Resp Flashcards
Pneumonia: Criteria for hospitalization
CURB-65
- Confusion: abbrev MT 7mmol/L
- RR > 30
- BP < 90 systolic
Score 0-1 = home
Score 2 = hospital therapy
Score >2 = severe pneumonia and may require ICU.
Community acquire pneumonia: organisms & empirical treatment
Organisms:
- Streptococcus pneum.
- Haemophilus Influenza
Treatment for mild:
- Oral amoxicillin 500mg/8hr OR
- Clarithromycin 500mg/12hrs
Treatment for moderate:
- IV amoxicillin + clarirthromycin at doses
above.
Treatment of severe case:
- Co-amoxiclav 1.2g/12hr IV or cefuroxime
- 5g/8hrs AND clarithromycin 500mg/12hr IV
- Add flucloxacillin if Staph suspected.
- Add vancomycin if MRSA suspected.
- Treat for 10 days.
Hospital acquired pneumonia: Organisms and treatment
Organisms
- Gram negative bacillus
- Pneudomonas
- Anaerobes
Treatment:
- Aminoglycoside IV + pipericillin (anti-
pseudo) IV. OR - 3rd generation cephalosporin IV.
Aspiration pneumonia: organisms + treatment
Organisms:
- Streptococcus
- Anaerobes
Treatment:
- Cefuroxime 1.5g/8hr IV + metronidazole 500mg/8h IV.
Differential diagnosis of lung nodule on chest XRY
- Primary or secondary malignancy
- Abscess
- Granuloma
- Carcinoid tumour
- Pulmonary hamartoma
- AV fistula
- Cyst
- Foreign body
Management of acute asthma attack: According to clinical oxford guidelines
- Assess the severity of attack
- ABC’s
- Can the patient talk/complete
sentences. - Level of consciousness
- Silent chest
- Immediate treatment
- Sit patient up
- High dose O2 in 100% non-
rebreathing bag. - Salbutamol 5mg + ipratropium
bromide 0.5mg nebulized with
oxygen. - Prednisalone 40-50mg IV or
hydrocortisone 100mg IV. - CXR to exclude pneumothorax
- Life threating features present
- Call for senior help
- Mg 1.2-2mg IV over 2 minutes.
- Salbutamol 5mg every 15 min => ECG
- Patient improving
- Decrease O2 to 40-60%
- Pred 40-50mg/24hrs PO for 5 days
- Neb salbutomol q4hr
- Monitor peak flow + O2 sats
- Patient not improving
- Continue 100% oxygen
- Salbutamol every 15 min
- Continue Ipratropium bromide 0.5mg
q4-6hrs.
- Still not improving
- Mg if not already given.
- Consider aminophylline: 5mg/kg IV
loading; 500ug/kg/hr - Adjust according to plasma levels.
- OR IV Salbutamol 3-20ug/min
- IPPV
- ITU
- Once patient has improved
- Wean off aminophylline over 24hrs
- Switch to inhaled B2 agonist
- Stop IV steroids; start oral
- Monitor PEF
- Look for cause.
Signs of severe asthma attack
- Unable to complete sentences
- RR > 25
- Pulse > 110
- PEF < 50% of predicted
Signs of life threatening attack
- Peak expiratory flow < 33% of predicted or best. - Silent chest. - Cyanosis - Decreased respiratory effort - Bradycardia or hypotension - Exhaustion, confusion, coma - ABG: PaCO2 > 4.6, PO2 < 8kPa/60mmHg
Salbutamol:
- MOA
- SE
- Method of adminitration
- Dose used in asthma
- Relax bronchial smooth muscle within
minutes - short acting. - SE: tachyarrhythmias, decreased K+,
tremor, anxiety. - Aerosol, powder, nebulizer, PO or IV.
- Inhaled aerosol 100-200ug/6hrs
Inhaled powder 200-400ug/6hrs
Nebulized (supervised) 2.5-5mg/6hrs
Salmeterol: Dose/puff and regimen
Inhaled aerosol
Dose/puff = 25ug
Recommended = 50-100ug/12hrs
Corticosteroids in asthma
- MOA
- SE
- Doses used in acute vs. long term
1 Act over days to decrease bronchial
mucosal inflammation.
