4) COPD Flashcards
Definition of COPD?
- Chronic, progressive airflow limitation with chronic inflammatory response
- FEV1 reduced, FEV1/FVC <0.7
What is chronic bronchitis?
Cough with sputum production for most days of 3 months for 2 years
What is emphysema?
Histological= enlarged air spaces distal to terminal bronchioles w/ destruction of alveolar walls
What is an exacerbation of COPD?
Acute, worsening of respiratory symptoms out of keeping with normal variability and will require a change in medication
Factors suggesting COPD over asthma?
- Age over 35
- Smoking
- Breathlessness chronic and progressive
- Sputum production
- Minimal diurnal/day to day variation
- No nightime waking
What is a pink puffer?
Increased alveolar ventilation, breathless but not hypoxic. At risk of T1 failure
What is a blue bloater?
decreased alveolar ventilation, hypoxic but not breathless. May get cor pulmonale, careful with o2 as hypoxic drive
Pathogenesis of COPD?
Increased oxidants and inflammation from chronic irritant gives increaased proteases. Combo of these 3 gives parenchymal tissue destruction, impaired defense and repair and increased luminal exudates
Signs and Symptoms of COPD?
Cough, sputum, dyspnoea, wheeze
Tacypnoea, accessory muscle use, hyperinflation, decreased cricosternal distance, cyanosis, cor pulmonale
COmplications of COPD?
Acute exacerbations, polycythaemia, resp failure, cor pulmonale, pneumothorax
Tests for COPD?
FBC: polycythaemia CXR: hyperinflation, bullae. decreased peripheral vascular markings ECG: RVH ABG: decreased PaO2 Lung Fx: Obstructive picture
Staging of COPD?
All have a FEV1/FVC of <0.7
Mild: FEV1 >80
Moderate: 50-79%
Severe: 30-49%
V Severe: <30%
When should you refer to specialist?
Uncertain on diagnosis Severe Cor pulmonale LTOT or steroid consideration Rapid decline Possible surgery Young and need a1antitrypsin excluded Lots of infections (?bronchiectasis) Haemoptysis
Managing stable COPD? (broad strategies)
1) STOP SMOKING, encourage exercise, treat poor nutrition
2) Inhaled therapy
3) Pulmonary rehab where appropriate
4) Manage any depression
5) Mucolytics may help
Stepwise pharmaceutical management of COPD?
1) SABA or SAMA as required
2) if FEV1 > 50% then LABA or LAMA
if FEV1< 50% then LABA+ICS or LAMA
3) if on LABA and deteriorates then LABA +ICS
if failure go to triple therapy
4) Long term corticosteroids (only if hard to wean them off post exac)
Benefit of LTOT?
50% increase in 3 year survival if kept >8kpa
When can you offer LTOT?
Clinically stable, non smoker with PaO2 of < 7.3 on two measurements 3 weeks apart
paO2 of 7.3-8 if pulm HTN, polycythaemia, oedema
terminal
If hypercapnic on LTOT?
Give NIV
When does flying become risky in COPD?
at FEV1 of less than 50%
Triggers for exacerbations of COPD
Infection
polllution
interruption of therapy
Differential Diagnoses of AEoCOPD?
Asthma pneumonia PE P effusion Pneumothorax Bronchiectasis
Presentation of exacerbation?
Increased dyspnoe Cough and sputum incr. incr. purulence of sputum wheeze, tightness fatigue confusion
Ix in suspected exacerbation?
Sats, ABG Bloods (theophyllline?) ECG CXR Sputum MC+S
Therapy in Exacerbation?
o2- Maintain 88-92% sats repeat ABG
Bronchodilators-
-Neb. salbutamol 2.5mg-5mg QDS and PRN
-Ipratropium 500mg ditto
Drive nebs by air if acidotic or hypercapnic and give o2 via nasal specs
Steroids- improve most things (though not mortality)
no need to taper if < 3 weeks
40mg OD 5days
Abx if consolidaiton or sputum indicates and obey local guidelines and culture
Theophylline if no response and beware interactions/toxicity
Theophylline bad sides?
Can cause seizures and arrhythmias
N+V can be a sign of toxicity
Wide variety of drug interactions, erythromycin reduces clearance, ocp, etc
Common organisms cultured in infective exacerbations?
H.Influenzae
S. Pneumoniae
Moraxella Catarrhalis (?sp)
Indications for Bilevel NIV?
T2RF
Poor response to medical therapy
pH<7.26, NIV given in HDU and have low threshold to intubate
CI to NIV?
Recent facial trauma Vomiting Fixed upper airway obstruction Low gcs copious secretions Severe comrbidity bowel obstruction pt declines
IV v NIV?
I: better control airway protection incr. pressures ITU and sedation
NIV:
decreased risk of VAP
can cough and communicate
cant use if vom or low gcs
