Section 4: Flashcards
Peripherally located lung cancers
Large cell carcinoma
Adenocarcinoma
Lung ca associated with cavitation
Large cell ca
Lung ca associated with pleural effusion with high hyaluronidase levels
Adenocarcinoma
Most common initial presentation of cystic fibrosis
Meconium ileus
Other clinical features of cystic fibrosis
Failure to thrive
Rectal prolapse
Persistent cough
May also present with
- Infertility
- Allergic bronchopulmonary aspergillosis
Cystic Fibrosis:
Best initial and most specific test
2 elevated sweat chloride concentrations (> 60 mEq/ L) obtained on separate days.
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 11299-11300). . Kindle Edition.
List the supportive care in the Rx of cystic fibrosis
Aerosol treatment
Albuterol/ saline
Chest physical therapy with postural drainage
Pancrelipase: Aids digestion in patients with pancreatic dysfunction.
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 11308-11309). . Kindle Edition.
List and explain Rx that improve survival in patients with cystic fibrosis
Ibuprofen is used to reduce inflammatory lung response and slows the patient’s decline.
Azithromycin has also been shown to slow rate of decline in FEV1 in patients < 13 years.
Antibiotics during exacerbations delay progression of lung disease.
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 11311-11314). . Kindle Edition.
What are the other management considerations in cystic fibrosis
Give all routine vaccinations plus pneumococcal and yearly flu vaccines.
Never delay antibiotic therapy (even if fever and tachypnea are absent).
Steroids improve PFTs in the short term, but there’s no persistent benefit when steroids are stopped.
Expectorants (guaifenesin or iodides) are not effective in the removal of respiratory secretions.
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 11316-11318). Kindle Edition.
Antibiotics to Rx cystic fibrosis
- Mild disease
- Documented infection with Pseudomonas or S. aureus
- Resistant pathogens
Mild disease: Give macrolide, trimethoprim-sulfamethoxazole (TMP-SMX), or ciprofloxacin
Documented infection with Pseudomonas or S. aureus: Treat aggressively with piperacillin plus tobramycin or ceftazidime
Resistant pathogens: Use inhaled tobramycin.
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 11319-11326). . Kindle Edition.
Features that indicate benign solitary lung nodule (on chest X-ray): “low risk”
Non-smokers
Lesions
Smooth distinct margins
Calcification typical of benign lesions
- Popcorn: Harmatomas
- Bull’s eye: Granulomas
No change in size of nodule compared to an older X-ray
Features that indicate benign solitary lung nodule (on chest X-ray): “high risk”
>50 years
Lesions >2cm
Smoker
Irregular contours
No calcification
Management of solitary pulmonary nodule
- Find old X-ray for comparison
- If available compare dates and determine doubling time (480 days means beningn lesion)
- Chest X-ray not available: determine low or high risk
- If low risk do spiral CT scan every 3 months for 2 years; nochange - stop CT scans with no further intervention BUT if lesion double manage with open lung biopsy and resection
- If high risk do open lung biopsy and resection
N/B: Doublimg time measures volume and not diameter - doubling time between 1 month and 480 days is suspicious for malignancy
What is A-a gradient?
A-a gradient is alveolar-arterial gradient (PAO2-PaO2 gradient). It is a useful calculation for the assessment of oxygenation. A-a gradient increases with age and is only valid in room air. It is calculated as follows:
PA02-Pa02 gradient = 150 - 1.25 X PaCO2 - PaO2
i.e.,
A-a gradient = [150 - (1.25 X PaCO2) - PaO2]
This gradient is between 5 and 15 mmHg in normal young adults. It increases with all causes of hypoxemia except hypoventilation and high altitude
List the typical physical findings in COPD
Barrel-shaped chest
Clubbing of fingers Increased anterior-posterior diameter of the chest Loud P2 heart sound (sign of pulmonary hypertension)
Edema as a sign of decreased right ventricular output (the blood is backing up due to the pulmonary hypertension)
Laboratory findings in COPD
EKG: Right axis deviation, right ventricular hypertrophy, right atrial hypertrophy
Chest x-ray: Flattening of the diaphragm (due to hyperinflation of the lungs), elongated heart, and substernal air trapping
CBC: Increased hematocrit is a sign of chronic hypoxia. Reactive erythrocytosis from chronic hypoxia is often microcytic. An erythropoietin level is not necessary.
Chemistry: Increased serum bicarbonate is metabolic compensation for respiratory acidosis.
ABG: Should be done even in office-based cases to assess CO2 retention and the need for chronic home oxygen based on pO2 (you expect the pCO2 to rise and the pO2 to fall).
Pulmonary function testing (PFT): You should expect to find the following:
– Decrease in FEV1
– Decrease in FVC from loss of elastic recoil of the lung
– Decrease in the FEV1/ FVC ratio
– Increase in total lung capacity from air trapping
– Increase in residual volume
– Decrease in diffusion capacity lung carbon monoxide (DLCO) caused by destruction of lung interstitium
Chronic medical therapy for COPD
Tiotropium or ipratropium inhaler
Albuterol inhaler
Pneumococcal vaccine: Heptavalent vaccine,
Pneumovax Influenza vaccine: Yearly
Smoking cessation
Long-term home oxygen if the pO2 < 55 or the oxygen saturation is < 88 percent
Name two interventions that lower mortality in COPD
Smoking cessation
Home oxygen therapy (continuous)
Spot Diagnosis: A case of COPD at an early age (< 40) in a nonsmoker who has bullae at the bases of the lungs.
Alpha-1 antitrypsin deficiency
Rx for alpha-1 antotrypsin deficiency
Alpha-1 antitrypsin infusion
What is the most accurate diagnostic test for bronchiectasis?
High-resolution CT scan of the chest.
Medication associated with lung fibrosis
Nitrofurantoin
What is the most common type of cancer in asbestosis?
Lung Cancer
(NOT MESOTHELIOMA)