COPD Flashcards
What is COPD
Long term deterioration, progressive obstruction with little variability
Bronchitis - obstruction
Emphysema - hyperinflation
What is bronchitis
Wha improves
Definition = Presence of productive cough for 3 months of the year >2 years in a smoker
Likely has COPD
Mucous gland hypertrophy = repeated infection
Increased goblet cells
Inflammation + fibrosis
Obstruction due to airway and alveoli damage
Normal X-Ray just inflammation
Improves if stop smoking
What is emphysema
Inflammation causes increase in size of airspaces due to dilation and destruction of walls
Leads to collapse and trapped air = hyperinflation
Lung tissue for gas exchange destroyed
Increased compliance
Decreased recoil so expiration difficult
What causes lung inflammation in COPD
Smoking and a1AT deficiency
Environment - smoking / pollution / infection
Leads to free radicals
Anti-protease inactivated
Genetics (a1-AT deficiency)
Lungs unable to prevent damage
Leads to inflammation -increased cytokines, protease and oxidative stress
How is A1AT deficiencyy inherited
AR
What does a1AT deficiency do
A1AT protects cells from damage so if deficient cannot protect from damage
Emphysema LL
Cirrhosis
Think in young person with COPD /asthma Sx refractory to Rx
What does smoking do
Increases neutrophils and proteases which cause lung damage
Inactivate anti-proteases
What are the types of emphysema
What can happen to bullae in scar
Centri-acinar - respiratory bronchioles / upper lobe
Pan-acinar - whole acinus
Scar - in periphery, bullae can rupture causing pneumothorax
What are the symptoms of COPD
What happens in severe disease
Suspect in any long term smoker SOB Rapid shallow breath Prolonged wheeze Persistent cough Sputum Recurrent chest infections Minimal variation Resp failure if severe
What are findings on examination
Cyanosis Reduced chest expansion Accessory muscles Barrel chest Hyperinflated chest Tachypnoea Decreased breath sounds Tremor - CO2 retention
What are symptoms RHF and how do you Rx
Hypoxia = Pulmonary hypertension -> RHF if severe which is known as cor-pulmonle Cyanosis Pursed lip on expiration Peripheral oedema Increased JVP Ascites Palpable liver
Rx = LTOT + loop diuretic
How is severity of COPD classed
For DX post bronchodilator FEV1/FVC ratio = <0.7 but severity = FEV1 >80% = mild 50-79 = moderate 30-49 = severe <30 = very severe
What are complications of COPD
Inactivity Depression Cardiac disease - cor pulmonate Loss of muscle mass Pneumothorax
How do you Dx COPD an other investigations
Clinical + spirometry = diagnostic
Spirometry - FVC / FEV1 <70 + PEFR low with minimal bronchodilator reversibility <12%
Other Pulmonary function - Gas transfer is low - TL and RV increased due to hyperinflation CXR Serum a1AT to look for deficiency CT for other Dx ABG - hypoxia + hypercapnia Sputum culture ECG + ECHO - RVH / assess heart BMI - for baseline FBC for anaemia or polythaemia from chronic hypoxia
How do you manage COPD non-pharmacology
Smoking cessation
Exercise
Vaccine - flu + pneumococcal
Mucolytic if chronic cough and other medical Rx failed - carbosistine
Pulmonary rehab to anyone who views as disabled / as soon as feels breathless regular activity as will improve exercise capacity
Nutrition
Physiological support - depression
What is drug therapy for COPD
SABA for mild or SAMA (Ipatropium) = 1st line
LABA (salmeterol) and LAMA (tiatropium) in more severe if no features of asthma
ICS + LABA if features of asthma
Use all therapies as FEV1 decreases
Consider theophylline if others tried or can’t inhale
When do you give long term O2 therapy and when should you assess with 2 ABG
PO2 <7.3 after bronchodilator or nocturnal hypoxaemia Peripheral edema Pulmonary hypertension Polycythaemia NOT if smoking
Assess if FEV1 <49% Sats <92% Cyanosis POlycyhthaemia due to chronic hypoxia Oedema Raised JVP
Why should you be careful when giving O2 in COPD and what is aim
If elevated PaCO2 (Type 2 respiratory failure) then body goes in to hypoxic drive (relies on low O2 not CO2 to stimulate ventilation)
Further oxygen = reduced drive and will lead to retention of CO2
Body won’t respond to high CO2
Eventually resp arrest
pH should not be allowed to fall below <7.25
Requires artificial ventilation
Always give O2 if person with COPD needs as can cure hypercapnia but can’t cure death
Aim sats 88-92 which can be titrated with Venturi
How do you treat a1AT deficiency
No smoking Bronchodilator Chest physio IV A1AT Lung transplant or reduction surgery
What are pink puffer COPD
Increased alveolar ventilation Normal PaO2 and normal or low PaCO2 SOB No cyanosis Type 1 res failure
What are blue puffer COPD
Deceased ventilation Low PaO2 High PaCO2 CYanosed Not breathless Insensitive to Co2
What are asthmatic features on top of COPD
Previous Dx asthma or atopy
High blood IgE
Variation in FEV1
Diurnal variation
When should you consider a Dx
> 35
Symptoms
Past or present smoker
What does spirometry show
PEFR reduced
FEV1 reduced <80%
FVC may be reduced
Ratio <70% even post bronchodilator indicates COPD as non reversible
