Biomedical subjects

D C Ray

Publications and source records attributed to D C Ray.

4 recordsLinked to original sources

PubMed1992

Effects of perceived responsibility on help-seeking decisions among elderly persons.

This study sought to clarify why elderly adults underutilize mental health services. One hundred ten elderly individuals were asked to imagine experiencing symptoms described in a vignette and to appraise their responsibility for the problem and for its solution, their willingness to seek help, and their preference among sources of help. Results indicated that perception of problems as either medical or psychological significantly affected how elders appraised responsibility. Although attributions were unrelated to help-seeking for medical problems, elderly persons feeling responsible for psychological problems were more likely to seek help for them. Perceived responsibility predicted the sources of help (e.g., social network, physicians, mental health workers) selected by elders who believed that their problems were medical, but not for problems thought to be psychological. A discussion of the reasons for their underutilization of mental health services is presented, with an emphasis on the practical implications of the results.

Aged↗

PubMed1991

Effect of adrenaline on plasma concentrations of bupivacaine following lower limb nerve block.

Twenty-two patients undergoing total knee arthroplasty received combined sciatic plus femoral "3 in 1" blocks as adjuncts to general anaesthesia. Eleven patients received 0.375% bupivacaine 45 ml (168.75 mg) with adrenaline 1 in 200,000 and the remaining 11 received plain solution according to a previously prepared, randomized list. The mean maximum plasma bupivacaine concentration was significantly greater with plain solution than when adrenaline was added (1.66 micrograms ml-1 compared with 0.98 micrograms ml-1) (P less than 0.05). Bupivacaine concentrations were greater at all times in the plain group compared with the group receiving adrenaline. These differences were statistically significant at 10, 15 and 20 min (P less than 0.05). The greatest peak concentration recorded was 3.13 micrograms ml-1 in one patient receiving plain bupivacaine. No patient developed signs of systemic toxic effects. Peak plasma concentrations were related inversely to body weight in patients receiving solution containing adrenaline (P less than 0.005), but no relationship existed in patients who received plain solution.

Adult↗

PubMed1991

Halothane hepatitis.

The historical background, clinical features, morphology, epidemiology and aetiology of halothane hepatitis have been presented. Animal models of halothane hepatotoxicity have been described, although their application to humans is of doubtful significance. Two, probably distinct, forms of liver damage associated with halothane have been identified. The much more common mild form may result from reductive biotransformation of halothane, possibly influenced by genetic factors, or reduced liver oxygenation, whereas the rare fulminant form is most likely to be immune-mediated. The role of altered calcium homeostasis has not yet been established. In addition, a common mechanism for liver dysfunction associated with halogenated volatile anaesthetic agents has been proposed. The hepatotoxicity of enflurane cannot be excluded; while hepatic dysfunction after isoflurane or nitrous oxide is considered unlikely, further attention is necessary. It is too soon to comment on the hepatotoxic potential of sevoflurane or desflurane.

Anesthesia, General↗

PubMed1990

A disposable blood pressure cuff. An assessment of its accuracy.

An empty 500-ml infusion bag was used as the cuff for a Lifestat 100 oscillotonometer. The systolic and mean blood pressures obtained in 40 subjects were not significantly different from those measured with a standard cuff. The diastolic pressure was unrelated between the two cuffs. The empty bag is a cheap and hygienic option in patients who present a high infection risk.

Blood Pressure↗