Respiratory Flashcards
Assessment of asthma control*
- Daytime symptoms >2x/ week
- Night waking
- Reliever use >2x/week
- Activity limitation
- Well controlled: none above
- Partly controlled: 1-2
- Poor controlled: 3-4
Step ladder for Asthma - GINA*
1 - symptoms <2/month
(Preferred: As needed low dose ICS-formoterol)
2 - symptoms >2/month, but less than daily
(Preferred: Daily low dose inhaled ICS/ As-needed low dose ICS-formoterol)
3 - symptoms most day/ waking with asthma >=1/week
(Preferred: Low dose ICS-LABA)
4 - symptoms most days/ waking with asthma >=1/week/ low lung function
(Preferred: Medium dose ICS-LABA)
5 - uncontrolled symptoms/ exacerbation
(Preferred: High dose ICS-LABA; Refer for specialist assessment of contributory factors +- add-on therapy eg: tiotropium, anti-IgE
Adjusting treatment for asthma*
> Step up
Assess the following before consider stepping up treatment:
i. Incorrect inhaler technique
ii. Poor adherence to medications
iii. Modifiable risk factors
iv. Symptoms due to co-morbid conditions
- Sustained step up (at least 2 - 3 months)-> persistent symptoms and/or exacerbations despite 2-3 months of controller treatment
- Short term step up (for 1 - 2 weeks) with written asthma action plan e.g. for during viral infection or allergen exposure
- Day-to-day adjustment by patient for those with mild asthma and on low dose ICS-formoterol as maintenance and reliever
> Step down
Indication: good asthma control for 3 months
Step down: reduce dosage of ICS by 25-50% at 2-3 month interval but never stop ICS unless the diagnosis is in doubt
Assessing the severity of acute asthma attack*
○ Severe attack § Unable to complete sentences in one breath § Respiratory rate >25/min § Pulse rate >110 beats/min § PEF 33-50%
○ Life-threatening attack § PEF <33% § Silent chest, cyanosis § Arrhythmia or hypotension § Exhaustion, confusion or coma § ABG: Normal/high PaCO2 >4.6kPa PaO2 <8Pa, or SaO2 <92%
Approach to acute exacerbation of Asthma
- Assess severity of attack
- Immediate treatment
- Supplemental O2 to maintain 94-98%
- Salbutamol 5mg nebulized with O2
- If severe + ipratropium 0.5mg/6h to nebulizers
- Hydrocortisone 100mg IV/ Prednisolone 40-50mg PO - Reassess every 15min
- If PEF <75% repeat Salbutamol nebulizer every 15-30min. Add ipratropium if not already given
- Monitor ECG; watch for arrhythmias - -> If not improving
- Refer ICU +- IV salbutamol
- > If improving
- Continue nebulized salbutamol every 4-6 hours
- Prednisolone 40-50mg PO OD for 5-7 days
What is FEV1, FVC and their normal value
- FEV1: the volume exhaled in the first second after deep inspiration and forced expiration (Normal: >80% predicted)
- FVC: the total volume of air that the patient can forcibly exhale in one breath (Normal: >80% predicted)
GOLD classification
COPD severity
- 1: Mild (FEV1 >= 80%)
- 2: Moderate (50-80)
- 3: Severe (30-50)
- 4: Very severe (<30)
MMRC Scale*
Grade of dyspnea
- 0: No except on strenous exercise
- 1: SOB hurrying on level/ walking up slight hill
- 2: Walk slower than same age/ stop for breath when walking at own pace on the level
- 3: Stop for breath after walking about 100m/ few minutes on the level
- 4: Too breathless to leave the house/ dressing
How to diagnose COPD
- Spirometry (FEV1/ FVC <70%, both pre and post bronchodilator)
X-ray sign for COPD**
- Hyperinflation
- Flat hemidiaphragm
- Large central pulmonary artery
- Decrease peripheral vascular marking
