| HA | H antigen; Hakim-Adams [syndrome]; halothane anesthesia; Hartley [guinea pig]; headache; health alli... |
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| HAA | hearing aid amplifier; hemolytic anemia antigen; hepatitis-associated antigen; hospital activity ana... |
| HTA | heterophil transplantation antigen; human thymocyte antigen; hydroxytryptamine; hypophysiotropic are... |
| LA | lactic acid; large amount; laser angioplasty; late abortion; late antigen; latex agglutination; left... |
| LFA | left femoral artery; left frontal craniotomy; left fronto-anterior [fetal position]; leukocyte funct... |
| shock | 1. <psychiatry> A sudden disturbance of mental equilibrium. 2. <cardiology> A condition of profound haemodynamic and metabolic disturbance characterised by failure of the circulatory system to maintain adequate perfusion of vital organs, it may result from inadequate blood volume (hypovolaemic shock), inadequate cardiac function (cardiogenic shock) or inadequate vasomotor tone (neurogenic shock, septic shock). (18 Nov 1997) |
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| shock, cardiogenic | Shock caused by heart failure. The heart fails to pump blood effectively. For example, a heart attack (a myocardial infarction) can cause an abnormal ineffectual heart beat (an arhythmia) with very slow, rapid, or irregular contractions of the heart, impairing the heart's ability to pump blood, lowering the volume of blood going to vital organs. Cardiogenic shock can also be due to drugs that reduce heart function or an abnormally low level oxygen in the blood (hypoxaemia) caused, for instance, by lung disease. Whatever be the cause, blood vessels constrict and adrenalin-like substances are secreted into the bloodstream, increasing the heart rate. Treatment of cardiogenic shock is aimed at improving the heart's function. Shock after a heat attack is extremely serious. The mortality rate is over 80%. (12 Dec 1998) |
| shock, hypovolaemic | Shock due to a decrease in blood volume. This is the 1 cause of shock. It can be due to loss of blood from bleeding, loss of blood plasma through severe burns, and dehydration. The treatment, first and foremost, is prompt intravenous administration of fluid. (12 Dec 1998) |
| shock index | The quotient of the cardiac rate divided by the systolic blood pressure; normally approximately 0.5, but in shock (e.g., rising pulse rate with falling blood pressure), the index may reach 1.0. (05 Mar 2000) |
| shock lung | In shock, the development of oedema, impaired perfusion, and reduction in alveolar space so that the alveoli collapse. Synonym: pump lung, wet lung, white lung. (05 Mar 2000) |
| shock, psychologic | Trauma due to psychological events, as in shell shock (now known as posttraumatic stress disorder). (12 Dec 1998) |
| shock, septic | Shock due to circulatory insufficiency caused most commonly by gram-negative bacteraemia. It is less often the result of the persistent presence of other micro-organisms in the blood (fungaemia, viraemia); in rare instances, it is caused by gram-positive organisms, but with different symptomatology. (12 Dec 1998) |
| shock, shell | The World War I name for what is known today as posttraumatic stress, this is a psychological disorder that develops in some individuals who have had major traumatic experiences (and, for example, have been in a serious accident or through a war). The person is typically numb at first but later has symptoms including depression, excessive irritability, guilt (for having survived while others died), recurrent nightmares, flashbacks to the traumatic scene, and overreactions to sudden noises. Posttraumatic stress became known as such in the 70s due to the adjustment problems of some vietnam veterans.shots, allergy: known medically as allergy desensitization or allergy immunotherapy, the injections are designed to stimulate the immune system with gradually increasing doses of the substances to which a person is allergic, the aim being to modify or stop the allergy war (by reducing the strength of the IgE and its effect on the mast cells). This form of treatment is very effective for allergies to pollen, mites, cats, and especially stinging insects (e.g., bees, hornets, yellowjackets, wasps, velvet ants, fire ants). Allergy immunotherapy usually takes 6 months to a year to become effective and injections are usually required for 3-5 years. (12 Dec 1998) |
| shock, surgical | Shock that occurs during or after surgical operation. (12 Dec 1998) |
| shock therapy | See: electroshock therapy. (05 Mar 2000) |
| shock, toxic | See Syndrome, toxic shock. (12 Dec 1998) |
| shock, traumatic | Any shock produced by trauma. (12 Dec 1998) |
| shock treatment | See: electroshock therapy. (05 Mar 2000) |
| shock tube | <radiobiology> A gas-filled tube used in plasma physics to quickly ionize a gas. A capacitor bank charged to a high voltage is discharged into the gas at one tube end to ionize and heat the gas, producing a shock wave that may be studied as it travels down the tube. (09 Oct 1997) |
| shock wave | <radiobiology> Wave produced (for example, in a gas or plasma) as a result of a sudden violent disturbance. To produce a shock wave in a given region, the disturbance must take place in a shorter time than the time required for sound waves to traverse the region. (09 Oct 1997) |