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Biomedical subjects

D J Cook

Publications and source records attributed to D J Cook.

At least 325 records · Page 18Linked to original sources

Pulmonary hypertension is not a risk factor for RVAD use and death after left ventricular assist system support.

Unlike transplantation candidates, patients with pulmonary hypertension (PHTN) and a high transpulmonary gradient do not appear to be at increased risk for right ventricular dysfunction after left ventricular assist system implant. To verify this observation, we reviewed 63 patients supported with the HeartMate (Thermo Cardiosystems, Inc, Woburn, MA) left ventricular assist system. Patients were divided into two groups: patients with PHTN (47 patients) had mean pulmonary artery pressure > 30 mm Hg and/or pulmonary vascular resistance > 4 Wood units, and the remainder of patients did not have PHTN (16 patients). Both groups were similar in age (mean, 51 years), gender distribution (% men, 83% vs 94%, not significant), and number of patients with ischemic cardiomyopathy (72% vs 69%, not significant). More patients in the group without PHTN required extracorporeal membrane oxygenation support (38% vs 12%, p = .06). Right ventricular assist device support was instituted in five (11%) patients with PHTN and four (25%) patients without PHTN. A significantly larger number of patients without PHTN died while on support (14% vs 44%, p = .01). Survival after transplantation in both groups was > 90%. Patients with PHTN have higher transpulmonary gradient, show a significant decrease in pulmonary pressure after left ventricular assist system implantation, and have a higher transplantation rate compared to patients without PHTN. A larger patient cohort is needed to determine if the absence of PHTN is a risk factor for RVAD need and poor outcome after LVAS support.

Cardiomyopathies↗

Ictal 99mTc-HMPAO single photon emission computed tomography in children with temporal lobe epilepsy.

Seventeen ictal 99mTc-HMPAO single photon emission computed tomography (SPECT) studies were performed in 15 children with temporal lobe epilepsy (TLE) aged 7-14 years (mean 10.3 years). Ictal SPECT was informative in 16 of 17 (94%) studies in 14 of 15 (93%) children, showing unilateral temporal lobe hyperperfusion. In all 16 informative ictal SPECT studies, lateralization was concordant with ictal EEG, magnetic resonance imaging (MRI), and pathology. In 4 children, ictal SPECT provided additional localizing information that was not apparent from concurrent ictal EEG recording. Blinded interpretation of ictal SPECT studies by two independent investigators showed correct lateralization of the epileptic focus in every child. Results of visual analysis of ictal SPECT images were corroborated by quantitative analysis. Although interictal SPECT studies showed a degree of temporal lobe hypoperfusion in all children, in 9 of 15 hypoperfusion was either minimal, bilateral, contralateral, or associated with extratemporal hypoperfusion. In children with TLE, ictal SPECT provides reliable lateralizing information to corroborate or supplement that obtained from surface EEG and MRI.

Adolescent↗

Evaluation of the protected brush catheter and bronchoalveolar lavage in the diagnosis of nosocomial pneumonia.

We assess the sensitivity and specificity of the protected brush catheter (PBC) and bronchoalveolar lavage (BAL) in diagnosing nosocomial pneumonia in nonimmunocompromised critically ill patients. Computerized bibliographic literature searches of MEDLINE were performed, and the reference list of each article selected was reviewed. Of 496 citations, there were 19 articles (describing 18 studies) that proved relevant. Study quality was assessed, and descriptive information concerning study populations, interventions, and clinically relevant outcome measurements was extracted. The sensitivity and specificity of PBC were high (pooled estimates, 89.9 and 94.5%, respectively). Criteria for a positive BAL have varied between studies, and sensitivity ranged from 53.3 to 100%, whereas specificity was 98.6%. Most studies did not report whether antibiotics were withheld on the basis of negative test results. In those that did, the incidence of adverse outcomes consequent on withholding antibiotics was low. BAL and PBC, combined with the use of quantitative cultures, appear to increase accuracy in diagnosing pneumonia. The strength of inference is hampered, however, by the absence of a "gold standard" for the diagnosis of pneumonia. Moreover, the generalizability of these findings is limited by the fact that there are so few methodologically sound studies from so few centers. A randomized trial of PBC is needed.

Bronchoalveolar Lavage Fluid↗

Critical appraisal of therapeutic interventions in the intensive care unit: human monoclonal antibody treatment in sepsis. Journal Club of the Hamilton Regional Critical Care Group.

Using the medical literature to solve patient problems is challenging and rewarding. For intensive care physicians, this evidence-based medicine approach is more compelling when basic critical appraisal skills are developed. We highlight the important methodological points for interpreting the literature on treatment, using a cogent example from the critical care literature--monoclonal antibody therapy in sepsis. It is likely that as we move into the 1990s, growth in the number of articles on immunotherapy in the sepsis syndrome will parallel the growth of the general biomedical literature.

