Medicine - Respiratory Flashcards
Describe the features and causes of T1RF
Lung issue (issue with gas exchange and the ability of the lungs to add O2/remove CO2 from the lungs) Low oxygen (<8kPa) but normal CO2
Causes:
- pneumonia
- pulmonary oedema
- PE
- shunt
- pneumothorax…
VENTILATION PERFUSION MISMATCH
Describe the features and causes of T2RF
Pump issue = lungs are working at removing CO2/adding O2, but there is an issue getting air into/out of the lungs in the first place! Low O2 (<8kPa) and high CO2 (>6kPa)
Causes:
- COPD
- asthma
- neuromuscular issue
- analgesia
- drugs
- CNS trauma
ALVEOLAR HYPOVENTILATION
Signs/symptoms of hypoxia?
SCCAR
- SOB
- cyanosis
- confusion
- agitated
- restless
Signs/symptoms of hypercapnia?
headache tachycardia bounding pulse tremor/flap peripheral vasodilation confusion drowsy papilloedema
Why must caution be taken when prescribing O2 to a patient with T2RF?
If they are a chronic CO2 retained then their respiratory centre relies on HYPOXIA for respiratory drive (rather than high CO2) therefore give O2 carefully as too much can depress respiratory drive
What is the most common cause of metabolic acidosis?
diarrhoea (loss of HCO3)
What is the most common cause of metabolic alkalosis?
Vomiting (loss of H+)
What is anion gap and why is it used?
Used to work out the cause of a metabolic acidosis
Calculated by cations (Na+ and K+) - anions (HCO3- and CL-)
- raised AG = presence of XS acid!
- normal AG = metabolic acidosis due to HCO3- loss!
Definition of COPD
FEV1/FVC <70%
% predicted FEV1 <80%
CB and E
Describe features of blue bloaters and pink puffers
BB = CB
- mild late SOB, copious sputum, cor pulmonale, T2RF, cyanosis, flapping tremor
PP = E
- severe early SOB, scanty sputum, no cor pulmonale, T1RF, wheeze and use of accessory muscles
What ECG features might you find in COPD?
R heart strain = S1 (large S waves in V1), Q3 (Q waves present in V3) and T3 (T wave inversion in V3)
Also seen in a PE!
What are the GOLD stages of COPD and why are they used
Used to guide treatment, based on FEV1 % of predicted stage 1 (mild) = >80% stage 2 (moderate) = 50-79% stage 3 (severe) = 30-49% stage 4 (v severe) = <30%
Describe the investigations for COPD
CXR Bloods (high PCV, ?a1-antitryptase deficiency) spirometry (diagnostic) ABG CT ECG
Describe the treatment of COPD
1 - lifestyle
2 - pharmacological:
- SABA/SAMA first
- if FEV1 >50% add LABA/LAMA OR if <50% add LABA+ICS
- then consider theophyllines/mucolytics
3 - pulmonary rehabilitation
4 - LTOT (use >15hrs/day for benefit)
What is the treatment for an acute COPD exacerbation?
Increase bronchodilator use Steroids Abx Oxygen Ben salbutamol/ipratropium Oral pred ?Diuretics
Describe the pharmacological treatment of asthma:
SABA + low dose ICS
Add LTRA
Add LABA
change ICS to high dose
Describe asthma and the features of airway remodelling you would find
thicker smooth muscle
thickened mucosa
increased goblet cell secretions
increased leukocyte recruitment and cell degranulation
How do you monitor an acute asthma attack?
Assess severity of attack
oxygen, salb nebs, IV hydrocortisone, oral pred
Monitor ECG (?arrhythmias)
Consider ipratropium/IV magnesium
How do you define a severe asthma attack?
PEF 33-50% predicted
unable to speak in complete sentences
RR >25
HR >110
How do you define a life threatening asthma attack?
PEF <33% predicted
confusion/silent chest
bradycardia
low O2 sats
What is the most likely causative agent/s of a CAP?
- strep pneumoniae
- haemophilus influenza
- staph aureus (common after the flu)
What is the most likely causative agent/s of a HAP?
- staph aureus (common after the flu)
- pseudomonas aeruginosa (ventilators!)
What is the likely causative infectious agent in a young pt presenting with few clinical findings but their CXR shows a much worse than expected pneumonia, and they have been feeling generally unwell and possibly have erythema multiforme rash?
mycoplasma pneumoniae
What is the most likely cause of pneumonia in a patient who has recently been travelling and may have drunk contaminated drinking water, with multi-system derangement (low Na, high CK, D&V, LFT derangement?)
legionella pneumoniae
Which type of pneumonia is commonly associated with birds and present with fever, epistaxis and joint pain?
chlamydophila psittaci
Which type of pneumonia is commonly associated with farmers/sheep/goats and present with Q-fever (flu-like symptoms)
coxiella burnetti
Define acute and chronic Q fever
acute = 2-3 week incubation period, flu-like symptoms chronic = endocarditis, hepatitis and osteomyelitis
Which type of pneumonia is commonly associated with alcoholics/poor dental hygiene?
klebsiella pneumoniae
What two types of pneumonia-infections are common in patients who are immunocompromised?
