Chapter 6 - Pulmonary Disorders Flashcards
PFTs: What is the FVC?
- Volume of gas forcefully expelled after maximum inhalation over the entire course of exhalation
- Normal 80-120% predicted
PFTs: What is the FEV1?
- Volume of gas expelled in the first second of the FVC
* Normal: 80-120% predicted
PFTs: What is the FEV1/FVC?
- A comparison of the amount of gas expelled in the first second with total amount of gas expelled
- Normal: within 5% of the predicted ratio
PFTs: What is the PEFR?
• Maximal airflow rate achieved in FVC maneuver, “peak flow”
Obstructive vs. Restrictive Lung Disease: Obstructive + examples
- Limitation of airflow
- Reduced airflow rates
- Examples: COPD, emphysema, bronchitis, asthma
Obstructive vs. Restrictive Lung Disease: Restrictive + examples
- Limitation of lung expansion
- Reduced volumes
- Examples: ARDS, pneumonia, bronchiolitis, idiopathic pulmonary fibrosis
PFT Spirogram: COPD vs. Normal
- COPD-er: lower FEV1, lower FEV, and it takes longer to expel all air (lungs have less volume and takes longer for lungs to empty)
- Normal: higher FEV1, higher FEV, and it takes less time to expel all air
PFT Indications
- Persistent cough
- Wheeze
- Breathlessness
- Crackles
- Abnormal CXR
- Monitoring for known pulmonary disease
- Investigation of patients with risk factors
- Pre-op evaluation
- Surveillance after lung transplant
PFT Contraindications
- MI within the last month
- Unstable angina
- Recent thoracic or abdominal surgery (causes ↑ ICP and intra-abdominal and intra-thoracic pressure)
- Thoracic and abdominal aneurysm
- Current pneumothorax
Pathophysiology of asthma
• “A common, chronic disorder of the airways that is complex and characterized by variable and recurring symptoms, airflow obstruction, BRONCHIAL HYPERRESPONSIVENESS, AND UNDERLYING INFLAMMATION”
Clinical manifestations of asthma
- Recurrent cough, wheeze, SOB, and/or chest tightness
- Symptoms occur or worsen at night, or with exercise, viral respiratory infections, aeroallergens, and/or pulmonary irritants
- Airflow obstruction that is at least partially reversible identified by an increase in FEV1 ≥ 12% from baseline after short-acting-beta-agonist
Spirometry vs. peak flow meter for asthma
- SPIROMETRY IS NEEDED FOR DIAGNOSIS
* PEAK FLOW METER IS USED FOR MONITORING, NOT DIAGNOSIS
Goals of asthma therapy
- Reduce impairment
- Reduce risk
- Optimize health and function
Assessment of asthma patient
- Classify asthma severity (initial visit) and asthma control (follow-up visits)
- Identify precipitating and exacerbating factors, including comorbid conditions that aggravate asthma
- Identify patients at high risk for exacerbations and death from asthma
- Regularly assess patient’s and family’s knowledge and skills for self-management, including medication device technique
General treatment guidelines for asthma patient
- Short-acting beta2-agonist as acute reliever
- Controller for persistent asthma (inhaled corticosteroid)
- Step-up therapy if not well-controlled
- Written asthma action plan
- Education
What are the two types of asthma reliever medications?
- Acute reliever (rescue) medications: SABAs
* Aggressive treatment for inflammation during flare: systemic corticosteroids
Asthma reliever medications: acute relievers (rescue)
- Short-acting beta2-agonists (SABA), such as albuterol (Proventil), pirbuterol (Maxair), levalbuterol (Xopenex)
- Beta2-agonists = activates the beta2 receptors in airways going to the two lungs
- All asthmatics should have a SABA regardless of asthma classification/severity
- Use > 2x/week (except for exercise) suggests a need for better control
- Drug of choice for preventing exercise-induced bronchospasm (EIB). Use 15-30 minutes prior to activity
Asthma reliever medications: aggressive treatment for inflammation
- Systemic corticosteroids
- Example: prednisone 40-60 mg/d x 3-10 days (average 5-7 days). No therapeutic benefit using an injectable when compared to oral product. Taper usually not needed with this dose and duration
What are the 3 types of asthma controller medications?
- Inhaled corticosteroids (ICS)
- Inhaled corticosteroid/long-acting beta2 agonist (ICS/LABA)
- Leukotriene receptor antagonists (LTRA), leukotriene modifiers (LTM)
Asthma controller medications: inhaled corticosteroids
- Mometasone (Asmanex)
- Fluticasone (Flovent)
- Bedusonide (Pulmicort)
- Beclomethasone (QVAR)
- Ciclesonide (Alvesco)
- Preferred treatment for persistent asthma
- Requires consistent, daily use for optimal effect
Asthma controller medications: Inhaled corticosteroid/long-acting beta2 agonist (ICS/LABA)
- Budesonide + formoterol (Symbicort)
- Fluticasone + salmeterol (Advair)
- Mometasone + formoterol (Dulera)
- ICS with LABA should not be used in patients whose asthma is well-controlled with an ICS alone
Asthma controller medications: Leukotriene receptor antagonists (LTRA), leukotriene modifiers (LTM)
- Montelukast (Singulair)
* Additional benefit with allergic rhinitis, most often used in conjunction with ICS
What are 2 additional medications that can be used for asthma treatment?
