Question

The nurse is caring for a 5-year old boy who has been admitted to the hospital with a diagnosis of asthma. On the admission assessment, the nurse notes an increased respiratory rate and wheezing throughout all lung fields. The child coughs frequently during the exam. a. Explain the signs and symptoms relative to the pathophysiology of asthma. b. Predict medications would you expect the prescriber to order.

Answer 1

a) pathophysiology of asthma

Bronchial asthma is a disorder characterized by airway hyperresponsiveness to a number of ubiquitous inflammatory triggering factors. bronchial hyperresponsiveness ia defined as increased bronchoconstrictor response to inhalational challenge with histamine or methacholine .bronchospastic triggers include exercise, cold air, dust, smoke powder, pollen, etc.

Allergic stimuli produce a biphasic clinical response in asthmatics: an early asthmatic response(EAR) and a late asthmatic response(LAR). The EAR develops within minutes of antigenic exposure, peaks at 10-30 minutes and lasts for about 1.5-3 hours.it is a classic antigen-antibody reaction wherein mast cells presensitised to the allergen are triggered by the 'antigen-specific IgE Antibody' complex on their surface. The mast cell release histamine, trypsin, prostaglandin D2, and leukotriene c4, and other additional mediators released include eosinophil and neutrophil chemotactic factors and platelet activating factors(PAF). The late asthmatic response(LAR) begins 3-4 hours after antigenic challenge peaks at 8-12 hours and lasts for 1-2 days. This phase is associated with airway inflammation. Initial cellular infiltrates consist of macrophages followed by eosinophils and lymphocytes. Macrophages release PAF and leukotriene B4.The lymphocyte release lymphokine of which interleukins 3 and 5 attract mast cells and eosinophils respectively.

The three components of asthmatic response therefore include

1)cellular component involving eosinophils, neutrophils, monocytes, mast cells, and platelets.

2)vascular component characterized by hyperemia, stasis, interstitial edema, and increased microvascular permeability.

3)morphological component characterized by hypertrophy of mucous glands and muscles., thickening of the basement membrane, shedding of cells and inspissation of secretions.

b)physician may suggest the following drugs.

1)Bronchodilators

a) B2 sympathomimetics:,salbutamol,terbutaline salmeterol.

b)methylxanthines: Theophylline,aminophylline

c)Anticholinergics:ipratropium bromide,tiotropium bromide.

2)Leukotriene antagonists

montelukast, zafirlukast

3)Mat cell stabilizers

sodium cromoglycate, ketotifen.

4)Corticosteroids:

a)systemic: hydrocortisone, prednisolone, and others.

b)inhalational:

beclomethasone,dipropionate

5)Anti IgE Antibody

omalizumab