The epithelial lining in the airway responds by becoming inflamed and edematous. Bronchospasm occurs in the smooth muscle of the bronchi and bronchioles; secretion increase in viscosity and elastic recoil decreases. These changes result in a reduction of the diameter of the airways, making breathing more difficult.
With continue exposure to inflammatory, it can lead to irreversible remodeling of the airway, making the management of asthma symptoms and disease control increasingly difficult.
The fundamental causes of asthma are not completely understood. The strongest risk factors for developing asthma are a combination of genetic predisposition with environmental exposure to inhaled substances and particles that may provoke allergic reactions or irritate the airways, such as:
- indoor allergens (for example, house dust mites in bedding, carpets and stuffed furniture, pollution and pet dander)
- outdoor allergens (such as pollens and moulds)
- tobacco smoke
- chemical irritants in the workplace
- air pollution.
Other triggers can include cold air, extreme emotional arousal such as anger or fear, and physical exercise. Even certain medications can trigger asthma: aspirin and other non-steroid anti-inflammatory drugs, and beta-blockers (which are used to treat high blood pressure, heart conditions and migraine).
Sign and Symptoms
People with asthma have different signs and symptoms-they can change overtime or depending on the situation.
Common signs and symptoms
- Wheezing (whistling sound when breathe)
- Chest tightness
- Difficulty breathing
- Increased mucus
- Spirometry- measuring the movement of air in and out of the lung after the patient takes the deeepest breath
- Chest X rays –show areas with hyperinflation with local atelectasis and flattened diaphragm.
- Complete blood count- reveals the increase eosinophil count.
- Pulse oximetry- show dcreased of oxygen saturation.
- Serum IgE level- may increase from an allergic reaction.
- Skin testing-may identify specific allergens.
- Arterial blood gas(ABG)– analysis may detect hypoxemia.
- Pulmonary function test– reveal airway obstruction and decrease peak expiration flow rate.
- Obtain history about previous attacks.
- Place the patient in high Fowlers position.
- Evaluate wheezes for location,duration and phase of respiration when they occur.
- Monitor pulse oximetry and ABG for oxygenation and acid-base balance.
- Identifies medications the patient is currently taking
- Administer medications as prescribed and monitors the response of patient to those medication.
- Administer fluids if the patients is dehydrated
- Assess frequently the vital sign as clients condition dictates.
- Provide reassurance to relieve anxiety.
- Alert the physician immediately.
- Observe the patient closely for respiratory arrest. Monitor his respiratory rate continuously and other vital signs every 5 minutes. Never leave the patient alone.
- Make sure the patient receives oxygen and bronchodilator and nebulizer therapies as ordered.
- Have emergency equipment brought to the bedside and prepare to assist with intubation and mechanical ventilation if respiratory arrest occurs.
- Obtain request for ABG for immediate blood gas analysis.
- Administer corticosteroids,epinephrine,sympathomimetic aerosol agents and IV aminophylline as ordered.
- Prepare to transfer the patient to the Intensive care unit.
Credits: www.who.int/en/ ; uvahealth.com