Medicine - Respiratory Flashcards
Why is it important to do an FBC in suspected COPD?
Need to investigate for secondary polycythaemia
What is the gold standard test for diagnosing COPD?
Spirometry
What are the indications for prescribing azithromycin to copd patients regularly?
- Non-smoker
- Optomised medical management
- Referred for pulmonary rehabilitation
- 4 or more infective exacerbations per year with at least 1 hospitilisation
Recall some conservative measures for managing COPD
Smoking cessation
Mucolytics
Vaccines
What is the 1st line for medically managing COPD?
SAMA or SABA prn
Give an example of a SAMA
Ipratropium
What is the 2nd line for medically managing COPD?
It depends if there are asthmatic features:
Asthmatic features: LABA + ICS
No asthmatic features: LABA + LAMA
Give an example of a LAMA
Tiotropium
What is Symbicort?
LABA + ICS
What would count as ‘asthmatic features’ in a patient with COPD?
- History of asthma/ atopy
- FEV1 variation over time
- Eosinophilia
- Diurnal variation in PEFR (>20%)
Recall some surgical options for managing emphysema
- Bullectomy
- Lung resection surgery (if emphysema is heterogenous)
- Endobrachial valve placement
- Lung transplant
Recall the requirements for long term oxygen therapy in COPD
Non smoker plus either:
- pO2 <7.3
- pO2 = 7.3-8 and one of secondary polycythaemia/ peripheral oedema/ pulmonary hypertension
Recall some possible local and systemic complications of COPD
Local: pneumothorax, lung Ca, bullae formation, lobar collapse
Systemic: pulmonary htn, cor pulmonale, polycythaemia
What are the best investigations for assessing the possibility of asthma in 5-16 year olds?
Spirometry with BDR (bronchodilator reversibility) test +/- FeNO test
What are the best investigations for assessing the possibility of asthma in adults?
FeNO test followed by spirometry with BDR (bronchodilator reversibility) test +/-:
- PEFV (peak expiratory flow variation)
- Bronchial challenge
What is a bronchial challenge?
Patient breathes in slowly whilst dose of metacholine/ histamine is increased (airway irritants) to see how high a dose they can tolerate
What is a ‘PC20’ in asthma diagnosis?
Measurement taken in bronchial challenge
Provocative concentration causing a 20% fall in FEV1
What is the positive test threshold for diagnosing asthma in a FeNO test?
> 40 parts per billion
What is the positive test threshold for diagnosing asthma using FEV1/FVC ratio?
<70% (indicative of obstructive picture)
What is the positive test threshold for diagnosing asthma in a BDR test?
> 12% variability and >200mL increase in volume after SABA administration
What is the positive test threshold for diagnosing asthma using peak flow variability?
> 20% PEFR variability
What is the positive test threshold for diagnosing asthma using a bronchial challenge?
PC20 <8mg/mL (with both histamine and metacholine challenge)
Systematically recall some differentials for wheeze
Respiratory: obstructive pathologies eg asthma, COPD, inhald foreign body
Rheumatological: granulomatosis with polyangiitis (obliterative bronchiolitis), rheumatoid arthritis
Cardiac: heart failure
At what PEFR should someone definitely be admitted to hospital for an acute asthma attack?
<33%
At what SaO2 is an acute asthma attack considered ‘life-threatening?
<92%
At what PEFR is an acute asthma attack considered ‘life-threatening?
<33%
When would an acute asthma attack be considered ‘near fatal’?
When the pCO2 is raised
When can you discharge someone following an acute asthma attack safely?
When they have been stable for 48 hours - then review 48 hours post-discharge
What is the acronym for things to counsel the patient on before discharge following an acute asthma attack?
TAME Technique (for inhalers) Avoidance (of triggers) Monitor (PEFR) Educate
What should be the TTA drugs following an acute asthma attack?
Either
Prednisolone 40mg OD, PO, 5 days (if they were admitted)
Or
Quadruple ICS dose for 14 days (if they weren’t admitted)
Recall the steps of acute asthma attack management in hospital
- Oxygen
- Nebulised salbutamol (5mg)
- Nebulised ipratropium bromide (0.5mg)
- Steroid: either PO prednisolone 50mg (to be taken for 5 days) or 100mg IV hydrocortisone
- Call for senior support
- IV Magnesium sulphate
- IV aminophylline
- ITU + intubation
When should someone be admitted to hospital because of an acute asthma attack?
Always if PEFR <33%
If PEFR is between 33 and 50% and there is no response to medication in A&E
How often can i) salbutamol and ii) ipratropium bromide nebulisers be given?
Salbutamol: back to back prn
Ipratropium: 4 hourly
If a patient’s sputum is described as ‘rusty’ in an SBA, what sort of pneumonia is it most likely referring to?
Streptococcus pneumoniae
Which type of typical pneumonia is associated with pre-existing lung disease?
Haemophilus influenzae
Which type of typical pneumonia is most strongly associated with smoking?
Moraxella catarrhalis
If a patient’s sputum is described as ‘red currant jelly’ in an SBA, what sort of pneumonia is it most likely referring to?
Klebsiella
Which type of atypical pneumonia is associated with erythema multiforme?
Mycoplasma pneumoniae
Which type of atypical pneumonia is associated with steven johnson syndrome?
Mycoplasma pneumoniae
Which type of typical pneumonia is most associated with alcoholism?
Klebsiella
Which type of typical pneumonia is most associated with diabetes?
Klebsiella
Which type of typical pneumonia is most associated with haemoptysis?
Klebsiella
What risk factors are C. Psittaci associated with?
Birds
Recall one important complication of C. Psittaci pneumonia
Haemolytic anaemia
What is the main association with C. burnetti pneumonia in SBAs?