HRCT finding for COPD
- Bronchial wall thickening
- Scarring
- Air space enlargement
Medication for acute COPD attack
- Nebulized bronchodilator: Salbutamol 5mg/4h and ipratropium 500mcg/6h
- Controlled oxygen therapy if SaO2 <88% or PaO2 <7 kPa
- Steroids: IV hydrocortisone 200mg and oral prednisolone 30mg OD (continue for 7-14 days)
- Antibiotics: if evidence of infection, eg: amoxicillin 500mg/8h PO
- IV Aminophylline: if no response to nebulizer and steroids
Causes of Bronchiectasis***
> Congenital
- cystic fibrosis
- primary ciliary dyskinesia
> Acquired
- TB
- pneumonia
- bronchial obstruction (tumor, foreign body)
Signs of bronchiectasis*
- Clubbing
- Coarse inspiratory crepitation
- Wheeze
Investigation for bronchiectasis***
> Initial Ix
- CXR (tram-line, cystic lesion)
- Spirometry (variable, may show obstructive pattern)
> To diagnosed bronchiectasis
- HRCT (signet ring appearance)
> To find the cause
- Mantoux test
- Sweat test
- FBC
- Sputum culture
- Bronchoscopy (locate site of hemoptysis, exclude obstruction)
Management for bronchiectasis***
- Airway clearance technique and mucolytic
- Antibiotics
- Bronchodilators (eg: nebulized salbutamol)
- Corticosteroid (eg: prednisolone)
- Surgery (indicated in local disease or to control severe hemoptysis)
History directing to asthma diagnosis
- Wheeze, SOB
- Diurnal variation
- Response to exercise, cold air, allergen
- Symptoms after aspirin, B-blocker
- History/ Family Hx of atopy/ asthma
Light’s criteria
> Transudate
- Fluid/Serum protein <=0.5
- Fluid/Serum LDH <=0.6
> Exudate
- Fluid/Serum protein >0.5
- Fluid/Serum LDH >0.6
Definition of bronchiectasis**
- Irreversible abnormal dilatation of the bronchial tree
- Divide macroscopically into: cylindrical, varicose, cystic
- Main organism: H. influenzae, Strep. pneumoniae, Staph. aureus
Complications of bronchiectasis*
- Recurrent pneumonia
- Empyema
- Lung abscess
- Progressive respiratory failure
- Cor pulmonale
Physical signs expected in COPD**
> General
- Breathlessness
- Cachexia
- Malnourished
- Evidence of respiratory distress
> Respiratory
- Reduced chest expansion
- Reduced breath sound
- Loss of cardiac dullness, downward displacement of liver - hyperinflated lungs
- Coarse crepitation - sign of pneumonia
> Cardiovascular
- Raised JVP
- Right displacement of apex beat
- Parasternal heave
- Peripheral edema, hepatomegaly
Examination finding for pneumothorax**
○ Inspection
- Respiratory distress
○ General examination
- Raised JVP
- Distended neck veins
- Tracheal deviation away
○ Respiratory examination
- Reduced chest expansion
- Hyper-resonance
- Absent breath sound
CXR features of pneumothorax**
- Exaggerated radiolucency
- Loss of vascular marking
- Contralateral shift of the trachea and mediastinum
- Flattening of the ipsilateral diaphragm
Definition of COPD - Keyword*
- Persistent, progressive
- Airway and/or alveolar abnormalities
Definition of chronic bronchitis*
- Chronic productive cough
- Most day for 3 months in 2 successive years
CXR features of COPD***
□ Hyperinflated lung - >6 anterior or 10 posterior ribs in the midclavicular line at diaphragm level □ Flat hemidiaphragms □ Large central pulmonary arteries □ Decrease peripheral vascular marking
Management of acute COPD***
- Nebulized bronchodilators (Salbutamol 5mg/4h and ipratropium 500mcg/6h)
Ix: CXR, ABG - Controlled O2 therapy if SaO2 <88% (start at 24-28%, aim sat 88-92%)