- Inhaled muscarinic antagonists (aka inhaled anticholinergics)
- Theophylline
Additional asthma medications: Inhaled muscarinic antagonists (AKA inhaled anticholinergics)
- Bronchodilator via blockage of cholinergic/muscarinic receptors
- Established role in asthma and COPD therapy
- Use primarily for prevention, not treatment, of bronchospasm and prevent asthma flare
- Example of short-acting muscarinic antagonist (SAMA): Ipratropium bromide (Atrovent)
- Example of long-acting muscarinic antagonist (LAMA): Tiotropium bromide (Spiriva)
Additional asthma medications: Theophylline
- Mild-to-moderate bronchodilator
- Usually reserved for when standard therapy isn’t working
- Use requires periodic monitoring of theophylline levels, multiple drug-drug interaction potentials limits clinical utility
- S/s of theophylline toxicity: SEIZURES, INTRACTABLE VENTRICULAR DYSRHYTHMIAS, rhabdo, tremor, vomiting, abdominal pain
Classification of asthma severity: intermittent
- Symptoms: ≤ 2 days/week
- Nighttime awakenings: ≤ 2x/month
- SABA Use: ≤ 2 days/week
- Recommended step for initiating treatment: Step 1, re-evaluate in 2-6 weeks and adjust accordingly if needed
Classification of asthma severity: mild
- Symptoms: > 2 days/week, but not daily
- Nighttime awakenings: 3-4x/month
- SABA Use: > 2 days/week, but not > 1x/day
- Recommended step for initiating treatment: Step 2, re-evaluate in 2-6 weeks and adjust accordingly if needed
Classification of asthma severity: moderate
- Symptoms: daily
- Nighttime awakenings: > 1x/week, but not nightly
- SABA Use: daily
- Recommended step for initiating treatment: Step 3, re-evaluate in 2-6 weeks and adjust accordingly if needed
Classification of asthma severity: severe
- Symptoms: throughout the day
- Nighttime awakenings: often 7x/week
- SABA Use: severe times per day
- Recommended step for initiating treatment: Step 4, re-evaluate in 2-6 weeks and adjust accordingly if needed
Step 1 Asthma Treatment
• SABA PRN
Step 2 Asthma Treatment
- SABA PRN
* Low-dose ICS
Step 3 Asthma Treatment
- SABA PRN
* Medium-dose ICS + LABA
Step 4 Asthma Treatment
- SABA PRN
* High-dose ICS + LABA and consider Omalizumab in those who have allergies
Step 5 Asthma Treatment
• High-dose ICS + LABA + oral corticosteroid and consider Omalizumab in those who have allergies
When needing to step up or down asthma treatment
- Step up if needed – but first check adherence, environmental control, and comorbid conditions
- Step down if possible – asthma well controlled at least 3 months
- If using a SABA > 2 days/week, their asthma is not well controlled
Asthma Exacerbation – Key Indicators and Clinical Management: Mild
- Clinical manifestations: dyspnea only with activity
- Initial PEF or FEV1 (based on personal best): ≥ 70%
- Management: home treatment is okay, SABA, consider systemic corticosteroids, confirm an asthma action plan
Asthma Exacerbation – Key Indicators and Clinical Management: moderate
- Clinical manifestations: Dyspnea interferes with or limits usual activity
- Initial PEF or FEV1 (based on personal best): 40-69%
- Management: Requires provider evaluation (either PCP or their pulmonologist), SABA, Systemic corticosteroids, Confirm an asthma action plan
Asthma Exacerbation – Key Indicators and Clinical Management: severe
- Clinical manifestations: dyspnea with rest, interferes with conversation
- Initial PEF or FEV1 (based on personal best): < 40%
- Management: ED treatment, likely hospitalization, SABA, systemic corticosteroids, adjunct therapies, confirm an asthma action plan
Asthma Exacerbation – Key Indicators and Clinical Management: life-threatening
- Clinical manifestations: to dyspneic to speak, profuse perspiration
- Initial PEF or FEV1 (based on personal best): < 25%
- Management: ED treatment, hospitalization with probable ICU, SABA, systemic corticosteroids, adjunct therapies, confirm an asthma action plan
Warning signs of impending respiratory arrest
- Drowsiness or confusion
- Paradoxical thoracoabdominal movement
- Absence of wheezing
- Bradycardia
- Absence of pulsus paradoxus
- Initial PEF or FEV1 < 25% of personal best/predicted value
Common oxygenation values based on asthma severity
- Mild: normal PaO2, SaO2 > 95%, PCO2 < 42 mmHg
- Moderate: ≥ 60 mmHg, SaO2 90-95%, PCO2 < 42 mmHg
- Severe: PaO2 < 60 mmHg, SaO2 < 90%, PCO2 ≥ 42 mmHg (ABGs indicated at this stage, when PaO2 < 42, consider respiratory failure and intubation)
COPD Pathophysiology
- COPD is a preventable and treatable disease with some significant extrapulmonary effects that may contribute to the severity in individual patients
- Its pulmonary component is characterized by AIRFLOW LIMITATION THAT IS NOT FULLY REVERSIBLE
- Exacerbations and comorbidities contribute to the overall severity in individual patients
What are the most common risk factors for COPD?
