Respiratory Flashcards
What type of histology is lung cancer most commonly?
- Adenocarcinoma (40%)
- Squamous cell carcinoma (20%)
- Small cell lung cancer (20%)
- Large cell carcinoma (10%)
Signs and symptoms of lung cancer?
SOB, cough, haemoptysis, finger clubbing, recurrent pneumonia, weight loss, lymphadenopathy
What is the pathophysiology of small cell lung cancer?
Neurosecretory granules that release hormones-> paraneoplastic syndromes
Investigations for lung cancer?
- CXR-> hilar enlargement, opacity, pleural effusions, collapse
- PET-CT
- Bronchoscopy + endobronchial US
- Histology-> bronchoscopy or skin
What might lung cancer show on a CXR?
Hilar enlargement, peripheral opacity, pleural effusion, collapse
Treatment for lung cancer (non-SCLC)?
- Surgery-> lobectomy etc
- Radiotherapy
- Chemo-> adjuvant or palliative
- Endobronchial treatment (palliative to relieve obstruction)
Treatment for lung cancer (SCLC)?
Chemo + radiotherapy
What are some of the extrapulmonary and paraneoplastic syndromes that can present in lung cancer?
- Recurrent laryngeal palsy
- Phrenic nerve palsy
- Horner’s syndrome
- SVC obstruction
- Cushing’s
- SIADH
- Hypercalcaemia
- Limbic encephalitis
- Lambert-Eaton myasthenic syndrome
How might SVC obstruction (complication of lung cancer) present?
Facial swelling, SOB, distended veins in neck/chest, Pemberton’s sign (hands above head causes facial swelling)
How might Horner’s syndrome present and what can cause it?
- Ptosis + anhidrosis + miosis
- Due to Pancoast’s tumour of pulmonary apex pressing on sympathetic ganglion
What is Lambert-Eaton myasthetic syndrome?
- In SCLC-> antibodies produced against tumour
- Target calcium channels on presynaptic terminals
- Symptoms include autonomic symptoms, proximal weakness, dysphagia etc
What is a mesothelioma?
- Mesothelial cells of pleura-> malignancy
- Linked with asbestos exposure
- Palliative chemo + poor prognosis
What is pneumonia?
Infection of the lung tissue causing inflammation + sputum production
When does hospital acquired pneumonia occur?
48 hours after admission
Signs + symptoms of pneumonia?
- SOB, cough, fever, haemoptysis, pleuritic chest pain, delirium, sepsis
- Bronchial breathing
- Focal coarse crackles
- Dullness to percussion
What is the CURB65 score and what are its components?
- Determines severity of community acquired pneumonia
- Confusion, urea >7, RR >30, BP <90/<60, age 65
What should be done for a patient with a CURB65 score of 0 or 1?
Treat at home
What should be done for a patient with a CURB65 score of 2?
Consider admission to hospital
What should be done for a patient with a CURB65 score of 3?
Consider ICU assessment
What organisms typically cause pneumonia?
- Strep pneumoniae (50%)
- H.influenzae (20%)
- Other-> moraxella catarrhalis, pseudomonas aeruginosa, s.aureus
What organisms can cause atypical pneumonia?
- Can’t be cultured normally or detected by gram stain
- Leigonnaire’s disease, mycoplasma pneumoniae, chlamydophilia, coxiella burnetti, chlamydia psittaci
What is fungal pneumonia and who does it usually present in?
Pneumocystis jiroveci-> in HIV patients with low CD4 cell count
What is the treatment for fungal pneumonia?
Co-trimoxazole
What is the treatment for atypical pneumonias?
- Macrolides (eg clarithromycin), fluoroquinolones (levofloxacin), tetracyclines (eg doxycyclines)
- NOT penicillins
Investigations for pneumonia?
- Bloods-> RBC, U+E, CRP (can guide treatment)
- CXR
- Sputum and blood culture
- Urinary antigen sample (legionella + pneumococcal)
What is the treatment of mild community acquired pneumonia?
- Amoxicillin oral for 5 days
- 2nd line-> clarithromycin or doxycycline
What is the treatment for moderate to severe community acquired pneumonia?
- Oral amoxicillin, clarithromycin or doxycycline for 7-10 days
- IV co-amoxiclav + clarithromycin or erythromycin for 5 days then review
Complications of pneumonia?
Sepsis, effusion, empyema, abscess, death
What is FEV1 and when is it reduced?
- Forced expiratory volume in 1 second
- Reduced in obstruction (ability of air to flow out of lungs)
What is FVC and when is it reduced?
