Monday, August 13, 2007

asthma !!!!!!

Asthma is a chronic disease of the respiratory system in which the airway occasionally constricts, becomes inflamed, and is lined with excessive amounts of mucus, often in response to one or more triggers( such as exposure to an environmental stimulant (or allergen), cold air, warm air, moist air, exercise or exertion, or emotional stress). Between episodes, most patients feel well but can have mild symptoms and they may remain short of breath after exercise for longer periods of time than the unaffected individual.
sign and symptoms:
1. shortness of breath (dyspnea) and either wheezing or stridor
2. some patients present primarily with coughing
3. sometimes produce clear sputum
4. wheezing, rapid breathing (tachypnea), prolonged expiration, a rapid heart rate (tachycardia), rhonchous lung sounds (audible through a stethoscope), and over-inflation of the chest.
5. accessory muscles of respiration (sternocleidomastoid and scalene muscles of the neck) may be used,shown as in-drawing of tissues between the ribs and above the sternum and clavicles
6. paradoxical pulse (a pulse that is weaker during inhalation and stronger during exhalation).
7. During very severe attacks, an asthma sufferer can turn blue from lack of oxygen, and can experience chest pain or even loss of consciousness

1. The most effective treatment for asthma is identifying triggers,and limiting or eliminating exposure to them. Desensitization to allergens has been shown to be a treatment option for certain patients.
2. Relief medication:
a.Short-acting, selective beta2-adrenoceptor agonists, such as salbutamol
b.Older, less selective adrenergic agonists, such as inhaled epinephrine and ephedrine
c.Anticholinergic medications, such as ipratropium bromide may be used
d.Inhaled glucocorticoids are usually considered preventive medications
3. Prevention medication:
a.Inhaled glucocorticoids (ciclesonide, beclomethasone, budesonide, flunisolide, fluticasone, mometasone, and triamcinolone).
b.Leukotriene modifiers (montelukast, zafirlukast, pranlukast, and zileuton).
c.Mast cell stabilizers (cromoglicate (cromolyn), and nedocromil).
d.Antimuscarinics/anticholinergics (ipratropium, oxitropium, and tiotropium), which have a mixed reliever and preventer effect. (These are rarely used in preventive treatment of asthma, except in patients who do not tolerate beta-2-agonists.)
e.Methylxanthines (theophylline and aminophylline)
g.Omalizumab, an IgE blocker,Methotrexate,
4. Long-acting β2-agonists
Long-acting bronchodilators (LABD) are similar in structure to short-acting selective beta2-adrenoceptor agonists, but have much longer sidechains resulting in a 12-hour effect, and are used to give a smoothed symptomatic relief (used morning and night). Currently available long-acting beta2-adrenoceptor agonists include salmeterol, formoterol, bambuterol, and sustained-release oral albuterol.

Emergency treatment
When an asthma attack is unresponsive to a patient's usual medication, other treatments are available to the physician or hospital:
a. oxygen to alleviate the hypoxia (but not the asthma per se) that results from extreme asthma attacks;
b. nebulized salbutamol or terbutaline (short-acting beta-2-agonists), often combined with ipratropium (an anticholinergic);
c. systemic steroids, oral or intravenous (prednisone, prednisolone, methylprednisolone, dexamethasone, or hydrocortisone). Some research has looked into an alternative inhaled route.[44]
d. other bronchodilators that are occasionally effective when the usual drugs fail:
o intravenous salbutamol
o nonspecific beta-agonists, injected or inhaled (epinephrine, isoetharine, isoproterenol, metaproterenol);
o anticholinergics, IV or nebulized, with systemic effects (glycopyrrolate, atropine, ipratropium);
o methylxanthines (theophylline, aminophylline);
o inhalation anesthetics that have a bronchodilatory effect (isoflurane, halothane, enflurane);
o the dissociative anaesthetic ketamine, often used in endotracheal tube induction
o magnesium sulfate, intravenous; and
e. intubation and mechanical ventilation, for patients in or approaching respiratory arrest.
f. Heliox, a mixture of helium and oxygen, may be used in a hospital setting. It has a more laminar flow than ambient air and moves more easily through constricted airways

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