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USMLE Step 3 > Pulmonology > Flashcards

Flashcards in Pulmonology Deck (235)
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1
Q

Therapy for COPD exacerbation

A

Bronchodilators (inhaled) = nebulized albuterol

Ipratropium (inhaled)

Steroids = prednisone or methylprednisone

Antibiotics = ceftriaxone

Counseling

Influenza vaccine

Pneumococcal vaccine

2
Q

List the most important features of a severe asthma exacerbation

A

Hyperventilation/ increased respiratory rate

Decrease in peak flow

Hypoxia

Respiratory acidosis

Possible absence of wheezing

3
Q

Enumerate the minimum management for patients with SOB

A

Oxygen

Continuous oximeter

CXR

ABG

4
Q

What is the best test to determine a diagnosis of reactive airway disease in an asymptomatic patient suspected of being asthmatic?

A

Methacholine stimulation testing

5
Q

What class of drug is methacholine?

A

Synthetic acetylcholine

6
Q

What happens when methacholine is administered to asthmatic?

A

Methacholine will decrease FEV1 if the patient has asthma.

7
Q

Name the two most frequently used pulmonary function tests

A

FEV1 (forced expiratory volume in one second)

FVC

8
Q

What is the normal adult FEV1/FVC ratio?

A

> 75%

9
Q

Describe the obstructive pattern in PFT

A

An FEV 1/FVC ratio of 70%

Total lung capacity (TLC) will be increased in some obstructive processes, such as COPD, whereas it may be normal or increased in asthma.

10
Q

Name some obstructive lung disease

A

COPD

Asthma

Chronic bronchitis

Bronchiectasis

11
Q

What is the meaning of DLCO

A

Diffusing capacity of carbon monoxide

12
Q

What does DLCO measure?

A

Measures the gas exchange capacity of the capilary-alveolar interface

13
Q

Why is DLCO normal in asthma

A

Because the alveoli are not affected

14
Q

What is the DLCO in COPD

A

The DLCO in COPD is decreased because some alveoli are destroyed and unavailable for gas exchange.

15
Q

Describe the restrictive pattern in PFT

A

Low FEV1, low FVC, but with normal or increased FEV1/FVC

Decreased TLC

An FVC of 80% is suggestive of restriction when the FEV1/FVC ratio is normal.

16
Q

Examples of diseases with restrictive pattern on PFT

A

Obesity

Interstitial lung disease

Inflammatory/fibrosing lung disease

Kyphosis

17
Q

Define hypoxia (or hypoxemia)

A

Defined as a room-air O2 saturation of 88%

or a PaO2 of 55 mm Hg on ABG measurement

or evidence of cor pulmonale.

18
Q

Diagnosis: Hypoxia not responding to supplemental oxygen

A

Shunt physiology

19
Q

Examples of diseases with ventilation-perfusion (V/Q) mismatch

A

Asthma

COPD

Nonmassive pulmonary embolus (PE)

Pneumonia.

20
Q

Features of ventilation-perfusion (V/Q) mismatch

A

Responds to oxygen

Increased arterial-alveolar oxygen (A-a) gradient

21
Q

What is the common cause of hypoventilation?

A

Oversedation from medications

22
Q

Features of hypoventilation

A

Responds to O2

Characterized by a normal A-a gradient

23
Q

Features of hypoxia due to decreased diffusion

A

Responds to O2

Characterized by an A-a gradient

Associated with a very low DLCO.

Le, Tao; Bhushan, Vikas; Herman Bagga (2010-09-21). First Aid for the USMLE Step 3, Third Edition (First Aid USMLE) (Kindle Locations 11153-11157). McGraw-Hill. Kindle Edition.

24
Q

Features of hypoxia due to high altitude

A

Responds to O2

Characterized by a normal A-a gradient

25
Q

Causes of SOB due to shunt physiology

A

Acute respiratory distress syndrome

Significant lobar pneumonia

Patent foramen ovale

Patent ductus arteriosus.

26
Q

Features of SOB due to shunt physiology

A

Typically does not respond to O2

Characterized by an increased A-a gradient

27
Q

Differential diagnosis of Asthma presenting as chronic cough

A

Allergic rhinitis

Postnasal drip

GERD

28
Q

Differential diagnosis of wheezing

A

Asthma

Foreign body aspiration

Laryngeal spasm or irritation

GERD

CHF

29
Q

In asthma management, can inhaled corticosteroids be used in pregnancy

A

Yes, they are safe

30
Q

What is the implication of a normal PaCO2 in during an episode of asthma exacerbation

A

A normal Pco2 suggests that the patient is tiring out and is about to crash

31
Q

Outline the management of acute asthma

A

Initiate short-acting β-agonist (albuterol) therapy (nebulizer or MDI)

Administer a systemic corticosteroid such as methylprednisolone or prednisone

Begin inhaled corticosteroids as well

Follow patients closely with peak flows, and tailor therapy to the response

Chronic antibiotics (without evidence of infection), anticholinergics, cromolyn, and leukotriene antagonists are generally not useful in this setting

32
Q

Outline and explain the management of chronic asthma

A
33
Q

Rx for exercise induced asthma

A

Inhaled bronchodilator prior to exercise

34
Q

What is the management of acute shortness of breath in a patient with COPD?

A

Oxygen and arterial blood gas (ABG)

Chest x-ray

Albuterol, inhaled

Ipratropium, inhaled

Bolus of steroids (e.g., methyl prednisolone)

Chest, heart, extremity, and neurological examination

If fever, sputum, and/ or a new infiltrate is present on chest x-ray, add ceftriaxone and azithromycin for community-acquired pneumonia.

35
Q

When to intubate patients with COPD?

A

Do not intubate patients with COPD for CO2 retention alone. These patients often have chronic CO2 retention. Only intubate if there is a worsening drop in pH indicative of a worse respiratory acidosis. Serum bicarbonate is often elevated due to metabolic alkalosis as compensation for chronic respiratory acidosis.