- Forced vital capacity (ie total air can inhale in full inhalation)
- Reduced in restrictive disease
What spirometry results would suggest obstructive disease?
FEV1 less that 75% of FVC ie FEV1:FVC ratio <75%
What spirometry results would suggest restrictive disease?
FEV1 and FVC equally reduced and FEV1:FVC ratio >75%
What are causes of obstructive lung disease?
Asthma (reversible) and COPD (non-reversible)
What are causes of restrictive lung disease?
Interstitial lung disease, neuro (eg MND), scoliosis, obesity
What is peak flow and how is it used?
- Measures peak expiratory flow rate
- Record as percentage of predicted based on sex/height/age
What is the pathophysiology behind asthma?
- Chronic inflammation causing episodic bronchoconstrcition due to hypersensitivity
- Smooth muscles contract + reduced diameter causes obstruction
- Reversible obstruction that responds to bronchodilators
Presentation of chronic asthma?
- Episodic dry cough + wheeze + SOB
- Diurnal variation (worse at night)
- Atopy and food allergies
- Bilateral polyphonic wheeze on exam
- Triggered by infection, exercise, animals, cold/damp, dust, stress
Investigations for chronic asthma?
- Peak flow diary
- Fractional exhaled NO spirometry + bronchodilator (for reversibility)
- Direct bronchial challenge with histamine
NICE guideline ladder for chronic asthma treatment?
- Step 1-> add SABA
- Step 2-> add low dose ICS
- Step 3-> add oral LRTA
- Step 4-> add LABA
- Step 5-> consider change to MART regime
- Step 6-> increase ICS to moderate dose
- Step 7-> consider increase to ICS high dose or oral theophylline or inhaled LAMA
- Step 8-> refer to specialist
- Additional-> self-management programme, yearly review, flu jab etc
What are the clinical signs of moderate acute asthma?
- PEFR 50-75% predicted
- Resp rate >25
- HR >110
- Unable to complete full sentences
What are the clinical signs of severe acute asthma?
- PEFR 33-50% predicted
- Resp rate >25
- HR >110
- Unable to complete full sentences
What are the clinical signs of life threatening acute asthma?
- PEFR <33%
- Sats <92%
- Tired
- No wheeze (no air entry, silent chest)
- Haemodynamic instability (shock)
Treatment options for acute asthma?
- Salbutamol nebs (5mg back to back)
- Ipratropium bromide nebs
- Steroids (oral pred or IV hydrocortisone 5 days)
- O2 if needed (94-98%)
- Aminophylline infusion
- IV salbutamol
- IV magnesium sulphate
Monitoring requirements in acute asthma?
- RR, respiratory effort, peak flow, sats, chest auscultation
- ABG-> may be respiratory alkalosis then normal pCO2 + hypoxia (concerning) then respiratory acidosis (concerning)
- May need K+ and HR monitoring when using salbutamol (hyper + tachy)
Long-term management when a patient has had an acute asthma attack?
- Discharge with asthma action plan
- Consider rescue pack ie steroids can initiate when needed
- Refer to specialist when 2+ attacks in 12 months
What is chronic obstructive pulmonary disease?
- Non-reversible deterioration of air flow through lungs usually due to damage from smoking
- Damage causes obstruction-> hard to ventilate-> prone to infection and exacerbations
Presentation of COPD?
- Smoker + chronic SOB, cough, sputum production, wheeze, recurrent respiratory infections
- Not usually any clubbing or haemoptysis-> consider alternative
Differentials for COPD?
Asthma, fibrosis, lung cancer, HF
What is the MRC dyspnoea scale and what are the different stages?
Assesses the disability caused by dyspnoea (SOB)
- Stage 1-> SOB on strenuous exercise
- Stage 2-> SOB when walking up hill
- Stage 3-> SOB when walking flat
- Stage 4-> have to stop when walk 100 meters on flat surface due to SOB
- Stage 5-> can’t leave house due to SOB
Investigations for COPD?
- FBC (eg polycythaemia in chronic hypoxia) + U&Es
- CXR
- Sputum culture (chronic pseudomonas)
- Spirometry-> obstructive picture ie when FEV1 less than 70% of FVC (FEV1/FVC <0.7)
- Transfer factor for CO ie TLCO (decreased)
- Serum alpha-1 antitrypsin deficiency (worse disease outcomes)
Long term management of COPD (with asthmatic/steroid-responsive features)?