- Oral candidasis - rise mouth after use
SE from oral - cushingoid - Oral steroids
Acute: prednisolong 40mg/24hr po
Long term: 5-10mg/24hrs poInhaled beclometasone
Dose/puff = 50ug, 100ug or 250ug
Recommended = 100ug/12hrs up to
1000ug/12hrs
Aminophylline
- MOA
- SE
- Indications
- Metabolized to theophylline
Inhibits phosphodiesterase = increases
cAMP = decreases bronchoconstriction - Arrhythmias, GI upset, seizures
- Used as an adjunct if inhaled therapy is
inadequate; given at night PO may
prevent morning dips; used IV in acute
severe asthma attacks.
Ipratropium bromide
- MOA
- SE
- Indications
- Dose
- Anticholinergic - decreases muscle spasm
- Not recommended in guidelines for
asthma
Used in severe asthma attacks
More benefit in COPD
4. Aerosol : Dose/puff = 20ug
Regimen 20-40ug/6hr
Powder: Dose/puff = 40ug
Regimen 40-80ug/6hrs
Nebulized: Doss/puff = 250ug/mL
Regmen = 250-500ug/6hrs
Define asthma
- Obstructive lung disease
- Characterized by
- Airway hypersensitivity,
- Reversible airflow obstruction
- Inflammation of bronchi
Classification of asthma
- Intermittent
- Day time asthma symptoms occur
less than 2x per week. - < 2 nocturnal awakenings per month
- Use SABA < 2/week
- No interference with daily activity
- FEV1 > 80% of predicted normal
- Normal FEV1/FVC
- Day time asthma symptoms occur
- Mild persistent
- Symptoms more than twice per week.
- 3-4 nocturnal wakings per mo
- SABA use for more than 2x week
- Minor interference with activities
- FEV1/FVC normal
- > 2 exacerbations requiring steroids
per year.
- Moderate persistent
- Daily symptoms
- Nocturnal wakings > 1x week
- Need BA daily
- Limitation in normal daily activities
- FEV1 = 60-80%
- FEV1/FVC < normal
- Severe persistent
- Symptoms of asthma throughout day
- Nocturnal waking every night
- Use SABA several times a day
- Extreme limitations to daily activity
- FEV1 < 60% of predicted
- FEV1/FVC < normal
Basic principals in managing asthma
- Lifestyle and triggers
- Education on proper technique
- Pharmcology
Step wise approach to managing asthma
Step 1 - For intermittent asthma - SABA - If need SABA more than 2x / week = step up.
Step 2
- Mild persistent asthma
- SABA + low dose glucocorticoid
(<800mcg/day).
Step 3
- Moderate persistent
- SABA + inhaled corticosteroids
- Add long acting B2 agonist
- +/- leukotriene antagonist (montelukast)
- +/- aminophylline
Step 4&5 - Severe persistent - Inhaled glucocorticoids high dose (up to 2000mcg/day) + LABA - +/- leukotriene antagonist or aminophylline - +/- Anti-IgE therapy = omalizumab } consider for patients with allergies.
Step 6
- Below + oral steroids
Investigations for asthma
- PFT: FEV1/FVC, PEFR
- Bronchial provocation testing with
histamine or metacholine. - Reversibility testing with B2 agonist }
FEV1 should increase by 12%. - Diurinal varability
- CXR for hyperinflation
- CBC = eosinophilia
- IgE = high
- RAST test
- Skin prick test
- O2 sats = aim > 92%
Asthma: What indicates good control?
Well controlled - Less than 2 day time symptoms per week. - No night time symptoms - Normal PEF
Partially controlled
- > 2 symptoms per week
Uncontrolled
- All of the above
Definition of COPD
- Characterized by irreversible airway obstruction. - Two subtypes: chronic bronchitis + emphysema. - Characterized by a gradual decline in FEV1 over years.
Chronic bronchitis:
- Definition
- Pathophys
- Signs & symptoms
- Chest XRY findings
- PFT
Chronic bronchitis
1. Productive cough on most days for at
least 3 consecutive months in 2
successive years.
