PubMed Health⌕ Search

Biomedical subjects

D Cook

Publications and source records attributed to D Cook.

At least 91 records · Page 5Linked to original sources
PubMed1999

Evaluating the performance of academic medical education administrators.

Educators have devoted little attention to formal evaluation of educational administrative personnel. The authors surveyed the educational administrators working in McMaster University's Department of Medicine residency program and found they felt they were receiving little useful feedback. The authors also surveyed the colleagues, residents, and administrative staff with whom the administrators worked and found they felt they had inadequate input into the administrators' evaluation. In response to these results, a measurement instrument was developed based on existing job descriptions and feedback was obtained on administrators' performance from relevant individuals. After three yearly evaluations, administrators and evaluators acknowledged much broader input into evaluation but saw little evaluation-related improvement in performance. Of the administrators, 85% felt the process should continue as did 91% of the evaluators. An evaluation process may not alter perceived performance when it is already good but there may be other benefits to rigorous evaluation.

Attitude of Health Personnel↗
PubMed1999

Aniseikonia.

Explore the source record for details and available documents.

Aniseikonia↗
PubMed1998

Novel mechanism by which hemoglobin induces constriction of cerebral arteries.

Since oxyhemoglobin (OxyHb) is implicated in the pathogenesis of cerebral vasospasm, we have investigated the role of protein tyrosine phosphorylation in OxyHb-mediated signalling in canine cerebral arteries and cultured canine cerebrovascular smooth muscle cells. OxyHb produced a contraction of basilar artery preparations, which was reversed by genistein, an inhibitor of tyrosine kinases, and PD098059, an inhibitor of mitogen-activated protein kinase. In cerebrovascular smooth muscle cells, OxyHb induced tyrosine phosphorylation of 42, 46, 54-60 and 80-100 kDa proteins with a time-course which paralleled the contractile action of OxyHb, suggesting that these events might be functionally linked. The 42 and 60 kDa proteins were immunologically related to the mitogen-activated protein kinase, extracellular signal regulated protein kinase (ERK2), and to p60c-Src (c-Src), respectively. The increase in protein tyrosine phosphorylation was attenuated by genistein, and the phosphorylation of the 42 kDa protein (ERK2) was inhibited by PD098059. These results suggest that OxyHb-mediated signalling utilizes a protein tyrosine kinase-based mechanism.

Animals↗
PubMed1998

Diagnosis of cytomegalovirus infection in HIV-infected patients with respiratory disease.

BACKGROUND: The role of the cytomegalovirus (CMV) in the respiratory morbidity and mortality of HIV-infected patients remains unclear. This is due in part to difficulties in making an accurate and rapid diagnosis. There has been a limited number of studies, often with few or no AIDS patients, on the use of DNA-DNA in situ hybridization (ISH) and polymerase chain reaction to diagnose CMV respiratory infection directly on bronchoalveolar fluid samples. OBJECTIVES: To compare the centrifugation culture (CC), ISH, and nested-primer polymerase chain reaction (npPCR) techniques (npPCR) techniques on bronchoalveolar fluid for the diagnosis of respiratory CMV infection. STUDY DESIGN: Samples were obtained prospectively from a group of 35 HIV-infected homosexual men evaluated for pneumonia at a university hospital. Sensitivity, specificity, and predictive values of the three techniques were measured and compared, using the conventional roller tube cell culture (CRTC) as the gold standard. RESULTS: Sensitivity, specificity, positive and negative predictive values were as follows: 86%, 86%, 90%, and 80% for the CC; 5%, 100%, 100%, and 41% for ISH; and 86%, 57%, 75%, and 73% for npPCR. Of the six false positive samples by npPCR, two were positive by CC (none by ISH). If the latter were considered true positives, the specificity and positive predictive values of npPCR would increase to 67% and 83%, respectively. CONCLUSIONS: CC appeared to be the best of the three techniques compared in this study for diagnosis of respiratory CMV infection in HIV-infected patients. The sensitivity and predictive values of DNA-DNA ISH were very poor. Results with npPCR were acceptable, and this technique may be considered in situations when rapid diagnosis of CMV infection is necessary.

AIDS-Related Opportunistic Infections↗
PubMed1998

Does this patient have deep vein thrombosis?

