S8C73 - COPD

Question 1

COPD defn

Answer 1

• airflow limitation that is not fully reversible
• generally progressive
• includes chronic bronchitis, bronchiectasis and emphysema and to a lesser extent ,asthma

Question 2

COPD: pathophys

Answer 2

• only 15% of smokers develop COPD
• irritants trigger inlm in airway, proteases break down parenchyma, stimulate mucus secretion and cells that normally secret surfactact and protease inhibitors are replaced by mucus-secreting cells
• loss of eleastic recoil, collapse of smaller airways
• airway obstruction is a result of secretions, edema, bronchospasm, bronchoconstriction
• pulmonary HTN occurs, RVH occurs, atrial and ventricular arrhythmias can result

Question 3

COPD: severity

Answer 3

Mild: FEV1 >80 predicted +/- chronic symptoms

Moderate: FEV1 50-79% predicted

Severe: FEV1 30-49% predicted

Very Severe: FEV1

Question 4

COPD: Diagnosis

Answer 4

spirometry:

FEV1

Question 5

COPD: Tx

Answer 5

Oxygen: long-term O2 reduces COPD mortality

-criteria = PaO2

Question 6

COPD: exacerbation

Answer 6

• O2 for SaO2 >90
• ventolin and atrovent
• corticosteroids: IV or PO
• Abx
• CXR, ECG, ABG, CBC, lytes

Question 7

ABG: resp acidosis

Answer 7

• acute resp acidosis: bicarb will rise by 1mEq/L for every 10mmHg increase in PCO2 and the pH will change by 0.008
• Chronic resp acidosis: bicarb will rise by 3.5mEq/L for every 10mmHg increase in Pco2 and the pH will change by 0.03x (40-PCO2)
• changes outside these ranges represent an accompanying metabolic d/o

Question 8

COPD: indications for intubation

Answer 8

-severe dypsnea with accessory muscles and paradoxical abdominal motion
-rr >35
-hypoxemia PaO2 60
resp arrest
Somnolence, impaired mental status
HoTN, shock, heart failure
NIPPV failure

Question 9

COPD: NIPPV

Answer 9

-contraindications: unccoperative, obtunded, inability to clear secretions, hemodynamic instability (HoTN), resp arrest, recent facial or gastroesophageal surgery, burns, poor mask fit, extreme obesity