PCP (pneumocystis jirovecci)
Aspergillosis
What is the CURB65 score used for and describe its components
Confusion Urea >7 RR >/=30 BP <90 syst / <60 dias 65yrs +++
Used for CAP to guide treatment
What antibiotics are commonly used to treat CAP?
amox
clarithromycin
levofloxacin
What antibiotics are commonly used to treat HAP?
doxycycline
co-amox
gent
What antibiotics are commonly used to treat aspiration pneumonia?
metronidazole
What antibiotics are commonly used to treat mycoplasma legionella?
macrolide (arythromycin) or tetracycline
What medicine/s are commonly used to treat PCP?
co-trimoxazole
What are the risk factors for PE? - think of the PERC score
PERC = pulmonary embolism rule-out criteria
(use this score if you have a LOW suspicion of PE, and if none of the components are present than the probability of a PE is <2%)
H - hormone therapy (HRT/COCP) A - age >50 D - prev DVT/PE C - coughing up blood (haemoptysis) L - leg swelling discrepancy O - O2 sats <94% T - tachycardia >100 S - surgery/trauma in last 4 weeks
What are the components of Virchow’s triad?
1) vessel injury
2) venous stasis
3) activation of the clotting system
Describe 3 signs/symptoms of PE?
Signs:
- pleural rub
- AF
- lung crackles
Symptoms:
- pleuritic chest pain
- SOB
- haemoptysis
What is the treatment for a PE?
Carry out the 2 level Well’s score
Score >4 = PE likely
-> immediate CTPA with interim DOAC, if CTPA positive then PE diagnosed, if CTPA negative then consider USS for DVT
Score = 4 = PE unlikely -> do D-dimer within 4hrs, positive D-dimer then do CTPA, negative D-dimer then consider alternative diagnosis
Patient unstable -> thrombolyse with alteplase
Patient stable ->
- Provoked DVT = 3 months DOAC
- Unprovoked DVT = 6 months DOAC
What are the 5 types/causes of a pneumothorax?
Spontaneous - primary/secondary Traumatic - iatrogenic/chest wall injury Closed Open Tension
What are the treatment options for a pneumothorax?
Primary pneumothorax:
<2cm and pt not SOB = self-resolve
>2cm or pt SOB = aspiration
If still >2cm or pt SOB after aspiration = chest drain
Secondary pneumothorax:
<1cm = give O2 and admit for 24hrs
1-2cm = aspirate
>2cm or failed aspiration = chest drain
What are the subtypes of lung cancer?
SCLC
- from neuroendocrine cell line
- chemosensitive
- normally not fit for surgery as mets at presentation
NSCLC
- from epithelial cell line
- squamous cell, large cells, adenocarcinoma, mesothelioma
- less chemosensitive but better candidates for surgery
What are the investigations and treatment options for lung cancer?
CXR CT Sputum cytology Bloods Bone scan Bronchoscopy
Treatment
- surgery
- radiotherapy
- chemotherapy (better for SCLC)
- palliative
Define and describe the pathophysiology of a pleural effusion
accumulation of an abnormal volume of fluid in the pleural space
rate of accumulation > removal
hydrostatic pressure > osmotic
Describe the causes and features (in Light’s criteria) of a exudate:
- occur when local factors are altered e.g. inflammation/inflammation, increased capillary permeability
- > high protein (>30g/L), LDH >2/3rds ULN, protein ratio in pleural fluid to serum is >0.5
- > usually unilateral
- > clear, cloudy, blood stained fluid
causes:
- pneumonia
- malignancy
- TB
Describe the causes and features (in Light’s criteria) of a transudate:
- occur when systemic factors are altered e.g. high hydrostatic pressure, low protein
- > low protein (>30g/L), LDH <2/3rds ULN, protein ratio in pleural fluid to serum is <0.5
- > usually bilateral
- > usually clear fluid
causes:
- HF
- cirrhosis
- renal failure
What investigations would you do for a suspected pleural effusion?
Bloods, CXR, aspiration and send for:
- cytology
- immunology
- bacteriology
- microscopy and culture
Describe the pathophysiology of OSA:
What are the signs and symptoms of OSA?
- recurrent episodes of partial/complete airway obstruction during sleep
- caused by narrowing of upper airway (anatomical, obesity, neuromuscular dysfunction)
S/Sx:
- snoring, witnessed apnoea
- choking, sweating, dry mouth
- autonomic sympathetic response: vasoconstriction (HTN) and cardiac arrhythmias
- reduced libido
- fatigue
- nocturia
- poor concentration/mood
- morning headache
What investigations are carried out for OSA?
