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D Fields

Publications and source records attributed to D Fields.

8 recordsLinked to original sources
PubMed2002

Measurement of spin-transfer observables in p p-->Lambda Lambda at 1.637 GeV/c.

Spin-transfer observables for p p-->Lambda Lambda have been measured using a transversely polarized frozen-spin target and a beam momentum of 1.637 GeV/c. Current models of the reaction near threshold are in good agreement with existing measurements performed with unpolarized particles in the initial state but produce conflicting predictions for the spin-transfer observables Dnn and Knn (the normal-to-normal depolarization and polarization transfer), which are measurable only with polarized target or beam. Measurements of Dnn and Knn presented here are found to be in disagreement with predictions from these models.

Journal Article↗
PubMed1997

Awareness and perceptions of a hospital's closed-circuit TV channels.

Closed-circuit television (CCTV) programs are used in many hospitals for patient education and entertainment. However, few studies have addressed how patients perceive CCTV programs and whether the educational and entertainment objectives have been satisfied. We studied these questions by surveying patients from a major suburban teaching hospital. We found that when care providers recommended viewing, patients were more likely to watch and to perceive the programs as valuable.

Awareness↗
PubMed1996

Oliguria during laparoscopic surgery: evidence for direct renal parenchymal compression as an etiologic factor.

Abdominal insufflation during laparoscopy has been associated with transient oliguria, which abates after desufflation. Direct renal compression evoking a Page kidney effect was proposed as a mechanism. In an effort to confirm this theory, the left kidney was subjected to 15 mm Hg compression in six anesthetized mongrel dogs. For this, a pressure cuff was placed around the kidney excluding the renal hilar structures. The contralateral kidney was left untouched to serve as a control. After a steady-state period, the pressure cuff was inflated to 15 mm Hg for 2 hours. Cuff desufflation was followed by a 1-hour recovery period. Urine output, glomerular filtration rate (GFR), and effective renal blood flow (ERBF) were measured for both kidneys during each clearance period. For the treated kidneys, the mean urine output decreased 63% (P < 0.05) during compression and increased 109% (P < 0.05) after cuff desufflation. The GFR decreased 21% (P < 0.01) during compression and increased 25% (P < 0.05) during recovery. The ERBF decreased 26% (P < 0.05) during compression, and during the 1-hour recovery period, ERBF did not recover to baseline values. For the control kidneys, there were no significant changes in urine output or GFR during the experimental and recovery periods. These data support the view that direct renal parenchymal compression is an important factor in the development of insufflation-induced oliguria. The clinical implications of insufflation-induced oliguria during laparoscopy deserve further investigation.

Animals↗
PubMed1994

Clinical assessment of extrapyramidal signs in nursing home patients given antipsychotic medication.

BACKGROUND: We sought to quantify the relationship between antipsychotic drug use and clinical evidence of extrapyramidal dysfunction in a large population of elderly nursing home patients. METHODS: Subjects were 251 residents (mean age, 84.1 years; range, 65 to 105 years) who were taking psychoactive drugs in 12 long-term care facilities. Patient characteristics and all medication use (both scheduled and as needed) were measured during a 1-month observation period. We then performed neuropsychological and functional testing on residents who received any psychoactive medications during the study month. The presence of rigidity, bradykinesia, or masklike facies was assessed in each patient by a research assistant who was unaware of diagnoses and medication use. RESULTS: The parkinsonian signs studied were found in 127 (50.6%) of these residents. Using logistic regression modeling to adjust for potential confounding, we found this outcome to be increased more than threefold in patients who took low-potency neuroleptics (odds ratio [OR], 3.49 for > or = 50 mg/d of chlorpromazine-type drugs; 95% confidence interval [CI], 1.28 to 9.57) and more than sixfold for use of 1 mg/d or more of haloperidol (OR, 6.42; 95% CI, 2.16 to 19.04). Age, gender, and use of nonneuroleptic psychoactive drugs were not associated with an increase in parkinsonian signs. CONCLUSIONS: Clinical evidence of extrapyramidal dysfunction is three to six times more common in institutionalized elderly patients given antipsychotic medication than in comparable patients not using such drugs. Its risk is substantially increased even in patients given low-potency chlorpromazine-type drugs, as well as those taking haloperidol. The effect is not explained by age or mental status and is not seen with other psychoactive medications. The expected frequency of parkinsonian symptoms can help to inform the balancing of risks vs therapeutic effect when the use of all drugs in this class is considered.

