8 Flashcards
(28 cards)
What is COPD?
- disease characterized by airflow limitation and persistent respiratory symptoms
- encompasses both emphysema and chronic bronchitis
- due to airways and/or alveolar abnormalities
- caused by significant exposure to noxious particles or gases
What is the aetiology of COPD?
- 90%: tobacco smoking
- air pollution
- occupational exposure
- alpha-1 antitrypsin defiiciency
- illicit drug use
What is the pathophysiology of COPD
-host response to inhaled cigarette smoke and other noxious substances causing chronic inflammatory process and oxidative injury
Pathological changes
- enlargement of mucus-secreting glands of the central airways
- increased number of goblet cells (which replace ciliated respiratory epithelium)
- ciliary dysfunction
- breakdown of elastin leading to destruction of alveolar walls and structure, and loss of elastic recoil
- formation of larger air spaces with reduction in total SA available for gas exchange
- vascular bed changes leading to pulmonary hypertension
- small airways disease
- parenchyma destruction
- see 2019-COPD slide 11
What is chronic bronchitis?
- phenotype of COPD
- final outcome excessive mucus secretion and impaired removal of the sections
- feels like exercising but breathing only through a straw (small airways)
- see 2019-COPD slide 12
What is emphysema?
- subtype of COPD
- final outcome is elastin breakdown and subsequent loss of alveolar integrity leading to permanent destructive enlargement of the airspace’s distal to the terminal bronchioles
- see 2019-COPD slide 13
What are the 6 main symptoms of COPD?
- Dyspnea that is:
- progressive over time
- characteristically worse with exercise
- persistent - Chronic cough:
- may be intermittent and may be unproductive
- recurrent wheeze - Chronic sputum production:
- any pattern of chronic sputum production may indicate COPD - Recurrent Lower Respiratory Tract Infections
- History of risk factors:
- host factors (such as genetics)
- tobacco smoke
- smoke from home cooking and heating fuels
- occupational dusts, vapours, fumes, gases and other chemicals - Family history of COPD
- for example low birthweight, childhood respiratory infections
What would you physically examine for in COPD?
-Tachypnoea: increased respiratory rate to compensate for hypoxia and hypoventilation.
-Use of accessory muscles of respiration (recall these muscles) due toN difficulty in moving air in and out of lungs. -Barrel chest (increased antero-posterior diameter of the chest) is due to hyperinflation and air trapping secondary to incomplete expiration
-Hyper- resonance on percussion due to hyperinflation and air trapping
-Reduced intensity (distant) breath sounds caused by barrel chest, hyperinflation, and air trapping.
-Reduced air entry (poor air movement) secondary to loss of lung
elasticity and lung tissue breakdown.
-Wheezing may be present
What investigations would you do for COPD?
Lung Function Tests:
-Spirometry shows an obstructive pattern with FEV1/FVC ratio <70% and limited reversibility following treatment with bronchodilators. Time volume plots (vitalograph) and Flow volume loops show the typical obstructive pattern.
monitored.
- Decreased diffusing capacity of the lung for carbon monoxide (DLCO) is na feature of emphysema
-CXR: Hyper inflated lungs may result in (a) a flattened diaphragm, (b) hyperlucent lungs and (c) an increased antero-posterior diameter of the chest. It may also show complications of COPD, such as pneumonia and pneumothorax, and is also useful to rule out other pathologies (e.g. lung CA in a patient presenting with chronic cough).
- Pulse oximetry and/or ABG analysis: is carried out in acutely unwell patients to asses for hypoxia and hypercapnia
- Alpha-1 antitrypsin level: Checked if there is high suspicion such as a Late features include positive family history and atypical COPD (young patients and non- smokers). The levels are low in patients with alpha-1 antitrypsin
What treatment should be given for COPD patients?
