| HEP | hemolysis end point; hepatoerythropoietic porphyria; high egg passage [virus]; high-energy phosphate... |
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| HFD | hemorrhagic fever of deer; high-fiber diet; high forceps delivery; hospital field director; human fa... |
| HFHV | high frequency, high volume |
| HFO | high-frequency oscillator; high-frequency oscillatory [ventilation] |
| HFT | high-frequency transduction; high-frequency transfer |
| root pressure | <botany> Pressure in the roots which, when the shoot is cut off, will cause liquid to ooze from the root stump, the mechanisms and tissues involved in this process are not clearly understood. (09 Oct 1997) |
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| wedge pressure | The intravascular pressure reading obtained when a fine catheter is advanced until it completely occludes a small blood vessel or is sealed in place by inflation of a small cuff; commonly measured in the lung to estimate left atrial pressure. (05 Mar 2000) |
| pleural pressure | The pressure in the pleural space between the visceral and parietal pleurae. (05 Mar 2000) |
| continuous positive airway pressure | A technique of respiratory therapy, in either spontaneously breathing or mechanically ventilated patients, in which airway pressure is maintained above atmospheric pressure throughout the respiratory cycle by pressurization of the ventilatory circuit. (05 Mar 2000) |
| continuous positive pressure breathing | Artificial ventilation in which all inspirations are provided by positive pressure applied to the airway. Synonym: continuous positive pressure breathing, continuous positive pressure ventilation, intermittent positive pressure breathing, intermittent positive pressure ventilation. (05 Mar 2000) |
| continuous positive pressure ventilation | Synonym: controlled mechanical ventilation. (05 Mar 2000) |
| coronary perfusion pressure | The pressure at which blood proceeds through the coronary circulation, mainly in diastole. (05 Mar 2000) |
| portal pressure | The venous pressure measured in the portal vein. (12 Dec 1998) |
| positive end-expiratory pressure | A technique used in respiratory therapy in which airway pressure greater than atmospheric pressure is achieved at the end of exhalation by introduction of a mechanical impedance to exhalation. (05 Mar 2000) |
| positive-negative pressure breathing | Inflation of the lungs with positive pressure and deflation with negative pressure by an automatic ventilator. (05 Mar 2000) |
| positive-pressure respiration | A method of mechanical ventilation in which pressure is maintained to increase the volume of gas remaining in the lungs at the end of expiration, thus reducing the shunting of blood through the lungs and improving gas exchange. (12 Dec 1998) |
| positive-pressure respiration, intrinsic | Non-therapeutic positive end-expiratory pressure occurring frequently in patients with severe airway obstruction. It can appear with or without the administration of external positive end-expiratory pressure (positive-pressure respiration). It presents an important load on the inspiratory muscles which are operating at a mechanical disadvantage due to hyperinflation. Auto-peep may cause profound hypotension that should be treated by intravascular volume expansion, increasing the time for expiration, and/or changing from assist mode to intermittent mandatory ventilation mode. (12 Dec 1998) |
| critical pressure | The minimum pressure required to liquefy a gas at the critical temperature. (05 Mar 2000) |
| postoperative pressure alopecia | Loss of hair over a circumscribed area usually on the posterior scalp, resulting from continuous pressure on the occiput in a lengthy operative procedure, or unconsciousness following a drug overdose. (05 Mar 2000) |
| pressure | 1. The act of pressing, or the condition of being pressed; compression; a squeezing; a crushing; as, a pressure of the hand. 2. A contrasting force or impulse of any kind; as, the pressure of poverty; the pressure of taxes; the pressure of motives on the mind; the pressure of civilization. "Where the pressure of danger was not felt." (Macaulay) 3. Affliction; distress; grievance. "My people's pressures are grievous." (Eikon Basilike) "In the midst of his great troubles and pressures." (Atterbury) 4. Urgency; as, the pressure of business. 5. Impression; stamp; character impressed. "All saws of books, all forms, all pressures past." (Shak) 6. <mechanics> The action of a force against some obstacle or opposing force; a force in the nature of a thrust, distributed over a surface, often estimated with reference to the upon a unit's area. Atmospheric pressure, Center of pressure, etc. See Atmospheric, Center, etc. <engineering> Back pressure, pressure which resists the motion of the piston, as the pressure of exhaust steam which does not find free outlet. Fluid pressure, pressure like that exerted by a fluid. It is a thrust which is normal and equally intense in all directions around a point. Pressure gauge, a gauge for indicating fluid pressure; a manometer. Origin: OF, fr. L. Pressura, fr. Premere. Source: Websters Dictionary (01 Mar 1998) |