Step Up - Diseases Of The Pulmonary System Flashcards
Emphysema - Definition:
Pathologic:
–> Permanent enlargement of air spaces distal to terminal bronchioles due to destruction of alveolar walls.
4th leading cause of death in the US:
COPD
Role of tobacco in asthma:
- Incr. number of activated PMNs and macros.
- Inhibits alpha-1 antitrypsin.
- Free radicals –> Oxidative stress.
In COPD (FEV1, FVC):
- FEV1/FVC <0.80.
- FEV1 is decreased.
- TLC is incr.
- RV is incr.
Pink puffers:
- Thin - due to incr. energy expenditure during breathing.
- When sitting, patients tend to lean forward.
- Patients have a barrel chest (incr. AP diameter of chest).
Blue bloaters:
- Overweight and cyanotic (2o to hypercapnia and hypoxemia).
- Chronic cough and sputum production are characteristic.
- Signs of cor pulmonale may be present in severe long standing disease.
COPD - Signs:
- PROLONGED Forced expiratory time –> >6sec.
- End-expiratory wheezes on forced expiration.
- Decr. breath sounds.
- Inspiratory crackles.
- Tachypnea/tachycardia.
- Cyanosis.
- Hyperresonance on percussion.
- Signs of cor pulmonale.
The lower the FEV1, the more…?
Difficulty one has breathing.
COPD - Definitive diagnostic test:
Spirometry.
COPD - Diagnosis - FEV1:
If FEV1 is 70% of predicted value –> Mild disease.
If FEV1 is 50% of predicted value –> Severe disease.
To diagnose airway obstruction, one must have:
- Normal or Incr. TLC.
2. Decr. FEV1.
Key points in taking history of COPD patients - General:
- History of cardiopulmonary diseases.
- Smoking.
- FHx - COPD, Heart disease, asthma.
- Occupation - industrial dusts, fumes.
- History of respiratory infections.
- Pulmonary medications.
Key points in taking history of COPD patients - Pulmonary symptoms:
- Dyspnea - quantitative severity.
- Cough.
- Sputum production - quantity, quality, duration, hemoptysis.
- Pulm. medications.
Obstructive vs Restrictive lung disease - FEV1:
O –> Low.
R –> Normal or slightly low.
O vs R lung disease - FEV1/FVC:
O –> Low.
R –> Normal or high.
O vs R lung disease - Peak expiratory flow rate:
O –> Low.
R –> Normal.
O vs R lung disease - RV:
O –> High.
R –> Low, normal, or high.
O vs R lung disease - TLC:
O –> High.
R –> Low.
O vs R lung disease - Vital capacity:
O –> Low.
R –> Low.
COPD - Diagnosis - CXR:
- Low sensitivity - Only severe, advanced emphysema will show typical changes.
- Useful in ACUTE EXACERBATION to rule out complications such as pneumonia or pneumothorax.
COPD - Diagnosis - ABG:
Chronic pCO2 retention + decr. pO2.
How faster does FEV1 decline in smokers?
3-4fold the normal rate. –> If smoker quits, then same rate of someone WHO HAS NEVER SMOKED.
In COPD, respiratory symptoms improve within?
1yr of quitting.
Clinical monitoring of COPD patients entails the following:
- Serial FEV1 measurements - this has the highest predictive value.
- Pulse oximetry.
- Exercise tolerance.
COPD - Treatment:
- Bronchodilators (beta-2 agonists, anticholinergics).
2. Steroids + antibiotics for acute exacerbations.
COPD - O2 therapy:
Shown to improve survival and quality of life in patients with COPD + Chronic hypoxemia.
Criteria for continuous or intermittent long-term O2 therapy in COPD:
- PaO2 55mmHg OR,
- SaO2<88% either at rest or during exercise, OR,
- PaO2 55-59mmHg + polycythemia or evidence of cor pulmonale.
COPD - Treatment guidelines - Mild to moderate disease:
- Begin with a bronchodilator in a metered-dose inhaler (MDI) formulation - Anticholinergics or beta-agonists are first-line.