"Blue bloaters" - decrease alveolar
ventilation, hypoxic drive, low PaO2,
high PaCO2.
- Pathophys: obstruction due to narrowing of the airways lumen by mucosal thickening and excessive mucus production.
- Symptoms:
- Chronic productive cough
- Purulent sputum
- Hemoptysis
- Dyspnea
Signs: - Cyanotic due to hypoexemia and
hypercapnea. - RHF; cor pulmonale
- Crackles; wheeze
- Prolonged expiration
- Chest XRY: Normal AP diameter, increased bronchovascular markings, enlarged heart with cor pulmonale.
- PFT: Decrease FEV1/FVC, Normal TLC, normal Dco2.
Emphsema
- Definition & Pathophys
- Signs
- Symptoms
- Chest XRY findings
- PFT
Emphysema
1. Definition & pathophy:
- Dilation and destruction of air spaces
distal to the terminal bronchioles
without obvious fibrosis.
- There is decreased elastic recoil =>
causing air trapping and alveolar
collapse.
- Pink puffers - increased alveolar
ventilation, normal PaO2, normal/low
PaCO2. Breathless but not
cyanosed.
- Symptoms
- Dyspnea
- Minimal cough
- Tachypnea
- Decreased exercise tolerance
- Signs
- Pink skin
- Accessory muscle use
- Cachetic appearance due to anorexia &
increased work of breathing. - Hyperinflation/barrel chest
- Hyperressonant percussion note
- Decreased breath sounds
- Decreased diaphargmatic excursion.
- Chest XRY
- Increased AP diameter
- Flat hemidiaphragm = 6 ribs anteriorly
- Decreased heart shadow
- Bullae
- Decreased vascular markings.
- PFTs
- Decrease FEB1/FVC
- Increase TLV = hyperinflation
- Increase RV = gas trapping
Severity / Stages of COPD
FEV1 determines severity
- Stage I - Mild symptoms
- FEV1/FVC < 70%
- FEV1 > 80% - Stage II - Moderate COPD
- Symptoms on exertion
- FEV1/FVC < 70%
- FEV1 = 50-80% - Stage III - Severe COPD
- Symptoms on minimal
exertion
- FEV1/FVC < 70%
- FEV1 30-50% - Stage IV - Very severe COPD
- Symptoms at rest
- FEV1 < 30%
Treatment of COPD based on severity
Stage I - Mild
- Stop smoking, influenza vaccine.
- Inhaled ipratropium bromide preferred prn
- Inhaled SABA prn
Stage II - Moderate
- As above
- Regular ipratropium bromide OR
- Long acting B2 agonist
Stage III - Severe
- As above + add in inhaled steroids.
Stage IV - Very severe
- Long term home oxygen.
Indications for home oxygen therapy
- PaO2 < 7.2 kPa
- Clinically stable non smoker
- PaO2 7.3-8 and pulmonary HTN + cor
pulm - Terminally ill patient
Acute exacerbation of COPD
- Definition
- Management
Acute exacerbation of COPD
1. Increased breathlessness, increased
sputum production.
- Managment
- ABC
- O2 24-28%
- Aim for: PaO2 > 8kPa with rise in PaCO2
not greater than 1.5kPa.
- Nebulized salbutamol 5mg/4hr +
impratropium bromide 500ug/6hrs
- Steroids: IV hydrocort 200mg +
PO prednisolone 30-40mg
Continue for 7-14 days
- Antibiotics if infection suspected
Amoxicillin 500mg/8hr PO - Physio: sputum expectoriation
- Not responding: Repeat nebulizer
Consider aminophylline - NR: Consider nasal PPV if RR > 30
- NR: Consider intubation/ventilation if CO2
rising.
Bronchiectasis
- Definition
- Signs and symptoms
- Findings: PFT & Chest XRY
- Principals in treatment
- Definition
- Irreversible dilatation of airways due to
inflammation and destruction of airway
walls from persistently infected mucus.