- Steroids: IV hydrocortisone 200mg and oral prednisolone 30mg OD (continue for 7-14 days)
- Antibiotics: if infection; amoxicillin 500mg/8h PO
- If no response to nebulizer and steroids -> IV aminophylline
- If no response -> consider non-invasive positive pressure ventilation
Pharmacological therapy for COPD**
> Bronchodilators
- Beta agonist: salbutamol (short) and salmeterol (long)
- SE: fine tremor, sinus tachycardia
- Antimuscarinic: ipratropium bromide (short), tiotropium (long)
- SE: dry mouth, metallic taste
> Corticosteroid
- eg: fluticasone, beclomethasone, budesonide
- SE: oral candidiasis, hoarseness of voice
> Phosphodiesterase-4 inhibitors
- eg: Roflumilast
Management for pneumothorax***
> Spontaneous
- Aspirate using 16-18G needle
- Insert chest drain and admit
> Tension
- Emergency needle thoracentesis (2ns ICS at midclavicular line, insert chest tube)
Definition of emphysema
- abnormal permanent enlargement of air spaces
- distal to the terminal bronchioles,
- accompanied by the destruction of alveolar walls
Definition of bronchiectasis
- Abnormal chronic dilatation of one or more bronchi
- Associated with building up of mucus making the person more vulnerable to infection
Finding differentiating COPD from bronchiectasis*
> COPD
- Reduced chest expansion bilaterally
- Breath sound: prolonged expiratory phase
- Wheezing
> Bronchiectasis
- Normal chest expansion, breath sound
- Coarse crackles
Classification of pneumothorax
> Main
- Traumatic
- Atraumatic -> primary (without known eliciting event); secondary (subsequently due to an underlying pulmonary disease)
> Alternative
- Simple
- Tension
- Open
Complication of smoking
- Cancer
- Heart disease
- Stroke
- Lung disease
- Diabetes
- COPD (eg: emphysema, chronic bronchitis)
Investigation for TB**
> Active
- CXR
- Sputum smear (culture still be required even if smear is negative -> possible of smear negative TB)
- Sputum culture
- Nucleic acid amplification test
> Latent
- Tuberculin skin testing (Mantoux test)
Light’s criteria**
- For pleural effusion
- Transudative:
Fluid/ Serum protein <= 0.5
Fluid/ Serum LDH <=0.6 - Exudative
Fluid/ Serum protein > 0.5
Fluid/ Serum LDH >0.6
Management for TB**
- 2 month intensive phase (Rifampicin, Isoniazid, Pyrazinamide, Ethambutol) + 4 month maintenance phase (Rifampicin, Isoniazid)
Management of close contact of TB**
> Asymptomatic
□ Mantoux test
□ CXR if Mantoux test >=10mm
> Symptomatic
□ CXR
□ Sputum AFB
□ Mantoux test
Side effect of TB medications**
- Rifampicin (enzyme inducer: care with warfarin, temporary discoloration of urine, sweat)
- Isoniazid (peripheral neuropathy)
- Pyrazinamide (hepatitis)
- Ethambutol (optic neuritis)
What is miliary TB*
- Massive dissemination of TB via hematogenous route to various organs, including lung itself
- Chest radiograph
□ Involve both lung predominantly lower lobes
□ Evenly distributed diffuse 2-3mm nodules
Physical signs for pleural effusion*
- Decrease chest expansion
- Stony dull percussion
- Diminished breath sound
- Decreased tactile vocal fremitus and vocal resonance
- Tracheal deviation
Investigation for pleural effusion*
- CXR: blunt costophrenic angle, meniscus sign, tracheal deviation
- Pleural fluid aspiration: biochemistry, Gram/ AFB stain, culture and sensitivity, cytology (WCC, malignant cells)
Monitoring of treatment for TB
> At 2 month
□ Repeat sputum AFB direct smear
□ Sputum MTB C&S if smear positive
□ CXR
> At 4 month and 6 month
□ Repeat sputum AFB direct smear
