Respiratory Flashcards
(93 cards)
What is type 1 respiratory failure?
Hypoxic on room air PaO2 < 8kPa and normal or low PaCO2. Ventilation profusion mismatch
What is type 2 respiratory failure?
Hypoxic on room air PaO2 < 8kPa and raised CO2 >6kPa. ventilatory failure
What are some causes of respiratory failure?
Acute asthma, exacerbation of COPD, PE, pneumonia, Pulmonary oedema, opiate or benzodiazepines overdose, guillian barre syndrome
What might you give in opiate overdose?
Naloxone 400mcg IV bolus ± IV Flumazenil 200mcg over 15s
What is a genetic cause of COPD?
Alpha 1 antitrypsin deficiency
A seriene protease inhibitor
Panacinar emphysema
What is Chronic Bronchitis?
Production of sputum for most days for at least 3 months in at least 2 years. Productive cough and lots of mucus. Elevated Hb (polycythaemia)
What type of respiratory failure happens in chronic bronchitis?
Type 2 - Low respiratory drive
hypoxic and hypercapnia. Loss of central sensitivity to CO2 and so reliant on hypoxia to stimulate breathing. aim for 88-92%
What is Emphysema?
Abnormal, permanent enlargement of the airspaces distal to the terminal bronchioles. Elasticity reduced and alveoli collapse - Air trapping
What type of respiratory failure occurs in emphysema?
Type 1 - hight respiratory drive
Hypoxia due to air trapping and hyperinflation of the chest - inefficient gas exchange.
Desaturate on exercise
What is panacinar emphysema?
Uniform enlargement from the level of the terminal bronchiole distally
What might be seen on spirometry in COPD?
Obstructive pattern
FEV1/FVC < 70%
What is first line in COPD management?
SABA - Salbutamol or
SAMA - Ipratropium
What other treatment would you give a COPD patient on SAMA or SABA who is still symptomatic?
Add LABA or
Stop SAMA and add LAMA
If further exacerbations - ICS - prednisolone or budesonide.
If further exacerbations consider -
Oral Theophylline, Roflumilast, azithromycin, Carbocisteine.
What is COPD?
Airflow obstruction that is usually progressive and not usually reversible, it does not change markedly over several months
What are some symptoms of an exacerbation of COPD?
Increasing cough, breathlessness, impaired consciousness, wheeze, decreased exercise capacity
What is the criteria for hospital admission in an exacerbation of COPD?
Marked increase in symptoms
New physical symptoms (cyanosis, peripheral oedema)
Significant co-morbidities
Not responding to initial management at home
> 70
Inadequate home support
In a COPD exacerbation, if there is no response to NIV or mechanical ventilation, what can you use?
Respiratory stimulant - Doxapram IV 1.5-4mg
How would you treat an acute exacerbation of COPD?
- Nebulised bronchodilators (Salbutamol 5mg/4h or ipratropium bromide 500mcg/6h)
- Controlled oxygen therapy - aim for 88-92%
- Steroids - IV hydrocortisone 50-100mg or oral prednisolone 30mg
- Antibiotics - amoxicillin 500mg/8h or clarithromycin 500mg or doxycycline 200mg
- Physiotherapy to aid sputum expectoration
IF NO RESPONSE - IV aminophylline
IF NO RESPONSE - a. NIV if RR > 30 pH < 7.35
b. Intubation and ventilation if paCO2 still rising with NIV pH <7.26 - Consider a respiratory stimulant - Doxapram 1.5-4mg
also may need to give enoxaparin 40mg
What is asthma
Inflammation of the airways characterised by intermittent airflow obstruction, hyper-responsive airways and reversible airflow obstruction
How do you define reversible airflow obstruction.
An improvement in FEV1 of >/=15% or 400ml after 5mg of nebulised salbutamol
Define a positive bronchial hypersensitivity test.
A fall in FEV1 by 20% after less than 8mg/ml of methacholine (or histamine or mannitol)
How does salbutamol/terbutaline work and what are potential SE?
Relaxes bronchial smooth muscle via increasing cAMP.
SE - tremor, hypokalaemia, hyperglycaemia, muscle cramps
What is the management options in asthma?
- SABA
- SABA + low dose ICS
- SABA + low dose ICS + LABA
- SABA + LABA + Medium dose ICS
- SABA + LABA + high dose ICS
How so SA and LA muscarinic antagonists work?
Works on M1 and M3
M1 counteracts bronchconstriction directly
M3 causes NO release - vasodilation
Nebulised risk of Acute angle closure glaucoma