- Usually medium to small sized airways
effected. - Signs and symptoms
- Chronic cough
- Purulent sputum
- Hemoptysis massive
- Recurrent pneumonia
- Local crackles = inspir + expir
- Wheeze
- Clubbing
- Difficult to differentiate from chronic
bronchitis - Findings on investigation
- PFT: Obstructive pattern
- XRY: Linear atelectasis, loss of volume,
honeycomb structures - Treatment
- Vaccination: influenza & pneumovax
- Antibiotics
- Inhaled steroids
- Oral steroids for acute exacerbations
- Chest physio
- Pulmonary resection if necessary
Definitions
- Hypoexemic
- Hypercapnic
- Hypoxemic
- PaO2 < 60mmHg
- PaO2 < 8kPa
- Hypercapnic
- PaCO2 > 50mmHg
- PaCO2 > 6kPa
Signs of hypoxemia
- Dyspnea
- Restlessness
- Agitation
- Confusion
- Central cyanosis
- Polycythemia
- Pulmonary hypertension
- Cor pulmonale
Signs of hypercapnia
- Headache
- Dyspnea
- Drowsiness
- Asteixis / flapping tremor
- Warm peripheries
- Plethora
- Raised ICP
- Tachycardia
- Bounding pulses
Causes of hypoxemia
- Low FiO2 = high altitude
- Hypoventilation
- Shunting
- Low mixed venous O2 content
- V/Q mismatch
Causes of hypercarbia
- High inspired CO2
- Low total ventilation
- High deadspace ventilation
- High CO2 production - fever, sepsis
Target O2 sat in COPD patients
COPD patients: Goal SaO2 88-92%
Everyone else: Goal SaO2 94-98%
Type I respiratory failure:
- Definition
- Cause
- Treatment
- Definition:
- Hypoxia: PaO2 < 8kPa
- Normal or low PaCO2 - Cause
- V/Q mismatch: asthma, COPD,
pulmonary edema, PE
- Shunt: alvelar collapse, intracardiac
shunt, intrapulmonary shut = AVM
- Low inspired O2: High altitude - Treatment
- Reverse pathology / underlying cause
- Maintain oxygenation
- Increase FiO2 Supplementing O2 won’t
work if shunting is the problem
- PEEF/CPAP: to recruit alveoli
Type II respiratory failure
- Definition
- Cause
- Treatment
- Definition
- PaCO2 increased = hypercapnia
- PaO2 decreased = hypoxia - Causes:
- Increased CO2 production: fever, sepsis
- Alveolar hypoventilation: COPD, asthma,
chest wall disorder, CF.
- Hypoventilation: Central = stroke
Drugs = opiates, benzo
NMJ = GB, MG, fatigue - Treatment
- Find and fix cause
- Same as above - maintain oxygenation,
mechanical ventilation if necessary.
Differential diagnosis of hemoptysis
Resp causes: - Infectious: TB, lung abscess - Airway disease: COPD, chronic bronchitis, bronchiectasis. - Pulm vasc disease: PHTN, vasculitis, PE - Parencymal disease: pneumonia, wegener's, goodpastures - Malignancy
Cardiac causes:
- MI
- CHF
- MS
Hem:
- Anemia
- Coagulopathy
Definition of finger clubbing
Loss of the angle between the nail and nail fold. The nail fold feels boggy.
Causes of finger clubbing
Respiratory causes:
- Lung ca, mesothelioma
- Chronic lung infection: bronchiectasis,
TB, empyema, abscess, cystic fibrosis.
GI:
- IBD (especially Crohn’s)
- Malabsorption = celiac
- GI lymphoma
- Cirrhosis
Cardiac:
- Cyanotic heart disease
- Endocarditis
- Atrial myxoma
- Aneurysms
Other:
- Thyroid acropachy
- Esophageal Ca.
Normal values:pH, PaO2, PaCO2, HCO3
pH: 7.35-7.45
PaCO2: 4.7-6kPa ; 35-45mmHg
PaO2: >10.6kPa ; 75-100mmHg
HCO3: 24mEq/L
Anion gap: Formula and when to calculate
If there is a metabolic acidosis - calculate the anion and osmolar gap.
