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Biomedical subjects

R S Wilson

Publications and source records attributed to R S Wilson.

At least 91 records · Page 5Linked to original sources
PubMed1997

The effects of endobronchial cuff inflation on double-lumen endobronchial tube movement after lateral decubitus positioning.

OBJECT: This study was designed to measure changes in tracheal and bronchial lumen distances from mainstem and secondary carina with lateral positioning, and to assess whether inflation of the endobronchial cuff before lateral positioning would further secure a double-lumen endobronchial tube (DLT) and reduce movement. DESIGN: Prospective study. SETTING: University-affiliated cancer center. PARTICIPANTS: Fifty adult patients scheduled for elective thoracic surgical procedures requiring the placement of a left DLT. INTERVENTIONS: Patients were sequentially assigned to either the endobronchial cuff-inflated group or the deflated group during lateral positioning. After induction of general anesthesia, a left polyvinylchloride (PVC) DLT was placed and the position confirmed. In the supine position, the distance from the tip of the tracheal lumen to main carina was measured using a fiberoptic bronchoscope (FOB) passed through the tracheal lumen, and the distance from the bronchial lumen to secondary carina was measured with the FOB passed through the bronchial lumen. The patients were then positioned laterally and a second set of measurements taken. Overall movement was determined by increases and decreases in tracheal and bronchial distances obtained by substracting supine values from lateral values. MEASUREMENTS AND MAIN RESULTS: There was significant tracheal movement in 40 of 50 patients, with a mean of 0.92 +/- 1.0 cm. This was predominantly in the upward direction, as seen in 35 of 50 patients. There was significant bronchial movement in 37 of 50 patients, with a mean of 0.92 +/- 1.15 cm. Also, predominance in the upward direction was seen in 34 of 50 patients. CONCLUSIONS: DLTs move with lateral positioning, regardless of endobronchial cuff inflation. The movement is predominantly in the upward direction. Therefore, fiberoptic visualization in the supine position should be used only to confirm that the endobronchial lumen is placed on the appropriate side and the cuff is at least 1 cm inside the left mainstem bronchus. Final positioning should always be verified in the lateral position.

Adult↗
PubMed1997

Sources of priming in text rereading: intact implicit memory for new associations in older adults and in patients with Alzheimer's disease.

The contributions of text meaning, new between-word associations, and single-word repetition to priming in text rereading in younger and older adults, and in patients with Alzheimer's disease. (AD), were assessed in Experiment 1. Explicit recognition memory for text was also assessed. Equivalent single-word and between-word priming was observed for all groups, even though patients with AD showed impaired explicit memory for individual words in the text. The contribution of generalized reading task skill to priming in meaningless text rereading in younger adults was assessed in Experiment 2. Generalized reading task skill was also found to contribute to priming. These results reveal 3 mechanisms of priming: new between-word associations for meaningful and meaningless text, individual word repetition for meaningless text, and general task or skill factors for meaningless text. All priming mechanisms appear to be intact in older adults and in patients with AD.

Adult↗
PubMed1997

Criterion-related validity of the Geriatric Depression Scale in Alzheimer's disease.

The effect of cognitive impairment on the criterion-related validity of the self-report Geriatric Depression Scale (GDS) was investigated in community-dwelling older adults. The GDS was administered to subjects with Alzheimer's disease (AD; n = 715) and normal cognitive function (NC; n = 93). The criteria consisted of the diagnosis of major depressive disorder and the total score on Hamilton Rating Scale for Depression, each derived from structured interview with a collateral informant to circumvent the effect of cognitive impairment on criterion measurement. Agreement between the GDS and both criteria was substantially attenuated in AD relative to NC subjects, differences primarily reflecting a lower than expected rate of item endorsement on the GDS in AD. A decrement in GDS validity coefficients was measurable across a broad range of cognitive impairment, suggesting limited utility of the scale in AD.

Aged↗
PubMed1997

Psychotic symptoms and physically aggressive behavior in Alzheimer's disease.

