RESP Flashcards
FEV1
Forced expiratory volume in 1 sec
if the FEV1 is 80% or greater than the predicted value = NORMAL
Thus is the FEV1 is less than 80% of the predicted value = LOW i.e abnormal
FVC
forced vital capacity, total amount forcible expired
low fvc = airway restriction
compared with the predicted values, if the FVC is 80% or greater than the predicted value = NORMAL
Thus is the FVC is less than 80% of the predicted value = LOW i.e abnormal
FEV1/FVC
if ratio below 0.7 = airway obstruction
If the ratio is high i.e. normal but the FVC is low = airway restriction
RESPIRATORY FAILURE:
Types: + differences
- TYPE 1 RESPIRATORY FAILURE:
• pO2 (partial O2 pressure) is low
• pCO2 (partial CO2 pressure) is low or normal
• With Type 1 = 1 change = low pO2 then normal/low CO2
• Pulmonary embolism (form of ventilation-perfusion mismatch) most commonly causes Type 1 - TYPE 2 RESPIRATORY FAILURE: • pO2 is low
• pCO2 is high
• WithType2=2changes=lowpO2+highpCO2 • Hypoventilation causes Type 2
Restrictive vs. Obstructive Respiratory Disease: -
Obstructive:
• FEV1/FVC below 0.7 • FEV1 lower than FVC • ASTHMA:
- Variable airflow obstruction - Reversible
• COPD:
- Relatively fixed airflow obstruction
- May be a mixture of restrictive and obstructive disease
(• Bronchiectasis -)
Restrictive:
• FEV1/FVC above 0.7
• FVC & FEV1 below 80% predicted value
• Due to restriction, lung volumes are small and most of breath is out in first second
• Interstitial lung disease:
- FIBROSING ALVEOLITIS - SARCOID
COPD
Clx:
Tx:
Characteristic symptoms are productive cough with white or clear sputum, wheeze and breathlessness, usually following many years of a smokers cough
On examination a patient with severe disease is breathless at rest with prolonged expiration, chest expansion is poor and the lungs are hyper inflated (barrel chest)
Lung function test:
• FEV less than 80% predicted value
• FEV1/FVC less than 0.7 - airway obstruction
• Stages:
- Stage 1 - FEV1 less than 80% of predicted value - Stage 2 - FEV1 50-79%
- Stage 3 - FEV1 30-49%
- Stage 4 - FEV1 less than 30% of predicted value
Bronchodilators:
• tiotropium bromide, a long- acting antimuscarinic agent initially with a rescue short acting B2 agonist e.g. salbutamol or terbutaline to prevent /reduce acute symptoms
• A long-acting B2 agonist e.g. formoterol or salmeterol is added in patients with persistent dyspnoea (difficulty breathing)
Corticosteroids: moderate/severe COPD, a trial recommended as proportion will have a reversible element to their disease and airway function improves considerably
• Prednisolone daily for two weeks- lung function before and after treatment period
• If improvement in airflow limitation (increase in FEV by more than 15%) =discontinue prednisolone and move to inhaled corticosteroid such as beclometasone twice daily
ASTHMA:
Types:
Management:
Allergic/eosinophilic asthma (70%):
- Allergens (e.g. fungal allergens and pets etc.) & atopy
Non-allergic/non-eosinophilic (30%):
- Exercise, cold air & stress
- Smoking & non smoking associated - Obesity associated
- Immediate management:
• Oxygen therapy to maintain O2 sat (94%-98%)
• Nebulised 5mg salbutamol (+ ipratropium if life threatening) - repeat/IV infusion
• Prednisolone (with or without hydrocortisone IV)
• Take arterial blood gases and repeat within 2 hours if severe attack
• Chest X-ray if fails to respond to tx
• Check PEFR within 15-30 mins/regularly
• Oximetry to ensure SaO2 is greater than 92% - SABA mild
- SABA + ICS
- SABA + LABA + ICS
- SABA + LABA + ICS + 4th drug e.g. anti-IgE monoclonal etc. severe
Bronchodilators:
Anti-inflammatory steroids:
Others:
• Beta2-agonists:
Short acting Beta agonist (SABA) (4 hours):
• Salbutamol (partial agonist)
• Terbutaline
Long acting Beta agonist (LABA) (12 hours):