36
Q

List the typical physical findings in COPD

A

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)

37
Q

Laboratory findings in COPD

A

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

38
Q

Chronic medical therapy for COPD

A

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

39
Q

Name two interventions that lower mortality in COPD

A

Smoking cessation

Home oxygen therapy (continuous)

40
Q

Spot Diagnosis: A case of COPD at an early age (< 40) in a nonsmoker who has bullae at the bases of the lungs.

A

Alpha-1 antitrypsin deficiency

41
Q

Rx for alpha-1 antotrypsin deficiency

A

Alpha-1 antitrypsin infusion

42
Q

What is the most accurate diagnostic test for bronchiectasis?

A

High-resolution CT scan of the chest.

43
Q

Medication associated with lung fibrosis

A

Nitrofurantoin

44
Q

What is the most common type of cancer in asbestosis?

A

Lung Cancer

(NOT MESOTHELIOMA)

45
Q

Causes of silicosis

A

Glass workers

Mining

Sandblasting

Brickyards

46
Q

Causes of berylliosis

A

Electronics

Ceramics

Fluorescent light bulbs

47
Q

Name the interstitial lung disease caused by mercury

A

Pulmonary fibrosis

48
Q

Name the interstitial lung disease caused by cotton

A

Byssinosis

49
Q

Enumerate the PFT in ILD

A

Decreased FEV1

Decreased FVC

FEV1/FVC ratio is normal or increased

Decreased total lung capacity

Decreased DLCO

All the measures are decreased, but they are decreased proportionately.

50
Q

List and explain the rare physical findings in Sarcoidosis

A

Eye: Uveitis that can be sight threatening

Neural: Seventh cranial nerve involvement is the most common.

Skin: Lupus pernio (purplish lesion of the skin of the face), erythema nodosum

Cardiac: Restrictive cardiomyopathy, cardiac conduction defects

Renal and hepatic involvement: Occurs without symptoms

Hypercalcemia: This occurs in a small number of patients secondary to vitamin D production by the granulomas of sarcoidosis.

51
Q

Best initial test for Sarcoidosis

A

Chest x-ray, which always shows enlarged lymph nodes.

52
Q

Most accurate diagnostic test for Sarcoidosis

A

Lung or lymph node biopsy showing noncaseating granulomas.

53
Q

Other important but non-specific tests for Sarcoidosis

A

Calcium and ACE levels may be elevated, but these are not specific enough to lead to a specific diagnosis.

Bronchoalveolar lavage shows increased numbers of helper cells.

54
Q

Therapy for Sarcoidosis

A

Steroids

55
Q

Secondary causes of pulmonary hypertension

A

Mitral stenosis

COPD

Polycythemia vera

Chronic pulmonary emboli

Interstitial lung disease

56
Q

Physical findings in pulmonary hypertension

A

Loud P2

Tricuspid regurgitation

Right ventricular heave

Raynaud’s phenomenon

57
Q

List and explain diagnostic tests in pulmonary hypertension

A

Transthoracic echocardiogram (TTE): Shows right ventricular hypertrophy and enlarged right atrium

EKG: Shows the same findings as well as right axis deviation

Most accurate test: Right heart catheterization (Swan-Ganz catheterization) with increased pulmonary artery pressure

58
Q

Enumerate Rx for pulmonary hypertension

A

Bosentan is an endothelin inhibitor that prevents growth of the vasculature of the pulmonary system.

Epoprostenol and treprostinil are prostacyclin analogs that act as pulmonary vasodilators.

Calcium channel blockers (weak efficacy)

Sildenafil

59
Q

Describe pulmonary embolism (PE)

A

PE presents with the sudden onset of shortness of breath and clear lungs in patients with risk factors for deep venous thrombosis (DVT).

60
Q

List the risk factors for DVT

A

Immobility

Malignancy

Trauma

Surgery, especially joint replacement

Thrombophilia, such a factor V mutation, lupus anticoagulant, or protein C and S deficiency

61
Q

What are the specific physical findings in PE?

A

None

62
Q

Diagnostic tests for PE

A

Chest x-ray: The most common result is normal. The most common abnormality found is atelectasis. Wedge-shaped infarction and pleural-based humps are rare.

EKG: The most common showing is sinus tachycardia. The most common abnormality is nonspecific ST-T wave changes. Right axis deviation and right bundle branch block are uncommon.

ABG: This shows hypoxia with an increased A-a gradient and mild respiratory alkalosis.

63
Q

List and explain the confirmatory test for PE

A

Spiral CT

A spiral CT is standard to confirm the presence of a pulmonary embolus. The spiral CT is excellent if it is positive because of its specificity. The sensitivity of spiral CT may not be ideal, and the test can miss some emboli if they are small and in the periphery. The spiral CT is clearly the test of choice if the x-ray is abnormal.

V/ Q Scan

For a V/ Q scan to be accurate, the chest x-ray must be normal. The less normal the x-ray, the less accurate the V/ Q scan. This is still a good test for PE. The problem is that only a truly normal scan excludes a PE. Of patients with low-probability scans, 15 percent still have a PE, and 15 percent of those with of high-probability scans don’t have a PE.

Lower Extremity Doppler

These are excellent tests if they are positive; if positive, no further diagnostic testing is necessary. The problem is that 30 percent of PEs originate in pelvic veins, and the Doppler scan is normal even in the presence of a PE. Hence, the sensitivity of lower extremity Doppler is about 70 percent.

D-Dimer Testing

This is a very sensitive test with poor specificity. If the D-dimer is negative, PE is extremely unlikely. The best use of D-dimer testing is in a patient with a low probability of PE in whom you want a single test to exclude PE.

Angiography

Angiography is the single most accurate test for PE. Unfortunately, angiography is invasive with a significant risk of death of about 0.5 percent.