- Inhaled steroids may be used as well - Use LOWEST DOSE POSSIBLE.
COPD at night?
In many patients with COPD, O2 levels decrease during sleep. Look for and treat nocturnal hypoxemia, if present (eg, oxygen, CPAP).
COPD - Treatment guidelines - Severe disease:
- Medications as above.
- Continuous O2 therapy (if patient is hypoxemic).
- Pulmonary rehabilitation.
- Triple inhaler therapy (long-acting beta-agonist plus a long acting anticholinergic plus an inhaled steroid).
Acute COPD exacerbation - Definition:
A persistent incr. in dyspnea (not relieved with bronchodilators).
- -> Incr. sputum + cough are common.
- -> Acute COPD exacerbation can lead to acute respiratory failure requiring hospitalization, and possibly mechanical ventilation - potentially fatal.
What is one of the main precipitants of COPD exacerbations?
Pulm. infection.
COPD - Complications:
- Acute exacerbations - MCC are infection, non compliance with therapy, and cardiac disease.
- Secondary polycythemia (Ht>55% in men, >47% in women) - compensatory response to chronic hypoxemia.
- Pulm. HTN and cor pulmonale - may occur in patients with severe, long-standing COPD who have chronic hypoxemia.
If a patient presents with COPD exacerbation, the following steps are appropriate:
- CXR.
- Beta-2 agonist + anticholinergic inhalers.
- Systemic corticosteroids.
- Antibiotics.
- Supplemental O2.
- Non invasive positive pressure ventilation (NPPV) if needed.
Asthma - Characteristically defined by the triad:
- Airway inflammation.
- Airway responsiveness.
- REVERSIBLE airflow obstruction.
Asthma can begin at what age?
At ANY age.
Signs of acute severe asthma attacks:
- Tachypnea
- Diaphoresis.
- Wheezing.
- Speaking in incomplete sentences.
- Use of accessory muscles of respiration.
Sign of impending respiratory failure:
Paradoxic movement of the abdomen and diaphragm on inspiration.
Asthma - MC finding on physical exam:
Wheezing - during BOTH inspiration + expiration.
All that wheezes is NOT asthma:
Any condition that mimics large-airway bronchospasm can cause wheezing:
- CHF - Due to edema of airways and congestion of bronchial mucosa.
- COPD - Inflamed airways may be narrowed, or bronchospasm may be present.
- Cardiomyopathies, pericardial diseases can lead to edema around the bronchi.
- Lung cancer - due to obstruction of airways (central tumor or mediastinal invasion).
Asthma - Dyspnea is common when?
When the patient is exposed to rapid changes in temperatures and humidity.
Asthma - Diagnosis - What is required?
Pulmonary function tests –> Show obstructive pattern.
Asthma - What confirms diagnosis:
Spirometry before and after bronchodilators can confirm diagnosis by proving reversible airway obstruction.
–> If inhalation of a bronchodilator results in an increase in FEV1 or FVC by at least 12%, airflow obstruction is considered reversible.
PFTs in asthma:
- Decr. FEV1, decr. FVC, decr. FEV1/FVC.
- Incr. in FEV1>12% with albuterol.
- Decr. in FEV1>20% with methacholine or histamine.
- Incr. in diffusion capacity of lung for CO.
In the ED, when patient is SOB, what is the quickest method of asthma diagnosis:
Peak flow measurement (peak expiratory flow rate).
Bronchoprovocation test:
- May be useful when asthma is suspected but PFTs are non diagnostic.
- Measures ease with which airways narrow in response to stimuli.
- Measures lung function before and after inhalation of increasing doses of methacholine –> Hyperresponsive airways develop obstruction at lower doses.
Asthma - Diagnosis - Role of CXR:
Normal in mild cases - severe asthma reveals hyperinflation.
–> Only necessary in severe asthma to exclude other conditions (eg pneumonia, pneumothorax, pneumomediastinum, foreign body).
