Obstructive Pulmonary Diseases Flashcards
Asthma - incidence
- 38% higher in blacks than whites
- Hispanics, especially from Puerto Rico have higher rates of asthma and age-adjusted death rates than all other racial and ethnic groups
- Black females have the highest mortality rates from asthma
Heterogeneous disease characterized by a combination of bronchial hyperresponsiveness with reversible expiratory airflow limitation - Signs and symptoms may vary
- Clinical course can be unpredictable
Significance and gender differences with asthma
1.7 million ED visits/year
Incidence increasing but mortality decreasing
Gender differences
- More men affected before puberty; more women in adulthood
- Women more likely to be hospitalized
- Higher mortality in women
Risk factors of asthma
- History of allergic rhinitis common
- Acute and chronic sinusitis might make asthma worse
- Major precipitating factor of an acute asthma attack
– Acute infection—reduced airway diameter and increased airway hyperresponsiveness
– Viral-induced changes may exacerbate asthma
Common triggers of asthma
- Cigarette Smoke
- Air Pollutants
- Occupational Factors
- Exercise
- Drugs and Food Additives
- GERD
- Genetics
- Role in development of asthma unclear
- Cockroaches
– Animal dander
– Dust mites
– Fungi
– Pollen
– Molds
Manifestations of asthma
- Characteristic manifestations: wheezing, cough, dyspnea, and chest tightness
– Hyperinflation and prolonged expiration due to air trapping in narrowed airways - Wheezing—unreliable to gauge severity of attack (must move air to make the sound)
– Mild attack—may have loud wheezing
– Severe attack—wheezing with forced expiration or no wheezing at all - Decreased or absent breath sounds may occur with exhaustion or inability to have enough muscle force for breathing
– “Silent chest”—ominous sign
– Severe airway obstruction or impending respiratory failure; may be life-threatening
Acute asthma attack signs
Acute attack—wheezing is most common
- Initially expiration, then with progression, both inspiration and expiration
Manifestations of asthma: hyperventilation and alveolar perfusion
Hyperventilation—increased lung volume from trapped air and limited airflow
Abnormal alveolar perfusion and ventilation
- Hypoxemic, decreased PaCO2, increased pH
- Respiratory alkalosis results in respiratory acidosis as patient tires; sign of respiratory failure
Cough variant asthma
- Cough is only symptom
- Bronchospasm is not severe enough to cause airflow obstruction
- May be nonproductive or productive with thick, tenacious secretions
Asthma classifications
Classifications
- Intermittent
- Mild persistent
- Moderate persistent
- Severe persistent
Impairment criteria:
- Frequency of symptoms
- Nighttime awakenings
- SABA use for symptoms
- Interference with normal activity
- Lung function: FEV1,FVC
Risk of exacerbation
Severity is used to guide treatment decisions initially, then addresses level of control
All patients should have an asthma action plan for acute attacks and to prevent future attacks
Patient education and adherence is emphasized
Complications of asthma: asthma attacks
Asthma attacks are variable and unpredictable
- Mild to life-threatening
- Last few minutes to hours
- Between attacks, often asymptomatic
- Compromised pulmonary function to debilitation
- Complications may include: pneumonia, tension pneumothorax, status asthmaticus or acute respiratory failure
Complications of asthma: status asthmaticus
Extreme acute asthma attack characterized by hypoxia, hypercapnia, and acute respiratory failure; life-threatening
emergency - need intubation, sedation, IV magnesium sulfate
Diagnostic studies for asthma
- Detailed history and physical exam
- Peak expiratory flow rate (PEFR)
- Peak flow meter
– Predict attack or monitor severity - Spirometry—lung volumes and capacities
– Stop bronchodilators 6 to 12 hours prior
– Reversibility of obstruction following bronchodilator is important for diagnosis - Fraction of exhaled nitric oxide (FENO)
– Increased levels with eosinophilic-induced inflammation - Serum eosinophils and IgE—increased levels with atopy
- Allergy testing
- Oximetry; ABGs
- Chest x-ray—rule out other disorders
- Sputum culture and sensitivity
– Rule out bacterial infection
Goal of treatment for asthma
to achieve and maintain control; return to best possible level of daily functioning
Medication guidelines based on steps
- Symptoms worse—step up medications
- Symptoms controlled—step down medications
Mild-moderate attack symptoms of asthma
- No more than 2x/week
- Minimal interference in ADLs
- Alert, oriented, speaks in sentences
- May have some chest tightness and dyspnea
- Increased use of asthma meds
- O2 saturation > 90% on room air
- PEFR > 50% predicted or personal best
Mild-moderate attack of asthma: treatment
- *Inhaled bronchodilators and oral corticosteroids
- Monitor VS
- Monitor as outpatient unless not responding to treatment or another contributing factor
- Follow-up with HCP
Severe asthma attack symptoms
- Alert and oriented but focused on breathing
– Frightened; agitated if hypoxemic - Tachycardia, tachypnea (>30 breaths/min)
- Accessory muscle use; sits forward
- Wheezing
- PEFR < 50% predicted or personal best
- Recurring symptoms interfere with ADLs
Severe asthma attack treatment
- ED -> hospital admission
- Supplemental O2 and oximetry
– PaO2 > 60 mmHg or SaO2 > 93% - Monitor PEFR, ABGs, VS
- Bronchodilators and oral corticosteroids
- Silent chest—immediately notify HCP
Quick relief/rescue medications for asthma
used to treat acute attacks
Bronchodilators:
- Short-acting inhaled beta2-adrenergic agonists (SABAs)—all patients should have this
- Inhaled anticholinergics; often used with SABA
Antiinflammatory Drugs
- IV corticosteroids
Long-term control medications for asthma
to achieve and maintain control
Bronchodilators:
- Long-acting inhaled or oral beta2-adrenergic agonists (LABAs)
- Methylxanthines
- Anticholinergics
Antiiflammatory Drugs
- Oral or inhaled corticosteroids (ICS)
- Leukotriene modifiers
- Anti-IgE
Short-acting beta-adrenergic agonists (SABA)
Example: albuterol
- Stimulate beta2 receptors in bronchioles to produce bronchodilation
- Most effective for relieving acute bronchospasm with acute attack
- Onset: minutes and duration: 4 to 8 hours
- Prevent release of inflammatory mediators from mast cells
– Take before exercise to prevent attack
- Too frequent use results in tremors, anxiety, tachycardia, palpitations, and nausea
- Not for long-term use
See: Drug Alert
Long-acting beta2-adrenergic agonist drugs (LABA)
Examples: Salmeterol (Serevent), formoterol (Foradil)
- Added to daily ICSs; combination ICS and LABA available
- Used once every 12 hours; decreases the need for SABAs
- Never used for acute attack
Methylxanthines: asthma
Example: theophylline
- Less effective long-term bronchodilator
- Used only as alternative for LABA
- Many drug interactions and side effects
- Action: unknown
- Narrow margin of safety—monitor blood levels
- Toxicity: nausea, vomiting, seizures, insomnia
Anticholinergic drugs for asthma
- Promote bronchodilation by preventing muscles around bronchi from tightening
- Less effective than SABAs for asthma
– Used more with COPD - Not used in routine management; except for severe acute asthma attacks
Three classes of anti-inflammatory drugs for asthma
Corticosteroids
Leukotriene modifiers
Monoclonal antibodies
- Anti-IgE
- Anti-Interleukin 5