Antibodies, Monoclonal↗

[Improving the quality of reports of meta-analyses of randomized controlled trials: the QUOROM Statement].

BACKGROUND: The Quality of Reporting of Meta-analyses (QUOROM) Conference was convened to address standards for improving the quality of reporting of meta-analyses of clinical randomised controlled trials (RCTs). METHODS: The QUOROM group consists of 30 clinical epidemiologists, clinicians, statisticians, editors, and researchers. In conference, the group was asked to identify items they thought should be included in a checklist of standards. Whenever possible, checklist items were guided by research evidence suggesting that failure to adhere to the item proposed could lead to biased results. A modified Delphi technique was used in assessing candidate items. RESULTS: The conference resulted in the QUOROM statement, a checklist, and a flow diagram. The checklist describes our preferred way to present the abstract, introduction, methods, results, and discussion sections of a report of a meta-analysis. it is organized into 21 headings and subheadings regarding searches, selection, validity assessment, data abstraction, study characteristics, and quantitative data synthesis, and in the results with 'trial flow', study characteristics, and quantitative data synthesis; research documentation was identified for eight of the 18 items. The flow diagram provides information about both the numbers of RCTs identified, included, and excluded and the reasons for exclusion of trials. INTERPRETATION: We hope this report will generate further thought about ways to improve the quality of reports of meta-analyses of RCTs and that interested readers, reviewers, researchers, and editors will use the QUOROM statement and generate ideas for its improvement.

Meta-Analysis as Topic↗

Primary pulmonary artery sarcoma mimicking pulmonary thromboembolism.

A 69-year-old woman presenting with dyspnea had a pericardial window created for fibrinous pericarditis. The patient subsequently developed pulmonary hypertension and a ventilation perfusion scan was compatible with pulmonary thromboembolism. A primary tumour of the pulmonary artery was suggested by angiography, computerized axial tomography and magnetic resonance imaging. Pathology confirmed a spindle cell pulmonary artery sarcoma.

Aged↗

Stress ulcer prophylaxis in critically ill patients. Resolving discordant meta-analyses.

PURPOSE: To resolve discrepancies in previous systematic overviews and provide estimates of the effect of stress ulcer prophylaxis on gastrointestinal bleeding, pneumonia, and mortality in critically ill patients. DATA IDENTIFICATION: Computerized search of published and unpublished research, bibliographies, pharmaceutical and personal files, and conference abstract reports. STUDY SELECTION: Independent review of 269 articles identified 63 relevant randomized trials for inclusion. DATA ABSTRACTION: We made independent, duplicate assessment of the methodologic quality, population, intervention, and outcomes of each trial. RESULTS: The source of discrepancies between prior meta-analyses included incomplete identification of relevant studies, differential inclusion of non-English language and nonrandomized trials, different definitions of bleeding, provision of additional information through direct correspondence with authors, and different statistical methods. The current overview demonstrates that prophylaxis with histamine2-receptor antagonists decreases the incidence of overt gastrointestinal bleeding (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.42 to 0.79) and clinically important bleeding (OR, 0.44; 95% CI, 0.22 to 0.88). There is a trend toward decreased overt bleeding when antacids are compared with no therapy (OR, 0.66; 95% CI, 0.37 to 1.17). Histamine2-receptor antagonists and antacids are associated with a trend toward lower clinically important bleeding rates than sucralfate is. There is a trend toward an increased risk of pneumonia associated with histamine2-receptor antagonists as compared with no prophylaxis (OR, 1.25; 95% CI, 0.78 to 2.00). Sucralfate is associated with a lower incidence of nosocomial pneumonia when compared with antacids (OR, 0.80; 95% CI, 0.56 to 1.15) and histamine2-receptor antagonists (OR, 0.77; 95% CI, 0.60 to 1.01). Sucralfate is also associated with a reduced mortality rate (OR, 0.73; 95% CI, 0.54 to 0.97) relative to antacids and to histamine2-receptor antagonists (OR, 0.83; 95% CI, 0.63 to 1.09). CONCLUSIONS: Our results emphasize the need for registries to include all randomized trials and demonstrate the importance of explicit methodology for systematic reviews. There is strong evidence of reduced clinically important gastrointestinal bleeding with histamine2-receptor antagonists. Sucralfate may be as effective in reducing bleeding as gastric pH-altering drugs and is associated with lower rates of pneumonia and mortality. However, the data are insufficient to determine the net effect of sucralfate compared with no prophylaxis.

Antacids↗