64
Q

When a patient has a pulmonary embolism and there is a contraindication to anticoagulation, what should be the next line of action?

A

Place an inferior vena cava filter

65
Q

Outline the Rx for PE

A

Heparin and oxygen: This is the standard of care in pulmonary embolism.

Warfarin: Should be used for at least 6 months after the use of heparin.

Venous interruption filter: This should be placed in all patients who have a contraindication to anticoagulation.

Thrombolytics: These are used in patients who are hemodynamically unstable. Hemodynamic instability can be defined as hypotension. Thrombolytics essentially replace embolectomy, which is rarely performed because of the high operative mortality.

66
Q

Diagnostic tests for pleural effusion

A

Best initial test: Chest x-ray. Decubitus films with the patient lying on one side should be done next to see if the fluid is freely flowing.

Chest CT may add a little more detail to a chest x-ray.

Most accurate test: Thoracentesis

67
Q

List the tests to be carried on pleural fluid for a patient with pleural effusion

A

Gram stain and culture

Acid-fast stain

Total protein (also order serum protein)

LDH (also order serum LDH)

Glucose

Cell count w/ differential

Triglycerides

pH

68
Q

Name causes of transudative pleural effusion

A

CHF

Pulmonary embolism

Liver Cirrhosis

Nephrotic syndrome

Atelectasis

69
Q

Name causes of exudative pleural effusion

A

Pneumonia (parapneumonic effusions)

Cancer (lung, breast, lymphoma)

Empyema

Pulmonary embolism

Tuberculosis (TB)

Collagen Vascular Diseases (RA, SLE)

Pancreatitis

Drug induced

70
Q

List the features of transudative pleural effusion

A

LDH (lactate dehydrogenase) of pleural effusion of

LDH Pleural/Serum ratio

Protein Pleural/Serum ratio

(Remember 200, 0.6 and 0.5)

71
Q

List the features of exudative pleural effusion

A

LDH (lactate dehydrogenase) of pleural effusion of >200 IU/mL

LDH Pleural/Serum ratio >0.6

Protein Pleural/Serum ratio >0.5

72
Q

Rx of pleural effusion

A

Small pleural effusions do not need therapy.

Diuretics can be used, especially for those caused by congestive heart failure (CHF).

For larger effusions, especially those caused by infection (empyema), a chest tube for drainage is placed.

If the effusion is large and recurrent from a cause that cannot be corrected, pleurodesis is performed. Pleurodesis is the infusion of an irritative agent, such as bleomycin or talcum powder, into the pleural space. This inflames the pleura, causing fibrosis so the lung will stick to the chest wall. When the pleural space is eliminated, the effusion cannot reaccumulate.

If pleurodesis fails, decortication is performed. Decortication is the stripping off of the pleura from the lung so it will stick to the interior chest wall. This is an operative procedure.

73
Q

Management of central sleep apnea

A

Central sleep apnea is managed by avoiding alcohol and sedatives.

It may respond to acetazolamide, which causes a metabolic acidosis. This may help drive respiration.

Some patients respond to medroxyprogesterone, which is also a central respiratory stimulant.

74
Q

Diagnosis: Patient presents as an asthmatic with worsening asthma symptoms who is coughing up brownish mucous plugs with recurrent infiltrates. There is peripheral eosinophilia. Serum IgE is elevated. Central bronchiectasis is visible.

A

Allergic Bronchopulmonary Aspergillosis (ABPA)

75
Q

Diagnostic tests for ABPA

A

Aspergillus skin testing

Measurement of IgE levels, circulating precipitins, and A. fumigatus-specific antibodies

76
Q

Rx of ABPA

A

Corticosteroids

Itraconazole for refractory disease

77
Q

List the causes of acute respiratory distress syndrome (ARDS)

A

Sepsis

Aspiration of gastric contents

Shock Infection: pulmonary or systemic

Lung contusion

Trauma

Toxic inhalation

Near drowning

Pancreatitis

Burns

78
Q

Diagnostics tests for ARDS

A

Chest x-ray: This shows diffuse patchy infiltrates that become confluent. May suggest congestive failure.

Normal wedge pressure

pO2/ FIO2 ratio < 200, with the FIO2 expressed as a decimal (e.g., room air is 0.21). For example, if the pO2 is 100/ 0.21, the ratio is 476.

79
Q

Rx of ARDS

A

Ventilatory support with low tidal volume of 6 mL per kg

Positive end expiratory pressure (PEEP) to keep the alveoli open

Prone positioning of the patient’s body

Possible use of diuretics and positive inotropes, such as dobutamine

Transfer the patient to the ICU if not already there

80
Q

What is the role of steroids in ARDS?

A

None; they are ineffective in ARDS

81
Q

Swan-Ganz (Pulmonary Artery) Catheterization. Types of shocks and features on pulm artery pressure

A
82
Q

Most likely organism for community-acquired pneumonia (CAP)

A

Pneumococcus

83
Q

Most likely organism for hospital-acquired pneumonia (HAP)

A

Gram negative bacilli

84
Q

Diagnostic tests for pneumonia

A

Best initial diagnostic test: Chest x-ray

Most accurate test: Sputum Gram stain and culture

Order tests as follows: All cases of respiratory disease (fever, cough, sputum) should have a chest x-ray and oximeter ordered with the first screen.

If there is shortness of breath, also order oxygen with the first screen.

If there is shortness of breath and/ or hypoxia, order an ABG.

85
Q

Rx for outpatient pneumonia

A

Macrolide (azithromycin, doxycycline, or clarithromycin)

Respiratory fluoroquinolone (levofloxacin, moxifloxacin)
86
Q

Rx for inpatient pneumonia

A

Ceftriaxone and azithromycin

Fluoroquinolone as a single agent

87
Q

What is ventilator-assisted pneumonia (VAP)?

