Pulmonology Flashcards
Describe the difference between obstructive and restrictive pulmonary disease on pulmonary function testing.
In COPD, the functional expiratory volume in one second divided by the total forced vital capacity (FEV1/FVC) is less than normal (normal is 0.75-0.80). In restrictive lung disease, FEV1/FVC is often normal. FEV1 may be equal in both conditions, but the ratio of FEV1/FVC is always different.
What causes emphysema?
Almost always due to smoking (even second-hand smoke). If you have a young person with minimal smoke exposure (fewer than 5 years), then think of alpha1-antitrypsin deficiency.
How do you recognize and treat asthma?
Watch for chronic wheezing in “allergic” children with a family history of asthma or allergies. In the acute setting, treat with beta2-agonists. Use steroids if the attack is severe or does not respond. Inhaled glucocorticoids, long-acting beta-agonists, leukotriene modifiers (zafirlukast, zileuton), and cromolyn are prophylactic agents and are not used for acute attacks. Phosphdiesterase inhibitors (theophylline, aminophylline) are older agents that are now infrequently used. Do NOT prescribe beta blockers for asthmatics or patients with COPD; they block beta2 receptors needed to open the airways.
What is a common cause of wheezing in children under age 2 years?
Respiratory syncytial virus infection, which classically occurs in the winter and causes a fever. Asthma also may be the cause but usually is associated with a chronic history.
What should you think if a patient with acute asthma stops hyperventilating or has a normal CO2 level?
Beware the asthmatic who is no longer hyperventilating or whose CO2 is normal or rising. The patient should be hyperventilating, which causes low CO2. If the patient seems calm or sleepy, do NOT assume that he or she is ok. Such patients are probably crashing; they need an immediate ABG analysis and possible intubation. Fatigue alone is sufficient reason to intubate. Remember also that any patient with COPD may normally live with a higher CO2 and lower O2 level. Treat the patient, not the lab value. If the patient is asymptomatic and talking to you, the lab value should not cause panic.
When should you intubate?
As a rough rule of thumb, think about intubation in any patient whose CO2 is more than 50 mmHg or whose O2 is less than 50 mmHg, especially if the pH in either situation is less than 7.30 while the patient is breathing room air. Usually, unless the patient is crashing rapidly, a trial of oxygen by nasal cannula or face mask is given first. If it does not work or if the patient becomes too tired (use of accessory muscles is a good clue), intubate.
What should you do if a patient has a solitary pulmonary nodule on chest radiograph?
Compare the current film with old films (if available). If the lesion has not changes in more than 2-3 years, it is very likely to be benign. A nodule that increased in size on serial imaging should be biopsied or excised. CT scans are used to evaluate and follow a solitary nodule. PET scan can be used to evaluate nodules with intermediate probability of being malignant.
Solitary pulmonary nodule. What should this classic clue make you think of: immigrant?
TB, do a skin test.
Solitary pulmonary nodule. What should this classic clue make you think of: SW United States exposure?
Coccidioides immitis
Solitary pulmonary nodule. What should this classic clue make you think of: cave explorer, exposure to bird droppings, or Ohio/Mississippi River valleys (Midwest)?
Histoplasmosis
Solitary pulmonary nodule. What should this classic clue make you think of: smoker over the age of 50?
Lung cancer, order bronchoscopy and biopsy
Solitary pulmonary nodule. What should this classic clue make you think of: under age 40 with no other risk factors?
Hamartoma
What should you know about pulmonary function in the setting of surgery?
Best indicator of possible postoperative pulmonary complications is preoperative pulmonary function. Best way to reduce pulmonary complications postoperatively is to stop smoking, especially if it is stopped at least 8 weeks prior to surgery. Aggressive pulmonary toilet, incentive spirometry, minimal narcotics, and early ambulation help to prevent or minimize postoperative pulmonary complications. Lastly, remember that the most common cause of a postoperative fever in the first 24 hrs is atelectasis.
How do you recognize and treat adult respiratory distress syndrome (ARDS)?
Results from acute lung injury and causes noncardiogenic pulmonary edema, respiratory distress, and hypoxemia. Common causes are sepsis, major trauma, pancreatitis, shock, near-drowning, and drug overdose. Look for it to develop within 24-48 hrs of the initial insult. Class patient has mottled/cyanotic skin, intercostal retractions, rales or rhonchi, and no improvement of hypoxia with O2 administration. Radiographs show pulmonary edema with normal cardiac silhouette. Treat with intubation, mechanical ventilation with high percentage oxygen, and positive end-expiratory pressure, while addressing the underlying cause.
How is pneumonia diagnosed?
Usually based on clinical findings (rales or rhonchi, fever) plus elevated WBC and abnormal CXR consistent with pneumonia. Sputum and/or blood cultures usually are obtained before empiric antibiotics therapy is begun.
What is the difference between typical and atypical pneumonia?
Typical pneumonia is usually caused by bacteria such as Strep. pneumo or Staph. aureus, the most common causes. Atypical pneumonia may be caused by influenza virus, Mycoplasma, Chlamydia spp., Legionella, Haemophilus, or adenovirus.
