Session 6 - COPD, Lower Respiratory Tract Infection and Pneumonia Flashcards
Give a brief outline of what COPD actually is
• Characterised by persistent airflow limitation that is usually progressive and associated with an enhanced chronic inflammatory response in the airways, which does not change markedly over several months
What is airflow obstruction?
- Reduced FEV1
* Reduced FEV1/FVC ratio
Outline the epidemiology of COPD
- 89% of the population is unaware
- 3.7 million affected in the UK
- 1 million symptomatic
- 30,000 deaths
- 1 million hospital inpatient days/year
What is COPD caused by?
- Abnormal inflammatory response of the lung to noxious particles or gases
- Noxious particles can come from cigarette smoke or atmospheric pollutants (not just cigarettes! Manual workers, indoor cooking fire)
What is a less common cause of emphysema?
• Inherited deficiency of a1-antitrypsin
Two ways in which inflammation causes pathology of COPD
- Inflammation amplified by host factors
- Oxidative stress
- Proteinases (followed by various repair mechanisms)
Give four changes in the airways in patients with COPD
- Changes in large airway
- Changes in small airways in COPD
- Changes in lung parenchyma
- Changes in pulmonary arteries
Give three main causes of COPD?
- Smoking
- Environmental factors
- Genetic predisposition
What are the mechanisms of COPD?
- Airway and systemic inflammation
- Alveolar destruction
- Hyperinflation
- Respiratory muscle ineffiency
- Skeletal muscle dysfunction
What are the main consequences of COPD?
- Airway obstruction
- Dyspnoea
- Exercise limitation
- Nutritional delpletion
- Respiratory failure
What are five impacts of COPD?
- Mobility
- Health status
- Moos
- Hospitalisations
- Death
How does COPD make itself worse?
- COPD -> Breathlessness -> Reduced exercise capacity -> Poor health related quality of life
- Breathlessness reduces exercsise capacity
Give four symptoms of COPD
• Productive cough
○ White or clear sputum
• Wheeze
• Breathlessness
Give four signs of COPD
• No signs or quiet wheezes
• Hyperventilation with prolonged expiration
○ Expiratory airflow limitation
• accessory muscles of respiration are used
• Hyperinflation of the lung
What are the five main factors which you must assess to determine a diagnosis of COPD
• History ○ Include MRC dyspnoea scale • Chest X-ray ○ To rule out lung cancer • FEV1 ○ Reduced FEV1 ○ Reduced FEV1/FVC ratio • Other lung function tests ○ Lung volumes, loop • High resolution CT scan ○ Detect emphysema (bola?)
What is the MRC dyspnoea scale?
- Not troubled by breathlessness except on strenuous exercise - 1
- Short of breath when hurrying or walking up a slight hill - 2
- Walks slower than contemporaries on level ground because of breathlessness, or has to sop for breath when walking at own pace
- Stops for breath after walking about 100m or after a few minutes one level ground - 4
- Too breathless to leave the house, or breathless when dressing or undressing - 5
What is spirometry?
- Patient fills their lungs from the atmosphere and breathes out as far and fast as possible through a spirometer
- Simple spirometery allows measurement of many lung volumes and capacities
What happens to respiratory rate, pO2 and CO2 in Type 1 Respiratory failure
- Respiratory rate increases
- pO2 decreases
- CO2 decreases
What happens to respiratory rate, pO2 and CO2 in type 2 respiratory failure
- Respiratory rate increases
- pO2 decreases
- CO2 increases
Give four principles of the management of respiratory failure?
- Correct underlying cause
- Supplementary oxygen
- Support ventilation
- Secretion management
What occurs in oxygen therapy?
• O2 given to patients to increase O2 saturation and alleviate symptoms.
What is O2 therapy a treatment for?
• Hypoxaemia, not breathlessness
Why is O2 therapy useful as a treatment?
- Long term
- Portable
- Intermittent
Can COPD be cured?
• No, only managed
Give 6 ways in which COPD can be treated
- Smoking cessation
- Drug therapy
- Oxygen therapy
- Pulmonary rehabilitaton
- A1 - antitrypsin replacement
- Treat co-morbid conditions
How can smoking cessastion help with COPD?
- Prevents future worsening of the condition
* Adds years onto life
How does drug therapy assist with COPD treatment?
• Used for short term management of exacerbation and the long term relief of symptoms
What drugs are used in COPD?
• Bronchiodilators ○ B2 antagonist • Corticosteroids ○ Immunosupressive • Antibiotics ○ Shortens exacerbations ○ Given as soon as sputum turns yellow or green
How does oxygen therapy help?
