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Biomedical subjects

S Ross

Publications and source records attributed to S Ross.

At least 109 records · Page 6Linked to original sources
PubMed1998

The value of routine posttracheostomy chest radiography.

OBJECTIVE: This study proposes to evaluate the efficacy of routine posttracheostomy chest radiography. DESIGN: A retrospective chart review provided the framework of this study. SETTING: The study took place at a university teaching hospital-level one trauma center. PATIENTS: The study included 293 patients undergoing elective tracheostomy between 1989 and 1993. MEASUREMENTS AND RESULTS: Data extracted from the charts included indication for tracheostomy, immediate preoperative and postoperative chest radiograph reports, management changes made secondarily to radiographic findings, including chest tube placement, institution of chest physiotherapy, and need for tracheal tube reposition. Complications were defined as findings not noted on the preoperative radiographs; these were pneumothorax, tube malposition, atelectasis, or clinical information resulting in management changes. All patients received postoperative chest radiographs in the trauma ICU. Statistical analysis of our data was carried out using the chi2 test. Patients with chest tubes in place at the time of surgery were the only group who were excluded so as not to confuse whether pneumothorax developed postoperatively. Of the initial 293 patients, 25 patients were excluded on the basis of having a chest tube. The remaining 268 charts were analyzed; 220 (82%) patients underwent tracheostomy for ventilator-dependent respiratory failure, 31 (12%) due to multiple facial fractures, 6 (2.1%) secondary to penetrating neck wounds, and 11 (4%) as a result of refractory vocal cord edema. One (0.3%) patient was found to have a postoperative 10% apical pneumothorax. Eight (2.4%) patients were found to have postoperative subsegmental atelectasis. There were no significant (p>0.05) management changes implemented as a result of these findings. No new infiltrates, effusions, or malpositioned tubes were noted. Deletion of routine posttracheostomy radiographs would save $52.39 per patient (cost) or $15,350 for 293 patients and $35,453 in total patient charges. CONCLUSIONS: Abnormalities revealed by routine chest radiography after tracheostomy did not appear to alter patient management frequently enough to warrant the costs. A randomized, prospective study should be performed to analyze the safety of abandoning this practice.

Humans↗
PubMed1998

Computer use by general practitioners in Scotland.

BACKGROUND: Despite the widespread adoption by general practitioners (GPs) of desktop computers, there has been very little evaluation of the way in which the computer is actually used during consultations and the way in which it affects patient satisfaction. AIM: To ascertain the extent to which the computer is used in the consultation and to investigate the possible relationship between computer use and patient satisfaction. METHOD: Six GPs completed a short questionnaire about the extent to which they use the computer during surgeries. Eighty-four consultations from the surgeries of these GPs were video recorded. Patient satisfaction data on these 84 patients were collected at the time of the surgery using the previously validated Consultation Satisfaction Questionnaire. RESULTS: All six GPs stated that they usually used the computer during consultations. However, video observation revealed that the computer was used in just 51% of surgeries. The proportion of time that the computer was used for varied from 0.03 to 0.4, with a mean value of 0.12. The commonest function for which the computer was used was prescribing. The consultations in which the computer was used (CU) were on average 148 seconds longer than the non-computerized consultations (NCU). There was no difference in patient satisfaction between the two groups. CONCLUSION: Despite this group of GPs having a self-declared interest in the use of computers, the extent to which the computer was used was much lower than expected from the GPs' self-reported use. This may be partly explained by the fact that using the computer takes up valuable time within the consultation and does not appear to contribute to patient satisfaction. If desktop computers are to be used to their full potential in general practice, more work is required to evaluate their impact on the consultation process itself.

Adolescent↗
PubMed1998

Computer applications in dental diagnosis.

Formerly, computer applications in the dental office were restricted mainly to administration and organization. The revolutionary potential of digital applications does not halt at other fields, however. Besides applications in dental therapy, computerized methods have entered all levels of classic dental diagnosis: acquisition of findings, evaluation, and categorization. All three components have a new quality, worthy of being reevaluated if not redefined. New systems are described and evaluated in relation to relevant practice requirements, from both the practitioner's and the scientific clinician's points of view.