- Host factors (genetics)
- Tobacco smoke
- Environmental exposures at home
- Occupational exposures
- Family history of COPD
- Childhood factors
What are the most common symptoms of COPD?
- Chronic cough
- Chronic sputum production
- Activity intolerance
- Symptoms typically progress over time
Who has at highest risk for COPD exacerbations and COPD death?
- Individuals with COPD with a history of ≥ 2 exacerbations within the last year
- FEV1 < 50% of predicted value and/or
- Hospitalization for COPD exacerbation in the past year
Assessment of COPD
Degree of airflow limitation
o SPIROMETRY IS REQUIRED FOR DIAGNOSIS
o FEV1: FVC < .70 (70%) post-bronchodilator confirms persistent airflow limitation/COPD
o Classification of severity determined by FEV1
Alpha-1 antitrypsin deficiency screening
o Perform when COPD develops in patients of Caucasian descent under 45 years old or with a strong family history of COPD
Clinical findings in emphysema vs. bronchitis
- Emphysema: increased AP diameter, hyperresonance on percussion, no mucus production
- Chronic bronchitis: normal AP diameter, normal percussion sounds, copious/blood-tinged mucus
- Findings in both: electrolyte triad (hypokalemia, hypochloremia, increased NaHCO3) and spirometric assessment consistent with obstruction
Lung Percussion Sounds
- Resonance = normal
- Hyperresonance = air-trapping
- Dull = fluid, collection of cells
Step 1 of COPD classification – spirometric classification
• Make the diagnosis of COPD: FEV1/FVC ratio < 70% (0.70)
• Determine the severity (GOLD category)
o GOLD 1 (mild): FEV1 ≥ 80% predicted
o GOLD 2 (moderate): 50% ≤ FEV1 < 80% predicted
o GOLD 3 (severe): 30% ≤ FEV1 < 50% predicted
o GOLD 4 (very severe): FEV1 < 30% predicted
Step 2 of COPD classification – symptom assessment
- COPD Assessment Test (CAT) Score
* Asks questions about coughing, activity, sleep, energy on a scale from 0-5
Step 3 of COPD classification – determine exacerbation risk
- 2 or more exacerbations within the last year indicates a high risk
- 1 or more exacerbations with hospitalization in the last year indicates a high risk
- *exacerbation = symptoms require aggressive treatment with corticosteroids
Combined Assessment of COPD
- Patient Group A: low risk/less symptoms, GOLD 1-2, ≤ 1 exacerbation, no hospitalizations, CAT < 10
- Patient Group B: low risk/more symptoms, GOLD 1-2, ≤ 1 exacerbation, no hospitalizations, CAT ≥ 10
- Patient Group C: high risk/less symptoms, GOLD 3-4, ≥ 2 exacerbations, ≥ 1 hospitalization, CAT < 10
- Patient Group D: high risk/more symptoms, GOLD 3-4, ≥ 2 exacerbations, ≥ 1 hospitalization, CAT ≥ 10
Initial Pharmacologic Therapy for Stable COPD: Group A
- Short-acting or long-acting bronchodilator
* SABA (Albuterol [Ventolin])
Initial Pharmacologic Therapy for Stable COPD: Group B
• LABA + long-acting muscarinic antagonist (tiotropium [Spiriva])
Initial Pharmacologic Therapy for Stable COPD: Group C
- Long-acting muscarinic antagonist (tiotropium [Spiriva])
* Patients with persistent exacerbations may benefit from a second long-acting bronchodilator or a combo LABA + ICS
Initial Pharmacologic Therapy for Stable COPD: Group D
- Long-acting muscarinic antagonist (tiotropium [Spiriva])
* LAMA/LABA can be used as initial therapy in patients with greater dyspnea and/or exercise limitation
COPD exacerbation: pathophysiology
- Exacerbation defined as an acute event characterized by worsening of the patient’s respiratory symptoms that is beyond the day-to-day variations and leads to a change in medication
- Usually a product of respiratory tract infection (viral or bacterial)
- Outpatient treatment is usually sufficient
COPD exacerbation: indications for hospital admission
- Marked increase in intensity of symptoms
- Acute respiratory failure
- Onset of new physical signs
- Failure to respond to initial medicinal treatment
- Presence of serious comorbidities (i.e., heart failure)
- Insufficient home support