If PaCO2 is INCREASED in a patient with asthma, what happened?
Incr. PaCO2 is a sign of respiratory muscle fatigue or severe airway obstruction –> Intubation is REQUIRED.
Drugs to be avoided in asthmatics:
Beta-blockers.
Side effects of inhaled steroids:
Due to oropharyngeal deposition:
- Sore throat.
- Oral candidiasis (thrush).
- Hoarseness.
How to minimize inhaled steroid side effects?
Using a spacer with MDIs are rinsing the mouth after use.
For acute asthma exacerbation, test to order:
- PEF - Decr.
- ABG - Incr. A-a gradient.
- CXR - Rule out pneumonia, pneumothorax.
Complications of asthma:
- Status asthmaticus - does NOT respond to standard medications.
- Acute respiratory failure - due to muscle fatigue.
- Pneumothorax, atelectasis, pneumomediastinum.
Aspirin-sensitive asthma should be considered in?
Patients with asthma + nasal polyp.
Bronchiectasis - General features:
PERMANENT, abnormal dilation + destruction of bronchial walls –> Cilia are damaged - Onset usually in CHILDHOOD.
Bronchiectasis - What precipitates the disease?
Infection in a patient with airway obstruction or impaired defense or drainage mechanism.
Bronchiectasis - Cause?
The cause is found in <50% of patients.
Bronchiectasis - Common today?
Less common today, due to modern antibiotics.
Bronchiectasis - Etiology:
- CF - MCC of bronchiectasis - Accounts for half of all cases.
- Infection, humoral immunodeficiency (abnormal lung defense), airway obstruction.
Bronchiectasis - Diagnostic test of choice:
High-resolution CT scan.
Bronchiectasis - Other diagnostic tests:
- PFTs reveal an obstructive pattern.
- CXR is an abnormal finding in most cases, but findings are non specific.
- Bronchoscopy applies in certain cases.
Bronchiectasis - Treatment:
- Antibiotics for acute exacerbations - superimposed infections are signaled by change in quality/quantity of sputum, fever, chest pain, etc.
- Bronchial hygiene is very important:
a. Hydration.
b. Chest physiotherapy to help remove the mucus.
c. Inhaled bronchodilators.
Main goal in treating bronchiectasis:
To prevent the complications of pneumonia + hemoptysis.
Main problem in CF:
Defect in chloride channel protein causes impaired chloride and water transport, which leads to excessively thick, viscous secretions in the respiratory tract, exocrine pancreas, sweat glands, intestines, and GUT.
CF - Typically results in:
- OBSTRUCTIVE lung disease.
- Chronic pulmonary infections (freq. Pseudomonas).
- Pancreatic insufficiency.
- Other GI complications.
CF - Treatment:
- Pancreatic enzyme replacement.
- Fat-soluble vitamin supplements.
- Chest physical therapy.
- Vaccinations (influenza and pneumococcal).
- Treatment of infections with antibiotics.
- Inhaled recombinant deoxy-ribonuclease (rhDNase) –> Breaks down the DNA in respiratory mucus that clogs the airways.
CF - Prognosis:
Median age of death is over 30 yrs.
Lung cancer - Risk factors:
- Cigarette smoking - accounts for >85% of cases –> LINEAR relationship.
- Passive smoke.
- Asbestos - synergistically with smoking.
- Radon - high levels found in basements.
- COPD - an independent risk factor after smoking is taken into account.
SCLC - Staging:
NOT with TNM:
A. Limited –> Confined to chest + supraclavicular nodes, but NOT cervical or axillary nodes.
B. Extensive –> Outside of chest + supraclavicular nodes (85%).
What is the main problem with lung cancer?
Signs + symptoms are generally NON specific for lung cancer, and by the time they are present, disease is usually widespread.
Superior vena cava syndrome in lung cancer patients:
Occurs in 5% of patients - Most commonly with SCLC.
Phrenic nerve palsy in lung cancer:
- Occurs in 1% of patients.