AG: Na - [(CL + HCO3)] = 10-15 mmol/L
If the anion gap is increased - is the change in the AG the same as the change in bicarbonate? If no = mixed picture.
Osmolar gap = measure - calculated osmolarity = (2[Na] + glucose + urea) = normal 10
Differential diagnosis of respiratory acidosis
**Characterized by increased PCO2 secondary to hypoventilation **
Resp center depression - Stroke - Drugs: opiates, sedatives, anesthesia - Raised ICP - Encephalitis - Central apnea - Supplemental O2 in CO2 retainers (COPD)
Neuromuscular disorders
- MG
- GB
- Poliomyositis
- Muscular dystrophies
- ALS
Lung disease - Airway obstruction: asthma, COPD, foreign body - Parenchymal disease: pneumonia, pneumothorax, pulm edema, ARDS
Other:
- Inadequate mechanical ventilation
Differential diagnosis of respiratory alkalosis
Characterized by decreased PaCO2 secondary to hyperventilation
Hypoxemia
- Pneumonia, PE, edema
- Severe anemia
- Heart failure
- High altitude
Resp center stimulation
- CNS disorders
- Hepatic failure
- Drugs: stimulants, ASA, catecholamines
- Pregnancy
- Anxiety
- Pain
Other cause:
- Mechanical hyperventilation
Causes of anion gap metabolic acidosis
MUDPILES Methanol Uremia DKA/starvation/alcoholic Paraldehyde Isopropyl alcohol/Iron/INH Lactic acidosis Ethylene glycol Salicylates
Causes of non-anion gap metabolic acidosis
HARDUP Hyperailmentation Acetazolamide RTA** Ureteroenteric fistual Pancreaticoduodenal fistula increased
Causes of metabolic alkalosis
- Vomiting = loss GI H+
- Exogenous alkali syndrome
- Milk alkali syndrome
- Diuretics = contraction alkalosis
- Post hypercapnea
- Hyperaldosterisms
- Hypokalemia
Interstitial lung disease
- Pathophy
- Causes of ILD by lung field effects
- Pathophy
- Inflammatory process in the alveoli that
results in thickening, destruction and
fibrosis.
- Restrictive lung disease
- Decreased lung compliance & lung
volumes. - Upper lung disease
- Farmers lung
- Ankylosing spondylitis
- Sarcoidosis
- Silicosis
- TB
- Neurofibromatosis
Lower lung disease
- Asbestosis
- Drugs: nitrofurantoin, amiodarone,
chemo
- Rhematological disease
- Scleroderma
Interstitial lung disease: Cause based on known and unknown etiology
Unknown etiology
- Idiopathic pulmonary fibrosis
- Sarcoidosis
- Histocytosis X
ILD associated with known systemic disease Rheumatological - Scleroderma - Rhematoid arthritis - SLE - Mixed CTD
Enviro/occupational
- Farmers lung
- Bird lung
- Air conditioners
- Silicosis
- Asbestosis
- Coal workers pneumoconiosis
- Berylliosis
Drugs
- Nitrofurantoi
- Methotrexate
- amiodarone
- Chemotherapy
- Ampetamines
- Radiation
Pulm vasclitis
- Wegeners
- Churg strauss
- Hypersensitivity reaction
Inherited disorders
- Neurofibromatosis
- Tuberous sclerosis
- Gauchers disease
Clinical features of interstitial lung disease
- Dyspnea on exertion
- Non productive cough
- Abnormal breath sounds
- Fine end inspiratory crepitations PF
- Weight loss
- Arthralagia (depending on type)
- Restrictive pattern on PFTs
- Decreased DL due to loss of SA for gas
exchange.
Pleural effusions:
- Lights criteria: transudate vs exudate
- Cause of transudate
- Cause of exudate
1. Lights criteria
Transudate: Protein [P/S] < 0.5
LDH [P/S] < 0.6
Pleural LDH < 2/3 upper limit
of N serum LDH
Exudate Protein [P/S] > 0.5
LDH [P/S] > 0.6
Pleural LDH > 2/3 upper limit
of N serum LDH
- Cause of transudate
- CHF
- Cirrhosis
- Nephrotic syndrome
- Pulmonary embolism
- Hypothryoidism - Causes of exudate
- Infectious: pneumonia, parapneumonic
effusion, empyema.
