COPD Flashcards
what is COPD
chronic respiratory symptoms caused by airway abnormalities and/or alveoli abnormalities that cause persistent, progressive airflow obstruction.
what are the two pathophysiologic categories of COPD
chronic bronchitis
emphysema
what are the key physiological markers of COPD
airflow obstruction and extensive airway destruction
what are the three classic respiratory symptoms of COPD
cough
dyspnea (SOB)
sputum production
what is the difference between chronic bronchitis and emphysema
chronci bronchitis is more central airway - thickening of the musculature and clogging with mucous
emphysema - less sputum production, more alveolar desctruction. leading to air trapped in the alveoli
what are the additional associated symptoms with COPD
- weight gain
- weight loss - associated w worse prognosis
- activity limitation (including sex)
- wheezing +/- chest tightness
- syncope
- anxiety/depression
what are risk factors for COPD
Fam Hx
smoking hx
environmental hx (exposure)
childhood pulmonary infections, HIV, or TB
asthma
How does mild COPD present
PE - mostly normal
may see:
prolonged expiration
faint end-expiratory wheeze w forced expiration
how does moderate/severe COPD present
lung hyperinflation (barrel chest)
decreased breath sounds/wheezes
crackles at the lung bases
distant heart sounds
increased AP diameter
How does end stage COPD present
- tripod posturing (calloused forearms, swollen bursae)
- accessory muscle use
- expire through pursed lips
- hoovers sign
- cyanosis
- rare nail clubbing
what are signs of heavy smoking
yellowing of fingers/nails
what is the comparison between presentations of chronic bronchitis v emphysema
Who should you screen for COPD
- adults who present with at least 1 of 3 cardinal symptoms
- adults who have a gradual decline in activity with risk factors for COPD
what are the 5 CAPTURE questions
- have you ever lived or worked in a place with dirty/polluted air, second hand smoke or dust
- does your breathing change with seasons, weather, or air quality
- does your breathing make it difficult to do things such as carry heavy loads, shovel dirt/snow, ect.
- compared to others of your age, do you tire easily
- in the past 12 months how many times did you miss work, school or ther due to a cold, bronchitis or pneumonia? (0 = no,2 or more = yes)
what CAPTURE scores are indicative of clinically significant COPD
2-4
what is the initial workup for COPD
spirometry before and after bronchodilator
what is additional initial testing for COPD
Pulse oximetry every visit
Labs - CBC, BMP, TSH, BNP/NT-proBNP, serum alpha-1 antitrypsin
CXR
what spirometry results suggest evidence of obstruction
FVC > 80% with FEV₁/FVC < 0.7
OR
FVC < 80% with TLC >80%
if a patient has a FVC of 90% but their FEV/FVC is .68 what should you do
Ratio between 0.6 - 0.8 = repeat spirometry on a separate day
when should DLco be considered for a COPD patient
- In presence of moderate / severe airflow limitations (FEV₁ ≤50% predicted)
- Resting O2 ≤92%
- Exertional hypoxemia (<90%)
- Severe dyspnea (mMRC ≥2)
what occurs to DLco in COPD
DLCO decreases in proportion to severity of disease
what are the indications for obtaining arterial blood gas in a COPD pt
- Low FEV₁ (< 40% predicted)
- Low O₂ saturation on pulse ox (< 92%)
- Depressed LOC
- Assessment of hypercapnia in “CO₂ retainers” who are given supplemental oxygen (risk of hypercapnic respiratory failure)
- Signs of right heart failure
what are expected arterial blood gas findings in COPD
mild - low pO2 and normal pCO2
mod/severe - worsening pO2 and elevated pCO2
what do the following measures mean in arterial blood gas:
pO2
pCO2
pH
SaO2
HCO3
Base excess
pO₂ - oxygen pressure in arterial blood
pCO₂ - amount of CO2 in arterial blood
pH - acidity or alkalinity of arterial blood
SaO₂ - oxygen saturation
HCO₃ - bicarb
Base excess - amount of acid or base required to restore a liter of blood to its normal pH at a PaCO2 of 40 mmHg