A
  • Fever
  • Hypoxia
  • New infiltrate
  • Increasing secretions
88
Q

Rx for VAP

A
  • Imipenem or meropenem, piperacillin/ tazobactam or cefepime;
  • Gentamicin; and
  • Vancomycin or linezolid
89
Q

When is steroid indicated in PCP?

A

Steroids are indicated if the pO2 < 70 or the A-a gradient > 35.

90
Q

Patient with pneumonia who had a recent viral infection, what is the likely causative agent?

A

Staphylococcus

91
Q

Patient with pneumonia who is an alcoholic, what is the likely causative agent?

A

Klebsiella

92
Q

Patient with pneumonia who has gastrointestinal symptoms and confusion, what is the likely causative agent?

A

Legionella

93
Q

Young healthy patient with pneumonia, what is the most likely causative organism?

A

Mycoplasma

94
Q

Patient with pneumonia who was present at the birth of an animal, what is the likely causative agent?

A

Coxiella burneti

95
Q

Pneumonia in an Arizona construction worker, what is the likely causative agent?

A

Coccidioidomycosis

96
Q

HIV Patient with pneumonia with a CD4+ count less than 200, what is the likely causative agent?

A

PCP

97
Q

Risk groups for tuberculosis (TB)

A

Immigrants

HIV-positive patients

Homeless patients

Prisoners

Alcoholics

98
Q

Diagnostic tests for TB

A

Best initial test: Chest x-ray

Sputum acid-fast stain and culture should be done to confirm the presence of TB

99
Q

Rx for TB

A

Once the acid-fast stain is positive, treatment with 4 antituberculosis medications should be started. Six months of therapy is the standard of care.

  1. Isoniazid (INH): 6 months
  2. Rifampin: 6 months
  3. Pyrazinamide: Stop after 2 months
  4. Ethambutol: Stop after 2 months
100
Q

List the complications of TB medications

A

Isoniazid: Peripheral neuropathy

Rifampin: Red/ orange-colored bodily secretions

Pyrazinamide: Hyperuricemia

Ethambutol: Optic neuritis

All of these medications can lead to liver toxicity. TB medications should be stopped if the transaminases reach 5 times the upper limit of normal

101
Q

Under what conditions should TB Rx be extended beyond 6 months

A

Osteomyelitis

Meningitis

Miliary tuberculosis

Cavitary tuberculosis

Pregnancy

102
Q

Diagnostic tests for latent TB

A

The PPD is a screening test for those in risk groups, such as the homeless, immigrants, alcoholics, health care workers, and prisoners. A positive test is as follows:

5 mm: Close contacts, steroid users, HIV-positive

10 mm: Those in the risk groups described above

15 mm: Those without an increased risk

If a patient has never been tested or it has been several years since the last test, 2-stage testing is recommended. This means that if the first test is negative, a second test should be performed in 1– 2 weeks to make sure the first test was truly negative.

103
Q

What are te steps to follow for a positive PPD?

A

If the PPD is positive, proceed as follows:

  1. A chest x-ray should be performed to make sure occult active disease has not been detected.
  2. If the chest x-ray is abnormal, sputum staining for tuberculosis is performed.
  3. If this is positive, then full-dose, 4-drug therapy is used.

Isoniazid alone is used for 9 months to treat a positive PPD. This reduces the 10 percent lifetime risk of developing tuberculosis to 1 percent. Once a PPD is positive, the test should never be repeated.

104
Q

What other screening tests can be performed in place of PPD?

A

Interferon gamma release assay (IGRA) (Quantiferon) is an in-vitro blood test that is used for the detection of latent tuberculosis. The indication for an IGRA is the same as for a PPD. The main difference is that the IGRA is more specific than a PPD. There are no false positives on an IGRA with previous BCG infection.

Bacille-Calmette Guerin (BCG) administration in the past has no effect or influence on these recommendations for treatment of latent TB. It does not matter if a patient has had BCG in the past; the patient must still take isoniazid if the PPD is positive. If BCG is an answer choice, it is always wrong according to current guidelines.

IGRAs have a 90 percent sensitivity for previous TB exposure. A positive test is treated with INH alone. A positive IGRA does not mean active infection. As with a PPD, a positive IGRA confers only a 10 percent lifetime risk of TB.

105
Q

Diagnosis: Decreased TLC, Decreased RV, Decreased VC, Normal FEV1, Normal FEV1/FVC ratio, Normal DLCO

A

Extra-parenchymal (extra-thoracic) restriction

  • Kyphosis
  • Obesity
106
Q

Diagnosis: Increased TLC, Increased RV, Decreased FEV1, Decreased FVC, Decreased FEV1/FVC ratio, Decreased DLCO

A

COPD

107
Q

Diagnosis: Normal or Increased TLC, Normal or Increased RV, Decreased FEV1, Decreased FVC, Normal or Decreased FEV1/FVC ratio, Normal or Increased DLCO

A

Asthma

108
Q

Diagnosis: Decreased TLC, Decreased RV, Decreased FEV1, Decreased FVC, Normal or Increased FEV1/FVC ratio, Decreased DLCO

A

Fibrotic (or Interstitial Lung) Disease

109
Q

List the minimum that should be done for all patients with shortness of breath (SOB)

A

Oxygen

Continuous oximeter

Chest X-ray

Arterial blood gas (ABG)

110
Q

Causes of low DLCO

A

Emphesema

Pneumonectomy

Interstitial lung disease

pulmonary embolism

Pulmonary HTN

111
Q

Arterial blood gases measurements

A

pH: 7.35 to 7.45

PCO2: 33-45mmHg

PO2: 75-105mmHg

112
Q

Which is the only form of interstitial lung disease that responds to steroid and why?

