Respiratory Flashcards
What are the three major characteristics of asthma
Airflow obstruction
Bronchial hyper-responsiveness
Inflammation
What is the difference between atopic and non-atopic asthma
Atopic has allergic triggers, is extrinsic, usually develops in childhood, is a type 1 hypersensitivity reaction
Non-atopic usually develops later and is triggered by cold/exercise/virus
Which immunoglobulin is associated with asthma
IgE
What will asthma show as on spirometry
Obstructive picture
Low FEV1
Low FEV1/FVC ratio
Bronchodilator reversibility
Bronchodilator reversibility in spirometry is an increase in FEV1 of X?
12% or 200ml
Management of asthma
Annual review Vaccinations - pneumococcal, flu Self monitor PEFR 1. SABA 2. Add low dose ICS 3. Add LABA 4. Increase ICS or add LTRA (consider stopping LABA) 5. Refer to specialist
Side effects of beta-2 agonists (Salbutamol, Salmeterol)
Tachycardia
Tremor
Hypokalaemia
Montelukast belongs to which class of medications?
Leukotriene receptor antagonists
Ipratropium belongs to which class of medications?
Antimuscarinics
Side effects of antimuscarinics (Ipratropium)
Dry mouth
Nausea
Headache
Theophylline belongs to which class of medications?
Phosphodiesterase inhibitors
Side effects of PDE inhibitors (theophylline)
Tachycardia
Arrhythmias
Agitation
Hypokalaemia
Features of severe acute asthma
PEF 33-50%
RR 25+
HR 110+
Cant complete sentences
Features of life threatening acute asthma
PEF <33% SpO2 <92% PaO2 <8 Normal CO2 Silent chest Cyanosis Poor effort Arrhythmia Hypotension Exhaustion Altered conscious level
Features of near-fatal acute asthma
Raised CO2 and/or requiring mechanical ventilation
Management of acute asthma
Oxygen - keep sats 94-98% Nebulised SABA driven by oxygen Steroids (and continue for 5 days) Nebulised ipratropium bromide Consider IV MgSO4
Acute asthma criteria for admission
Severe that isnt responding to treatment
Any life-threatening or near fatal
Acute asthma criteria for discharge
PEF >75% 1hr at treatment
No significant sx or concerns
How soon after an acute asthma attack should patients inform/see their GP
Inform GP within 24hrs of discharge
See GP 48hrs after
COPD can be seen as the combination of which 2 diseases
Chronic bronchitis
Emphysema
Which genetic disorder can lead to COPD
Alpha-1-antitrypsin deficiency
What may you find on percussion and auscultation in COPD
Hyper-resonant percussion due to hyperinflation
Inspiratory coarse crackles and wheeze
Decreased breath sounds if advanced
Describe the pathophysiology of cor pulmonale
Alveolar hypoventilation → hypoxic pulmonary vasoconstriction → pulmonary hypertension → cor pulmonale
Features of hypercapnia
Dilated pupils Bounding pulse Hand flap Myoclonus Confusion Drowsiness Coma
What are the spirometry findings of COPD
Obstructive picture
Low FEV1
Low FEV1/FVC ratio (<70%)
No bronchodilator reversibility
Which classification system can be used to assess severity of COPD
GOLD
GOLD Severity of COPD
Mild 80+
Moderate 50-79%
Severe 30-49%
Very severe <30%
Management of COPD
Smoking cessation Vaccinations - pneumococcal, flu Pulmonary rehab + physio SABA, LABA, Ipratropium, Theophylline ICS only if severe Mucolytics (Carbocysteine) Oxygen therapy
Hoe do you define HAP?
