Respiratory Flashcards
How does acute bronchitis present?
Symptoms typically peak after 2-3 days and then gradually clear → this can take 3-4 weeks.
- Cough → main symptom
- May be productive with clear, white, or discoloured sputum.
- May have substernal or chest wall pain when coughing
- Fever
- Headache
- Cold symptoms
If appropriate (eg, immunocompromised or failing to improve), what antibiotic is first-line for acute bronchitis?
Doxycycline
What is the most common cause of bacterial pneumonia across all ages?
Streptococcus pneumoniae
What bacteria is associated with pneumonia in those with COPD?
haemophilus influenzae
How is the severity of pneumonia assessed?
- CRB-65 is used in the community & CURB-65 in hospital. Predicts mortality & is used when deciding management. Consider hospital admission if CRB-65 is more than 0.
- C - Confusion → new disorientation in person, place, or time
- U - Urea >7 mmol
- R - Respiratory rate >30
- B - Blood pressure <90/60
- 65 - Age >65
What are the main causes of pulmonary hypertension?
- Idiopathic pulmonary hypertension, or connective tissue disease (SLE)
- Left heart failure → MI, systemic HTN
- Chronic lung disease → COPD, pulmonary fibrosis
- Pulmonary vascular disease → PE
- Other → sarcoidosis, haematological disorders
How does pulmonary hypertension present?
Symptoms:
- Due to gradually worsening right ventricular function
- SOB
- Weakness & fatigue
- Chest pain
- Syncope
Signs:
- Loud S2
- 3rd heart sound
- Pansystolic murmur (tricuspid regurgitation) & diastolic murmur (pulmonary regurgitation)
- Later signs
- Ascites
- Peripheral oedema
- Parasternal heave
- Elevated JVP
- Hepatomegaly
What investigations are done for pulmonary hypertension?
- ECG: signs of R-sided heart strain (p pulmonale, RVH, RAD, RBBB)
- CXR: dilated pulmonary arteries
- Raised BNP
- Right heart catheterisation: gold standard as allows the pulmonary arterial pressure to be measured
What are the risk factors of asthma?
- Non-modifiable
- Personal or family history of atopy
- Male sex (asthma development) or female sex (persistence to adulthood)
- Prematurity & low birth weight
- Maternal smoking during pregnancy
- Modifiable
- Exposure to smoke & dust
- Obesity
- Social deprivation
- Infections in infancy
What are some triggers of asthma?
- Respiratory infections
- Allergens → dust, animals, food
- Pollutants → smoke
- Cold air
- Exercise
- Medications → NSAIDs, beta-blockers (particularly non-selective ones, eg propranolol)
What is the order of investigations recommended for an asthma diagnosis? What is a positive finding for each?
Initial Investigations:
- Fractional Exhaled Nitric Oxide (FeNO) - >40ppb
- Spirometry with bronchodilator reversibility -> FEV1/FVC ratio <70%, with >12% reversibility
Next Steps:
- Peak flow variability - >20% variability positive
- If still uncertainty then do a direct bronchial challenge test
What supportive management is indicated in asthma?
- Asthma plan → treatment, treatment escalation, when to seek help
- Annual asthma reviews
- Vaccinations → childhood, pneumococcal, influenza, covid
- Lifestyle measures → smoking cessation, weight loss, avoid triggers if possible
What is the progression of asthma treatment?
- Short-acting beta-2 agonist (salbutamol) + low-dose inhaled corticosteroid
- Add long-acting beta-2 agonist (salmeterol) OR change to maintenance & reliever therapy (MART)
- Increase the ICS, OR add a leukotriene receptor antagonist (montelukast)
- Specialist management
When should asthma treatment be reviewed for additional management?
Review when using >3 doses of SABA a week or using >1 inhaler device in a month
What are some side effects of SABA inhalers?
- Tachycardia
- Vasodilation
- Arrhythmia
- Tremor
- Hypokalaemia
- Insomnia
What are the different severities of an acute exacerbation of asthma?
Moderate exacerbation features:
Peak flow 50 – 75% best or predicted
Severe exacerbation features:
Peak flow 33-50% best or predicted
Respiratory rate above 25
Heart rate above 110
Unable to complete sentences
Life-threatening exacerbation features:
Peak flow less than 33%
Oxygen saturations less than 92%
PaO2 less than 8 kPa
Becoming tired
Confusion or agitation
No wheeze or silent chest
Haemodynamic instability (shock)
What are the medical management options for an acute exacerbation of asthma?
- Oxygen → if hypoxic
- SABA → high dose, either with inhaler + spacer, nebulisers, IV
- Corticosteroids → 40-50mg prednisolone PO for 5 days
- Ipratropium bromide → if severe or failure to respond
- IV magnesium sulphate → for severe, life-threatening
What is COPD defined as?
= a long-term, progressive lung disease characterised by emphysema, chronic bronchitis, and small airway fibrosis.
Definitions:
- Chronic bronchitis → a productive cough for at least 3 months in 2 consecutive years.
- Emphysema → damage & dilatation of the alveolar sacs & alveoli, decreasing the surface area for gas exchange.
What is the medical management of COPD?
- SABA + SAMA (ipratropium bromide)
- If asthmatic/steroid responsive features → LABA + ICS (fostair). If no asthmatic features →LABA + LAMA (anoro ellipta)
- LABA + LABA + ICS → trimbo, trelegy ellipta
What are the common causes of COPD exacerbation?
- Bacterial
- H.influenzae
- S.pneumoniae
- M.catarrhalis
- Viruses
- Rhinovirus
- Influenza
How is a COPD exacerbation managed?