A

Berryliosis, because it is a granulomatous disease

113
Q

List the diagnostic tests in ILD and explain the findings in each test

A

CXR: interstitial fibrosis

High-resolution CT scan: more detail of interstitial fibrosis

Lung biopsy

PFT

114
Q

What is BOOP?

A

Bronchiolitis obliterans organizing pneumonia

115
Q

What is another name for bronciolitis obliterans organizing pneumonia (BOOP)?

A

Cryptogenic organizing pneumonia (COP)

116
Q

Compare BOOP/COP and ILD

A
  • Fever, myalgias, malaise (clubbing uncommon) present in BOOP; No fever, no myalgias in ILD
  • Symptoms presents over days to weeks in BOOP; Symptoms present over six months or more in ILD
  • Patchy infiltrates in BOOP; Interstitial infiltrates in ILD
  • Steroids effective in BOOP; ILD rarely responds to steroids
117
Q

The two most common lung cancers

A

Adenocarcinoma

Squamous cell carcinoma

118
Q

Centrally located lung carcinomas

A

Squamous cell ca

Small cell ca

119
Q

What lung ca is associated with Eaton-Lambert syndrome, syndrome of inappropriate antidiurectic hormone and other paraneoplastic syndromes

A

Small cell ca

120
Q

Type of lung ca most commonly associated with venocaval obstruction syndrome

A

Small cell ca

121
Q

Peripherally located lung cancers

A

Large cell carcinoma

Adenocarcinoma

122
Q

Lung ca associated with cavitation

A

Large cell ca

123
Q

Lung ca associated with pleural effusion with high hyaluronidase levels

A

Adenocarcinoma

124
Q

Most common initial presentation of cystic fibrosis

A

Meconium ileus

125
Q

Other clinical features of cystic fibrosis

A

Failure to thrive

Rectal prolapse

Persistent cough

May also present with

  • Infertility
  • Allergic bronchopulmonary aspergillosis
126
Q

Best initial and most specific test

A

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.

127
Q

List the supportive care in the Rx of cystic fibrosis

A

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.

128
Q

List and explain Rx that improve survival in patients with cystic fibrosis

A

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.

129
Q

What are the other management considerations in cystic fibrosis

A

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.

130
Q

Antibiotics to Rx cystic fibrosis

A

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.

131
Q

Features that indicate benign solitary lung nodule (on chest X-ray): “low risk”

A

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

132
Q

Features that indicate benign solitary lung nodule (on chest X-ray): “high risk”

A

>50 years

Lesions >2cm

Smoker

Irregular contours

No calcification

133
Q

Management of solitary pulmonary nodule

A
  • 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

134
Q

What is A-a gradient?

A

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

135
Q
A
136
Q

List the typical physical findings in COPD

A

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)

137
Q

Laboratory findings in COPD

A

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

138
Q

Chronic medical therapy for COPD

A

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

139
Q

Name two interventions that lower mortality in COPD

A

Smoking cessation

Home oxygen therapy (continuous)

140
Q

Spot Diagnosis: A case of COPD at an early age (< 40) in a nonsmoker who has bullae at the bases of the lungs.

A

Alpha-1 antitrypsin deficiency

141
Q

Rx for alpha-1 antotrypsin deficiency

A

Alpha-1 antitrypsin infusion

142
Q

What is the most accurate diagnostic test for bronchiectasis?

A

High-resolution CT scan of the chest.

143
Q

Medication associated with lung fibrosis

A

Nitrofurantoin

144
Q

What is the most common type of cancer in asbestosis?

A

Lung Cancer

(NOT MESOTHELIOMA)

145
Q

Causes of silicosis

A

Glass workers

Mining

Sandblasting

Brickyards

146
Q

Causes of berylliosis

A

Electronics

Ceramics

Fluorescent light bulbs

147
Q

Name the interstitial lung disease caused by mercury

A

Pulmonary fibrosis

148
Q

Name the interstitial lung disease caused by cotton

A

Byssinosis

149
Q

Enumerate the PFT in ILD

A

Decreased FEV1

Decreased FVC

FEV1/FVC ratio is normal or increased

Decreased total lung capacity

Decreased DLCO

All the measures are decreased, but they are decreased proportionately.

150
Q

List and explain the rare physical findings in Sarcoidosis

A

Eye: Uveitis that can be sight threatening

Neural: Seventh cranial nerve involvement is the most common.

Skin: Lupus pernio (purplish lesion of the skin of the face), erythema nodosum

Cardiac: Restrictive cardiomyopathy, cardiac conduction defects

Renal and hepatic involvement: Occurs without symptoms

Hypercalcemia: This occurs in a small number of patients secondary to vitamin D production by the granulomas of sarcoidosis.

151
Q

Best initial test for Sarcoidosis

A

Chest x-ray, which always shows enlarged lymph nodes.

152
Q

Most accurate diagnostic test for Sarcoidosis

A

Lung or lymph node biopsy showing noncaseating granulomas.

153
Q

Other important but non-specific tests for Sarcoidosis

A

Calcium and ACE levels may be elevated, but these are not specific enough to lead to a specific diagnosis.

Bronchoalveolar lavage shows increased numbers of helper cells.

154
Q

Therapy for Sarcoidosis

A

Steroids

155
Q

Secondary causes of pulmonary hypertension

A

Mitral stenosis

COPD

Polycythemia vera

Chronic pulmonary emboli

Interstitial lung disease

156
Q

Physical findings in pulmonary hypertension

A

Loud P2

Tricuspid regurgitation

Right ventricular heave

Raynaud’s phenomenon

157
Q

List and explain diagnostic tests in pulmonary hypertension

A

Transthoracic echocardiogram (TTE): Shows right ventricular hypertrophy and enlarged right atrium

EKG: Shows the same findings as well as right axis deviation

Most accurate test: Right heart catheterization (Swan-Ganz catheterization) with increased pulmonary artery pressure

158
Q

Enumerate Rx for pulmonary hypertension

A

Bosentan is an endothelin inhibitor that prevents growth of the vasculature of the pulmonary system.