Develops >48hrs after being admitted or within 10 days of discharge
Typical bacteria that cause CAP
Strep.pneumoniae
H.influenzae
Bacteria that cause HAP
Pseudomonas aeruginosa
Enterobacteria
Staph aureus
Which organism typically causes VAP
Pseudomonas aeruginosa
How does a typical pneumonia present
Severe malaise Fever/chills Productive cough Crackles Dull to percussion Pleuritic chest pain - often associated pleural effusion
How may atypical pneumonia present
Slower onset Dry cough SOB Fatigue Headache Myalgia Less remarkable auscultation
CURB-65 score
Confusion (disorientation, impaired consciousness)
Urea > 7 mmol/L (20 mg/dL)
Respiratory rate ≥ 30/min
Blood pressure: systolic BP ≤ 90 mm Hg or diastolic BP ≤ 60 mm Hg
Age ≥ 65 years
CURB score of ? indicated hospital treatment needed
2+
Complications of pneumonia
Pleural effusion Pleuritis Sepsis Respiratory failure ARDS
How long after a pneumonia should you follow up and do CXR
6 weeks
Time frames for symptoms resolving after a pneumonia
1 week: fever should have resolved
4 weeks: chest pain and sputum production should have substantially reduced
6 weeks: cough and breathlessness should have substantially reduced
3 months: most symptoms should have resolved but fatigue may still be present
6 months: most people will feel back to normal.
What is the chance of getting primary TB if exposed to an infectious case
30%
What percentage of patients with primary TB get
a) progressive TB disease
b) containment
a) 5-10%
b) 90-95%
What percentage of patients who develop containment after primary TB infection get reactivation of the disease?
10%
Two organisms that can cause TB
Mycobacterium tuberculosis Mycobacterium bovis (cows milk)
What is latent TB
A condition in which a person is infected with Mycobacterium tuberculosis but does not have any symptoms of disease (e.g., fever, night sweats, weight loss, productive cough) and is not infectious. The tuberculin skin test or interferon-gamma release assay are positive.
What is active TB
A condition in which the infection with Mycobacterium tuberculosis becomes symptomatic, often due to the patient being immunocompromised. Symptoms may include fever, night sweats, weight loss, and/or productive cough (if the lungs are affected). The patient is contagious.
Treatment regimen for active TB
Isoniazid, Rifampin, Pyrazinamide, and Ethambutol for the first 2 months. Treatment is then continued with Isoniazid and Rifampin alone for 4 months.
Symptoms of active TB (primary or reactivated)
Fever, weight loss, night sweats
Fatigue, lymphadenopathy
Dyspnea
Productive cough +/- haemoptysis lasting >3 weeks
What are the potential sites of extrapulmonary TB
Most common: Bones Pleura Lymphatics Liver Other: Urogenital Skin Heart CNS GI
What is a Ghon complex on CXR?
A finding of primary TB
Particularly common in children.
Calcified granuloma usually in the middle to lower lobes with an associated lymph node; retains TB bacteria and therefore is a source of reinfection
CXR findings of
a) Primary TB
b) Reactivated TB
a) Hilar lymphadenopathy, pleural effusions, Ghon complex
b) Upper lobe cavitating lesion
What stain do you use to identify TB on sputum microscopy
Acid fast stain (Ziehl-Neelsen)
How is the tuberculin skin test (Mantoux) used?
A test to assess for latent TB, in which 5 units of purified protein derivative tuberculin is injected intradermally. The diameter of the induration at the injection site is measured after 48–72 hours, and determines if further TB testing is necessary. The test only becomes positive 6–8 weeks after infection. A healthy individual without any risk factors for TB infection who has an induration smaller than 15 mm is considered negative for TB
How is the IGRA (interferon gamma release assay) used in the assessment of TB?
An ELISA test that measures the level of interferon-γ expressed by T cells after coming into contact with Mycobacterium tuberculosis. Used to diagnose latent tuberculosis infection in at-risk populations. Elevated interferon-γ levels indicate a positive result. In contrast to tuberculin skin testing, there are no false-positive results with IGRA in patients who received the bacillus Calmette-Guérin (BCG) vaccine.
Treatment for latent TB
Isoniazid monotherapy for 9 months in patients with positive interferon-γ and/or PPD test but without clinical signs of active TB
Alternative regimens: 6 months of isoniazid, 4 months of rifampin, or 3 months of isoniazid and rifapentine
Side effects of Isoniazid
Hepatotoxicity (acute hepatitis, chronic liver failure).
Peripheral polyneuropathy and other symptoms of pyridoxine deficiency (e.g., stomatitis, glossitis, convulsions, and anemia).
