| ventilators, negative-pressure | Body ventilators that assist ventilation by applying intermittent subatmospheric pressure around the thorax, abdomen, or airway and periodically expand the chest wall and inflate the lungs. They are relatively simple to operate and do not require tracheostomy. These devices include the tank ventilators ("iron lung"), portalung, pneumowrap, and chest cuirass ("tortoise shell"). (12 Dec 1998) |
|---|---|
| positive-negative pressure breathing | Inflation of the lungs with positive pressure and deflation with negative pressure by an automatic ventilator. (05 Mar 2000) |
| negative end-expiratory pressure | A subatmospheric pressure at the airway at the end of expiration. (05 Mar 2000) |
| negative pressure | Pressure less than that of the ambient atmosphere. (05 Mar 2000) |
| lower body negative pressure | External decompression applied to the lower body. It is used to study orthostatic intolerance and the effects of gravitation and acceleration, to produce simulated haemorrhage in physiologic research, to assess cardiovascular function, and to reduce abdominal stress during childbirth. (12 Dec 1998) |
| blood pressure | <cardiology, physiology> The force that the circulating blood exerts on the walls of the arteries. This measurement is divided into systolic (pressure during contraction of the heart) and diastolic (pressure during relaxation phase). Blood pressure varies with age and sex of the individual. A rough rule of thumb for normal systolic pressure is 100 + Age of individual. In children 2 x (age) + 80 = systolic BP The diastolic pressure should be roughly 2/3 the systolic pressure. (27 Sep 1997) |
| blood pressure determination | Techniques for measuring blood pressure. (12 Dec 1998) |
| blood pressure, high | High blood pressure (hypertension) is a repeatedly elevated blood pressure exceeding 140 over 90 mmHg. High blood pressure is also called the silent killer. Chronically high blood pressure can cause blood vessel changes in the back of the eye (retina), thickening of the heart muscle, kidney failure, and brain damage. No specific cause for high blood pressure is found in 95% of patients. High blood pressure is treated with salt restriction, regular aerobic exercise, and medications. (12 Dec 1998) |
| blood pressure monitoring, ambulatory | Method in which prolonged blood pressure readings are made while the patient undergoes normal daily activities. It allows quantitative analysis of the high blood pressure load over time, can help distinguish between types of hypertension, and can assess the effectiveness of antihypertensive therapy. (12 Dec 1998) |
| blood pressure monitors | Devices for continuously measuring and displaying the arterial blood pressure. (12 Dec 1998) |
| high blood pressure | <cardiology> Persistently high arterial blood pressure. Hypertension may have no known cause (essential or idiopathic hypertension) or be associated with other primary diseases (secondary hypertension). This condition is considered a risk factor for the development of heart disease, peripheral vascular disease, stroke and kidney disease. (29 Sep 1997) |
| systolic blood pressure | <cardiology, physiology> The pressure exerted on the walls of the arteries during the contraction phase of the heart. Considered abnormally elevated if consistently over 150 mmHg. Systolic blood pressure varies with age, sex, size and relative condition. (27 Sep 1997) |
| diastolic blood pressure | The pressure exerted on the walls of the arteries when the heart is in the relaxation phase (diastole). Considered abnormally elevated if consistently over 90 mmhg. (27 Sep 1997) |
| differential blood pressure | The arterial blood pressure at corresponding points on the two sides of the body. (05 Mar 2000) |
| bone scan: falsely negative metastases | <radiology> Anaplastic tumours, reticulum cell sarcoma, renal cell carcinoma, thyroid carcinoma, histiocytosis, neuroblastoma, multiple myeloma (positive scan usually due to recent or impending fracture) (12 Dec 1998) |