OBJECTIVE: To review the validity of the clinical assessment and diagnostic tests in patients with suspected deep vein thrombosis (DVT). METHODS: A comprehensive review of the literature was conducted by searching MEDLINE from 1966 to April 1997. RESULTS: Individual symptoms and signs alone do not reliably predict which patients have DVT. Overall, the diagnostic properties of the clinical examination are poor; the sensitivity of the clinical examination ranges from 60% to 96%, and the specificity ranges from 20% to 72%. However, using specific combinations of risk factors, symptoms, and physical signs for DVT, clinicians can reliably stratify patients with suspected DVT into low, moderate, or high pretest probability categories of actually suffering from DVT. This stratification process in combination with noninvasive testing, such as compression ultrasonography, simplifies the management strategies for patients with suspected DVT. CONCLUSIONS: Use of a clinical prediction guide that includes specific factors from both the history and physical examination in combination with noninvasive tests simplifies management strategies for patients with suspected DVT.

Decision Trees↗
PubMed1998

A comparison of sucralfate and ranitidine for the prevention of upper gastrointestinal bleeding in patients requiring mechanical ventilation. Canadian Critical Care Trials Group.

BACKGROUND: Critically ill patients who require mechanical ventilation are at increased risk for gastrointestinal bleeding from stress ulcers. There are conflicting data on the effect of histamine H2-receptor antagonists and the cytoprotective agent sucralfate on rates of gastrointestinal bleeding, ventilator-associated pneumonia, and mortality. METHODS: In a multicenter, randomized, blinded, placebo-controlled trial, we compared sucralfate with the H2-receptor antagonist ranitidine for the prevention of upper gastrointestinal bleeding in 1200 patients who required mechanical ventilation. Patients received either nasogastric sucralfate suspension (1 g every six hours) and an intravenous placebo or intravenous ranitidine (50 mg every eight hours) and a nasogastric placebo. RESULTS: The patients in the two groups had similar base-line characteristics. Clinically important gastrointestinal bleeding developed in 10 of 596 (1.7 percent) of the patients receiving ranitidine, as compared with 23 of 604 (3.8 percent) of those receiving sucralfate (relative risk, 0.44; 95 percent confidence interval, 0.21 to 0.92; P=0.02). In the ranitidine group, 114 of 596 patients (19.1 percent) had ventilator-associated pneumonia, as compared with 98 of 604 (16.2 percent) in the sucralfate group (relative risk, 1.18; 95 percent confidence interval, 0.92 to 1.51; P=0.19). There was no significant difference between the groups in mortality in the intensive care unit (ICU) (23.5 percent in the ranitidine group and 22.9 percent in the sucralfate group) or the duration of the stay in the ICU (median, nine days in both groups). CONCLUSIONS: Among critically ill patients requiring mechanical ventilation, those receiving ranitidine had a significantly lower rate of clinically important gastrointestinal bleeding than those treated with sucralfate. There were no significant differences in the rates of ventilator-associated pneumonia, the duration of the stay in the ICU, or mortality.

Aged↗
PubMed1998

Influence of airway management on ventilator-associated pneumonia: evidence from randomized trials.

OBJECTIVE: Ventilator-associated pneumonia (VAP) is a serious complication of critical illness, conferring increased morbidity and mortality. Many interventions have been studied to reduce the risk of VAP. We systematically reviewed the influence of airway management on VAP in critically ill patients. DATA SOURCES: Studies were identified through searching MEDLINE and EMBASE from 1980 through July 1997 and by searching SCISEARCH, the Cochrane Library, bibliographies of primary and review articles, personal files, and contact with authors of the randomized trials. STUDY SELECTION: We selected randomized trials evaluating ventilator circuit and secretion management strategies on the rate of VAP. DATA EXTRACTION: Two investigators independently abstracted key data on design features, the population, intervention, and outcome of the studies. DATA SYNTHESIS: The frequency of ventilator circuit changes and the type of endotracheal suction system do not appear to influence VAP rates (3 trials, none with significant difference; range of relative risks [RRs], 0.84-0.91). However, lower VAP rates may be associated with avoidance of heated humidifiers and use of heat and moisture exchangers (5 trials, only 1 showing a significant difference; range of RRs, 0.34-0.86), use of oral vs nasal intubation (1 trial; RR, 0.52; 95% confidence interval, 0.24-1.13), subglottic secretion drainage vs standard endotracheal tubes (2 trials, 1 showing a significant difference; range of RRs, 0.46-0.57), and kinetic vs conventional beds (5 trials, only 1 showing a significant difference; range of RRs, 0.35-0.78). CONCLUSIONS: Some ventilator circuit and secretion management strategies may influence VAP rates in critically ill patients. Whether these strategies are adopted in practice depends on several factors such as the magnitude and precision of estimates of benefit and harm, as well as access, availability, and costs.