- Smoking cessation
- Patient education;
- Pneumococcal vaccination is strongly recommended in COPD patients
- Patient weight, nutrition status, and physical activity should be monitored
- bronchodilators
- inhaled corticosteroid
- pulmonary rehab: many patients try to avoid exercise, so rehab involves a multi-disciplinary team to help them
- long-term oxygen treatment: extended periods of hypoxia causes pulmonary hypertension, so low dose oxygen therapy at home helps
- surgical intervention: such as lung transplant, lung volume reduction or removal of large bullae
Look at 2019-COPD slide 31-45
What is acute exacerbation of COPD?
- characterized by a change in the patient’s baseline dyspnoea, cough and/or sputum that beyond normal day-to-day variations and is acute in onset
- presents with acute, severe shortness of breath, fever and chest pain
What management would occur for acute exacerbation of COPD?
- Monitoring for hypoxia and hypercapnia, using Pulse oximetry and ABG analysis
- Appropriate antibiotics particularly to cover Haemophilus influenzae and Streptococcus pneumoniae is very important,
- Nebulised bronchodilators
- Oral steroids (a short course of high dose oral prednisolone)
- 24% or 28% oxygen therapy while keeping under review for CO2 retention
- consider non-invasive ventilation for worsening type 2 resp failure
What complications can occur with COPD?
- recurrent pneumonia
- pneumothorax: occurs because of lung parenchyma damage with sub-pleural formation and rupture
- resp failure
- cor pulmonale (right heart failure)
By definition, what is an exacerbation of COPD?
-acute worsening of respiratory symptoms that result in additional therapy
Who’s at risk of COPD exacerbations?
- Previous exacerbations always strongest risk factor, “frequent exacerbator” phenotype
- Disease severity: airflow obstruction, MRC dyspnoea score
- Gastro-oesophageal reflux
- Pulmonary hypertension
- Respiratory failure
What is pneumonia?
-inflammation of the lung parenchyma due to infection
What is pneumonitis?
-inflammation due to non-infective causes, such as physical or chemical damage
LOOK AT 2019-LRTI and pneumonia’s all slides
What is a common feature of pneumonia?
-cellular exudate in the alveolar spaces
What are the 4 main types of pneumonia?
- Community acquired pneumonia
- Hospital acquired pneumonia
- aspiration pneumonia
- pneumonia in the immune-compromised patient
Explain community acquired pneumonia (CAP)
- common causative organism: streptococcus pneumoniae
- less commonly caused by: haemophilus influenzae, moraxella catarrhalis, klebsiella pneumonia and staph aureus
- can also be caused by atypical organisms that lack cell walls such as Mycoplasma pneumoniae
Explain nosocomial/hospital acquired pneumonia
- an infection of the lower resp tract in hospitalized patients
- it occurs >48 hours after admission and was not incubating at the time of admission
- is more often associated with impaired defences
- different range of organisms is usual
- important causative organism: Gram negative bacteria and staph aureus including MRSA
What is aspiration pneumonia?
- aspiration of food, drink, saliva or vomitus can lead to pneumonia
- happens more in individuals whose level of consciousness is altered, due to anaesthesia, alcohol or drug abuse or have swallowing related problems due to neuromuscular problems or oesophageal diseases
- causative organism: oral flora and anaerobes
Explain how pneumonia works in the immunocompromised patient
-patients with immune response are susceptible to a range of organisms such as pneumonia jiroveci, aspergillus, cytomegalovirus and others
What are the clinical features of pneumonia?
- malaise
- fever
- productive cough of sputum
- sputu may be purulent, rusty coloured or frankly blood stained
- pleuritic chest pain
- dyspnoea
- pneumonia may be of very rapid onset
How do you assess the severity of pneumonia?
CURB-65 (presence of 2 or more of the following features)
C: new mental confusion U: urea > 7mmol/L R: resp rate > 30 per minute B: blood pressure age: > 65 years
Chest X-ray
-will usually reveal shadowing in at least one section of the lung field
Microbiology
- gram stain and culture of sputum
- in severely ill patients blood culture is important