- Phrenic nerve courses through the mediastinum to innervate the diaphragm.
- Results in hemidiaphragmatic paralysis.
Recurrent laryngeal nerve palsy in lung cancer?
- Occurs in 3%.
2. Causes hoarseness.
Horner’s syndrome in lung cancer:
Due to invasion of CERVICAL SYMPATHETIC chain by an apical tumor.
- Unilateral facial anhidrosis (no sweating).
- Ptosis.
- Miosis.
Pancoast’s tumor:
- An apical tumor involving C8 and T1-T2 nerve roots –> Shoulder pain radiating down the arm.
- Usually SCC.
- Associated with Horner’s syndrome 60% of the time.
- Malignant pleural effusion - occurs in 10-15% of patients - Prognosis is very poor - equivalent to distal metastases.
Lung cancers - Paraneoplastic syndromes - Hypertrophic pulmonary osteoarthropathy:
Adenocarcinoma + SCC –> Severe long bone pain may be present.
Prognosis of small cell lung carcinoma:
- For limited disease –> 5yr is 10-15% –> Median survival is 15-20months.
- For extensive disease –> 5yr survival rate is 1-2% –> Median survival is 8-13 months.
Steps for lung cancer diagnosis:
- CXR.
- CT scan.
- Tissue biopsy to confirm diagnosis.
- Determine histologic type.
Lung cancer - Diagnosis - CXR may show what?
Pleural effusion –> Should be examined for malignant cells.
Lung cancer diagnosis - CT scan with IV contrast:
- For staging.
- Extent of local + distant metastases.
- Very accurate in revealing lymphadenopathy in mediastinum.
Lung cancer - Diagnosis - Cytological exam of sputum:
- Diagnoses central tumors (80%) but not peripheral lesions.
- Provides highly variable results; if negative and clinical suspicion is high, further tests are indicated.
Regardless of the findings of CXR and CT, what is required for definitive diagnosis of lung cancer?
Pathologic confirmation.
NSCLC - Treatment:
- Surgery.
- Radiation therapy is an important adjunct.
- Chemo is of uncertain benefit.
SCLC - Treatment:
Limited disease –> Combination of chemo + radiation therapy are used initially.
Extensive disease –> Chemo is used alone as initial treatment. If respond, prophylactic radiation decreases incidence of brain metastases and prolongs survival.
Solitary pulmonary nodule?
A single, well-circumscribed nodule seen on CXR (usually incidentally) with no associated mediastinal or hilar lymph node involvement.
Features that favor benign over malignant nodules:
- Age –> Over 50% chance of malignancy if patient is over 50.
- Smoking –> More likely to be malignant.
- Size of nodule –> The larger the nodule, the more likely to be malignant (small is 2cm).
- Borders - Malignant nodules have more irregular borders. Benign lesions have smooth/discrete borders.
- Calcification - Eccentric asymmetric calcification suggest malignancy. Dense central calcification suggests benign lesion.
- Change is size - enlarging suggests malignancy.
Low probability nodules - Do:
Serial CT scan.
Intermediate probability nodules smaller than 1cm - Do?
Serial CT scan.
Intermediate probability nodule 1cm or larger - Do:
PET scan. If positive, excise the nodule.
High probability nodule - Do:
Excision.
In the evaluation of solitary pulmonary nodule, what is very helpful?
Previous CXR.
Solitary pulmonary nodule - Testing:
- Flexible bronchoscopy - good for central lesions.
- Transthoracic needle biopsy.
- PET scan - determines whether content of lesion is malignant.
Mediastinal masses - MCC:
Metastatic cancer (especially from lung cancer).
Mediastinal masses - MCC according to location:
- Anterior mediastinum –> Thyroid, teratogenic tumors, thymoma, lymphoma.
- Middle mediastinum –> Lung cancer, lymphoma, aneurysms, cysts, Morgagni hernia.
- Posterior mediastinum –> Neurogenic tumors, esophageal masses, enteric cysts, aneurysms, Bochdalek’s hernia.