Databases as Topic↗
PubMed1998

What happens when doctors stop prescribing temazepam? Use of alternative therapies.

We investigated the withdrawal of temazepam in a single general practice using two alternative prescribing policies: an alternative benzodiazepine; or an alternative group of drugs recommended for short-term management of insomnia, including sedative antihistamines and chloral hydrate. The study showed that temazepam prescribing in general practice can be reduced or stopped by using a simple intervention. An alternative benzodiazepine is useful in helping patients to stop their use of hypnotic agents. The use of antihistamines as substitute hypnotics is not advocated on the basis of our findings.

Adult↗
PubMed1997

Troglitazone action is independent of adipose tissue.

We have investigated the antidiabetic action of troglitazone in aP2/DTA mice, whose white and brown fat was virtually eliminated by fat-specific expression of diphtheria toxin A chain. aP2/DTA mice had markedly suppressed serum leptin levels and were hyperphagic, but did not gain excess weight. aP2/DTA mice fed a control diet were hyperlipidemic, hyperglycemic, and had hyperinsulinemia indicative of insulin-resistant diabetes. Treatment with troglitazone alleviated the hyperglycemia, normalized the tolerance to intraperitoneally injected glucose, and significantly decreased elevated insulin levels. Troglitazone also markedly decreased the serum levels of cholesterol, triglycerides, and free fatty acids both in wild-type and aP2/DTA mice. The decrease in serum triglycerides in aP2/DTA mice was due to a marked reduction in VLDL- and LDL-associated triglyceride. In skeletal muscle, triglyceride levels were decreased in aP2/DTA mice compared with controls, but glycogen levels were increased. Troglitazone treatment decreased skeletal muscle, but not hepatic triglyceride and increased hepatic and muscle glycogen content in wild-type mice. Troglitazone decreased muscle glycogen content in aP2/DTA mice without affecting muscle triglyceride levels. The levels of peroxisomal proliferator-activated receptor gamma mRNA in liver increased slightly in aP2/DTA mice and were not changed by troglitazone treatment. The results demonstrate that insulin resistance and diabetes can occur in animals without significant adipose deposits. Furthermore, troglitazone can alter glucose and lipid metabolism independent of its effects on adipose tissue.

Adipose Tissue↗
PubMed1997

Patients with chronic fatigue syndrome and accurate feeling-of-knowing judgments.

Many Chronic Fatigue Syndrome (CFS) patients complain of memory impairments which have been difficult to document empirically. Subjective complaints of memory impairment may be due to a deficit in metamemory judgment. CFS patients and matched controls were tested with a computerized Trivia Information Quiz that required them to rate their confidence about correctly recognizing an answer in a multiple choice format that they had been unable to remember in a fact-recall format. Even though CFS patients reported significantly greater amounts of fatigue, cognitive, and physical symptoms, the accuracy of their confidence levels and recognition responses were similar to controls. This finding suggests that a metamemory deficit is not the cause of the memory problems reported by CFS patients.

Adult↗
PubMed1997

Caval occlusion alters the shape of the ischemic and nonischemic pressure-length loop.

