Obstructive Airway Conditions Flashcards
Air trapping results in:
HYPOventilation and HYPERcapnia
Chronic LOW O2 and HIGH CO2
What does obstructive mean?
Narrowed airways
-Casues airway obstruction worse on EXPIRATIONS
Causes increased work of breathing
-emptying of the lungs is slowed
-FEV1
-Use or accessory muscles
All obstructive diseases cause V/Q mismatch and hypoxemia
Dyspnea and wheezing are present in ALL obstructive diseases
Define air trapping
A person not able to fully EXHALE (cannot get out) = HIGH CO2
Air is trapped in the alveoli(a person works harder to breathe, and lungs are hyperinflated
Asthma
Chronic inflammation of the bronchial airways (NOT aveoli)
-causes bronchial HYPERRESPNSIVENESS, constriction of the airways and variable airflow obstruction that is reversible
Chronic disease state with exacerbations
Risk factors for Asthma
-Usually starts in childhood (highly associated with ALLERGIES)
-Familial link (1000 genes identified)
-Levels of allergen exposure
-Urban residency
-Exposure to indoor and outdoor air pollution
-Tobacco exposure/smoke
-Recurrent respiratory tract viral infections, and GERD
Pathophysiology of Asthma
-Exposure to antigen (trigger factor)
-Lots of immune cells involved in these processes (dendritic cells, T-helper 2 cells, B lymphocytes, mast cells, neutrophils, basophils, EOSINOPHILS
Common Asthma Triggers
-Activity
-Secondhand smoke
-Climate conditions
-Exposure to dust mites
-Pet dander
-Pollen
Early vs. Late Responses
Asthma
Early: initial response cascade of release of inflammatory mediators occurs within minutes
-Vasodilation, increased capillary permeability, mucosal edema, bronchial smooth muscle contraction and mucus secretion
Late: 4-8 hours later
-Recruitment of eosinophils, neutrophils, and lymphocytes during the acute response, causes another release of inflammatory mediators inciting the same process
Airway Remodeling
Chronic Asthma
Untreated inflammation can lead to long-term airway damage that is IRREVERSIBLE
Two responses of Asthma
Bronchoconstriction
#1 symptom of asthma attack
Inflammation
-The biggest problem and causes the seriousness of the disease
How do we diagnose Asthma?
History of allergies, recurrent episodes of wheezing, dyspnea, and course/exercise intolerance
PFTs (Pulmonary Function Tests)
-Measures lung function with respect to time
-GOLD STANDARD for diagnosing
-Decreased expiratory flow rate
-Decreased forced expiratory volume in 1 second
Symptoms with Asthma
Classic
-Wheezing
-SOA (breathlessness, dyspnea)
-Cough
-Chest tightness
Severe Attacks
-Use of accessory muscles
-Distant breath sounds
-Diaphoresis
-Inability to speak one or two words before taking a breath
RESPIRATORY FAILURE
-inaudible breath sounds
-repetitive hacking cough
Asthma Management
-Avoid asthma irritants
-Use peak flow meters
-Low-dose corticosteroids (mainstay for exacerbations), short-acting beta-agonist inhalers for milder forms
More severe
-Antiinflammatory medications are essential and INHALED corticosteroids, long-acting beta-agonist inhalers, or leukotriene antagonists
Status Asthmaticus
SEVERE SYMPTOMS
Unrelenting asthma attack
-Silent chest
-pCO2 >70 mmhg
LIFE-THREATENING EMERGENCY
May have epi pen for potential episode
treatment of status asthmaticus
-avoidance of precipitating factors and prophylactic
-bronchodilators, corticosteroids, and oxygen therapy are mainstays of treatment for an acute attack
-asthma meds are classified as either; 1.) preventors, 2.) relievers or rescue meds