A simple method for producing fine stainless steel dissecting needles and microscalpels.
An apparatus is described with which one can, with ease, manufacture very fine stainless steel dissection needles as well as microscalpels.
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Biomedical subjects
R Dell
Publications and source records attributed to R Dell.
Comparison of the cardiocirculatory effects of exercise and isoproterenol in children with pulmonary or aortic valve stenosis.
Isoproterenol infusion during cardiac catheterization as a simulator of exercise was evaluated with hemodynamic studies in children with pulmonary (15) or aortic (8) valve stenosis. Cardiac function was monitored during rest, mild exercise and isoproterenol infusion. Similar heart rates were maintained in both procedures. Peak pulmonary and aortic valve gradients as well as right and left ventricular dp/dt/p were significantly higher and cardiac index significantly lower with isoproterenol as compared to exercise. Isoproterenol induced a significantly greater decrease in systemic vascular resistance, and systemic blood pressure than did exercise. Left ventricular systolic pressure rose to similar levels and this resulted in substantially higher peak aortic gradients with isoproterenol. A consistent correlation was observed for peak valvular gradients measured during exercise and isoproterenol in both groups of patients. Accordingly, regression equations were obtained allowing reasonably accurate prediction of exercise valvular gradients on the basis of the isoproterenol data.
Adolescent↗
Cardiac output in infants and children after open-heart surgery.
Green dye measurements of cardiac index (in liters per minute per square meter) were compared in 32 infants and 58 children, 6 and 24 hours after normothermic cardiopulmonary bypass. Cardiac index was significantly lower in infants under one year of age, as compared to older infants and children. This parameter was also lower in patients with total anomalous pulmonary venous drainage, truncus arteriosus, and tetralogy of Fallot. Five infants who died had 6-hour cardiac index determinations of 2.0 L./min./sq. M. Only 2 of 27 survivors had cardiac indices below this level. Simultaneously recorded heart rate and central venous pressure did not correlate with cardiac index. Systolic blood pressure was significantly lower in infants in whom the cardiac index was less then 2.0 L./min./sq. M. (p less than 0.01). However, in individual situations, determination of systemic blood pressure lacked specificity in predicting outcome. Measurements of cardiac index are helpful in the management of infants and children following intracardiac repair by (1) assessing the hemodynamic status, (2) providing a useful indication of the cardiocirculatory effects of therapeutic interventions, and (3) predicting outcome.
Adolescent↗