OBJECTIVES: The effects of changes in preload on paradoxical myocardial wall motion during ischemia have been previously studied. However, the studies have been performed using slow volume changes. It was decided to study the effects of fast changes in preload, which would occur during caval occlusion, on the regional pressure-length loops during ischemia. DESIGN: Retrospective trial. SETTING: Experimental animal laboratory in a university medical center. PARTICIPANTS: Ten anesthetized adult dogs. INTERVENTIONS: In an open chest preparation, regional ischemia was achieved by occluding the left anterior descending coronary artery for 10 minutes, with sudden caval occlusions being performed to assess the influence of preload on wall motion. MEASUREMENTS AND MAIN RESULTS: Left ventricular pressure and regional segmental lengths were measured. During caval occlusion, beat by beat, percent postsystolic shortening and percent systolic bulging in the ischemic region, percent isovolumetric shortening in the nonischemic region, and percent systolic shortening in both regions were calculated. Caval occlusion significantly decreased the end-diastolic pressure (12.62 +/- 1.02 to 3.39 +/- 0.59 mmHg) and length. In the ischemic area, although systolic shortening became more negative (-1.8 +/- 0.79% to -9.65 +/- 1.08%), postsystolic shortening (9.66 +/- 0.73% to 15.53 +/- 1.2%) and systolic bulging (4.6 +/- 0.49% to 12.67 +/- 1.04%) increased. In the nonischemic area, systolic shortening decreased slightly but significantly (18.01 +/- 3.24% to 14.93 +/- 3.64%) as isovolumetric shortening increased (2.77 +/- 0.68 to 7.37 +/- 1.29%). Caval occlusion increased the rightward shift and accentuated the distortion of the ischemic loop. The nonischemic loop displayed a leftward shift of the systolic isovolumetric component and a slight decrease in percent total length change. CONCLUSION: Caval occlusion modifies the shape of the pressure-length loop of the ischemic myocardium. This change in shape may interfere with the assessment of regional systolic indexes obtained by caval occlusion in ischemic hearts.

Animals↗
PubMed1997

Studies on the mechanism underlying the antifibrillatory effect of the A1-adenosine agonist, R-PIA, in rat isolated hearts.

Previous studies in pigs have shown that the A1-adenosine receptor agonist, R-PIA, is a potent antifibrillatory agent during myocardial ischaemia and that this effect can be overriden by atrial pacing. However, reports of A1-adenosine receptor down-regulation following chronic exposure to A1-receptor agonists suggest that this may limit their use as potential antiarrhythmic therapy. The acute and chronic effects of R-PIA were examined on ventricular arrhythmias and hemodynamics in Langendorff-perfused rat isolated hearts subjected to acute regional myocardial ischemia in an attempt to confirm the heart rate dependency of the antifibrillatory mechanism of R-PIA and to assess the effects of chronic treatment on this protection. Acute challenge with R-PIA (10(-10) to 5 x 10(-8) M; n = 10 for all groups) produced a concentration-dependent bradycardia prior to coronary occlusion. Coronary artery occlusion in control hearts (n = 20) resulted in an immediate increase in perfusion pressure, from 61 +/- 6 to 87 +/- 7 mmHg within 5 minutes, followed by a gradual continued rise reaching a maximum of 123 +/- 9 mmHg by the end of the 30-minute experimental period. R-PIA significantly attenuated the sustained increase in perfusion pressure in a non-concentration-dependent manner. A concentration of 10(-10) M R-PIA had no effect on the incidence of ventricular fibrillation (VF), while all higher concentrations reduced the incidence of VF to a similar degree (from 60% in controls to 10%, 20%, 10%, and 0% with 10(-9), 5 x 10(-9), 10(-8), and 5 x 10(-8) M R-PIA, respectively). R-PIA also reduced the total ventricular premature beat (VPB) count, but in a concentration-dependent manner. Chronic treatment of the rats with R-PIA (50 microg/kg i.p., bd; n = 10) for 7 days caused a significant attenuation of the bradycardic response to acute perfusion in vitro with R-PIA (10(-8) M) and abolished the attenuation of the sustained rise in perfusion pressure during myocardial ischemia. The antifibrillatory effect of R-PIA, however, was unaffected by chronic pretreatment (VF incidence 0% vs. 70% in control hearts from rats that had been given chronic saline ip injections n = 10; P < 0.01). These results suggest that the bradycardia induced by acute R-PIA may not be the mechanism underlying the antifibrillatory effect of R-PIA, while the reduction in the less severe arrhythmias is heart rate dependent. Furthermore, while chronic treatment with R-PIA significantly attenuates the heart rate response to acute R-PIA challenge, the antifibrillatory properties remain intact.

Adenosine↗
PubMed1997

Value of early postoperative plain radiography following BOP fusion in cervical spinal surgery.