- Malignancy
- Inflammatory: collagen vascular disorder,
RA, SLE, pulmonary embolism
- Intra-abdo: Meigs syndrome,
pancreatitis, esophageal rupture.
- Trauma
Pleural fluid analysis: Protein, glucose, pH, cytology
Protein content
- < 30g/L = transudate
- > 30g/L = exudate
- Between 25-35g/L use Lights criteria
Glucose content
- < 3.3 mmol/L = malignancy, TB, RA
pH < 7.2 = infection or malignancy, requires drainage.
Cell types - Neutrophilia = infection - Lymphocytes = TB, lymphoma, malignancy - RBC = trauma, cancer, lymphoma
Classification of pleura effusion: simple vs complication
Simple effusion:
pH > 7.2, LDH < 1/2 serum, glucose > 2.2
Complicated
pH < 7.2, LDH > 1/2 serum, glucose < 2.2, positive gram stain = needs drainage
Differential diagnosis of solitary pulmonary nodule
Nodule is defined as being < 3cm
Mass > 3cm
- Infectious granuloma
- Abscess
- Aspergilloma
- Hamartoma
- Bronchiogenic cyst
- Fibroma
- AVM
- Rheumatoid nodule
- Sarcoidosis
- Primary lung ca
- Secondary lung ca
- Pulmonary carcinoid
Features of benign vs. malignant pulmonary nodule
Benign pulmonary nodule
- < 3cm, round, regular
- Smooth
- Calcified pattern
- Doubles in > 2 years
Malignant pulmonary nodule
- > 3cm, irregular, spiculated
- Ill defined or noticed
- NOT calcified
- Doubles in < 1 month or < 2 years.
Paraneoplastic syndrome associated with small cell carcinoma of lung “oat cell”
- ACTH = cushing
- SIADH
- Eaton Lambert
Paraneoplastic syndrome associated with NSC lung cancer
Squamous cell carcinoma
PTH-related peptide = hypercalcemia + hypophosphatemia
Pleural effusions: amount of fluid required before it can be detected clinically
500mL
Signs and symptoms of PE
Symptoms:
- Acute breathlessness
- Pleuritic chest pain
- Hemoptysis
- Dizziness
- Collapse
Signs:
- Pyrexia
- Tachycardia
- Tachpnea
- Hypotension
- Raised JVP
- Pleural rub
- Pleural effusion
Wells score for investigating a suspected DVT
Risk factors
- Active cancer (1)
- Paralysis/immobility (1)
- Major surgery (1)
Clinical signs
- Tenderness along leg (1)
- Entire leg swollen (1)
- Calf circumference > 3cm (1)
- Pitting edema (1)
- Collateral superficial veins visible (1)
Other:
- Alternative as likely or more likely than
DVT (-2)
Investigation of PE
- CXR
- ABG: decreased PaO2 and PaCO2
- ECG: S1Q3T3 pattern
- D-dimers: High sen, low spec
Can exclude PE if normal in
low risk patient. - CTPA: Sen & spec; First line
- V/Q scan: If CXR normal and no lung
disease. - Bilateral venograms
Management of Pulmonary Embolus
- Give 100% oxygen
- Morphine 10mg for pain relief
- If critically ill with passive PE consider
immediate thrombolysis (50mg Alteplase) - IV access
- SC LMWH: Dalteparin 200U/kg o.d
Enoxaparin 1mg/kg bid
No lab monitoring
Avoid in renal failure - UF Heparin IV: 10,000U bolus
Then 18U/kg/h guided by
aPTT - Systolic BP: > 90 = Warfarin 10mg od
< 90 = 500mL colloid
Dobutamine 2.5-
10ug/kg/min - Continue warfarin and heparin for 5 days
or until INR 2-3.
Duration of anti-coagulation following PE
- If reversible cause = 3-6 mo
- PE unprovoked = 6mo to indefinite
- Ongoing risk present = indefinite
