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R Widman

Publications and source records attributed to R Widman.

6 recordsLinked to original sources
PubMed1998

Transcranial cerebral oximetry in random normal subjects.

Near infrared optical spectroscopy is becoming a useful method for monitoring regional cerebral oxygenation status. The method is simple, reliable and noninvasive and the information which it provides is clinically significant in managing a growing number of neurological ailments. Use of this technique has been described previously by numerous authors. In the present study, regional cerebral oxygen saturation was measured at rest in 94 subjects randomly selected from a diverse population of individuals. This sample consisted of 38 males and 65 females (age range 18-70 years). There were 68 light-skinned individuals and 35 with darker skin comprising various ethnic and cultural backgrounds. Mean regional cerebral hemoglobin oxygen saturation was recorded as 67.14 +/- 8.84%. The association of the man regional cerebral hemoglobin oxygen saturation in various groups of individuals with relationship to their age, race, sex and skin color is examined.

Adolescent↗
PubMed1998

Cerebral oximetry--techniques.

The use of techniques to measure cerebral oxygen saturation is gradually gaining wide popularity. The main methods available today can mainly be classified as invasive or noninvasive. The invasive technology uses the parenchyma probes, which measure oxygen and biochemical parameters, depending upon the type of probe used. The noninvasive techniques use near infrared spectroscopy for transcranial cerebral oximetry. At present there is no universally accepted indication for the use of either technique but with time and wider use they are expected to become better understood. We discuss our experience and the techniques used in cerebral oximetry.

Brain↗
PubMed1996

The influence of carbon dioxide and body position on near-infrared spectroscopic assessment of cerebral hemoglobin oxygen saturation.

Near-infrared spectroscopy may allow continuous and noninvasive monitoring of regional brain hemoglobin oxygen saturation by measuring the differential absorption of infrared light by oxyhemoglobin and deoxyhemoglobin. We have previously examined the correlation between the spectroscopic signal generated by a prototype cerebral oximeter (Invos 3100; Somanetics, Troy, MI), and global brain hemoglobin oxygen saturation calculated from arterial and jugular venous bulb oxygen saturations. Because the technology does not distinguish between arterial and venous hemoglobin saturation, changes in the proportion of cerebral arterial and venous blood volume, which may result from changes in blood flow or venous distending pressure, may confound measurements. In eight conscious volunteers breathing hypoxic oxygen mixtures, we examined the influence of supine, 20 degrees Trendelenburg, and 20 degrees reverse Trendelenburg positions on the correlation of the spectroscopic measurement of cerebral oxygen saturation in the field assessed by the probe (CSfO2) and the calculated brain hemoglobin oxygen saturation (CScombO2), estimated as 0.25 x arterial saturation plus 0.75 x jugular venous bulb oxygen saturation. We found that changes in position did not influence the association between CSfO2 and CScombO2 (r2 = 0.69-0.885) during hypoxic challenge. In a second set of eight volunteers, we studied the influence of hypercapnia and hypocapnia and body position on the association between CSfO2 and CScombO2, and found that they were less well correlated (r2 = 0.366-0.976) in individual patients. Because changes in body position and Paco2 confound the relationship between CSfO2 and CScombO2, changes in CSfO2 can best be assessed if position and Paco2 are constant.

Adult↗
PubMed1996

Lead exposure of people with developmental disabilities: success of control measures.

In a developmental center, blood lead level was determined by atomic absorption for individuals who were admitted, discharged, or had pica. In 1977, blood lead level was 0 to 29 ug/dL in 298 (92%), 30 to 49 ug/dL in 20 (6%), and 50 to 79 ug/dL in 5 (2%) of the 323 individuals screened. In contrast, in 1994, blood lead level was 0 to 4 ug/dL in 58 (88%) and 5 to 9 ug/dL in 8 (12%) of 66 individuals screened. The observed marked decline in blood lead levels in this population has been the result of effective pica management, several local lead abatement measures, and reduced environmental lead contamination. Medical Practice Guidelines are suggested for prevention of lead poisoning in developmental centers.

Adolescent↗
PubMed1995

Parvovirus B19 outbreak in a developmental center.

Of 49 employees serving developmentally disabled persons, 13 (27%) were found to have parvovirus B19 infection on the basis of serum positivity for parvovirus B19 IgM by enzyme-linked immunosorbent assay. Two employees had severe peripheral symmetric polyarthropathy lasting longer than 6 months. Infection control measures are described.

Adult↗