Critical Illness↗
PubMed1998

Acquired neuromuscular disorders in critically ill patients: a systematic review. Groupe de Reflexion et d'Etude sur les Neuromyopathies En Reanimation.

OBJECTIVE: To summarize the prospective clinical studies of neuromuscular abnormalities in intensive care unit (ICU) patients. STUDY IDENTIFICATION AND SELECTION: Studies were identified through MEDLINE, EMBASE, references in primary and review articles, personal files, and contact with authors. Through duplicate independent review, we selected prospective cohort studies evaluating ICU-acquired neuromuscular disorders. DATA ABSTRACTION: In duplicate, independently, we abstracted key data regarding design features, the population, clinical and laboratory diagnostic tests, and clinical outcomes. RESULTS: We identified eight studies that enrolled 242 patients. Inception cohorts varied; some were mechanically ventilated patients for > or = 5 days, others were based on a diagnosis of sepsis, organ failure, or severe asthma while others were selected on the basis of exposure to muscle relaxants, or because of participation in muscle biochemistry studies. Weakness was systematically assessed in two of the eight studies, concerning patients with severe asthma, with a reported frequency of 36 and 70%, respectively. Electrophysiologic and histologic abnormalities consisted of both peripheral nerve and muscle involvement and were frequently reported, even in non-selected ICU patients. In a population of patients mechanically ventilated for more than 5 days, electrophysiologic abnormalities were reported in 76 % of cases. Two studies showed a clinically important increase (5 and 9 days, respectively) in duration of mechanical ventilation and a mortality twice as high in patients with critical illness neuromuscular abnormalities, compared to those without. CONCLUSIONS: Prospective studies of ICU-acquired neuromuscular abnormalities include a small number of patients with various electrophysiologic findings but insufficiently reported clinical correlations. Evaluation of risk factors for these disorders and studies examining their contribution to weaning difficulties and long-term disability are needed.

Adult↗
PubMed1998

Adjudicating ventilator-associated pneumonia in a randomized trial of critically ill patients.

PURPOSE: The purpose of this study was to evaluate an adjudication strategy for diagnosing ventilator-associated pneumonia (VAP) in a randomized trial. MATERIALS AND METHODS: In a double-blind trial of sucralfate versus ranitidine, one of four pairs of adjudicators examined each case of clinically suspected VAP. Nurse and physician notes and all relevant laboratory data were allocated to each adjudication pair in groups of five patients. Each reader in the pair decided whether the patient had VAP; differences were resolved by consensus discussion. RESULTS: The overall unadjusted study odds ratio for VAP was 0.82 (P = .21) representing a trend toward less pneumonia with sucralfate compared with ranitidine. The odds ratio adjusted for adjudication pair was 0.85 (P = .27). The proportion of charts adjudicated as VAP positive among pairs ranged from 50% to 92%; crude agreement between readers in each pair varied from 50% to 82%. When adjudicators disagreed, the final consensus was split evenly between the two adjudicators' initial opinions in two pairs; in the other two pairs, the final decision reflected one dominant initial opinion. Personnel time to adjudicate all patients with a suspicion of VAP was 74 days. CONCLUSIONS: Though adjudication of outcomes such as VAP is time-consuming, consistent decision-making requires strict criteria, training, and calibration. Patients should be assigned to adjudication teams through random allocation.

Anti-Ulcer Agents↗
PubMed1998

The mechanism by which aminoglycoside antibiotics cause vasodilation of canine cerebral arteries.