- good Hx
- examination: Mallampati score, BP, BMI, tonsils, ?nasal polyps, sleep questionnaire
- polysomnography
- epworth sleepiness scale
- TOSCA (transcutaneous O2/CO2 assessment)
What are the treatment options for OSA?
weight loss mandibular advancement device avoid smoking and alcohol sleep position trainers CPAP Inform DVLA!
Describe the three categories of interstitial lung disease:
1 - Those with a known cause: drugs, occupational, infections…
2 - Those associated with systemic disorders: sarcoidosis, RA, renal tubular acidosis…
3 - Idiopathic: IPF, non-specific interstitial pneumonitis
Define and describe the pathophysiology of IPF:
- the commonest cause of interstitial lung disease
- a type of progressive fibrosing interstitial pneumonia
- causes can be: occupational, drug induced, genetic, idiopathic, viral
- scarring and fibrosis affects the blood/gas barrier limiting O2 perfusion into the blood
Describe bronchiectasis and its causes:
abnormal dilation of bronchi
chronic inflammation -> permanent dilatation -> sputum production increases -> scarring
Can be congenital, post-infectious or other causes
CONGENITAL:
- CF, ciliary dyskinesia
POST-INF:
- pneumonia, measles, pertussis, bronchiolitis, TB…
OTHER:
- caused by bronchial obstruction (by a tumour/foreign body)
- allergic aspergillosus
- RA
- UC
- idiopathic
What are the main causative organisms of bronchiectasis?
Pseudomonas aeruginosa
H influenza
Strep pneumoniae
Staph aureus
Define cor-pulmonale
RV dysfunction secondary to chronic respiratory disease
Leads to pulmonary HTN and RV failure/enlargement/hypertrophy
What are the causes of cor-pulmonale
Obstructive
- COPD
- asthma
- bronchiectasis
Vascular
- primary pulmonary HTN
- vasculitis
- PE
- ARDS
Restrictive
- IPF
- drugs
- anatomy
- neuromuscular
Central
- OSA
- obesity
What might you hear when you listen to the heart of a patient with cor-pulmonale?
1) pansystolic murmur (TR)
2) S2 splitting (AV valve closes slightly before PV due to increased pulmonary pressure)
3) Gallop rhythm = tachycardia + 3/4th HS
- > 3 HS = physiological in children
- > 4 HS = pathological
How is cor-pulmonale managed?
Oxygen (LTOT)
Furosemide
Use of vasodilators
Define pulmonary oedema and its causes
Fluid accumulation in lung tissues and alveoli
Can be cardiogenic or non-cardiogenic
cardiogenic = heart failure! failure to remove blood from pulmonary circulation leading to increased hydrostatic pressure in pulmonary capillaries which pushes fluid into the lungs
non-cardiogenic = ARDS, chronic high altitude, AKI/CKD, PE
What are the presenting features of pulmonary oedema?
Hamoptysis: bloody, frothy sputum SOB, orthopnoea and PND Reduced exercise tolerance Leg and abdominal swelling Cyanosis JVP Bibasal creps Displaced apex beat RV heave tachycardia and 3/4th heart sounds
Describe sarcoidosis and how it may present
A multi-system disease
Non-necrotising granulomatous inflammatory disease
Mainly affects lungs and intra-thoracic LNs
Presents with dry cough, SOB, chest pain, splenomegaly, hepatomegaly, erythema nodosum and BHL (bilateral hilar lymphadenopathy)
Raised ACE and Ca
Name causes of a raised AG
MUDPILES methanol uric acid (uricaemia) DKA Paraldehyde Iron/isoniazide Lactic acid Ethanol s aSpirin/salycilates
Name causes of a normal AG
diarrhoea
renal tubular acidosis
What is the only cause of increased vocal resonance?!
consolidation (pneumonia)
What are the 5 MRC stages of dyspnoea?
1 - breathless on strenuous exercise 2 - breathless when walking up a hill 3 - breathless walking on flat ground 4 - breathless when walking <100m 5 - too breathless for ADL
Name a complication of quickly treating pneumothorax
re expansion pulmonary oedema
Name some complications of lung cancer
- local mets
- SVC obstruction
- non-metaplastic paraneoplastic syndromes
- > cushings (ACTH secreting)
- > SIADH (ADH secreting)
- > hypercalcaemia (PTH secreting)
What is Meig’s syndrome?
R sided pleural effusion + ovarian fibroma
How is IPF investigated?
Bloods (all normal + autoimmune condition screen)
Imaging (CXR and CT - honeycomb)
PFTs (restrictive pattern)
Bronchoscopy -> BAL/biopsy
Video-assisted lung biopsy
Others: urinary Ca excretion (?sarcoidosis)
Name causes of fibrosis predominantly in the upper lobes of the lungs
CHARTS coal workers (pneumoconiosis) hypersensitivity pneumonitis ankylosing spondylitis radiation TB sarcoidosis
