Lecture 12:COPD/A1AT Flashcards
wht is the COPD?
- -Chronic Obstructive Pulmonary Disease (COPD) is a preventable and treatable disease with some significant extra-pulmonary effects that may contribute to the severity in individual patients. Its pulmonary component is characterized by airflow limitation that is not fully reversible (vs asthma). The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gases.
- -A lung disease caused by inflammation of the small airways. Includes chronic bronchitis (characterized by productive cough ≥ 3 months in 2 consecutive years) and emphysema (dilation of the air spaces distal to the terminal bronchioles). Most cases of COPD (~ 90%) are caused by smoking.
what are the subtypes of COPD?
1)Chronic Bronchitis
“Cough productive of sputum on most days for at least 3 months for at least 2 consecutive years with no other attributable cardiac or respiratory cause”
2)Emphysema
“Abnormal and permanent enlargement of the airways distal to the terminal bronchiole”
what is the epidemiology of COPD?
- -200 million people worldwide
- -4th leading cause of death worldwide
- -Predicted to become the 3rd most common cause worldwide by 2030
- -Prevalence of COPD varies throughout different countries ranging from as low as 4% to 20%
- -Sex: 3:2 male/female ratio
- -The third most common cause of death worldwide
- -Prevalence:
what are the risk factors of COPD?
–Cigarette smoking
95% of cases
–Biomass fuel burning (Developing world)
–Cessation decreases respiratory symptoms and rate of decline in lung function
–Pipe, cigar smokers, marijuana have a higher risk for COPD than non-smokers
–Sulphur dioxide and particulates (PM10) associated with chronic bronchitis, COPD
–Occupational dust: coal, silica, quartz, cadmium welding fumes
–Chest infections in 1st year of life
–Adenovirus/HIV
what is the main risk factor of COPD?
Smoking is the main cause of COPD, but only one in five smokers is affected, so it is likely that a genetic predisposition also plays a role in development of the disease.
- -Those who have quit ≥ 10 years ago are not at increased risk.
- -Passive smoking: If precautions against smoke exposure not taken, those who live in close proximity to smokers (e.g., children, relatives) have a significantly higher risk of COPD. The risk of asthma progressing to COPD also increases with exposure to smoke.
what are the endogenous factors associated with COPD?
- -α1-Antitrypsin deficiency
- -Antibody deficiency syndrome (e.g., IgA deficiency)
- -Primary ciliary dyskinesia (e.g., Kartagener syndrome)
what are the baseline symptoms of COPD?
1)Cough Initially intermittent 2)Sputum production purulent with exacerbation 3)Dyspnoea on exertion initially but becomes progressive 4)Wheeze/chest tightness - Initially intermittent, eventually chronic
natural history in a patient with COPD?
- -Smokers
- -Increasing symptoms: days to weeks
- -Presence of baseline symptoms
- Age profile
***New onset symptoms / rapid deterioration: suggests an alternate dx
what are the general inspection signs in a patient with COPD?
1) Central cyanosis
2) Accessory muscles of respiration
3) Nature of breathing
- -pursed-lip
- -prolonged expiration
- -hyperinflation
what are the respiratory P/E signs in patient with COPD?
- -Decreased
- -Rhonchi/wheeze
- -Prolonged expiratory time
what are the P/E signs in acute COPD?
- -Vital signs: RR, SaO2
- -Hands: warm, sweaty, dilated veins, asterixis
- -Hyperinflation / Hoover’s sign
- -Auscultation: breath sounds, prolonged expiration, wheeze
what are the differential diagnoses of COPD?
- -Acute CHF (CXR)
- -Acute MI/tachyarrhythmia (ECG)
- -Acute PE (Normal CXR/ decreased pCO2/ increased-D dimers)
- -Pneumonia (CXR)
- -Asthma (Peak expiratory flow rate/PFTs w’ reversibility)
- -Mucus plugging (CT thorax/bronchoscopy)
what investigations should be performed in acute exacerbation of COPD?
- -Arterial blood gas (ABG)
- -CXR
- -FBC, U&E, CRP
what ar the goals of management of acute exacerbation of COPD?
- -Adequate oxygenation
- -pH homeostasis
- -Relief of bronchospasm
- -Treat concurrent infection
what are the oxygenation goals in acute exacerbation of COPD?
- -pO2 >8.0 kPa
- -SaO2 >90%
- -Venturi face mask
- -FiO2: 28% - 40% (starting)
- *Do not hyper oxygenate
- **Do not under oxygenate
pH homeostasis in acute COPD?
- -Maintain pH >7.27
- -Therapeutic options
1) NIPPV with BiPaP (non invasive positive pressure ventilation with bi-level positive pressure)
2) Invasive ventilation (may not be appropriate depending on stage of disease and predicted outcome)
**CPAP contraindicated
what are the medications used in acute exacerbation of COPD?
- -Bronchodilators
- -Steroids
- -Antibiotics
what are the medications used for bronchodilation in the acute exacerbation of COPD?
- -Nebulised
1) Ipratropium Bromide (Atrovent)
2) Salbutamol (Ventolin) - -Repeat until symptomatic relief
- -Maintenance 4 – 6 hourly
what steroids are used for acute exacerbation of COPD?
- -Hydrocortisone IV 6 hourly
- -Switch to oral prednisolone (within 48 – 72 hours)
- -Tapering dose of prednisolone on discharge