After anterior decompression and interbody fusion with biocompatible osteoconductive polymer (BOP) for cervical degenerative disease it is common practice to perform early radiography to evaluate the results, as a questionnaire sent to 136 consultants neurosurgeons in UK demonstrated. Radiographs of 39 patients following the procedure were analysed and it was concluded that the practice is of no value.

Biopolymers↗
PubMed1997

Beneficial effect of concomitant administration of isoflurane and nicorandil.

In common with halogenated anaesthetics, nicorandil, a new KATP channel opener, has been shown to have cardioprotective and vasodilator effects. Recent studies have also suggested that the vasodilator and protective effects of halogenated anaesthetics are mediated partly via KATP channel opening. This study examined the effects of concurrent administration of nicorandil and isoflurane on haemodynamic state and ventricular function before, during and after 15 min of ischaemia. We studied left ventricular function in 40 anaesthetized rabbits using ultrasonomicrometry. Measurements were obtained before, during and after 15 min of regional ischaemia. Regional ventricular function was assessed in terms of systolic shortening (SS%) and preload recruitable work area (PRWA, the area beneath the regional stroke work vs end-diastolic length relationship) during reperfusion. Four groups were studied: group F (n = 10) received a bolus dose of fentanyl 100 micrograms kg-1 and then 400 micrograms kg-1 h-1 throughout; group 1 (n = 10) received 2.05% end-tidal concentration of isoflurane (1 MAC); group FN (n = 10) received fentanyl, a bolus does of nicorandil 100 micrograms kg-1 and then 25 micrograms kg-1 min-1, 15 min before occlusion; and group IN (n = 10) received isoflurane and nicorandil. Isoflurane decreased left ventricular systolic pressure and ventricular contractility (+dP/dtmax, slope of preload recruitable stroke work, and SS%). Nicorandil increased -dP/dtmax in group FN. Post-ischaemic regional left ventricular contractility in group I did not differ from that in group F, however, groups receiving nicorandil recovered to a greater extent. Group IN showed better recovery compared with all other groups when ventricular contractility was assessed by PRWA normalized to pre-occlusion values (mean 99.3 (SEM 10.5)% vs 73.4 (7.5)%, 50.2 (5.8)% and 52.4 (3.7)% at 120 min reperfusion in groups FN, I and F, respectively). Tissue ATP and lactate contents did not differ between groups. We conclude that concurrent administration of nicorandil and isoflurane enhanced post-ischaemic recovery compared with isoflurane anaesthesia or nicorandil and fentanyl administration.

Adenosine Triphosphate↗
PubMed1997

Heterogeneity in intensive care units: fact or fiction?

Reports and guidelines concerning intensive care practice have been issued recently. However, the introduction of such centrally issued recommendations may be difficult because of marked heterogeneity between intensive care units. This study examined the facilities (number of beds, consultant sessions, nursing establishment), annual workload (number and types of patients admitted) and outcome (intensive care unit mortality) in the (old) Anglia Region. There were significant differences in the distribution of patients' ages, severities of illness, diagnoses, durations of admission and outcomes. Such heterogeneity may make multicentre trials more difficult to conduct and create problems when uniform measures designed to improve intensive care services are being planned.

APACHE↗
PubMed1997

Attitudes of general practitioners who practice in remote island communities.

OBJECTIVE: To describe the personal, social and medical attitudes of doctors who practice on the islands off the West coast of Scotland. DESIGN: Questionnaire survey with a single follow-up. SUBJECTS: All 65 general practitioners (GPs) who practice on the 17 islands located off the West coast of Scotland. RESULTS: Fifty-two (80%) responded after a single reminder. The main advantages identified were continuity of care, personal relationships with patients and involvement with the local community. Other important reasons were the opportunity to exercise clinical skills and appreciation of their local environment such as the beauty of the scenery. Disadvantages were associated with isolation, difficulty in obtaining cover, in attending refresher courses and the burden of sole responsibility. CONCLUSION: The GPs who practice in remote island practices believe that the advantages outweigh the disadvantages. They value continuity of care and their relationships with patients and communities. This survey suggests that the difficulties of staffing remote island communities may partly be addressed by allowing undergraduate students and postgraduate colleagues access to these general practitioners.

Adult↗