OBJECTIVE: To examine the relationship between psychotic symptoms and subsequent physically aggressive behavior in outpatients with Alzheimer's disease. DESIGN: This observational study used a time series design to measure the presence and frequency of physically aggressive behavior over a 52-week period. Multiple regression models were used to evaluate delusions and hallucinations, assessed at baseline, as predictors of physical aggression, controlling for demographic and clinical variables. SETTING AND PARTICIPANTS: Of 315 consecutive eligible outpatients from the Rush Alzheimer's Disease Center, referred for evaluation for dementia, 270 (86%) participated in the study. All participants met NINCDS/ADRDA criteria for probable Alzheimer's disease; Mini-Mental State Examination scores ranged from 0 to 27, with a mean of 14.9 (SD = 5.6). MEASUREMENTS: Psychotic symptoms, previous episodes of physical aggression, and demographic variables were measured at baseline through a structured interview with an informant living in the same household. Physically aggressive behavior was measured sequentially at 1-week intervals over a period of 52 consecutive weeks and also through structured informant interviews. RESULTS: A total of 75 persons had one or more episodes of physical aggression during the 52 weeks of observation. The presence of delusions significantly predicted the presence and frequency of physical aggression. Of participants with high rates of physical aggression (> 1 episode/month), 80% had delusions. This effect was robust, even after controlling for the effects of other clinical variables. By contrast, hallucinations did not reliably predict episodes of physical aggression. CONCLUSIONS: These data suggest that delusions, but not hallucinations, predict physically aggressive behavior in persons with Alzheimer's disease. In light of the persecutory nature of most delusional ideation in Alzheimer's disease, delusions may be associated with distortions in the perception of threat in common social situations.

Aged↗
PubMed1997

Running a domiciliary nebuliser service.

A nebuliser service should be provided locally, according to local needs. It should be centralised and administered by a designated consultant or consultants and written guidelines should be provided for medical and para-medical staff. The service should: (1) provide compressor/nebuliser units suitable for the prescribed treatment, (2) provide a system for equipment replacement, repair and maintenance, and (3) show patients how to use the equipment and give them comprehensive written instructions.

Costs and Cost Analysis↗
PubMed1997

Metric properties of nurses' ratings of parkinsonian signs with a modified Unified Parkinson's Disease Rating Scale.

We evaluated the ability of nurse clinicians to assess parkinsonian signs in older persons with a modified version of the motor section of the Unified Parkinson's Disease Rating Scale (UPDRS). After completing a structured training protocol, three nurse clinicians and a neurologist with expertise in movement disorders administered a modified UPDRS to 75 older persons. The nurses repeated the assessment about 3 weeks later. Inter-rater agreement and short-term temporal stability were estimated for each item, the total modified UPDRS score, and for summary measures of bradykinesia, postural reflex impairment, rigidity, and tremor, and a global parkinsonian sign score. We performed our assessment in Catholic religious communities in the Chicago area, using consecutive subjects at four communities participating in the Religious Orders Study, a longitudinal, clinical-pathologic study of older persons. Our results showed that nurses were not a significant source of variability, with intraclass correlations exceeding 0.97 for all items, and they showed good to excellent agreement with the neurologist for most modified UPDRS items. Correlations between nurses and neurologist exceeded 0.90 for the total modified UPDRS, ranged from 0.76 to 0.95 for the four parkinsonian domain scores, and exceeded 0.90 for the global parkinsonian sign score. Nurses showed fair to good agreement with themselves over the 3-week interval for most modified UPDRS items. Correlations over the 3-week interval exceeded 0.90 for the total modified UPDRS score, ranged from 0.70 to 0.95 for the four domain scores, and exceeded 0.90 for the global parkinsonian sign score. Ratings of parkinsonian signs by nurse clinicians corresponded closely to those of a neurologist with expertise in movement disorders and showed good inter-rater agreement and temporal stability. With appropriate training, nurse clinicians can reliably administer the modified UPDRS.

Aged↗
PubMed1997

Lung isolation. Tube design and technical approaches.

Airway management for thoracic surgery frequently requires isolation of a portion of the respiratory system. In some circumstances lung isolation is mandatory and in others elective. Several techniques utilizing specialized endotracheal tubes and blockers are currently available. There are specific advantages and complications associated with each that, in part, determine optimal outcome in this specialized group of surgical patients.

Anesthesia↗
PubMed1997

Does the lens diameter increase or decrease during accommodation? Human accommodation studies: a new technique using infrared retro-illumination video photography and pixel unit measurements.

