Week 6: Asthma: Lower Respiratory Disorder Flashcards
What is Asthma?
- chronic lung disease characterized by intermittent, reversible airway obstruction resulting from inflammation of the lung’s airways and tightening of the muscles that surround the airways
- chronic disorder of the airways that results in intermittent an reversible airflow obstruction of the bronchioles
How does the Obstruction of the airway occur in asthma?
inflammation of the airway or hyperresponsiveness
What does asthma affect?
the bronchial airways, not the alveoli
How is bronchial hyperresponsiveness and underlying inflammation of the small airways triggered by?
-exposure to irritants, exercise, cold weather, or risk factors
Types of Irritants
- cigarette smoke
- mold
- pollen
- dust
- animal dander
- air pollutants
- occupational irritants
- strong odors (perfume)
Risk Factors
- viral infections
- nasal polyps
- allergic rhinitis
- food and medication allergies
- emotional stress
- older adults
- GERD
- family history of asthma
- eczema
- exposure to chemical irritants or dust
What happens when there is an exposure to a trigger?
Inflammatory Response
-IgE antibodies bind to receptors on mast cells, causing degranulation and the release of inflammatory mediators, such as histamine and leukotriene, which cause vasodilation and increase capillary permeability.
-there is edema of the airways and an increase in basophils, eosinophils, and neutrophils, which stimulate the production of mucous
>the resulting thick, tenacious mucous causes a thickening of the airways and bronchial hyperresponsiveness
-the release of histamine causes constriction and spasm of the smooth muscles surrounding the bronchial tubes, causing bronchospasm of the bronchial tubes
>bronchospasms cause further narrowing of the airways
-bronchospasms, mucus production, and edema produce obstruction to the flow of air into and out of the lungs
Clinical Manifestations
- inability to speak in full sentences
- wheezing
- dyspnea
- coughing
- increased sputum
- increased respiratory rate
- chest tightness
- anxiety/stress
- use of accessory muscles
- poor oxygen saturation
- barrel chest or increased chest diameter
- tachycardia
- mucosal edema
- bronchoconstriction
- excessive mucous production
Diagnosis
- detailed patient history
- pulmonary function tests
- chest x-ray
- pule oximetry
- arterial blood gases (ABGs)
Diagnostic Procedures
- pulmonary function tests
- chest-xray
Pulmonary Function Tests (PFTs)
most accurate tests for diagnosing asthma and its severity; group of tests used to evaluate the functioning of the respiratory system
- spirometry
- peak expiratory volume
- pulse oximetry
Pulmonary Function Tests: Spirometry
test that measures airflow and lung volumes such as forced expiratory volume (FEV)
- one of the major tests of pulmonary function is the forced expiratory volume in 1 second (FEV1); measures the amount of air forced out of the lungs after a full inspiration
- a decrease in this test of 15-20% below the predicted value for age and gender is diagnostic of asthma
Pulmonary Function Tests: Peak Expiratory Flow
measure the maximum airflow expired during a forced expiration
- patients peak flow readings are compared to the personal best reading with a reading obtained during an exacerbation or “asthma attack”
- the reading done during an exacerbation as compared to a personal best allows the patient to recognize the severity of the respiratory distress
Pulmonary Function Test: Pulse Oximetry
a non-invasive method of measuring oxygen saturation (SpO2)
-normal value: 95%-100%
Arterial Blood Gas
Invasive sampling of arterial blood to measure the oxygenation of the blood (PaO2)
-provide the best information with regard to identifying the patients response to oxygen and ventilation therapy and medications
PaO2
partial pressure of oxygen in arterial blood
-reflects a more accurate measure of oxygen in arterial blood than SpO2
-once the PaO2 in arterial blood falls below the threshold of 60 mmHg, there is a steep reduction in SpO2
-range: 80-95 mmHg
(even though 60 mmHg is acceptable)
Asthma is classified as?
- mild asthma
- moderate asthma
- severe asthma
- uncontrolled asthma
Why is a chest x-ray performed?
