Search PubMed⌕ Search

Biomedical subjects

S Waldman

Publications and source records attributed to S Waldman.

47 records · Page 3Linked to original sources

Baroreceptors in preterm infants: their relationship to maturity and disease.

Using passive tipping to a 45 degrees head-up position, an attempt was made to elicit reflex vasoconstriction in 13 non-distressed preterm infants and 27 infants with hyaline membrane disease, all between 26 and 38 weeks gestation. An increase in vascular tone associated with a significant reduction in peripheral blood-flow was found in 11 of the 13 non-distressed infants, while the same response was lacking in 23 of the 27 distressed infants. No infant demonstrated significant tachycardia with tilting, and the non-distressed infants failed to maintain their mean aortic blood-pressure during tilting. The results suggest that reflex control of vascular tone is present in non-distressed infants as early as 26 weeks gestation, but not in infats with hyaline membrane disease, possibly because of a maximal increase in vascular tone as a response to illness. This is indicated by the findings of significantly higher resting peripheral vascular resistance and lower peripheral blood-flow in infants with this diesease.

Aging↗

Pulmonary function following feeding in low-birth-weight infants.

Determination of functional residual capacity, arterial gas tensions and pH, and arterial-alveolar differences was carried out in a group of nondistressed premature infants to determine if significant alterations in lung volumes or ventilation perfusion relationships sufficiently large to cause cyanosis could be detected after feeding. The only statistically significant changes observed in these parameters were immediately following feeding, a fall of .01 pH units and a fall of 6 mm Hg in arterial oxygen tension; and 15 minutes after feeding, a fall of .01 pH units and a rise in arterial PCO2 of 3 mm Hg. In addition, significant falls in peripheral blood flow were observed five minutes after feeding in association with marked elevations in peripheral vascular resistance. The mild impairment in pulmonary function in association with the more profound changes in limb blood flow are consistent with other studies in premature and full-term infants. These data suggest that cyanotic attacks following feeding may have a complex etiology and require an aggressive multisystem approach for adequate diagnosis and therapy.

Apnea↗

Noninvasive estimation of arterial oxygenation in newborn infants.

Two noninvasive methods of estimating arterial oxygenation were compared in a group of 48 infants ranging in birth weight from 870 to 4,000 gm, with diagnoses including apnea of prematurity, hyaline membrane disease, meconium aspiration, and congenital heart disease. Both transcutaneous oxygen measurements and ear oximetry gave reasonably accurate estimations of arterial oxygen levels within commonly used clinical ranges (PO2 50 to 70 mm Hg, arterial saturation 90 to 98%). Infants with shock demonstrated a wide range of values for transcutaneous oxygen levels, suggesting that this method has limited usefulness in this situation. Ear oximetry had limited ability to distinguish high, but safe, levels of arterial oxygen from excessively elevated levels. While neither method can be recommended for replacement of arterial oxygen sampling, both methods may be useful in a clinical setting if care is exercised in interpretation of the results and if the values obtained are checked against those from arterial blood.

Apnea↗

10. Issues in designing a national program of long-term care benefits.

This paper discusses a major policy area in long-term care--the design of a comprehensive national program of long-term care benefits--for which a broad base of information is needed. In the continuum of social welfare, a program for long-term care is veiwed as being in the middle ground between health care and income maintenance. Significant issues include the extent of coverage in terms of population groups and types of services, and the relative emphasis given to institutional care, to organized services enabling persons to remain in their homes, and to support of informal care from relatives and friends. Other considerations are methods of controlling costs and utilization, sharing of responsibility between federal and state governments, and establishement and enforcing of standards for providers of services. Two proposals introduced in the 93rd Congress illustrate current approaches to comprehensive long-term care benefits.

Costs and Cost Analysis↗

Skin reflectance in the newborn infant.

Skin reflectance in red, green, and blue light was measured at the sternum of 99 Caucasian infants ranging in gestational age from 26 to 44 weeks. Skin reflectance was consistently higher in female infants, but this difference was not statistically significant. Highly significant (P less than 0.001) increases in reflectance at all wave lengths were found when sternal reflectance during the first 48 hr of life was related to gestational age. The dispersion of data points about the regression line does not permit this method to be relied upon as the sole means of determining gestational age of infants. Serial studies indicate that reflectance increases in premature infants not given phototherapy, whereas premature infants receiving phototherapy show a fall in reflectance for the duration of therapy. This suggests that phototherapy may cause tanning of the skin.

Gestational Age↗