• Increase blood oxygen saturation by administering oxygen
How does pulmonary rehabilitation help?
- Exercise training can modestly increase exercise capacity
* Regular training periods can be used at home
What physiological effects does pulmonary rehabillitation have?
• Physiological ○ Muscle mass ○ Mitochondrial density • Health ○ Improved activity ○ Reduced care costs • Increases patients MRC grade by 1 point if done effectively
What can you do in hospitals to keep patients physically fit?
• Get them to the gym lad
How does a1-antitrypsin replacement work
• Replaces if deficient
What co-morbidities must be treated to fully effect improvement in COPD?
- Cardiac
- Metabolic
- Nutritional
- Osteoporosis
- Anxiety/depression
What is exacerbation of COPD?
- Worsening of previous stable condition
- Increased wheeze, dyspnoea, sputum volum & colour
- Chest tightness
What is NIPPV (Non-invasive positive pressure ventilation)in COPD?
• Acute exacerbation
○ Causes severe acidosis
○ Confusion
What surgery can be used to reduce effects emphsema?
• Lung volume reduction surgery
How do you calculate oxygen delivery?
• SaO2 x Hb x Cardiac Output
What is the definition of respiratory failure at sea levels in PaO2
- <7.3 kPa PaO2
* 6.5 kPa pCO2 (may or may not be present)
Give four pulmonary causes of respiratory failure
- Hypoventilation
- Ventilation/perfusion imbalnce
- Alveolar/capillary diffusion block
- True shunt
How does hypoventilation cause respiratory failure?
Raised PaCO2
How is ventilation/perfusion imbalance caused
- Asthma
* Pulmonary embolism
How is a alveolar/capillar diffusion block caused?
- Pulmonary oedema
* Fibrosing alveolitis
What is a true shunt?
• VSD and malformation
What does pO2 need to be to avoid hypercapnia?
• 88-92%
Outline four of the most common normal flora of the respiratory tract
- Viridans streptococci
- Neisseria spp
- Anaerobes
- Candida spp
Give five less common flora in the URT
- Streptococcus pneumonia
- Streptococcus pyogenes
- Haemophillus influenza
- Pseudomonas
- E. coli
Give three of the main natural defences of the respiratory tract
- Cough and sneezing reflex
- Muco-ciliary clearance mechanisms
- Respiratory mucosal immune system
What are the muco-ciliary clearance mechanisims?
- Ciliated columnar epithelium
* Nasal haris
What is the respiratory muscoal immune system?
- Lymphoid follicles of the pharynx and tonsils
- Alveolar macrophages
- Secrete IgA and IgG
List 5 upper respiratory tract infections
- Rhinitis
- Pharyngitis
- Epiglottitis
- Laryngitis
- Sinusitis
What are URT infections most commonly caused by?
• Viruses ○ Rhinovirus ○ Corona virus ○ Influenze ○ Respiratory Syncytial virus
What do bacterial super-infections cause?
• Common with sinusitis and otitis media • Can lead to ○ Mastoiditis ○ Meningitis ○ Brain abscess
What is pneumonia?
• General term denoting inflammation of the gas exchnage system of the lung, usually due to infection. Pneumonia is therefore an infection of the lung parenchyma.
What is lung inflammation due to other causes such as physical or chemical damage called?
Pneumonitis
What is lobar pneumonia?
- Pneumonia localised to a particular lobe of the lung
* Most often due to streptoccocus pneumoniae
What is broncho pneumonia
- Pneumonia that is diffuse and patchy. Infection starts in the airways and spreads to adjacent alveoli and lung tissue.
- Streptoccous pneumonia, Haemophilus influenza, Staphylococcus aureus, anaerobes
What is aspiration pneumonia
- Aspiration of food, drink, saliva or vomit can lead to pneumonia.
- Most likely individuals with altered level of conciousness due to anathessia, alcohol or drug abuse - Also problems swallowing
- Oral flora and anaerobes
What is interstitial pneumonia?
- Inflammation of the interstiticium of the lung
* Alveolar epithelium, pulmonary capillary endothelium, basement membrane, perivascular and perilymphatic tissues)
What is chronic pneumonia?
• Inflammation of the lungs that persists for an extended period of time
What is the pathology of pneumonia?
- Fluid filled air spaces and consolidation
* Gas exchange is impared - Results in systemic and local symptoms
In what four ways is pneumonia classified?
