Respiratory Flashcards
COPD definition
COPD is caused by chronic bronchitis and emphysema.
Progressive airflow obstruction, due to an abnormal inflammatory response within the lungs due to cigarette smoke / other inhaled particles.
MRC dyspnoea scale
- No breathlessness except on strenuous exercise
- SOB when hurrying or walking up a slight hill
- Walks slower than contemporaries on level ground due to SOB, or has to stop for breath
- Stops for breath after walking 100m or for a few minutes
- Too SOB to leave the house or breathless when dressing
GOLD COPD staging
I (mild) - FEV1 >80% predicted
II (moderate) - FEV1 50-80% predicted
III (severe) - FEV1 30-50% predicted
IV (very severe) - <30% predicted or >50% + chronic respiratory failure
Investigations for COPD
Bedside: lung function studies, sputum culture, observations, peak flow
Bloods: FBC (anaemia), CRP + WCC (infection), albumin (chronic disease), ABG (hypoxaemia +/- hypercapnia), A1AT levels
Imaging: CXR and HRCT
Other: BMI calculation, echo (to evaluate for pulmonary HTN)
What treatments are available to help patients stop smoking?
Behavioural: ‘5 A’s’ approach endorsed by BTS, group counselling
Nicotine replacement therapy (patches, gum, inhalers, nasal sprays)
Medications: bupriopion, varenicline
What are the treatment options available for COPD?
Non-pharmacological: pulmonary rehab, optimise nutrition, vaccination (influenza + pneumococcal)
Pharmacological:
1. Short-acting bronchodilators - short-acting b2 agonists and short-acting anticholinergics (combination treatment)
2. Long-acting bronchodilators - long-acting b2 agonists and long-acting anticholinergics
3. LABA + ICS if asthmatic features or steroid-responsive
3. LABA + LAMA if no asthmatic features or steroid responsiveness
4. LABA + LAMA + ICS
5. Theophylline - not recommended for initial treatment
Oxygen: LTOT - indicated in patients with Pa02 <7.3 or Pa02 <8 with secondary polycythaemia, nocturnal hypoxaemia, cor pulmonale, pulmonary HTN. 15h / day
NIV: considered in pts with chronic T2RF despite adequate treatment
Describe the role of surgery in patients with COPD
Lung volume reduction surgery
Bullectomy
Lung transplant
What causes an acute exacerbation of COPD?
60% infection:
- viruses (rhinovirus, influenza, parainfluenza, coronavirus, adenovirus), - bacteria (haemophilus influenza, moraxella catarrhalis, strep pneumoniae, pseudomonas)
10% environmental pollution
30% unknown aetiology
How are infective exacerbations of COPD treated?
Controlled o2 to achieve o2 sats of 88-92%
Salbutamol + ipratropium nebs
Oral corticosteroids: improve lung function and reduce length of hospital stay
Antibiotics: initially empirical tx with aminopenicillin, macrolides or tetracycline
Aminophylline: not recommended as first-line treatment due to side effects
Discharge planning should involve a community COPD treatment team
Describe the use of NIV in the treatment of IECOPD
BIPAP - provides pressure support via a facemask with higher IPAP than EPAP
- improves oxygenation, increases removal of co2, increases functional residual capacity, increases tidal volume, decreases respiratory effort
- has been shown to decrease the need for I + V, reduces mortality, results in fewer complications.
Indications for NIV
pH <7.35 despite maximal medical and controlled o2 therapy.
Able to consent to treatment and have potential for recovery for QOL acceptable for patient.
Exclusion criteria: life-threatening hypoxaemia, severe comorbidity, facial injuries, vomiting, upper airway obstruction, undrained pneumothorax, bowel obstruction, upper GI surgery, haemodynamic instability.
Pre-requisites for starting NIV
Ceiling of care and resus decision needs to be made prior to starting.
Initial pressures: IPAP 12-16 and EPAP 4-5 with oxygen adjusted to reach target sats of 88-92%.
How does CPAP differ from NIV?
CPAP maintains the same pressure support throughout the breathing cycle, splinting open the upper airways, recruiting collapsed alveoli and reducing ventilation / perfusion mismatch.
It is used in the treatment of acute pulmonary oedema, OSA and T1RF.
What is cor pulmonale? What is its significance?
Right-sided cardiac dysfunction secondary to pulmonary hypertension. The pulmonary HTN must be of a respiratory cause.
Untreated cor pulmonale causes right-sided heart failure and death.
What are the indications for LTOT?
LTOT targets = o2 for >16 hours/day, with aim of achieving Pa02 >8 kPa.
Pa02 <7.3 or Pa02 7.3 - 8 kPa in a patient with cor pulmonale.
All patients with FEV1 <30% predicted, signs of RHF and o2 sats <92% should be considered for LTOT.
How would you classify severity of COPD?
Based on the presence of symptoms and the percentage predicted of their FEV1.
GOLD staging:
Mild: FEV1 >80%
Moderate: FEV1 50-80%
Severe: FEV1 30-50%
Very severe: FEV1 <30%
Name the common causes of community-acquired pneumonia.
Common: strep pneumoniae, haemophilus influenzae, staph aureus
Atypical: mycoplasma pneumoniae, legionella pneumophila, coxiella burnetii
Viruses: influenza, CMV, VZV, Covid-19
List the possible complications of pneumonia.
Parapneumonic effusion
Empyema
Cavitation
Lung abscess
Septic shock
Respiratory failure / ARDS
Hepatitis
Haemolytic anaemia
Erythema multiforme
How can we assess the severity of community-acquired pneumonia?