Mediastinal masses - Clinical features:
- Usually asymptomatic.
- When symptoms are present, they are due to compression or invasion of adjacent structures.
- Cough, sometimes hemoptysis.
- Chest pain, dyspnea.
- Postobstructive pneumonia.
- Dysphagia (compression of esophagus).
- SVC syndrome.
- Compression of nerves:
a. Hoarseness (recurrent laryngeal nerve).
b. Horner’s syndrome (sympathetic ganglia).
c. Diaphragm paralysis (phrenic nerve).
Mediastinal masses - Diagnoses:
- Chest CT is test of choice.
2. Usually discovered incidentally on a CXR performed for another reason.
If CT suggests a benign mass and the patient is asymptomatic, what should be done?
Observation is appropriate.
Pleural effusions - When are they well tolerated?
If the patient has minimal lung compromise.
In the presence of lung disease –> May lead to respiratory failure.
Pleural effusion - Transudate - Etiology:
- CHF
- Cirrhosis
- PE
- Nephrotic syndrome
- Peritoneal dialysis
- Hypoalbuminemia
- Atelectasis
Pleural effusion - Exudate - Etiology:
- Bacterial pneumonia, TB.
- Malignancy, metastatic disease.
- Viral infection.
- PE.
- Collagen vascular diseases.
If an exudative effusion is suspected, perform the following tests on the pleural fluid:
- Differential cell count.
- Glucose.
- pH.
- Amylase.
- Triglycerides.
- Microbiology.
- Cytology.
Pleural effusion - MCC:
CHF
Pleural effusion - Etiology:
- CHF (MCC).
- Pneumonia (bacterial).
- Malignancies: lung (36%), breast (25%), lymphoma (10%).
- PE.
- Viral diseases.
- Cirrhosis with ascites.
Pleural fluid pearls - Elevated pleural fluid amylase:
- Esophageal rupture.
- Pancreatitis.
- Malignancy.
Pleural fluid pearls - Milky, opalescent fluid:
Chylothorax (lymph in the pleural space).
Pleural fluid pearls - Frankly purulent fluid:
Empyema (pus in the pleural space).
Pleural fluid pearls - Bloody effusion:
Malignancy.
Pleural fluid pearls - Exudative effusions that are primarily lymphocytic:
TB
Pleural fluid pearls - pH<7.2?
Parapneumonic effusion or empyema.
Pleural effusion - Clinical features - Symptoms:
- Often asymptomatic.
- Dyspnea on exertion.
- Peripheral edema.
- Orthopnea, paroxysmal nocturnal dyspnea.
Pleural effusion - Signs:
- Dullness to percussion.
- Decr. breath sounds over the effusion.
- Decr. tactile fremitus.
Pleural effusion - Diagnosis - CXR:
PA + Lateral - Look for:
- Blunting of the costophrenic angle.
- About 250mL (!) of fluid must accumulate before an effusion can be detected.
- Lateral decubitus films: More reliable than PA and lateral CXRs for detecting small pleural effusions.
Pleural effusion - Diagnosis - CT scan:
More reliable than CXR for detecting effusions.
Pleural effusion - Diagnosis - Thoracentesis:
- Useful if etiology is NOT obvious. Diagnosis in 75% of patients, and even when NOT diagnostic it provides important clinical information.
- Therapeutic - symptom relief.
- Send fluid –> 4 Cs –> Chemistry (glucose, protein), cytology, cell count (CBC with differential, and Culture.
Pleural effusion - Thoracentesis - Complication:
Pneumothorax –> Complication seen in 10-15% of thoracenteses, but it requires treatment with a chest tube in DO NOT perform if effusion is <10mm thick on lateral internal decubitus CXR.
Pleural effusion - Transudate - Treatment:
- Diuretics and sodium restriction.
2. Therapeutic thoracentesis - only if massive effusion is causing dyspnea.
Pleural effusions - Exudate - Treatment:
Treat underlying disease.