- Step 1-> SABA or SAMA
- Step 2-> add LABA + ICS
- Step 3-> LABA + LAMA + ICS
- Other options (severe)-> oral theophylline, mucolytic therapy (eg carbocysteine), prophylactic antibiotics (azithromycin)
Long term management of COPD (without asthmatic/steroid responsive features)?
- Step 1-> SABA or SAMA
- Step 2-> add LABA + LAMA
- Step 3-> LABA + LAMA + ICS
- Other options (severe)-> oral theophylline, mucolytic therapy (eg carbocysteine), prophylactic antibiotics (azithromycin)
When is long term oxygen therapy contraindicated in COPD?
-Current smoker (fire hazard)
What is the pathophysiology behind respiratory acidosis?
- Raised CO2 makes blood acidotic due to breakdown to carbonic acid (H2CO3)-> cause low pH
- Chronically compensated by raising bicarb but takes a long time (so not good in acute) and may be chronically high (eg COPD)
Why does COPD exacerbation result in respitatory acidosis?
Chronic CO2 retention-> kidneys produce bicarbonate to balance acid + normalise pH-> can’t keep up during acute exacerbation
What will you see on a blood gad result for type 1 respiratory failure?
Low pO2 + normal pCO2
What will you see on a blood gad result for type 1 respiratory failure?
Low pO2 + raised pCO2
What is the target range for oxygen saturations when managing a patient with COPD and why?
- Usually 88-92% unless proved to not retain CO2 (eg bicarb normal)
- Chronic CO2 retention-> respiratory drive not determined by this and is instead by hypoxia-> correcting hypoxia may reduce respiratory drive
Treatment for acute exacerbation of COPD?
- Salbutamol nebs
- Ipratropium nebs
- Steroids-> prednisolone (oral 30mg for 7-14 days) or hydrocortisone
- Antibiotics if indicated
- Chest physio
- IV aminophylline
- NIV
- Intubation + ventilation
What is BiPAP (bilevel positive airway pressure)?
Cycle of high and low pressure ventilation to correspond to inspiration and expiration
When is BiPAP (bilevel positive airway pressure) used?
Type 2 respiratory failure refractory to treatments
What is an important thing to rule out before using BiPAP (bilevel positive airway pressure)?
Pneumothorax
What is CPAP (continuous positive airway pressure)?
Air is continuously given to the lungs to keep airway expanded and allow air to travel in and out
What are the indications for CPAP (continuous positive airway pressure)?
Obstructive sleep apnoea, congestive HF, pulmonary oedema
What is interstitial lung disease?
An umbrella term for conditions affecting the lung parenchyma (tissue) causing inflammation and fibrosis
What is fibrosis?
When elastic functional tissue is replaced with stiff scar tissue
Investigations for interstitial lung disease (general)?
- Clinical diagnosis
- High resolution CT-> ‘ground glass’ appearance
- Lung biopsy + histology
Management of interstitial lung disease (general)?
- Treat underlying causes
- Home oxygen
- Smoking cessation
- Chest physio
- Pulmonary rehab
- PCV + flu vaccines
- Lung transplant
What is idiopathic pulmonary fibrosis?
Progressive lung fibrosis with no clear cause
How might idiopathic pulmonary fibrosis present?
- SOB and dry cough for over 3 months
- Usually over 50s
- Bibasal fine inspiratory crackles
- Finger clubbing
Treatment options for idiopathic pulmonary fibrosis?
- Pirfenidone-> antifibrotic + anti-inflammatory
- Nitedanib-> monoclonal antibody
What drugs can cause pulmonary fibrosis?
Amiodarone, methotrexate, nitrofurantoin, cyclophosphamide
What conditions can cause secondary pulmonary fibrosis?
RA, SLE, systemic sclerosis, A1AT deficiency
What is hypersensitivity pneumonitis (ie extrinsic allergic alveolitis)?
A type III hypersensitivity reaction to an environmental allergen causing parenchymal inflammation and destruction
What are some examples of hypersensitivity pneumonitis (ie extrinsic allergic alveolitis)?
Bird fancier’s lung, farmer’s lung, mushroom worker’s lung
Investigation of choice for hypersensitivity pneumonitis (ie extrinsic allergic alveolitis)?
Bronchoalveolar lavage + bronchoscopy-> wash with fluid + collect for testing (will see raised lymphocytes and mast cells)
Treatment of hypersensitivity pneumonitis (ie extrinsic allergic alveolitis)?
- Remove allergen
- Oxygen
- Steroids
What is asbestosis?
- Lung disease due to asbestos exposure
- Fibrogenic + carcinogenic
What is the pathophysiology behind asbestosis?