Aged↗
PubMed1992

A randomized trial of a program to reduce the use of psychoactive drugs in nursing homes.

BACKGROUND: Although psychoactive medications have substantial side effects in the elderly, these drugs are used frequently in nursing homes. Few interventions have succeeded in changing this situation, and little is known about the clinical effects of such interventions. METHODS: We studied six matched pairs of nursing homes; at one randomly selected nursing home in each pair, physicians, nurses, and aides participated in an educational program in geriatric psychopharmacology. At base line we determined the type and quantity of drugs received by all residents (n = 823), and a blinded observer performed standardized clinical assessments of the residents who were taking psychoactive medications. After the five-month program, drug use and patient status were reassessed. RESULTS: Scores on an index of psychoactive-drug use, measuring both the magnitude and the probable inappropriateness of medication use, declined significantly more in the nursing homes in which the program was carried out (experimental nursing homes) than in the control nursing homes (decrease, 27 percent vs. 8 percent; P = 0.02). The use of antipsychotic drugs was discontinued in more residents in the experimental nursing homes than in the control nursing homes (32 percent vs. 14 percent); the comparable figures for the discontinuation of long-acting benzodiazepines were 20 percent vs. 9 percent, and for antihistamine hypnotics, 45 percent vs. 21 percent. In the experimental nursing homes residents who were initially taking antipsychotic drugs showed less deterioration on several measures of cognitive function than similar residents in the control facilities, but they were more likely to report depression. Those who were initially taking benzodiazepines or antihistamine hypnotic agents reported less anxiety than controls but had more loss of memory. Most other measures of clinical status remained unchanged in both groups. CONCLUSIONS: An educational program targeted to physicians, nurses, and aides can reduce the use of psychoactive drugs in nursing homes without adversely affecting the overall behavior and level of functioning of the residents.

Aged↗
PubMed1992

Cardiovascular responses to phlebotomy and sitting in middle-aged and elderly subjects.

BACKGROUND: Responding appropriately to hypotensive challenges is an important determinant of health and functional independence in elderly individuals. Cardiovascular responses to phlebotomy and postural change were evaluated using a large database developed in a study designed to establish the safety of blood donation by older individuals. METHODS: The groups studied included 464 subjects aged 65 years and younger (range, 52 to 65 years) and 532 subjects more than 65 years old (range, 66 to 78 years old). Blood pressure and pulse rate measurements were followed by the withdrawal of 500 mL of blood. These measurements were repeated, first in the supine and then in the sitting position. RESULTS: Nearly all individuals studied remained hemodynamically stable after these two challenges. Age was not an independent predictor of blood pressure change after either phlebotomy or postural change. Large decreases in diastolic blood pressure were equally rare in both age groups. However, more older subjects (15.2%) exhibited a decline of 20 mm Hg or more in systolic blood pressure following phlebotomy, compared with the middle-aged group (6.9%). These age-related differences did not persist after controlling for the higher initial systolic blood pressures observed in the older subjects. Postphlebotomy postural change to the sitting position had little additional effect. CONCLUSIONS: These results indicate that the ability to respond to hypovolemia and postural change remains relatively intact in healthy elderly individuals. The higher prevalence of a significant drop in systolic blood pressure after phlebotomy, orthostasis, and possibly other homeostatic challenges in older subjects is probably due to the presence of higher basal blood pressure readings, including hypertension. In spite of these differences, blood donation is appropriate and should be encouraged in healthy elderly individuals in this age group.

Aged↗