Pleural effusion - Parapneumonic effusion - Pleural effusion in the presence of pneumonia - Treatment:
A. Uncomplicated –> Antibiotics alone (in most cases).
B. Complicated effusions or empyema:
1. Chest tube drainage.
2. Intrapleural injection of thrombolytic agents (streptokinase or urokinase) - May accelerate drainage.
3. Surgical lysis of adhesions may be required.
Empyema can occur?
If exudative pleural effusions are left untreated.
–> Most cases occur as a complication of bacterial pneumonia, but other foci of infection can also spread to the pleural space (eg mediastinitis, abscess).
Empyema - Diagnosis:
- CXR
2. CT scan of the chest are the recommended tests.
Empyema - Treatment:
- Treat empyema with AGGRESSIVE drainage of the pleura (via thoracentesis) + antibiotic therapy.
- Infection is very DIFFICULT to eradicate, and recurrence is common, requiring repeated drainage.
- If empyema is severe and persistent, rib resection and open drainage may be necessary.
Pneumothorax - Definition:
Air in the normal AIRLESS pleural space.
Pneumothorax - 2 major categories:
- Spontaneous
2. Traumatic
Traumatic pneumothoraces are often iatrogenic. Always obtain a CXR after the following procedures:
- Transthoracic needle aspiration.
- Thoracentesis.
- Central line placement.
Spontaneous pneumothorax - Recurrence rate?
50% in 2 yrs.
Secondary (complicated) pneumothorax:
- Occurs as a complication of underlying lung disease, MC COPD.
- More life-threatening because of lack of pulmonary reserve in these patients.
1st step in treatment of spontaneous pneumothorax:
Supplemental O2 hastens the resorption of air in pleural space and is the first treatment.
Pneumothorax - Symptoms:
- Ipsilateral chest pain, usually SUDDEN in onset.
- Dyspnea.
- Cough.
Pneumothorax - Signs:
- Decr. breath sounds over the affected side.
- Hyperresonance over the chest.
- Decr. or absent tactile fremitus on affected side.
- Mediastinal shift TOWARD side of pneumothorax.
Pneumothorax - Diagnosis:
CXR confirms diagnosis - Shows the visceral pleural line.
Pneumothorax - Treatment of primary spontaneous pneumothorax:
A. If small and patient is asymptomatic:
–> Observation - should resolve spontaneously in approx. 10days.
–> Small chest tube (with 1-way valve) may benefit some patients.
B. If larger and/or patient is symptomatic:
–> Administration of supplemental O2.
–> Chest tube insertion to allow air to be released and lung to re-expand.
2o spontaneous pneumothorax - Treatment:
Chest tube drainage.
Tension pneumothorax - General features:
- Accumulation of air within the pleural space such that tissues surrounding the opening into the pleural cavity act as valves, allowing air to enter but not to escape.
- Accumulation of air under (positive) pressure in the pleural space collapses the ipsilateral lung and shifts the mediastinum AWAY from the side of the pneumothorax.
Tension Pneumothorax - Etiology:
- Mechanical ventilation associated with barotrauma.
- CPR.
- Trauma.
Tension pneumothorax - Clinical features:
- Hypotension - cardiac filling is impaired due to compression of the great veins.
- Distended neck veins.
- Shift of trachea AWAY from side of pneumothorax on CXR.
- Decr. breath sounds on affected side.
- Hyperresonance to percussion on side of pneumothorax.
Tension Pneumothorax - Treatment:
Must be treated as a MEDICAL EMERGENCY –> If the tension in the pleural space is NOT relieved, the patient is likely to die of hemodynamic compromise.
—> Immediately perform chest decompression with a large-bore needle (in the 2nd or 3rd intercostal space in the midclavicular line), followed by chest tube.
Malignant mesothelioma - Features:
- Most cases 2o to asbestos exposure.
- Dyspnea, weight loss, and cough are common findings.
- Bloody effusion is common.
- Prognosis is dismal (few month’s survival).