Fibrogenic + oncogenic-> pleural thickening + plaques-> fibrosis, adenocarcinomas and mesothelioma
What is important to do when a patient dies of asbestosis?
Refer to the coroner
What is a pleural effusion?
Collection of fluid in the pleural cavity
What are the two types of pleural effusion?
- Exudative-> high protein count (>3g/dL)
- Transudative-> lower protein (<3g/dL)
What are the causes of exudative pleural effusion?
- Inflammatory-> protein leaks out of tissues into pleural space
- Lung cancer, pneumonia, RA, TB
What are the causes of transudative pleural effusion?
- Fluid in pleural space
- CCF, hypoallbuminaemia, hypothyroidism, Meig’s syndrome (right effusion + ovarian malignancy)
What is Meig’s syndrome?
Right sided pleural effusion + ovarian malignancy
How might a pleural effusion present?
SOB, dull to percussion, reduced breath sounds, tracheal deviation (away from)
What findings may be present on CXR in a pleural effusion?
- Blunting of costophrenic angles
- Fluid in lung fissures
- Meniscus-> curve up where meets chest wall + mediastinum
- Tracheal + mediastinal deviation (when large)
Investigations for pleural effusion?
- CXR
- Fluid sample via aspiration or drain-> protein count, pH, glucose, LDH, microbiology
Treatment for pleural effusion?
- Conservative if small
- Pleural aspiration-> needle in + relieve pressure
- Chest drain-> can prevent recurring
What is an empyema?
Effusion caused by infection
When might you suspect an empyema
Pneumonia that’s improving but new/ongoing fever
Investigation for empyema?
- CXR
- Aspirate-> pus, acidic pH, low glucose, high LDH
Treatment for empyema?
Chest drain + antibiotics
What is a pneumothorax?
Air in the pleural space-> separates lung from chest wall
What can cause a pneumothorax?
- Spontaneous
- Trauma
- Iatrogenic (lung biopsy, mechanical ventilation)
- Pathology-> infection, asthma, COPD
How does pneumothorax present?
- Often a tall, young, thin man
- Sudden SOB + pleuritic chest pain
- Often after playing sports
Investigation for pneumothorax?
- CXR-> gold standard + measure from lung edge to chest wall at hilum level (horizontal)
- CT thorax-> for small PTX
CXR findings for pneumothorax?
- Area between lung tissue + chest wall where no lung markings
- Often a line demarcating PTX
Management of pneumothorax (when <2cm on CXR)?
- None needed
- 2-4 week follow up
Management of pneumothorax (when >2cm air on CXR + SOB)?
- Aspiration and reassessment
- Chest drain if aspiration fails twice
When is a chest drain indicates when treating a pneumothorax?
- Aspiration fails twice
- Bilateral
- Secondary PTX
- Unstable patient
Where is a chest drain inserted in pneumothorax treatment?
- Triangle of safety-> 5th IC space (inferior nipple line) + mid axillary (lat dorsi edge) + anterior axillary line (pec major edge)
- Insert needle above rib-> avoid NV bundle
- Always check position with CXR
What is a tension pneumothorax?
When a 1-way valve is created into the pleural space due to trauma
Why can a tension pneumothorax cause cardio-respiratory arrest?
Air trapped during inspiration + can’t get out when expire-> pressure in thorax-> pushed mediastinum across + kink big vessels-> CR arrest
What are the clinical signs of tension pneumothorax?
Tracheal deviation (away), reduced air entry, increases resonance to percussion, tachycardia, hypotension
Treatment for tension pneumothorax?
- Immediately insert large bore cannula into 2nd IC space + mid clavicular line
- Chest drain after
What usually causes a pulmonary embolism?
Thrombus from DVT (usually) travels through venous system + to right heart + pulmonary arteries-> block blood flow to lung tissue-> puts strain on right heart
What are the risk factors for developing a PE/DVT?
Immobility, recent surgery, long haul flights, pregnancy, oestrogen (OCP/HRT), malignancy, polycythaemia, SLE, thrombophilia
What is used for prophylaxis of PE/DVT?
LMWH eg enoxaparin
What are the contraindications for using LMWH as PE/DVT prophylaxis?
Active bleeding, recent stroke, warfarin/DOAC therapy
What are the contraindications to anti-embolic compression stockings for PE/DVT prophylaxis?
Peripheral arterial disease
Presentation of PE?
Symptoms-> SOB, cough, haemoptysis, pleuritic chest pain
Signs-> tachycardia, high RR, low fever, hypotension, signs of DVT
Investigations for PE?