- Regular inhalers or nebulisers
- Steroids → 30mg OD for 5 days
- Antibiotics
- Respiratory physiotherapy to help clear sputum
- If severe:
- IV amiophylline
- NIV
- Intubation & ventilation
What is bronchiectasis & how does it develop?
= a chronic respiratory disease characterised by permanent dilation of the bronchi, due to irreversible damage to the bronchial wall.
Pathophysiology:
- Poorly understood
- An initial insult results in immune cells being recruited to the bronchi → these secrete cytokines & proteases, leading to inflammation
- This inflammation damages the muscle & elastin → bronchial dilation
- Normally, this bronchial dilation is reversible after the resolution of the initial insult to the bronchi → in bronchiectasis, several factors prevent the bronchial dilation from reversing
- Dilated bronchi are predisposed to persistent microbial colonisation, as mucus is trapped.
- Vicious cycle of microbial colonisation causing inflammation, which worsens the bronchiectasis, which increases the risk of further colonisation
How does bronchiectasis present on imaging?
- CXR
- Tram-track opacities
- Ring shadows
- High-resolution CT → gold-standard imaging test
- Signet ring sign
How is bronchiectasis managed?
General:
- Vaccines
- Chest physio
- Smoking cessation
- Long-term antibiotics → if >3 exacerbations per year, azithromycin
- LABA → for breathlessness
- LTOT → if chronically reduced saturations
- Surgical lung resection or transplant
Infective Exacerbations:
- Sputum culture
- Extended course of antibiotics
- 7-14 days
- Ciprofloxacin → usual choice for exacerbations caused by pseudomonas aeruginosa
What does interstitial lung disease show on imaging?
- CXR → reticular (fine) opacities
- High-resolution CT → honeycombing, dilated airways
What are the two medications that slow disease progression in someone with idiopathic pulmonary fibrosis?
pirfenidone & nintedanib
What investigations are done for suspected pneumothorax?
Bedside:
- Pulse oximetry
- RR, HR
Laboratory Investigations:
- FBC & clotting screen → in trauma cases, in case of transfusion
- ABG → respiratory alkalosis secondary to hyperventilation, or it may show type 1 respiratory failure
Imaging:
- Erect CXR → first line for a suspected simple pneumothorax
- CT Thorax → can detect a pneumothorax that is too small to be seen on CXR.
How is a simple pneumothorax managed?
- Management is mainly guided by symptoms & the degree of physiological compromise.
- High-risk characteristics means a chest drain is required. (haemodynamically unstable, significant hypoxia, bilateral, underlying lung disease, >50yrs old with significant smoking history)
- Low risk with <2cm → conservative management
- Low risk with >2cm → management based on patient’s priority (proceudure avoidance - conservative, symptom relief - needle aspiration or ambulatory device)
When is surgical intervention required for a simple pneumothorax, and what are the options?
- Required if → chest drain fails to correct the pneumothorax, the drain is persistently leaking, the pneumothorax reoccurs.
- Abrasive pleurodesis → creates an inflammatory reaction in the pleural lining sticks together & the pleural space becomes sealed.
- Chemical pleurodesis → talc power
- Pleurectomy
What staining is required for TB culture?
Zeihl-Neelsen stain → a special staining which turns them bright red against a blue background.
What is the disease course of TB?
- Spread → inhaling saliva drops from infected people
- Once in the body, there are several possible outcomes:
- Immediate clearance of the bacteria (70% cases)
- Primary active TB (active infection after exposure)
- Latent TB (presence of bacteria without being symptomatic or contagious)
- Secondary TB (reactivation of latent TB to active infection)
- Miliary TB → when the immune system cannot control the infection, causing disseminated & severe disease.
What two tests are used to check for an immune response to TB?
Mantoux Test:
- Tuberculin is injected into the intradermal space on the forearm (no live bacteria)
- The infection creates a bleb under the skin → after 72hrs the test is checked, and if >5mm then this is a positive result
Interferon-Gamma Release Assays:
- A blood sample is mixed with antigens from M.TB bacteria
- After previous contact with TB, WBCs become sensitised to the bacteria antigens & will release interferon-gamma during the test → this is a positive result
How will TB look on a CXR?
- Primary TB → patchy consolidation, pleural effusions, hilar lymphadenopathy
- Reactivated TB → patchy, nodular consolidation with cavitation, typically in the upper zones
- Disseminated miliary TB → millet seeds uniformly distributed across the lung fields
How is latent TB managed?
- Isoniazid + rifampicin → 3 months
- or Isoniazid → 6 months
How is active TB managed?
- R - rifampicin (6 months)
- I - isoniazid (6 months)
- Pyridoxine (vitamin B6) co-prescribed to reduce risk of peripheral neuropathy
- P - pyrazinamide (2 months)
- E - ethambutol (2 months)
What are the side effects of Rifampicin?
- Red/orange discolouration of secretions, such as urine & tears
- Inducer of cytochrome P450 enzymes, reduces the effect of the COCP
- Hepatotoxicity
- “red-im-pissing”
What are the side effects of Isoniazid?
- Peripheral neuropathy
- Pyridoxine (vitamin B6) prescribed to reduce the risk
- Hepatotoxicity
- “I-so-numb-azid”
What are the side effects of pyrazinamide?
- Hyperuricaemia, resulting in gout & kidney stones
- Hepatotoxicity
What are the side effects of ethambutol?
- Colour blindness & reduced visual acuity
- “eye-thambutol”