The effects of aminoglycoside antibiotics were examined in canine cerebral arteries and in cultured cerebrovascular smooth muscle cells stimulated with oxyhemoglobin (OxyHb), a blood constituent which has been implicated in the pathogenesis of cerebrovascular spasm. In cerebral arterial rings precontracted with OxyHb (10 microM), the aminoglycosides caused a concentration-dependent decrease in isometric tension. The EC50s for the relaxation were 0.46+/-0.1 mM (n=6), 0.53+/-0.08 mM (n=12), 1.6+/-0.3 mM (n=7) and 3.9+/-0.5 mM (n=5) for neomycin, gentamicin, streptomycin and kanamycin, respectively. This order of potency corresponds approximately to the number of positive charges in the molecules. The aminoglycosides also inhibited the contractions to prostaglandin F2alpha (1 microM) and depolarizing concentrations of potassium chloride (60 mM). The order of potency was neomycin > gentamicin > streptomycin > kanamycin. The relaxation was maintained in vascular preparations denuded of endothelium. Neomycin (5 mM) abolished the Ca2+-independent contraction to PGF2alpha. In Fura-2-loaded cerebrovascular smooth muscle cells, OxyHb (1 microM) significantly enhanced the concentration of intracellular calcium ([Ca2+]i) by 330%. The administration of neomycin, gentamicin, kanamycin and streptomycin in concentrations corresponding to the EC50 from contractility studies, reduced the effects of OxyHb on [Ca2+]i by about 50% to 221+/-35 nM (n=7), 270+/-31 nM (n=7), 229+/-33 nM (n = 6) and 240+/-6 nM (n = 5), respectively. These results suggests that the effects of the aminoglycosides on the OxyHb-induced contraction and the long-term increase in [Ca2+]i, may arise from several effects, including inhibition of PLC, protection of calcium extrusion mechanisms, and interference with the process of [Ca2+]i accumulation.

Animals↗
PubMed1998

Screening for atrial fibrillation in primary care.

OBJECTIVE: To investigate a population of elderly people for atrial fibrillation and to determine how many of the cases identified might benefit from treatment with anticoagulants. METHODS: From a practice of four primary care physicians, 1422 patients aged 65 years and over were identified, of whom 1207 (85% of the total population) underwent electrocardiographic screening to detect the presence of atrial fibrillation. Patients with the arrhythmia were further evaluated by echocardiography and interview, to stratify their risk of stroke based on echocardiographic and clinical risk factors, their perceived risk from anticoagulation, and their attitude towards this treatment. Their primary care physician was also interviewed to determine the factors influencing the prescription of anticoagulants. RESULTS: The arrhythmia occurred in 65 patients (5.4% overall), its prevalence increasing markedly with age (2.3% in 65 to 69 years age group; 8.1% in those over 85). Warfarin was being prescribed to 21.4% of these patients, although the findings of the study indicate that a further 20% were eligible for this treatment. Symptoms suggestive of cardiac failure were common (32.1%) and coexisting pathology was often identified by cardiac ultrasound in these patients (left ventricular hypertrophy, 32.1%; impaired left ventricular contractility, 21.4%; left atrial dilation, 80.4%; mitral annular calcification, 42.9%; mitral stenosis, 7.1%; mitral regurgitation, 48.2%; aortic stenosis, 8.9%). In all but one case, the decision to anticoagulate was based on the clinical rather than the echocardiographic findings. CONCLUSIONS: Individual risk-benefit assessment in elderly patients with atrial fibrillation suggests that almost half (41.4%) are eligible for full anticoagulation with warfarin, whereas presently only one fifth are receiving this treatment. The decision to anticoagulate can be made on clinical grounds in most cases. If these results are confirmed, a doubling of the current number of patients taking anticoagulants can be anticipated.

Age Factors↗
PubMed1998

Development of a health-related quality-of-life questionnaire (PCOSQ) for women with polycystic ovary syndrome (PCOS).

OBJECTIVE: To develop a self-administered questionnaire for measuring health-related quality of life (HRQL) in women with polycystic ovary syndrome (PCOS). METHODS: We identified a pool of 182 items potentially relevant to women with PCOS through semistructured interviews with PCOS patients, a survey of health professionals who worked closely with PCOS women, and a literature review. One hundred women with PCOS completed a questionnaire in which they told us whether the 182 items were relevant to them and, if so, how important the issue was in their daily lives. We included items endorsed by at least 50% of women in the analysis plus additional items considered crucial by clinicians and an important subgroup of patients in a factor analysis. We chose items for the final questionnaire taking into account both item impact (the frequency and importance of the items) and the results of the factor analysis. RESULTS: Over 50% of the women with PCOS labelled 47 items as important to them. Clinicians chose 5 additional items from the infertility domain, 4 of which were identified as important by women who were younger, less educated, married, and African-American. The Cattell's Scree plot from a factor analysis of these 51 items suggested 5 factors that made intuitive sense: emotions, body hair, weight, infertility, and menstrual problems. We chose the highest impact items from these 5 domains to construct a final questionnaire, the Polycystic Ovary Syndrome Questionnaire (PCOSQ), which includes a total of 26 items and takes 10-15 minutes to complete. CONCLUSIONS: We have used established principles to construct a questionnaire that promises to be useful in measuring health-related quality of life. The questionnaire should be tested prior to, or concurrent with, its use in randomized trials of new treatment approaches.

Adult↗