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Biomedical subjects

J Eason

Publications and source records attributed to J Eason.

24 records · Page 2Linked to original sources

Systemic air embolism during laser bronchoscopy.

We report a case of massive, fatal, systemic gas embolism which occurred during the course of laser bronchoscopic resection of a bronchial carcinoma. The clinical features of systemic air embolism are discussed.

Aged↗

Controlled investigation of deaths from asthma in hospitals in the North East Thames region.

One hundred and thirty deaths definitely or potentially due to asthma occurring in hospitals in the North East Thames region over one year were identified from death certificates and Hospital Activity Analysis records. Thirty five of these deaths were considered after independent assessment to have been directly due to asthma. Control patients who left hospital alive after acute asthma attacks were selected and matched with cases for sex, age, and hospital. Management was compared in the two groups. Inadequate monitoring, including failure to monitor arterial blood gas values, and inadequate use of nebulised beta agonists occurred significantly more often in fatal cases. Use of sedation, inadequate treatment with steroids, exposure to potentially toxic doses of aminophylline, and inadequate clinical assessment were more common in cases than controls, but not significantly so. Failure to institute artificial ventilation contributed to seven deaths. Assessors considered important defects in management to have occurred in 83% (29/35) of the cases and 40% (14/35) of the controls. Nevertheless, most of the hospital deaths (19/35) were considered not to have been preventable. Eight other deaths in the region were attributed to the complications of asthma or its treatment. Three of these were associated with gastrointestinal bleeding and one with perforation of a duodenal ulcer. Before considering policies aimed at speeding admission to hospital of patients with acute attacks of asthma it is crucial that the general standard of hospital care offered to all patients with asthma should be improved.

Adult↗

Influence of anisotropy on local and global measures of potential gradient in computer models of defibrillation.

A heart-torso model including fiber orientation is used to calculate electric field strength in an active-can transvenous defibrillation system and estimate errors due to inadequate description of the anisotropy of the myocardium. Using a minimum potential gradient (5 V/cm) in a critical mass (95%) of the tissue, the estimated defibrillation voltage threshold for a right ventricular transvenous lead placement differs by only 4.5% when using isotropic myocardial conductivity compared to a model with realistic fiber architecture. In addition, pointwise comparisons of the two solutions reveal differences of 10.8% rms in potential gradient strength and 31.6% rms in current density magnitude in the myocardium, resulting in a change in the location of the low gradient regions. These results suggest that if a minimum potential gradient throughout the heart is necessary to avoid reinitiation of fibrillatory wave fronts, then isotropic models are adequate for modeling the electric field in the heart. Alternatively, the model demonstrates the use of physiologically based descriptions of anisotropy and fiber orientation, which will soon allow simulations of shock induced membrane polarization during defibrillation.

Adult↗