□ CXR
Type of respiratory failure***
> Type 1 (normocapnia)
- VQ mismatch
- Cause: right to left shunt, alveolar hypoventilation
- Mx: correcting hypoxia -> supplementary O2
> Type 2 (hypercapnia)
- CO2 retention
- Cause: weakness in resp muscle, obstructive lung disease (asthma, COPD)
- Mx: correcting ventilation -> non-invasive/ invasive mechanical ventilation
Asthma vs COPD***
> Asthma
- Age before 40
- Episodic symptoms with interspersed symptoms free period
- Trigger: laughter, exercise
- History of atopy
- Relieved by bronchodilator, ICS
> COPD
- Age after 40
- Chronic and progressive
- History of smoking, noxious fume
- Bronchodilator only provide limited relief
Investigation for COPD*
- FBC: leukocytosis, polycythemia
- ABG: respiratory acidosis
- ECG: right atrial and ventricular hypertrophy
- Sputum C&S
- CXR
- Spirometry
Discharge criteria for COPD
- Inhaled SABA requirement not more frequent than 4 hours
- Able to ambulate
- Able to eat and sleep without frequent awakening by SOB
- Clinically and ABG stable for 12-24 hours
Triggering factor for asthma exacerbation*
- Viral respiratory infection
- Allergen exposure
- Food allergy
- Poor adherence with ICS
- Exercise
- Change in weather
- Laughter
What is Respimat, Seretide
- Respimat: tiotropium
- Seretide: fluticasone + salmeterol
Risk factor for COPD
- Tobacco smoking
- Occupational exposure to dust, fumes
- Childhood respiratory infections
Content of Seretide
- Fluticasone (Steroid) + Salmeterol (LABA)
- Purple color, round inhaler
What are classes of COPD
> No or 1 exacerbation not leading to hospitalization
- A: mMRC 0-1
- B: mMRC >=2
> > =2 exacerbation or >=1 exacerbation leading to hospitalization
- C: mMRC 0-1
- D: mMRC >=2
Investigation for asthma
> To diagnosed asthma - Spirometry □ FEV1/FVC <70% □ Positive reversible test (FEV1 improve >200cc and 12% from baseline, after 10-15 minutes after 200-400mcg salbutamol) - PEFR □ Diurnal variation >10%
> During exacerbation
- Spirometry
□ If possible, recorded before treatment is initiates
- ABG
□ For patient with PEF or FEV1 <50% predicted, or do not respond to initial treatment
- CXR
□ Not responding to treatment and a pneumothorax is suspected
Mechanism of O2 induced hypercapnia in COPD
- The Haldane effect: rightward displacement of the CO2-hemoglobin dissociation curve in the presence of increased oxygen tension
- Modest decrease in minute ventilation, which also reduces alveolar ventilation, due to decreased stimuli from peripheral chemoreceptor to the central respiratory center
ECG changes of pulmonary embolism
> S1Q3T3 (McGinn-White sign)
- Classic pattern of acute cor pulmonale
- Large S wave in lead I, Q wave in lead III and inverted T wave in lead III
Management of pulmonary embolism
> Hemodynamic unstable
- Systemic thrombolysis: IV rtPA
- Others: percutaneous catheter-directed thrombolysis, surgical embolectomy
> Stable
- Anticoagulation: SC LMWH, fondaparinux
- Rescue thrombolysis: if serum troponin +ve and RV dysfunction present
> Long-term
- Anticoagulation: min 3 months for all patient
Important investigation for pulmonary embolism
- ECG: S1 Q3 T3
- CXR: oligemia of affected segment, dilated pulmonary artery, pleural effusion, wedge shape opacities
- D dimer: +ve suggestive of PE
- CTPA: look for filling defect in pulmonary artery due to embolus
Classification of cough based on duration
- Acute: <3 weeks
- Subacute: 3-8 weeks
- Chronic: >8 weeks