PURPOSE: To describe a new technique for viewing and measuring the lens diameter during accommodation. METHODS: The accommodative lens activity, in a young female carrier of ocular albinism, was evaluated using retro-illumination infrared video photography and pixel unit measurements. RESULTS: Right and left lens diameter measurements were 498 pu and 501 pu, respectively, during natural accommodation. In pharmacologic non-accommodation (Tropicamide), the average lens diameter was 524 pu (range 518-528) while in accommodation (Pilocarpine), the average lens diameter was 485 pu (range 479-491). CONCLUSIONS: Right and left lens measurements were essentially identical. All measurements were reliable, repeatable and extremely accurate. The lens diameter consistently reduced during accommodation and enlarged during non-accommodation. The theories, similar to Tscherning's, which imply that the lens diameter increases in accommodation, are clearly disproven.

Accommodation, Ocular↗
PubMed1996

Value of perioperative Doppler echocardiography in patients undergoing major lung resection.

BACKGROUND: The effects of major lung resection on right heart function have not been well established. Our goal was to evaluate these effects using serial Doppler echocardiography in the perioperative period. METHODS: In 86 patients undergoing lobectomy (n = 47) and pneumonectomy (n = 39), we examined the effects of pulmonary resection on perioperative changes in right heart function by transthoracic echocardiography. Serial echocardiograms were performed preoperatively, on postoperative day 1, and again between postoperative days 2 and 6 (median, 3 days) to evaluate cardiovascular function and to estimate right ventricular systolic pressure by the tricuspid regurgitation jet Doppler velocity method. RESULTS: Right or left atrial size, right atrial pressure, and estimated right ventricular systolic pressure did not differ between groups on the preoperative or postoperative day 1 examinations. However, on postoperative days 2 through 6 patients who underwent pneumonectomy had higher (mean +/- standard deviation) right ventricular systolic pressure values than lobectomy patients (31 +/- 15 versus 25 +/- 10 mm Hg, respectively; p < 0.05 by analysis of variance). In the subset of patients with percent predicted forced expiratory volume in 1 second less than 60% undergoing pneumonectomy (9/39), preoperative right ventricular systolic pressure was inversely correlated with percent predicted forced expiratory volume in 1 second values (r = -0.78; p < 0.04). This correlation was not significant in corresponding lobectomy patients. Postoperative right ventricular enlargement determined by echocardiography occurred with similar frequency in both groups and was associated with poor short-term prognosis in patients in whom severe respiratory failure developed. CONCLUSIONS: Preoperative indices of right heart function were within the normal range in both groups. Pneumonectomy but not lobectomy was associated with mild postoperative pulmonary hypertension that was not accompanied by significant right ventricular systolic dysfunction. Postoperative echocardiography may be useful to evaluate right heart function in critically ill patients after lung resection.

Adult↗
PubMed1995

Elastin fibers and the diagnosis of bacterial pneumonia in the adult respiratory distress syndrome.

OBJECTIVE: It has been inferred from previous work that 40% potassium hydroxide preparations of lower respiratory tract secretions that demonstrate elastin fibers have a 100% specificity and positive predictive value in diagnosing bacterial pneumonia in intubated, mechanically ventilated patients without the adult respiratory distress syndrome (ARDS). Our aim was to assess the specificity of 40% potassium hydroxide preparations in diagnosing bacterial pneumonia in patients with ARDS and suspected pneumonia. DESIGN: Prospective, case-referral clinical study. SETTING: Referral hospital. PATIENTS: Of 24 patients with ARDS who were intubated and mechanically ventilated with suspected bacterial pneumonia, 22 were assessable and evaluated for this report. INTERVENTIONS: Tracheo-bronchial aspirates were obtained from all patients and analyzed for elastin fibers using 40% potassium hydroxide. MEASUREMENTS AND MAIN RESULTS: Of the 22 assessable patients, ten patients did not have a complicating bacterial pneumonia. Six of these ten patients had potassium hydroxide preparations that demonstrated elastin fibers (false positives). The other four patients had preparations that did not demonstrate elastin fibers (true negatives). Specificity was 40%. CONCLUSION: Elastin fiber preparations are not specific for diagnosing bacterial pneumonia in patients with ARDS.

Adult↗