Farm animals
Recall the CURB65 score for assessing pneumonia
Confusion (AMTS<8) Urea >7 Resp rate >30 BP <90/60mmHg Age >65
What is the most common pathogen implicated in early-onset (<48 hours) vs late-onset (>4 days) hospital-acquired pneumonia?
Early-onset: Streptococcus pneumonia
Late-onset: enterobacteria (E coli/ Klebsiella pneumoniae) > MRSA
What is the antibiotic of choice for MRSA pneumonia?
Vancomycin
What is the antibiotic of choice according to NICE for non-severe vs severe hospital-acquired pneumonia?
Non-severe: co-amoxiclav or doxycycline
Severe: Piptazobactam (tazocin)
Which tests for TB will be positive if the infection has been eliminated by the acquired immune response?
Tuberculin skin testing
IGRA (interferon gamma release assay)
Which tests for TB will be positive in latent TB?
Tuberculin skin testing
IGRA (interferon gamma release assay)
Which tests for TB will be positive in subclinical TB?
Tuberculin skin testing
IGRA (interferon gamma release assay)
(Intermittently a sputum culture)
Recall a possible side effect of each of the drugs used most commonly in multi-drug therapy for TB
Rifampicin: orange secretions Isoniazid: neuropathy Pyrizinamide: Liver toxicity Ethambutol: eye toxicity Mnemonic = ONLY
How can histology be obtained when investigating TB (and other lung diseases)?
EBUS (endobronchial ultrasound-guided transbronchial needle)
At what CD4 count should someone with HIV be given PCP prophylaxis?
<200
What counts as ‘extremely drug-resistant TB’?
Resistant to rifampicin, isoniazid, fluoroquinolones and at least 1 injectable
Which lung infection typically gives a history of desaturating on exercise?
PCP pneumonia
Recall 3 possible extrapulmonary signs of PCP pneumonia
Hepatosplenomegaly
Lymphadenopathy
Choroid lesions (pneumocystis choroiditis)
What stain is the most useful for investigating for PCP pneumonia and what will it show?
Silver stain
Cysts
What is the management for i) mild-moderate and ii) severe PCP pneumonia?
Mild-moderate: co-trimoxazole
Severe: IV pentamidine
What is the quickest vs the gold standard method for diagnosing active TB from sputum?
Quickest: NAAT (takes 24-48 hours, 50-80% sensitive)
Gold-standard: culture (takes 1-3 weeks)
Which stain for sputum is used for TB screening vs diagnosis?
Screening: auramine
Diagnosis: Ziehl-Neelson
Recall some immediate, early and late complications of a chest drain
Immediate: pain, failure, haemorrhage, pneumothorax
Early: infection, haematoma, blockage, long thoracic nerve damage (–> winged scapula)
Late: scar formation
When is bubbling normal in a chest drain?
Pneumothorax
nb: abnormal in pleural effusion
If NO bubbling in pneumothorax then there is likely to be a blockage
In what patients would a pneumothorax be counted as secondary?
Age >50
Smoking history
Evidence of underlying lung disease on exam or CXR
How should secondary pneumothoraces be managed?
If >2cm or breathless proceed straight to chest drain
If 1-2cm, try aspiration, and only try chest drain if still >1cm
If <1cm, or successful aspiration –> admit, high flow oxygen and observe for 24 hours
How should primary pneumothoraces be managed?
If >2cm or breathless –> attempt aspiration
If aspiration unsuccessful (still >1cm) –> chest drain
If aspiration successful –> consider discharge and review in OPC
If <2cm, consider discharge straight away and review in OPC
What is a flail chest?
3 or more consecutive ribs fracture in 2 or more locations resulting in part of the chest wall moving paradoxically and independently of the rest
This is a life-threatening condition
In which direction does the flail segment move during inspiration vs expiration in a flail chest?
Inspiration –> inwards
Expiration –> outwards
Why is flail chest so dangerous?
Increases work of breathing and pulmonary contusions
Free rib can puncture the lung and cause a tension pneumothorax
What might be seen on CXR in flail chest?
Rib fractures
Subcutaneous emphysema
Pneumothorax
Mediastinal shift if tension
What are the principles of management of flail chest?
Analgesia and chest physiotherapy for all
Some may also need CPAP and/or surgical fixation
Differentiate some causes of exudate vs transudate pleural effusion
Exudate (‘eggsudate’) involves protein - causes include: infection, PE, malignancy, trauma and pancreatitis
Transudate is caused by a disturbance of osmotic or colloid pressure - so organ dysfunction is the main cause as organs stop regulating these pressures: liver (cirrhosis), kidney (nephrotic syndrome), heart (CCF). Can also be caused by myxoedema and Meig’s syndrome (nb ascites is a component of this so osmotic pressure must be unbalanced)
Recall some important bedside investigations for the cause of a pleural effusion
Examination
Basic obs
Urine dip for protein (nephrotic syndrome –> transudate pleural effusion)
Recall some useful forms of imaging in investigating a pleural effusion
- CXR
- If confirmed on CXR –> contrast CT (especially if cause is exudative)
- If cause is CCF (transudate) do an echo
What equipment should be used for a pleural tap?
21G needle and 50mL syringe
What pH, LDH and glucose would a pleural tap show in empyema?
pH<7.2
LDH high
Glucose low
How are exudate and transudate defined?
Exudate = >30g/L protein Transudate = <30g/L protein
What are Light’s criteria used for and what are the 3 criteria?
Light’s Criteria = used in pleural effusion to establish whether fluid is exudate or transudate when protein is 25-35g/L
An exudate is likely if pleural fluid/ serum:
1. Protein >0.5
2. LDH >0.6
Or if pleural fluid LDH >2/3rds upper limit of normal of serum LDH