- By clinical setting - Community/hospital acquired
- By presentation - Acute/sub acute and chronic
- By organism - Bacteria/Viral/fungal
- By lung pathology - Lobar pneumonia/bronchopneumonia/interstitial pneumonia
What are the three most common bacterial causes of community acquired infection
- Streptococcus pneumoniae
- Haemophilus influenza
- Klebsiella pneumoniae
Give three atypical bacteria involved in community based pneumonia
- Chlamydia pneumophillia
- Mycoplasma pneumoniae
- Legionelle pneumophilia
What are the three most comon causes of hospital acquired baceria/
- Pseudomonas
- Staphylococcus aureus
- MRSA
What are the two most common bacterial causes of aspiration pneumonia
- Anaerobes
* Oral flora
What are the associated features of S. Pneumniae
• Elderly, co-morbidities, acute onset , high fever, pleuritic chest pain
What are the associated features of H. Influenza
COPD
What are the associated features of legionella
- Recent travel
- Younger patient
- Smoker
- Illness
- Multisystem involvement
What are the associated features of mycoplasm pneumonia
- Young
- Prior to antibiotics
- Extra-pulmonary involvement (haemolysis, skin and joint)
What are the associated features of staph aureus pneumonia
- Post viral
* Intravenous Drug User
Give an associated feature of chalmydia pneumonia
• Contact with birds
Give an associated feature of coxiella pneumonia
• Animal contact
Give an associated feature of klebsiella pneumonia
• Thrombcytopenia, leucopenia
Give an associated feature of s.milleri
- Dental infections
- Abdominal source
- Aspiration
Outline the symptoms always present in pneumonia
- Fever
- Malaise
- Productive cough
- Pleuritic chest pain
- Breathlessnes
What will the sputum of someone with pneumonia look like?
• Purulent or rusty coloured
How quick is the onset of pneumonia, and what types are the fastest?
- Very rapid onset
* Pneumoccoccal or staphylococcal, fatal outcome
Give some specific features of hospital acquired pneumonia
- Pneumonia occuring 48 hours after hospital
- Make up 15% of all hospital acquired infections
- Common in ventilated post surgical patients
How can the symptoms of pneumonia be assessed?
• CURB 65 score - presence of two or more indication for hospital treatment, patients with higher scores may require ICU treatment.
○ C - new mental Confusion (AMT 7mmol/l
○ R - Respiratory rate >30 per minute
○ B - Blood pressure (systolic 65
What does CURB 65 score assess?
• The severity, NOT the resistance of the pneumonia
Where are samples collected from to investigate pneumonia?
- Sputum
- Nose and throat swabs
- Endotracheal aspirate
- Broncho alveolar lavage fluid
- Blood culture
What microbiological investigations can be done for pneumonia?
• Macroscopic ○ Sputum, purulent, blood stained • Microscopy ○ Gram staining, acid fast • Culture ○ Bacteria and viruses • PCR ○ Respiratory viruses • Antigen detection ○ Legionella • Antiobody detection ○ Serology
What is an opportunistic infection?
• Pathogens infecting immunosupressed hosts
Give an example of 4 different types of opportunistic pathogen
- Viruses - Cytomegalovirus
- Bacteria - Mycobacterium avium intracellulare
- Fungi - Aspergillus candida, pneumocystitis jirovecil
- Protozoa - Toxoplasmosis
Outline management of pneumonias
• Oral fluid /IV fluid if severe ○ Avoids dehydration • Anti-pyretic drugs ○ Reduce fever and malaise • Stronger analgesics ○ Deal with the pain • Oxygen ○ If there is cyanosis • Specific anti-biotics
What kind of anti-biotics is a community acquired pneumonia treated with
• Pneumococcus, which is sensitive to penicillin (antibiotics which affect the cell wall)
What kind of anti-biotics is hospital acquired pneumonia treated with?
• Target organism is more likely to be gram -‘ve, making it necessary to use antibiotics that cover these organsims
Give the three main outcomes of pneumonia
- Resolution
- Complications
- Death
hat is involved in resolution of pneumonia?
Organisation (fibrous scarring)
What are three possible complication of pneumonia?
- Lung abscess
- Bronchiectasis
- Empyema (pus in pleural cavity)
How can pneumonia be prevented?
• Immunization
○ Flu vaccine, given anually to high risk patients
○ Pneumococcal vaccine - two vaccines
• Chemoprophylaxis
○ Oral penicillin/erthromycin to patients with high risk of lower respiratory tract infections
○ Asplenia, dysfunctional spleen, immunodefiency