Epoprostenol and treprostinil are prostacyclin analogs that act as pulmonary vasodilators.

Calcium channel blockers (weak efficacy)

Sildenafil

159
Q

Describe pulmonary embolism (PE)

A

PE presents with the sudden onset of shortness of breath and clear lungs in patients with risk factors for deep venous thrombosis (DVT).

160
Q

List the risk factors for DVT

A

Immobility

Malignancy

Trauma

Surgery, especially joint replacement

Thrombophilia, such a factor V mutation, lupus anticoagulant, or protein C and S deficiency

161
Q

What are the specific physical findings in PE?

A

None

162
Q

Diagnostic tests for PE

A

Chest x-ray: The most common result is normal. The most common abnormality found is atelectasis. Wedge-shaped infarction and pleural-based humps are rare.

EKG: The most common showing is sinus tachycardia. The most common abnormality is nonspecific ST-T wave changes. Right axis deviation and right bundle branch block are uncommon.

ABG: This shows hypoxia with an increased A-a gradient and mild respiratory alkalosis.

163
Q

List and explain the confirmatory test for PE

A

Spiral CT

A spiral CT is standard to confirm the presence of a pulmonary embolus. The spiral CT is excellent if it is positive because of its specificity. The sensitivity of spiral CT may not be ideal, and the test can miss some emboli if they are small and in the periphery. The spiral CT is clearly the test of choice if the x-ray is abnormal.

V/ Q Scan

For a V/ Q scan to be accurate, the chest x-ray must be normal. The less normal the x-ray, the less accurate the V/ Q scan. This is still a good test for PE. The problem is that only a truly normal scan excludes a PE. Of patients with low-probability scans, 15 percent still have a PE, and 15 percent of those with of high-probability scans don’t have a PE.

Lower Extremity Doppler

These are excellent tests if they are positive; if positive, no further diagnostic testing is necessary. The problem is that 30 percent of PEs originate in pelvic veins, and the Doppler scan is normal even in the presence of a PE. Hence, the sensitivity of lower extremity Doppler is about 70 percent.

D-Dimer Testing

This is a very sensitive test with poor specificity. If the D-dimer is negative, PE is extremely unlikely. The best use of D-dimer testing is in a patient with a low probability of PE in whom you want a single test to exclude PE.

Angiography

Angiography is the single most accurate test for PE. Unfortunately, angiography is invasive with a significant risk of death of about 0.5 percent.

164
Q

When a patient has a pulmonary embolism and there is a contraindication to anticoagulation, what should be the next line of action?

A

Place an inferior vena cava filter

165
Q

Outline the Rx for PE

A

Heparin and oxygen: This is the standard of care in pulmonary embolism.

Warfarin: Should be used for at least 6 months after the use of heparin.

Venous interruption filter: This should be placed in all patients who have a contraindication to anticoagulation.

Thrombolytics: These are used in patients who are hemodynamically unstable. Hemodynamic instability can be defined as hypotension. Thrombolytics essentially replace embolectomy, which is rarely performed because of the high operative mortality.

166
Q

Diagnostic tests for pleural effusion

A

Best initial test: Chest x-ray. Decubitus films with the patient lying on one side should be done next to see if the fluid is freely flowing.

Chest CT may add a little more detail to a chest x-ray.

Most accurate test: Thoracentesis

167
Q

List the tests to be carried on pleural fluid for a patient with pleural effusion

A

Gram stain and culture

Acid-fast stain

Total protein (also order serum protein)

LDH (also order serum LDH)

Glucose

Cell count w/ differential

Triglycerides

pH

168
Q

Name causes of transudative pleural effusion

A

CHF

Pulmonary embolism

Liver Cirrhosis

Nephrotic syndrome

Atelectasis

169
Q

Name causes of exudative pleural effusion

A

Pneumonia (parapneumonic effusions)

Cancer (lung, breast, lymphoma)

Empyema

Pulmonary embolism

Tuberculosis (TB)

Collagen Vascular Diseases (RA, SLE)

Pancreatitis

Drug induced

170
Q

List the features of transudative pleural effusion

A

LDH (lactate dehydrogenase) of pleural effusion of <200 IU/mL

LDH Pleural/Serum ratio <0.6

Protein Pleural/Serum ratio <0.5

(Remember 200, 0.6 and 0.5)

171
Q

List the features of exudative pleural effusion

A

LDH (lactate dehydrogenase) of pleural effusion of >200 IU/mL

LDH Pleural/Serum ratio >0.6

Protein Pleural/Serum ratio >0.5

172
Q

Rx of pleural effusion

A

Small pleural effusions do not need therapy.

Diuretics can be used, especially for those caused by congestive heart failure (CHF).

For larger effusions, especially those caused by infection (empyema), a chest tube for drainage is placed.

If the effusion is large and recurrent from a cause that cannot be corrected, pleurodesis is performed. Pleurodesis is the infusion of an irritative agent, such as bleomycin or talcum powder, into the pleural space. This inflames the pleura, causing fibrosis so the lung will stick to the chest wall. When the pleural space is eliminated, the effusion cannot reaccumulate.

If pleurodesis fails, decortication is performed. Decortication is the stripping off of the pleura from the lung so it will stick to the interior chest wall. This is an operative procedure.

173
Q

Management of central sleep apnea

A

Central sleep apnea is managed by avoiding alcohol and sedatives.

It may respond to acetazolamide, which causes a metabolic acidosis. This may help drive respiration.

Some patients respond to medroxyprogesterone, which is also a central respiratory stimulant.

174
Q

Diagnosis: Patient presents as an asthmatic with worsening asthma symptoms who is coughing up brownish mucous plugs with recurrent infiltrates. There is peripheral eosinophilia. Serum IgE is elevated. Central bronchiectasis is visible.