CURB-65 score
0-1: low-risk, consider home treatment
2: increased risk
3-5: high risk, admit, consider ITU referral
Confusion (AMTS 8 or less)
Urea >7 mmol/l
Resp rate >30/min
BP <90 systolic and <60 diastolic
Age >65 years
Define hospital-acquired pneumonia.
HAP occurs >72 hours after admission to hospital.
What is the difference between an empyema and a complicated parapneumonic effusion?
Empyema is pus in the pleural cavity with pH <7.2
Complicated parapneumonic effusion has pH <7.2 but is clear
Parapneumonic effusion has pH >7.2 and is clear
How would consolidation be differentiated from effusion on clinical examination?
Tactile vocal fremitus: sound is increased through tissue (consolidation) and decreased through fluid (effusion)
Vocal resonance: is indicative of consolidation when whispered sounds are heard clearly through affected lung tissue
Other than guiding the clinical management of the patient, what other information does a CURB-65 score offer?
Indicates mortality associated with the severity of the pneumonia. Higher score = higher mortality rate.
0-1 <5% mortality rate
2- 9% mortality rate
3-5 15-40% mortality rate
Which patients are at high risk of pneumonia?
COPD, immunocompromised, the elderly, alcoholics
Respiratory causes of clubbing
ABCDEF
Abscess / asbestosis
Bronchiectasis
Cystic fibrosis
Dirty tumours (mesothelioma / bronchogenic carcinoma)
Empyema
Fibrosing alveolitis (IPF)
What is the pathogenesis of CF?
Autosomal recessive disease due to defect on CFTR gene on chromosome 7. F508 is the most common mutation.
Frequency in Caucasians is 1:2500 live births (1 in 25 chance of being a carrier).
CFTR gene located in all exocrine tissues. Defective CFTR prevents chloride moving out of cells, which results in osmosis of water into cells, resulting in thick viscous secretions, easily amenable to infection.
What other systems are affected in CF patients?
Multisystem disease, with lung disease being the major cause of morbidity and mortality.
GI: pancreatic enzyme insufficiency (malabsorption, diabetes, focal biliary cirrhosis, cholelithiasis)
Reproductive: male subfertility due to defective sperm transport
MSK: osteoporosis
ENT: sinus disease and nasal polyps
What organisms commonly colonise the respiratory tract in CF patients?
Haemophilus influenza
Staph aureus
Pseudomonas species
Burkholderia cepacia complex (CI to transplantation in some centres)
What is the prognosis for CF patients?
Median survival is 32 years and increasing, many patients live into their 40s and lead active lives.
What are the main complications of bronchiectasis?
Pulmonary: recurrent infection, haemoptysis, empyema, cor pulmonale
Extrapulmonary: anaemia, metastatic infections, secondary amyloidosis
What other conditions are known to be associated with bronchiectasis?
CTD (e.g., RA)
Chronic sinusitis
Inflammatory bowel disease
Marfan’s syndrome
What are the major pathogens associated with bronchiectasis?
Pseudomonas aeruginosa
Streptococcus
Haemophilus influenza
What is bronchiectasis?
Abnormal and permanently dilated airways with bronchial wall thickening.
This manifests as a cough with production of thick sputum.
What are the causes of bronchiectasis? (PMMII)
Post-infective bronchial damage: severe bacterial / viral pneumonias, measles and pertussis, TB and other mycobacterial infections.
Mucociliary clearance defects: CF, primary ciliary dyskinesia, Kartagener’s syndrome, Young’s syndrome
Mechanical: obstruction (tumour, foreign body)
Immunodeficiency: primary (immunoglobulin deficiency), secondary (HIV)
Immunological: allergic bronchopulmonary aspergillosis
What is the differential diagnosis of bilateral lower-zone crackles?
Bronchiectasis: coarse crackles heard in early-mid inspiration
Lung fibrosis: fine end-inspiratory crackles
Pulmonary oedema: fine/coarse bibasal crackles with signs of overload
Bilateral pneumonia: coarse crackles with fever / bronchial breathing
What organisms are commonly found in the sputum of patients with CF, and which are most important for prognosis?
Haemophilus influenzae, staph aureus, moraxella catarrhalis, strep pneumoniae, atypical mycobacteria.
Burkholderia cepacia, pseudomonas and mycobacterium abscessus infection are poor prognostic indicators.
What are the respiratory complications associated with CF?
Infective exacerbations
Pneumothorax
Haemoptysis
Aspergillus lung disease
Respiratory failure
Are you aware of any new treatments available for CF?
The CFTR modulators - Ivacaftor, Orkambi, Symkevi (make the chloride channel functional)
What are the risk factors for active pulmonary TB infection?
Place of birth - sub-Saharan Africa and Asia
Age
HIV / AIDS
Homelessness
Previous prison stays
Sex workers
Co-morbidities: diabetes, renal disease, malignancy
Immunosuppressed
How do you treat pulmonary TB?
Notifiable disease: contact tracing
Antibiotics (RIPE): rifampicin, isoniazid, pyrazinamide, ethambutol. RI continued for 4 months, P and E stopped after 2 months.
What are the side effects of TB medications?
Rifampicin: reduces efficacy of AEDs and COCP. Red discolouration of secretions and urine
Isoniazid: hepatitis, peripheral neuropathy
Pyrazinamide: hepatic toxicity, peripheral neuropathy, gout
Ethambutol: optic neuritis (e, for eye)