• Salmeterol
• Formoterol (full agonist)
Muscarinic antagonists: - Short-acting e.g. ipratropium - Long acting e.g. tiotropium - has high affinity and disassociates slowly from muscarinic receptors - Act on airway M3 receptors
Methylxanthines:
- phosphodiesterase (PDE) inhibitors: prevent conversion of cyclic-AMP to 5’-AMP = build up of cyclic-AMP and thus increased smooth muscle relaxation
- Long-acting; theophylline (non-selective so has wide range of side effects e.g. CVS, CNS & GI tract) & aminophylline
• Inhaled corticosteroids (ICS):
- Prednisolone
• Beclomatasone
• Budesonide
-Leukotriene receptor antagonist e.g. montelukast
• Oral corticosteroid needed for those not controlled on inhaled corticosteroids e.g. prednisolone
- Steroid-sparing agents:
• Methotrexate
• Ciclosporin
• IV immunoglobulin
• Anti-IgE monoclonal antibody - omalizumab
HYPERSENSITIVITY PNEUMONITIS/EXTRINSIC ALLERGIC ALVEOLITIS:
Tx:
Chronic:
Corticosteroids e.g. prednisolone
BRONCHIECTASIS:
Dx:
Major pathogens on sputum culture:
Tx:
- Haemophilus influenza
- Streptococcus pneumoniae - -Staphylococcus Aureus
- Pseudomonas aeruginosa
Antibiotics: 2 weeks
• If pseudomonas aeruginosa then high dose oral ciprofloxacin twice daily
• Haemophilus influenzae is common and responds to oral amoxicillin, co-amoxiclav or doxycycline - some multi-resistant species need IV cephalosporin
• If staphylococcus aureus then give flucloxacillin
- Bronchodilators such as nebulised salbutamol is useful for asthma or COPD
sufferers
- Anti-inflammatory agents e.g. long term azithromycin can reduce exacerbation frequency
CF:
Tx:
Prophylaxis antibiotics:
• Flucloxacillin - Staphylococcus Aureus
• Amoxycillin - Haemophilus influenzae
Pseudomonal & flu vaccine
MRSA present then treat with Rifampicin and Fucidin
Pseudomonas aeruginosa present then treat with Ciprofloxacillin and nebulised Colomycin
Regular chest physiotherapy (postural drainage, forced expiratory techniques)
B2 agonists (salbutamol) & inhaled corticosteroids (beclometasone) - purely for symptomatic relief
Mucolytics such as Dornase alfa (nebulised) or inhaled DNAse - to clear airways of mucus
Amiloride - inhibits Na+ transport thus less thick mucus Bilateral lung transplant:
SARCOIDOSIS:
Staging:
Tx:
CXR:
• Used for staging:
- Stage 0 - normal
- Stage 1 - Bilateral hilar lymphadenopathy (BHL)
- Stage 2 - Pulmonary infiltrates with BHL
- Stage 3 - Pulmonary infiltrates without BHL
- Stage 4 - Progressive pulmonary fibrosis, bulla formation (honeycombing - confluence of two or more elements of the bronchial tree) & bronchiectasis
- Corticosteroids:
• Prednisolone orally then gradually reduce dose • In severe illness give IV methylprednisolone
• If steroid-resistant then: - Methotrexate but close monitoring required
IDIOPATHIC PULMONARY FIBROSIS (IPF):
RF:
Tx:
Risk factors:
- Factors implicated in triggering the aberrant wound healing include:
• Cigarette smoking
• Infectious agents (CMV, Hep C, EBV)
• Occupational dust exposure (metals, woods)
• Drugs - methotrexate, imipramine (anti-depressant)
• Chronic gastro-oesophageal reflux disease (GORD)
• Genetic predisposition
Pirfenidone - an antifibrotic agent that can slow the rate of FVC decline (need to check eligibility)
PULMONARY HYPERTENSION: def
defined as an mPAP of above 25mmHg as measured at right heart catheterisation and secondary right ventricular failure
Warfarin - due to intrapulmonary thrombosis
- Diuretics for oedema
- Oral calcium channel blockers as pulmonary vasodilators
- Oral endothelin receptor antagonist e.g. bosenten
- Phosphodiesterase-5 inhibitors
- Prostanoid (mediators of vasoconstriction) analogues e.g. inhaled iloprost
PLEURAL EFFUSION: def
the excessive accumulation of fluid in the pleural space