A

Allergic Bronchopulmonary Aspergillosis (ABPA)

175
Q

Diagnostic tests for ABPA

A

Aspergillus skin testing

Measurement of IgE levels, circulating precipitins, and A. fumigatus-specific antibodies

176
Q

Rx of ABPA

A

Corticosteroids

Itraconazole for refractory disease

177
Q

List the causes of acute respiratory distress syndrome (ARDS)

A

Sepsis

Aspiration of gastric contents

Shock Infection: pulmonary or systemic

Lung contusion

Trauma

Toxic inhalation

Near drowning

Pancreatitis

Burns

178
Q

Diagnostics tests for ARDS

A

Chest x-ray: This shows diffuse patchy infiltrates that become confluent. May suggest congestive failure.

Normal wedge pressure

pO2/ FIO2 ratio < 200, with the FIO2 expressed as a decimal (e.g., room air is 0.21). For example, if the pO2 is 100/ 0.21, the ratio is 476.

179
Q

Rx of ARDS

A

Ventilatory support with low tidal volume of 6 mL per kg

Positive end expiratory pressure (PEEP) to keep the alveoli open

Prone positioning of the patient’s body

Possible use of diuretics and positive inotropes, such as dobutamine

Transfer the patient to the ICU if not already there

180
Q

What is the role of steroids in ARDS?

A

None; they are ineffective in ARDS

181
Q

Swan-Ganz (Pulmonary Artery) Catheterization. Types of shocks and features on pulm artery pressure

A
182
Q

Most likely organism for community-acquired pneumonia (CAP)

A

Pneumococcus

183
Q

Most likely organism for hospital-acquired pneumonia (HAP)

A

Gram negative bacilli

184
Q

Diagnostic tests for pneumonia

A

Best initial diagnostic test: Chest x-ray

Most accurate test: Sputum Gram stain and culture

Order tests as follows: All cases of respiratory disease (fever, cough, sputum) should have a chest x-ray and oximeter ordered with the first screen.

If there is shortness of breath, also order oxygen with the first screen.

If there is shortness of breath and/ or hypoxia, order an ABG.

185
Q

Rx for outpatient pneumonia

A

Macrolide (azithromycin, doxycycline, or clarithromycin)

Respiratory fluoroquinolone (levofloxacin, moxifloxacin)
186
Q

Rx for inpatient pneumonia

A

Ceftriaxone and azithromycin

Fluoroquinolone as a single agent

187
Q

What is ventilator-assisted pneumonia (VAP)?

A
  • Fever
  • Hypoxia
  • New infiltrate
  • Increasing secretions
188
Q

Rx for VAP

A
  • Imipenem or meropenem, piperacillin/ tazobactam or cefepime;
  • Gentamicin; and
  • Vancomycin or linezolid
189
Q

When is steroid indicated in PCP?

A

Steroids are indicated if the pO2 < 70 or the A-a gradient > 35.

190
Q

Patient with pneumonia who had a recent viral infection, what is the likely causative agent?

A

Staphylococcus

191
Q

Patient with pneumonia who is an alcoholic, what is the likely causative agent?

A

Klebsiella

192
Q

Patient with pneumonia who has gastrointestinal symptoms and confusion, what is the likely causative agent?

A

Legionella

193
Q

Young healthy patient with pneumonia, what is the most likely causative organism?

A

Mycoplasma

194
Q

Patient with pneumonia who was present at the birth of an animal, what is the likely causative agent?

A

Coxiella burneti

195
Q

Pneumonia in an Arizona construction worker, what is the likely causative agent?

A

Coccidioidomycosis

196
Q

HIV Patient with pneumonia with a CD4+ count less than 200, what is the likely causative agent?

A

PCP

197
Q

Risk groups for tuberculosis (TB)

A

Immigrants

HIV-positive patients

Homeless patients

Prisoners

Alcoholics

198
Q

Diagnostic tests for TB

A

Best initial test: Chest x-ray

Sputum acid-fast stain and culture should be done to confirm the presence of TB

199
Q

Rx for TB

A

Once the acid-fast stain is positive, treatment with 4 antituberculosis medications should be started. Six months of therapy is the standard of care.

  1. Isoniazid (INH): 6 months
  2. Rifampin: 6 months
  3. Pyrazinamide: Stop after 2 months
  4. Ethambutol: Stop after 2 months
200
Q

List the complications of TB medications

A

Isoniazid: Peripheral neuropathy

Rifampin: Red/ orange-colored bodily secretions

Pyrazinamide: Hyperuricemia

Ethambutol: Optic neuritis

All of these medications can lead to liver toxicity. TB medications should be stopped if the transaminases reach 5 times the upper limit of normal

201
Q

Under what conditions should TB Rx be extended beyond 6 months

A

Osteomyelitis

Meningitis

Miliary tuberculosis

Cavitary tuberculosis

Pregnancy

202
Q

Diagnostic tests for latent TB

A

The PPD is a screening test for those in risk groups, such as the homeless, immigrants, alcoholics, health care workers, and prisoners. A positive test is as follows:

5 mm: Close contacts, steroid users, HIV-positive

10 mm: Those in the risk groups described above

15 mm: Those without an increased risk

If a patient has never been tested or it has been several years since the last test, 2-stage testing is recommended. This means that if the first test is negative, a second test should be performed in 1– 2 weeks to make sure the first test was truly negative.

203
Q

What are te steps to follow for a positive PPD?

A

If the PPD is positive, proceed as follows:

  1. A chest x-ray should be performed to make sure occult active disease has not been detected.
  2. If the chest x-ray is abnormal, sputum staining for tuberculosis is performed.
  3. If this is positive, then full-dose, 4-drug therapy is used.

