight has remained less than 15 percent during the past 20 years (see p. 95). Despite the reduction in mortality, too many babies under 1500 grams still die, and too many who survive do not attain optimal physical, intellectual, or emotional development. Thus the need for continued research is obvious, but with a change in emphasis. The little babies-those under 1250 to 1500 grams-as well as the sick babies must be studied if we are to define and understand

Development of the sex difference in blood pressure of the chick.

In order to establish the age and manner in which the sex difference in blood pressure of the adult white leghorn chicken develops, periodical blood pressure measurements were made on chicks between 3 and 34 weeks of age. There were no consistent differences in pressure between the sexes under 8 weeks of age. Between the 8th and 13th weeks, pressures began to diverge, and within 4–8 weeks a 26–30-mm sex difference in systolic pressure developed. Significant divergences occurred also in diastolic and pulse pressure. The sex divergence was due primarily to a rise in male pressure, the female level remaining comparatively stable. Net changes in male parameters during the period of rapid development of the sex difference in pressure were: body weight + 219 gm, systolic pressure + 26 mm, diastolic pressure + 16 mm and heart rate –22/ min. The age at which the sex difference in pressure begins and its rate of development appear to be related to sexual maturation in the male. However, no significant correlation between the rising male pressure and testes or comb size could be shown. Normal chick blood pressure values prior to the sex divergence differ within strains of white leghorns and for the two groups used here, between 7 and 9 weeks of age, were 150/130 and 162/136 mm Hg.

BLOOD PRESSURE LEVELS IN THE NETHERLANDS DURING THE WAR

DURING the years of occupation, 1940 to 1945, the weight of many inhabitants of the Netherlands decreased as noted both in the clinics1and among the general population.2At the same time, there was a fall in blood pressure to levels far below those regarded as normal. However, before one can judge whether or not these levels were actually low, it is necessary to investigate the standards that are applied in the determination of normal blood pressure. The literature abounds in information on normal values for blood pressure. Until twenty or thirty years ago, many authors accepted a maximum blood pressure of 150 to 160 mm. of mercury as normal, stating that the most frequently prevailing systolic range was 130 to 140 mm.3These reports did not tend to fix a definite limit but drew attention to the variability of a normal blood pressure and the

Experimental Technic for Measuring Mean Systolic Blood Pressures During Activity, Rest, and Natural Sleep.

Blood pressures are conventionally determined in the dog either directly by a mercury or a Hamilton manometer connected to a cannula or needle introduced into a large artery or indirectly by auscultation or palpation distal to a modified Riva-Rocci blood pressure cuff about an extremity or a Van Leersum arterial loop. The positioning or training required for these methods precludes blood pressure determinations during normal emotional and physical activity, rest, and sleep. Accordingly reported normal blood pressure values have varied significantly, A new technic for blood pressure determination that permits frequent readings during varying phases of activity or rest was therefore devised and tested. It has not to the knowledge of the authors been previously described. Healthy dogs were anesthetized and placed on one side on an operating table with the upper leg externally rotated. The lower half of the upper side of the turnk and the groin and thigh were then shaved and prepared. Employing aseptic technic, the iliac and the upper femoralartery was exposed above and below the inguinal ligament through a 3-inch incision. A 1-inch square of sterile fine mesh gauze was next placed beneath each artery. A small rubber balloon fashioned from 1/2 inch of the tin of small finger cot and attached over a short segment of 18-gague needle to a 4-fot length of fine plastic tubing was then placed above and in direct contact with each artery. Each gauze was folded about the artery and the balloon to form a cuff and sutured snugly in place. Care was taken to avoid arterial injury or constriction. Each cuff was carefully filled and tested by the introduction of sterile water under pressure. The 2 plastic tubes were then guided subcutaneously around the flank and out through a stab wound located over the first lumbar spine.