to diagnose changes in chest structure over time
Complications
- respiratory failure (persistent hypoxemia related to asthma can lead to respiratory failure)
- status asthmaticus
Status Asthmaticus
- life threatening episode of airway obstruction that is often unresponsive to common treatment. It involves extreme wheezing, labored breathing, use of accessory muscles, distended neck veins, and creates a risk for cardiac and/ or respiratory distress
- an acute exacerbation of asthma that is unresponsive to repeated doses or treatment with the typical rescue medications (bronchodilators)
Status Asthmaticus Clinical Manifestations
can vary from mild to severe with:
- bronchospasm, inflammation, and excessive mucus production with mucus plugging
- patients report chest tightness, wheezing, dry cough, SOB, and severe respiratory distress
- results in: CO2 retention, hypoxemia, and ultimately respiratory failure
Status Asthmaticus Triggers
- recent onset of viral respiratory illness
- exposure to potential irritant or allergies
- exercising in the cold
Treatment for Status Asthmaticus
-oxygen
-IV fluids
-systemic bronchodilators
-and steroids to open the airways and decrease inflammation
>endotracheal intubation may be necessary in severe cases until symptoms are under control
Laboratory Tests
- arterial blood gases (ABGs)
- sputum cultures
-Medications
pharmacological treatment is based on patients response to previous treatments and the level of engagement in self-management plan
- anti-inflammatories
- bronchodilators
- anti-cholinergics
- leukotriene modifiers
Anti-inflammatories
typically inhaled corticosteroids, reduce mucus production and swelling, making the airways less sensitive and less likely to react to asthma triggers that cause asthma symptoms
-for prophylaxis and used to decrease airway inflammation
Bronchodilators
such as beta2-adrenergic agonists relax the bronchial smooth muscle, helping to open the airway and decreasing obstruction
-relax the bronchioles or small airways
Anti-cholinergics
another group of bronchodilators, but different from beta 2 adrenergic agonists
-relax the muscles around the larger airways or bronchi
Leukotriene Receptor Agonists
may be used to enhance asthma control if the usual medications are not effective
-not steroids; inhibit leukotriene-mediated inflammatory process
Medication Falls into 2 categories…
- Long-term control
- Rescue
Medications catergories: Long-term
-used daily regardless of the symptoms a patient is experiencing to achieve and maintain control of the asthma
>most effective: inhaled anti-inflammatories, or oral theophylline
Medication catergories: Rescue
used once n asthma attack has started
- usually short-acting bronchodilators
- short-acting beta2-adrenergic agonists are gold standard because they are most effective
- short-acting beta 2 adrenergic agonists should be used for acute exacerbations of asthma
- prednisone may also be used for acute exacerbation
Nursing Interventions: Assessment
- assess vital signs; pulse rate, temperature, respiratory rate, and peak flow measure
- oxygen saturation
- ABGs
- breath sounds
- level of consciousness
- ability to speak in full sentences
- cough
- use of accessory muscles
- tripod-position (sitting up-right with arms propped on the table) in attempt to decrease the work of breathing
- monitor dyspnea (visual analog dyspnea scale)
- previous intubation
Nursing Care: Actions
- provide oxygen therapy
- administer medication as ordered (bronchodilators, anti-inflammatories, anti-cholinergics)
- position the client to maximize ventilation (high-fowlers)
- monitor cardiac rate and rhythm for changes during an acute attack (can be irregular, tachycardia, or with PVCs)
- monitor respiratory rate for changes in effort, symmetry, SaO2; auscultate lung sounds
- initiate and maintain IV access
- remain calm and reassuring
- provide rest periods for older adults who have dyspnea. design room and walkways with opportunities for rest. Incorporate rest in ADLs
- encourage prompt medical attention for infections and appropriate immunizations
Interprofessional care
- respiratory services should be consulted for inhalers and breathing treatments for airway management
- nutritional services can be contacted for weight loss or gain related to medications or diagnosis
- rehabilitation care can be consulted if the client has prolonged weakness and needs assistance with increasing level of activity
Therapeutic Procedures
-asthma action plan; assessment, monitoring, control of environmental factors, pharmacological treatment, and education
Medications: Bronchodilators: Short Acting beta 2 agonists
-albuterol
-levalbuterol
provide rapid relief of acute manifestations and prevent exercise-induced asthma
Medications: Bronchodilators: Long-acting beta 2 agonists
-salmeterol
-formoterol
used for asthma attack prevention
Medications: Bronchodilators: Anticholinergic medications
-ipratropium (short)
>block the parasympathetic nervous system; allows for the sympathetic nervous system effects of increased bronchodilation and decreased pulmonary secretion
-tiotropium (long)
>prevent bronchospasm
Medications: Bronchodilators: Methylxanthines
-theophylline
require close monitoring of blood medication levels due to a narrow therapeutic range
-use only when other treatments are ineffective
Medications: Anti-inflammatory agents: Corticosteroids
- fluticasone (inhaled)
- beclomethasone (Inhaled)
- prednisone (oral)
- hydrocortisone (IV)
- methylprednisone (IV)
Client Education
- avoidance of risk factors
- pursed-lip breathing (keeps airways open longer and prolongs exhalation, allowing increased time for oxygen and carbon dioxide exchange)
- medication education
- peak flow meter
- smoking cessation
- proper inhaler technique
- cleaning of respiratory equipment
What does it mean when a patient has diminished or absent breath sounds?
decrease in movement of air due to increased obstruction or respiratory exhaustion
What does it mean when a patient’s wheezing decreased and he has little or no breath sounds?
patient is not moving air throughout the system
- medical emergency
- indicates respiratory failure
- may require mechanical ventilation
