COPD pathophys, diagnosis, and assessment

stephens

what is COPD

heterogenous lung condition characterized by chronic respiratory symptoms due to airway abnormalities or alveoli abnormalities

what are characteristic symptoms of COPD

dyspnea (shortness of breath), cough, sputum production, exacerbations, wheezing, chest tightness, fatigue

what airway abnormality is associated with COPD

bronchitis

what alveoli abnormality is associated with COPD

emphysema — walls of alveoli are damaged and destroyed

what is acute bronchitis

small airway (bronchioles) inflammation with airway swelling and mucus production

what are symptoms of acute bronchitis

cough, dyspnea, wheezing, fever, rhinorrhea, fatigue

what can cause acute bronchitis

viruses (flu, RSV, COVID, etc)

smoke or other irritants

what patients are at risk for acute bronchitis

asthma, COPD, GERD, autoimmune disorders, exposure to smoke/chemicals/toxins

what is chronic bronchitis

inflammation of the airways (trachea and bronchi) that leads to swelling and excessive mucus secretion

what are the symptoms of chronic bronchitis

chronic cough and sputum production most days for > 3 months per year for 2 consecutive years

what is the main cause of chronic bronchitis

smoking

what is emphysema

destruction of alveoli → loss of gas exchange surfaces

what are the symptoms of emphysema

dyspnea, wheezing, cough, chest tightness, fatigue, weight loss

what gender is at higher risk of COPD

women

what age group is at higher risk for COPD

>65 years old

what environmental factors cause a higher risk of COPD

rural population, low education, smoking

how do we G.E.T COPD

genetics, environment, trajectories/time

what is the most common environmental risk factor for COPD

cigarette smoking — greater annual decline of FEV1, higher mortality

what genetic factor is most associated with COPD

alpha-1 antitripsyn deficiency

what environmental factors are associated with COPD

cigarette smoking

secondhand smoking

occupational exposures

air pollution

socioeconomic status

what lung trajectories are associated with COPD

poor lung growth — in utero nicotine exposure, pneumonia < 3 yo, asthma, premature birth, low birthweight, BPD

infections (HIV, TB)

what ages do lungs stop developing

20-25 yo

what % of COPD patients have normal peak with accelerated FEV1 decline

50%

what cell lines are involved in the inflammatory process of COPD

macrophages

neutrophils

lymphocytes

epithelial cells

eosinophils — in some patients

what causes type 2 inflammation in COPD

eosinophilic inflammation (IL4, IL5, IL9, IL13) → airway remodeling, mucus plugging, immune response dysregulation

what % of COPD patients have type 2 inflammation

20-40%

what are the consequences of small airway disease or parenchymal destruction

decreased lung emptying

decreased FEV1

decreased FEV1/FVC ratio

gas trapping

lung hyperinflation

what are the clinical indicators of COPD

dyspnea that is progressive, worse with exercise, or persistent

recurrent wheezing

chronic cough

chronic sputum production

recurrent lower respiratory tract infection

history of risk factors

consider the diagnosis of COPD and perform spirometry if present

what is FVC

forced vital capacity — total amount of air you can forcefully blow out after taking the biggest breath possible

what is FEV1

forced expiratory volume in 1 second — amount of air you can forcefully blow out in 1 second

what is FEV1/FVC

percentage of total air that came out in the first second — in COPD, FEV1 is lower, so ratio is lower

because small airways collapse → hard to expel air quickly → low FEV1

what spirometry reading is diagnostic for COPD

symptomatic patients and/or risk factors — post-bronchodilator FEV1/FVC <70% (0.7), repeat at next visit if ratio = 0.6-0.8

what questionnaires/surveys are used to assess COPD symptoms

mMRC, CAAT, CCQ, VAS, CRQ, SGRQ

what is mMRC

modified medical research council dyspnea scale — self-administered survey that assesses dyspnea

how is mMRC scored

from 0-4

score > 2 shows increased symptoms

what is CAAT/CAT

chronic airway assessment test — self-administered assessment that assesses multiple COPD symptoms

recommended over mMRC

how is CAAT scored

8 questions with a scale of 0-5

scored from 0-40

total score > 10 shows increased symptoms

what characteristics in a physical exam are indicative of COPD

shortness of breath, respiratory distress, anxiety (pt appearance)

use of accessory breathing muscles

wheezing, prolonged expiratory phase

what labs can be indicative/help diagnose COPD

O2 sat, decreased PaO2, increased PaCO2, increased Hct

what is the GOLD class of a patient with FEV1 >80% of predicted

GOLD 1 — mild airflow obstruction

what is the GOLD class of a patient with FEV1 50% < 80% of predicted

GOLD 2 — moderate airflow obstruction

what is the GOLD class of a patient with FEV1 30% < 50% of predicted

GOLD 3 — severe airflow obstruction

what is the GOLD class of a patient with FEV1 <30% of predicted

GOLD 4 — very severe airflow obstruction

how are GOLD classes determined

confirm patient has obstruction — FEV1/FVC post-dilator is <0.7

determine what their FEV1 is compared to their predicted FEV1 (based on age, sex, etc)

what is a COPD exacerbation

acute worsening of respiratory symptoms that leads to increase rate of lung function decline and worsens prognosis

what increases COPD exacerbation risk

more than one exacerbation requiring steroids and/or antibiotics

more than one exacerbation requiring hospitalization

what is the best predictor of frequent exacerbations

history of exacerbations in the past 12 months

what can blood eosinophil count predict

magnitude of ICS response in preventing exacerbations — will ICS be effective in this patient???

what are common comorbid conditions with COPD

CVD, metabolic syndrome, osteoporosis, depression, anxiety

what conditions can COPD increase the risk of

TB, lung cancer

what does group A COPD mean

patient has low risk and less symptoms (mMRC <2, CAAT <10), no exacerbations

what does group B COPD mean

patient has low risk and high symptoms (mMRC >2, CAAT >10, 0 moderate or severe exacerbations)

what is group E COPD

patient has high risk of exacerbations (>1 moderate or severe exacerbation in the past year) with any amount of symptoms/CAAT or mMRC

what additional assessments can be performed for COPD

body plethysmography

alpha 1 antitrypsin deficiency screening

pulse ox, ABG

exercise testing

chest XR or CT

what is the BODE index

for mortality risk

BMI, obstruction (FEV1), dyspnea (mMRC), exercise tolerance