AsthmaALLIANZE UNIVERSITY COLLEGE OF MEDICAL SCIENCES

Prepared by Clarinda Clare LinusDMS003/11 – January 2011 intake

Lecturer : Dr. Angelo M. Nino Santos (Immunology)

Asthma is a chronic lung disease that inflames and narrows the airways.

People who suffer from this chronic condition (long-lasting or recurrent) are said to be asthmatic.

Introduction

Phatogenesis

People who have asthma have inflamed airways. This makes them swollen and very sensitive. They tend to react strongly to certain inhaled substances.

When the airways react, the muscles around them tighten. This narrows the airways, causing less air to flow into the lungs. The swelling also can worsen, making the airways even narrower.

Cells in the airways might make more mucus than usual. Mucus is a sticky, thick liquid that can further narrow the airways.

Type I hypersensitivity is also known as immediate or anaphylactic hypersensitivity.

The reaction may involve skin (urticaria and eczema), eyes (conjunctivitis), nasopharynx (rhinorrhea, rhinitis), bronchopulmonary tissues (asthma) and gastrointestinal tract (gastroenteritis).

The reaction may cause a range of symptoms from minor inconvenience to death. The reaction usually takes 15 - 30 minutes from the time of exposure to the antigen, although sometimes it may have a delayed onset (10 - 12 hours).

Type 1 Hypersensitivity

Morphology

ETIOLOGY

An inherited tendency to develop allergies, called atopy

Inherited by parents who have asthma

Certain respiratory infections during childhood

Contact with some airborne allergens or exposure to some viral infections in infancy or in early childhood when the immune system is developing

Etiology

Certain asthma triggers can set off the cascade of asthma symptoms. Some asthma triggers may include:

Air pollution Allergies Cold air A cold or flu virus Sinusitis Smoke Fragrances aspirin

Asthma triggers

SIGNS & SYMPTOMS

Coughing from asthma often is worse at night or early in the morning, making it hard to sleep.

Wheezing. Wheezing is a whistling or squeaky sound that occurs when you breathe.

Chest tightness. This may feel like something is squeezing or sitting on your chest.

Shortness of breath. Some people who have asthma say they can't catch their breath or they feel out of breath. You may feel like you can't get air out of your lungs.

Signs & Symptoms

DIAGNOSTIC

TESTING

Mild-to-moderate hypoxemia is a common arterial blood gas (ABG) finding.

Hypocapnia and respiratory alkalosis may be present due to the increased respiratory rate of an acute asthma exacerbation

prolonged or severe symptoms may results in hypercapnea and metabolic acidosis.

Arterial blood gas (ABG)

Findings can include hyperinflation of the lungs with flattened diaphragm if there is significant air trapping, supporting the diagnosis of asthma.

Chest radiography (CXR)

In patients who have associated chest pain or a history of CHF, an ECG may be helpful to evaluate for other potential causes of the patient's difficulty breathing or wheezing.

Electrocardiogram (ECG)

Pulmonary Function Tests (PFTs) performed at the bedside are the most useful objective test to aid in the treatment and disposition of a patient with an acute exacerbation of asthma.

These tests confirm that the patient's symptoms are due to obstructive lung disease, assess the severity of the exacerbation, and monitor the response to treatment.

Pulmonary Function Tests (PFTs)

TREATMENTS

β2-Adrenergic Agonists Anticholinergic agents Corticosteroids Epinephrine Magnesium sulfate Antibiotics Theophylline Heliox Non-invasive positive pressure ventilation Intubation

Treatments

PREVENTION

Avoiding or minimizing contact with the substance you are allergic to can help prevent an asthma attack.

Avoid Smoke Smoke and asthma are a bad mix. Minimize exposure

to all sources of smoke, including tobacco, incense, candles, fires, and fireworks. 

Avoid Colds Avoid close contact with people who have a cold or

the flu since your asthma symptoms may worsen if you catch the infection from them

…Prevention

Asthma medicines can be taken in pill form, but most are taken using a device called an inhaler. An inhaler allows the medicine to go directly to your lungs.

http://www.webmd.com/asthma/guide/asthma-prevention

http://www.nhlbi.nih.gov/health/health-topics/topics/asthma/treatment.html

references