Isoniazid alone is used for 9 months to treat a positive PPD. This reduces the 10 percent lifetime risk of developing tuberculosis to 1 percent. Once a PPD is positive, the test should never be repeated.

204
Q

What other screening tests can be performed in place of PPD?

A

Interferon gamma release assay (IGRA) (Quantiferon) is an in-vitro blood test that is used for the detection of latent tuberculosis. The indication for an IGRA is the same as for a PPD. The main difference is that the IGRA is more specific than a PPD. There are no false positives on an IGRA with previous BCG infection.

Bacille-Calmette Guerin (BCG) administration in the past has no effect or influence on these recommendations for treatment of latent TB. It does not matter if a patient has had BCG in the past; the patient must still take isoniazid if the PPD is positive. If BCG is an answer choice, it is always wrong according to current guidelines.

IGRAs have a 90 percent sensitivity for previous TB exposure. A positive test is treated with INH alone. A positive IGRA does not mean active infection. As with a PPD, a positive IGRA confers only a 10 percent lifetime risk of TB.

205
Q

Diagnosis: Decreased TLC, Decreased RV, Decreased VC, Normal FEV1, Normal FEV1/FVC ratio, Normal DLCO

A

Extra-parenchymal (extra-thoracic) restriction

  • Kyphosis
  • Obesity
206
Q

Diagnosis: Increased TLC, Increased RV, Decreased FEV1, Decreased FVC, Decreased FEV1/FVC ratio, Decreased DLCO

A

COPD

207
Q

Diagnosis: Normal or Increased TLC, Normal or Increased RV, Decreased FEV1, Decreased FVC, Normal or Decreased FEV1/FVC ratio, Normal or Increased DLCO

A

Asthma

208
Q

Diagnosis: Decreased TLC, Decreased RV, Decreased FEV1, Decreased FVC, Normal or Increased FEV1/FVC ratio, Decreased DLCO

A

Fibrotic (or Interstitial Lung) Disease

209
Q

List the minimum that should be done for all patients with shortness of breath (SOB)

A

Oxygen

Continuous oximeter

Chest X-ray

Arterial blood gas (ABG)

210
Q

Causes of low DLCO

A

Emphesema

Pneumonectomy

Interstitial lung disease

pulmonary embolism

Pulmonary HTN

211
Q

Arterial blood gases measurements

A

pH: 7.35 to 7.45

PCO2: 33-45mmHg

PO2: 75-105mmHg

212
Q

Which is the only form of interstitial lung disease that responds to steroid and why?

A

Berryliosis, because it is a granulomatous disease

213
Q

List the diagnostic tests in ILD and explain the findings in each test

A

CXR: interstitial fibrosis

High-resolution CT scan: more detail of interstitial fibrosis

Lung biopsy

PFT

214
Q

What is BOOP?

A

Bronchiolitis obliterans organizing pneumonia

215
Q

What is another name for bronciolitis obliterans organizing pneumonia (BOOP)?

A

Cryptogenic organizing pneumonia (COP)

216
Q

Compare BOOP/COP and ILD

A
  • Fever, myalgias, malaise (clubbing uncommon) present in BOOP; No fever, no myalgias in ILD
  • Symptoms presents over days to weeks in BOOP; Symptoms present over six months or more in ILD
  • Patchy infiltrates in BOOP; Interstitial infiltrates in ILD
  • Steroids effective in BOOP; ILD rarely responds to steroids
217
Q

The two most common lung cancers

A

Adenocarcinoma

Squamous cell carcinoma

218
Q

Centrally located lung carcinomas

A

Squamous cell ca

Small cell ca

219
Q

What lung ca is associated with Eaton-Lambert syndrome, syndrome of inappropriate antidiurectic hormone and other paraneoplastic syndromes

A

Small cell ca

220
Q

Type of lung ca most commonly associated with venocaval obstruction syndrome

A

Small cell ca

221
Q

Peripherally located lung cancers

A

Large cell carcinoma

Adenocarcinoma

222
Q

Lung ca associated with cavitation

A

Large cell ca

223
Q

Lung ca associated with pleural effusion with high hyaluronidase levels

A

Adenocarcinoma

224
Q

Most common initial presentation of cystic fibrosis

A

Meconium ileus

225
Q

Other clinical features of cystic fibrosis

A

Failure to thrive

Rectal prolapse

Persistent cough

May also present with

  • Infertility
  • Allergic bronchopulmonary aspergillosis
226
Q

Best initial and most specific test

A

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.

227
Q

List the supportive care in the Rx of cystic fibrosis

A

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.

228
Q

List and explain Rx that improve survival in patients with cystic fibrosis

A

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.

229
Q

What are the other management considerations in cystic fibrosis

A

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.

230
Q

Antibiotics to Rx cystic fibrosis

A

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.

231
Q

Features that indicate benign solitary lung nodule (on chest X-ray): “low risk”

A

<35 years

Non-smokers

Lesions <2cm

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

232
Q

Features that indicate benign solitary lung nodule (on chest X-ray): “high risk”

A

>50 years

Lesions >2cm

Smoker

Irregular contours

No calcification

233
Q

Management of solitary pulmonary nodule

A
  • Find old X-ray for comparison
    • If available compare dates and determine doubling time (<1 month or >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

234
Q

What is A-a gradient?

A

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

235
Q

The diagnosis of allergic bronchopulmonary aspergillosis (ABPA) is based on clinical, radiographic, and immunologic criteria. List them

A
  • A history of asthma
  • immediate skin test reactivity to Aspergillus antigen
  • Precipitating serum antibodies to Aspergillus fumigatus
  • Serum total IgE concentration of greater than 1000 ng/mL
  • Peripheral blood eosinophilia greater than 500 per cubic millimeter
  • Lung infiltrates, usually involving the upper lobes
  • Central bronchiectasis

N/B: If the skin prick test is negative, the diagnosis of ABPA is extremely unlikely

(UW)