Section 1: Asthma and COPD 1 Flashcards

(49 cards)

1
Q

Therapy for COPD exacerbation

A

Bronchodilators (inhaled) = nebulized albuterol

Ipratropium (inhaled)

Steroids = prednisone or methylprednisone

Antibiotics = ceftriaxone

Counseling

Influenza vaccine

Pneumococcal vaccine

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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

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3
Q

Enumerate the minimum management for patients with SOB

A

Oxygen

Continuous oximeter

CXR

ABG

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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

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5
Q

What class of drug is methacholine?

A

Synthetic acetylcholine

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6
Q

What happens when methacholine is administered to asthmatic?

A

Methacholine will decrease FEV1 if the patient has asthma.

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7
Q

Name the two most frequently used pulmonary function tests

A

FEV1 (forced expiratory volume in one second)

FVC

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8
Q

What is the normal adult FEV1/FVC ratio?

A

> 75%

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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.

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10
Q

Name some obstructive lung disease

A

COPD

Asthma

Chronic bronchitis

Bronchiectasis

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11
Q

What is the meaning of DLCO

A

Diffusing capacity of carbon monoxide

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12
Q

What does DLCO measure?

A

Measures the gas exchange capacity of the capilary-alveolar interface

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13
Q

Why is DLCO normal in asthma

A

Because the alveoli are not affected

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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.

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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.

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16
Q

Examples of diseases with restrictive pattern on PFT

A

Obesity

Interstitial lung disease

Inflammatory/fibrosing lung disease

Kyphosis

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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.

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18
Q

Diagnosis: Hypoxia not responding to supplemental oxygen

A

Shunt physiology

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19
Q

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

A

Asthma

COPD

Nonmassive pulmonary embolus (PE)

Pneumonia.

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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
Causes of SOB due to shunt physiology
Acute respiratory distress syndrome Significant lobar pneumonia Patent foramen ovale Patent ductus arteriosus.
26
Features of SOB due to shunt physiology
Typically does not respond to O2 Characterized by an increased A-a gradient
27
Differential diagnosis of Asthma presenting as chronic cough
Allergic rhinitis Postnasal drip GERD
28
Differential diagnosis of wheezing
Asthma Foreign body aspiration Laryngeal spasm or irritation GERD CHF
29
In asthma management, can inhaled corticosteroids be used in pregnancy
Yes, they are safe
30
What is the implication of a normal PaCO2 in during an episode of asthma exacerbation
A normal Pco2 suggests that the patient is tiring out and is about to crash ## Footnote
31
Outline the management of acute asthma
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
33
Rx for exercise induced asthma
Inhaled bronchodilator prior to exercise
34
What is the management of acute shortness of breath in a patient with COPD?
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
When to intubate patients with COPD?
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. ## Footnote
36
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)
37
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
38
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
39
Name two interventions that lower mortality in COPD
Smoking cessation Home oxygen therapy (continuous)
40
Spot Diagnosis: A case of COPD at an early age (\< 40) in a nonsmoker who has bullae at the bases of the lungs. ## Footnote
Alpha-1 antitrypsin deficiency
41
Rx for alpha-1 antotrypsin deficiency
Alpha-1 antitrypsin infusion
42
What is the most accurate diagnostic test for bronchiectasis?
High-resolution CT scan of the chest. ## Footnote
45
Diagnosis: Decreased TLC, Decreased RV, Decreased VC, Normal FEV1, Normal FEV1/FVC ratio, Normal DLCO
Extra-parenchymal (extra-thoracic) restriction * Kyphosis * Obesity
46
Diagnosis: Increased TLC, Increased RV, Decreased FEV1, Decreased FVC, Decreased FEV1/FVC ratio, Decreased DLCO
COPD
47
Diagnosis: Normal or Increased TLC, Normal or Increased RV, Decreased FEV1, Decreased FVC, Normal or Decreased FEV1/FVC ratio, Normal or Increased DLCO
Asthma
48
Diagnosis: Decreased TLC, Decreased RV, Decreased FEV1, Decreased FVC, Normal or Increased FEV1/FVC ratio, Decreased DLCO
Fibrotic (or Interstitial Lung) Disease
49
List the minimum that should be done for all patients with shortness of breath (SOB)
Oxygen Continuous oximeter Chest X-ray Arterial blood gas (ABG)
50
Causes of low DLCO
Emphesema Pneumonectomy Interstitial lung disease pulmonary embolism Pulmonary HTN
51
Arterial blood gases measurements
pH: 7.35 to 7.45 PCO2: 33-45mmHg PO2: 75-105mmHg
52
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**