How can you reduce the side effects of Isoniazid?
Simultaneous pyridoxine (vitamin B6) administration
Side effects of Rifampicin
Hepatotoxicity
Red or orange body fluids (e.g., urine, tears).
Thrombocytopenia.
Flu/GI sx.
Side effects of Pyrazinamide
Hepatotoxicity
Hyperuricemia
Arthralgia
Myopathy
Side effects of Ethambutol
Optic neuritis
Poly-resistance to TB meds is resistance to….
More than one medication other than both Rifampicin and Isoniazid
Multi-drug resistant TB is resistant to….
Both Rifampicin and Isoniazid
What are the 3 types of non-small cell lung cancer
Adenocarinoma
Squamous cell carcinoma
Large cell carcinoma
Which type of lung cancer occurs idiopathically/without strong smoking history?
Adenocarcinoma
What is SVC syndrome
Full sensation in head, oedema of upper extremities and face, prominent veins on chest/face/upper extremities, worse in the mornings
Can be caused by lung cancer obstructing the SVC
Paraneoplastic syndromes associated with small cell lung cancer
Cushing’s syndrome
SIADH
Lamber-Eaton syndrome
Peripheral neuropathy
Paraneoplastic syndromes associated with non-small cell lung cancer
Hypertrophic osteoarthropathy (clubbing and arthralgia)
Hypercalcaemia + PTHrP (SCC)
Gynaecomastia (LCC)
VTE, thrombophlebitis, verrucous endocarditis (adenocarcinoma)
What is a pancoast tumour and what symptoms/signs may it cause?
An apical lung cancer
Severe localised pain in the axilla and shoulder
Horner syndrome (miosis, partial ptosis, facial anhidrosis)
Hand/arm muscle atrophy
SVC syndrome
Loss of/filling of supraclavicular fossa
What tool can be used to assess cancer risk of a lung nodule
Brock calculator
Which lung cancers tend to be centrally located
SCLC
Squamous cell carcinoma
When lung cancers tend to be peripherally located
Adenocarcinoma
Large cell carcinoma
Causes of transudative pleural effusion
Congestive HF
Hepatic cirrhosis
Nephrotic syndrome
CKD
Causes of exudative pleural effusin
Infection Malignancy PE Vasculitis/SLE/RA/Sarcoid Pancreatitis Haemothorax Chylothorax
Thoracocentesis findings in transudative pleural effusion
Doesn't froth or clot Low specific gravity (<1.016) Low cholesterol (<60) Low total protein (<30) High glucose (60+) Low-ish pH (7.4-7.55)
Lights criteria:
Fluid:serum protein <0.5
Fluid:serum LDH <0.6
Low fluid LDH (<2/3 upper limit of normal serum LDH)
Thoracocentesis findings in exudative pleural effusion
Cloudy/straw coloured/froths/clots High specific gravity (>1.016) High cholesterol (>60) High total protein (>30) Low glucose (<60) Really low pH (7.3-7.45)
Lights criteria:
Fluid:serum protein >0.5
Fluid:serum LDH >0.6
High fluid LDH (>2/3 upper limit of normal serum LDH)
Differentials of white out on CXR
Trachea pulled towards;
Collapse
Pneumonectomy
Pulmonary agenesis/hypoplasia
Trachea central;
Pulmonary oedema/ARDS
Consolidation
Mesothelioma
Trachea pushed away;
Pleural effusion
Causes of type 1 respiratory failure
Pneumonia
Pulmonary oedema/ARDS
Pulmonary fibrosis
PE
Causes of type 2 respiratory failure
Asthma
COPD
NMJ/Chest wall disease
Causes of raised anion gap metabolic acidosis
MUDPILES Methanol Uraemia Diabetic ketoacidosis Propylene glycol Iron tables/Isoniazid Lactic acidosis Ethylene glycol Salicylates
Causes of normal anion gap metabolic acidosis
HARD-ASS Hyperalimentation Addisons disease Renal tubular acidosis Diarrhoea Acetazolamide Spironolactone Saline infusion
