What do you understand by the term COPD? What diseases
make up COPD?
Answer
Chronic obstructive lung disease is associated
with:
Describe the pathological findings of chronic bronchitis.
The answer
Chronic Bronchitis:
- Mucous within bronchial lumina
- Chronic inflammation of the
bronchial wall, marked increase in the size of the mucous glands (increase in Reid
Index)
- Patches of squamous metaplasia
- Acute bronchitis:
- mucosa/submucosal edema
- inflammatory cells
(also
in sputum)
Describe the pathological findings of emphysema.
The answer
Emphysema:
- Gross
- hyper inflated lungs
- blebs, particularly near apices
- Microscopic
- destruction of alveoli creating large air spaces scattered throughout
both lungs
- scattered small pulmonary arteries showing smooth muscle
hypertrophy
What kind of cyanosis can you expect to see in chronic bronchitis? What is the
pathophysiology of cyanosis in COPD?
The answer
- Central cyanosis
- Mechanism for hypoxia
- Ventilation perfusion imbalance
- Poor ventilation causes decreased 02 (less 02
available to couple with hemoglobin)
- Increased deoxygenated hemoglobin leads to cyanosis
Explain why you see a barrel shaped chest in COPD.
The answer
- Increased A-P chest diameter at the FRC position
- Reflects hyperinflated lungs
- Loss of lung elasticity permits chest wall to recoil to a
position closer to total lung capacity position, thus increasing AP diameter
and reducing transverse diameter of chest
Compare and contrast breath sound in chronic bronchitis and
emphysema.
The answer
- Decreased breath sounds when the patient is making a phenomenal
effort to breathe (with hyper-resonance) is the most important physical
finding for emphysema
- Breath sounds are harsh in pure chronic bronchitis
- Remember that in a given patient there is usually a
combination of emphysema and chronic bronchitis
- Prolonged expiration is common
to all of the chronic obstructive lung diseases
What are the anticipated findings on cardiac auscultation in a
patient with COPD?
The answer
- Soft heart sounds: Interposition of lung between the
heart and chest wall (hyper inflated lungs)
- Loud S2: P2 is accentuated with
pulmonary hypertension
- Splitting of S2 is caused by delay in closure of pulmonary
valve (pulmonary hypertension)
- S4: Reflects forceful right atrial
contraction against an altered right ventricular
wall compliance
- lower left sternal border indicates it is originating from
the right ventricle
What are the anticipated changes in arterial blood gas in
patients with stable advanced COPD?
The answer
- Chronic respiratory acidosis with near complete
compensation
- compensated (pH is near normal)
- CO2 is high hence respiratory
- bicarbonate is high
- renal compensatory effort
- Hypoxia
- poor V/Q matching
- alveolar hypoventilation
- Hypercapnia
- due to reduced alveolar ventilation
- increased dead space
Hypoxia in COPD could be due to:
- Alveolar hypoventilation
- High altitude (Low FIO2)
- V/Q mismatch
- Diffusion barrier
- Anatomical shunt
Which of these is responsible for hypoxia in COPD?
The answer
- V/Q mismatch
- Alveolar hypoventilation
Patient with COPD presents with acute bronchitis. What is the
most likely organism responsible for it?
The answer
Probable organisms causing the
respiratory infection include:
-
Streptococcus pneumonia
- Hemophilus influenza
- Branhamella catarrhalis
Describe the CXR findings in a patient with COPD.
The answer
Hyperinflation
Emphysema
Pulmonary hypertension
What are the spirometric findings in COPD?
The answer
- The most important evidence is that FEV1/FVC is decreased
- The forced expiratory volume in 1 second FEV1 measures the average
flow rate during the first second of the forced vital capacity (FVC) maneuver
- FEV1
declines in direct proportion with clinical worsening of airway obstruction
- normal percent of predicted
FEV1 > 80%
- this is valid in the absence of a restrictive defect
Describe the pathology of the heart in COPD.
The answer
- Right ventricular/right atrial hypertrophy
- Pulmonary artery dilatation and atheromatous changes due to
hypertension
- Chronic passive
congestion of the liver
What are the EKG findings in a patient with COPD?
The answer
The electrocardiogram:
- Right axis deviation
- Right ventricular hypertrophy with strain
- the R is
greater than S in lead V1
- the T wave is inverted in leads V1-V2
- strain suggests ischemia during diastole in a hypertrophied
wall
- S waves are deep in the
left precordial leads
- Right atrial hypertrophy
- by voltage
- especially
noted in leads II and AVF
Which antibiotic will you use to treat acute bronchitis in a patient
with chronic bronchitis? Give your reasoning. What is the role of sputum culture
before starting antibiotics?