- Well’s score-> CTPA if likely + D-dimer if unlikely
- D-dimer-> CTPA if positive
- CTPA-> IV contrast + chest CT
- VQ scan-> when CTPA unsuitable (eg renal impairment) + will be perfusion deficit (blocked by clot)
- ABG-> respiratory alkalosis (due to high RR so blow off CO2)
How does a ventilation-perfusion (V/Q) scan work?
Radioactive isotopes inhaled (V) + contrast with isotopes injected (Q)-> compare images
Management of PE?
- Apixaban or rivaroxaban first line
- Continue for 3 months (reversible cause), 3-6 months (unclear cause or recurrent) or 6 months + review (active cancer)
- Use LMWH + bridge to warfarin long-term if DOACs unsuitable
- Thrombolysis if massive + haemodynamic instability
When is thrombolysis used in PE and what does it involve?
- When massive PE with haemodynamic compromise present-> large risk of bleeding
- IV cannula + inject fibrinolytic meds-> eg strektokinase or alteplase
- Can also use catheter-directed (ie onto thrombus) but risk of artery damage
What is pulmonary hypertension?
Increased resistance + pressure of blood in pulmonary arteries-> right heart strain-> back pressure into systemic venous system
What are the five groups of causes of pulmonary hypertension?
1-> primary or due to connective tissue disease (SLE etc)
2-> left HF (eg MI) or systemic hypertension
3-> chronic lung disease (eg COPD)
4-> pulmonary vascular disease (eg PE)
5-> Misc-> sarcoidosis, glycogen storage disease, haem disorders
Signs and symptoms of pulmonary HTN?
SOB, syncope, tachycardia, raised JVP, hepatomegaly, peripheral oedema
Investigations for pulmonary HTN?
- CXR-> dilated arteries + RV hypertrophy
- ECG-> right axis deviation, large R waves on V1-3 (right side) + large S waves on V4-6 (left side), RBBB
- Raised BNP
- Echo-> can estimate pressures
Management of pulmonary HTN?
Primary-> epoprostenol, macitentan, sildenafil
Secondary-> treat the underlying cause
Supportive-> when resp failure arrhythmias, HF
What is sarcoidosis?
Granulomatous nodules of inflammation full of macrophages throughout body (usually lungs)
What is the typical presentation of sarcoidosis?
20-40 year old black lady with a dry cough, SOB and shin nodules
What organs can sarcoidosis affect and how might this present?
- Lungs-> nodules, pulmonary fibrosis, mediastinal lymphadenopathy
- Systemic-> fever, fatigue, weight loss
- Liver-> nodules, cirrhosis, cholestasis
- Eyes-> uveitis, conjunctivitis, optic neuritis
- Erythema nodosum-> tender red nodules on shins
- Lupus pernio-> raised purple lesions on cheeks + nose
- Granulomas
- Heart, kidneys, PNS, bones
What is Lofgren’s syndrome and how does it present?
Specific presentation of sarcoidosis presenting with triad of-> erythema nodosum + bilateral hilar lymphadenopathy + polyarthralgia
Investigations for sarcoidosis?
- Histology (gold standard)-> via bronchoscopy + detect granulomas
- Bloods-> high serum ACE, hypercalcaemia, high CRP etc
- CXR-> hilar lymphadenopathy
- Other imaging-> high resolution CT thorax, brain MRI, PET-scan
- U+Es, urine dip, LFTs, ECG etc-> depends on other organ involvement
Treatment options for sarcoidosis?
- Mild-moderate-> none
- Need treatment-> oral steroids for 6-24 months + bisphosphonates
- Can also use MTX, azathioprine etc
- Lung transplant
What is the prognosis for sarcoidosis?
- Often spontaneously resolves in 6 months
- May result in fibrosis + HTN + death
What is obstructive sleep apnoea?
When a patient stops breathing for a few minutes during sleep due to collapse of pharyngeal airway
What are some of the risk factors for obstructive sleep apnoea?
Middle aged, male, obese, alcohol, smoking
How might obstructive sleep apnoea present?
- Often reported by partner-> apnoea + snoring
- Morning headache, wake up unrefreshed, daytime sleepiness
What are the complications of obstructive sleep apnoea (ie what can it put you at risk of)?
HTN, HF, MI, stroke
What are the management options for obstructive sleep apnoea?
- Referral to ENT or sleep clinic-> urgent if HGV driver etc
- Sleep studies-> monitor sats, HR, RR, breathing
- Correct risk factors
- CPAP machine
- Uvulopalatopharyngoplasty