The answer
- A sputum culture would probably not be ordered routinely in
COPD
- The sputum
culture would probably show mixed flora
- A gram stain of the sputum might be a more
helpful and economical first step
- A sputum culture would be indicated if the first
antibiotic failed to clear the infection
| Common organisms |
Antibiotic |
Hemophilus Influenza
Streptococcus Pneumonia
Brahmella catarrhalis
|
First line |
Second line |
Penicillin allergy |
Amoxicillin
Doxycycline
Trimethaprim/Sulfamethaxazole |
Azithromycin
Ciproflaxin
Augmentin |
Erythromycin |
| Virus |
None |
What are the treatable components of chronic bronchitis and
how would you treat them? Explain the rationale for your decision.
The answer
| Pathophysiology |
Therapeutic option |
| Irritation of bronchi by cigarettes |
Stop smoking |
Narrowing of bronchi::
- Lymphocytic inflammation
- Mucosal thickening/Glandular hyperplasia
- Bronchospasm
|
? Steroids
Bronchodilators |
Secretions:
- Tenacious secretions
- Bacterial infections
|
?Mucolytic agents/Expectorants
Empiric Antibiotics |
Which bronchodilators will you use in COPD?
The answer
Bronchodilators
| Site of action |
Bronchodilators |
| Beta2 agonists |
Albuterol inhalers |
|
Ipratropium bromide |
|
Theophylline |
How would you treat congestive heart failure of COPD/ Cor pulmonale? How will you alter the
pathophysiology of Cor pulmonale?
The answer
| Pathophysiology |
Therapeutic options |
Pulmonary hypertension
- Hypoxia
- Loss of vascular bed
|
Continuous Oxygen |
| LV dysfunction if any |
Digoxin and diuretics |
How can we control pulmonary hypertension in COPD? How will
you alter the pathophysiology of pulmonary hypertension?
The answer
| Pathophysiology |
Therapeutic option |
| Alveolar hypoxia/Vasoconstriction |
Oxygen |
| Loss of vascular bed |
Lung transplant |
What is the optimal arterial oxygen level to aim for in the treatment of
hypoxia of COPD patients? Explain your reasoning.
The answer
- Target PaO2 of 55-60
- Rationale
- maximal oxygen carrying capacity with minimal risk for
shutting off hypoxic drive
What do you understand by the terms:
- Low FIO2 and high FIO2
- Low and high flow oxygen
Which of these will you prescribe for COPD patients?
The answer
- Low and high FIO2 refers to oxygen concentration
- >50% high FIO2
- <50% low FIO2
- risk for toxicity is high with high FIO2
- Low and high flow refers to amount of ventilation with the desired
FIO2
- High flow > 2.5 times the minute ventilation
- Low flow is less than minute ventilation
- Optimal strategy for oxygen prescription to COPD patients
- Low FIO2: 1-4 Liters
by nasal cannula
- Hypoxia due to V/Q mismatch is easily correctable
- Acute phase: High flow (Venturi mask)
- varying minute ventilation
- provides an environment with fixed FIO2
concentration
- Stable phase: Low flow (Nasal cannula)
What is hypoxic drive? How do you titrate the amount of oxygen
to COPD patients in respiratory failure?
The answer
- Concern for hypoxic drive
- carotid body chemo receptors
- Titrate Oxygen
- target PaO2 of 55-60
- to maintain pH over 7.25
- Administer oxygen like any medication
with consideration
- for dose
- method of delivery
- complication
- comfort
- cost
How can you decrease the effort of breathing?
The answer
| Pathological basis |
Therapeutic options |
| Increased airway resistance |
Bronchodilators |
| Airway collapse |
Pursed lip breathing |
| Inefficient diaphragmatic position |
Lean forward with diaphragmatic breathing |
| Anxiety |
No sedatives for fear
of respiratory depression |
What is the role for steroids in COPD?
The answer
Anti-inflammatory
- Acute bronchitis
-
Acute exacerbation
- Chronic bronchitis
How do you treat emphysema?
The answer
Primary treatment is symptomatic.
New strategies for treatment for emphysema include:
| Pathophysiology |
Therapeutics |
| Loss of alveolar septa/and elastic
recoil/hyperinflation/Blebs and bullae |
Lung reduction surgery |
| |
Lung transplant |
| Loss of capillary bed/Pulmonary hypertension |
Heart/Lung transplant |
What measures are available for smoking cessation?
The answer
- Advise patient to stop smoking: strong influence of
physician
- Nicotine patches/Gum
- Smoking cessation programs
- Support groups
- Hypnosis
- Address weight concerns of quitting smoking