Resp Basics Flashcards
Features of an inspiratory wheeze?
Monophonic
upper airways
tracheal tumour/TB
Features of expiratory wheeze?
Polyphonic
Bronchoconstriction
Asthma
What is obstructive lung disease?
Narrowing of airways that prevents outflow from the lungs for gas exchange
Types of obstructive lung disease? Features?
Asthma - reversible airway obstruction - mast cell degranulation of histamine
CODP - Irreversible airway obstruction, long term smoking damage
What is SOB?
Difficulty breathing - use of accessory muscles and increased breathing rate
- ‘dyspnoea’
What make SOB worse?
Blood loss
Ventilation problem - Choking
Heart failure
Causes of SOB?
Lung problem:
- Asthma
- COPD
- Pulmonary fibrosis
- Interstitial lung disease
- Pneumonia
Heart problem:
- Failure = inadequate O2 supply
- MI
Blood problem:
- Anaemia (low Hb = low O2)
- Diabetic ketoacidosis = fast breathing = retention of metabolic acid from ketones
Joint cardiac and resp problems:
- Anxiety - fight/flight, hyperventilation, tachycardia
- PE - ventilation/perfusion problem
What is the normal respiratory rate?
12-16 breaths/min
What resp rate indicates tachypnoea?
20 breaths/min
Criteria of an acute severe asthma attack?
Resp rate over 25/30 per min
Peak flow is 50% below expected
Cannot complete sentences
Hr >110/min
When does an asthma attack become life threatening?
PEF <33%
SpO2<92%
Cyanosis
Exhaustion
What is FEV1?
Forced expiratory volume over the 1st second of breathing out
What is FVC?
Forced vital capacity = vol of air that can be forcibly blown out after a full insp
What is the normal FEV1/FVC?
0.8 or more
What is the FEV1/FVC for obstructive disease?
What indicates asthma?
0.7 or less
Asthma needs to demo reversibility - give bronchodilator and repeat (if improves FEV1/FVC = asthmatic)
How to measure breathing?
Spirometer = measures volume breathed out in one forced breath (FVC)
Peak flow meter = breath out as far as you can as fast (how fast you breathe)
How does an asthmatic’s breathing differ?
Cannot breathe out fast = peak flow (and FEV1) is lower but FVC is same
What is a spirometer?
Measures volume of air breathed out in one forced breath (FVC)
(how much air)
Helps diagnose and monitor lung conditions
Compare results to someone their age, height and sex
What is a peak flow meter?
Measures how fast someone can breathe out (PEF)
(how fast)
Helps diagnose asthma
Use at home twice daily when trying to diagnose asthma
Characteristics of a restricted disease?
Lower FVC (lower vol) FEV1 = same
Inhalers: What do relievers do? Examples?
Manage attacks Dilate bronchi to normal Short acting beta agonists Salbutamol Ipratropium bromide
Inhalers: What do preventers do? Examples?
Do not relieve attacks
Decrease number of attacks
Long acting beta agonists
Steroids - Beclometasone, budesonide, fluticasone
What disorders require inhalers?
COPD and asthma
What is resp failure I?
<8KPa PaO2
Low/normal PaCO2
Caused by pneumonia, asthma
Tx - give O2
What is resp failure II?
<8PKa PaO2
>6KPa PaCO2
Caused by overdose, trauma, COPD, neuromuscular
Tx - give O2, care in chronic
What drives normal breathing?
CO2 as adapting receptor (increase CO2 = breathe faster)
What drives breathing in COPD?
O2 = non-adapting factor = lack of O2 to tissues
Define COPD
Airway obstruction as bronchial tubes inflamed = trapped air in lungs = decrease FVC and low FEV1
= FEV1/FVC = less than 70%
How to calculate if smoking is significant?
Cigarettes a day x number of years
Divided by 20
If more than 10PYH = significant
Define asthma
Reversible airway obstruction due to crosslinking of receptor bound IgE antibodies = mast cell degranulation of histamine =
- Mucus hypersecretion
- Mucus plugging
- Mucosal oedema
- Bronchoconstriction
What questions to ask when assessing asthma control?
Meds Last A&E visit for asthma attack ITU Freq of attacks Func limitations
What is the acute tx for asthma?
Salbutamol through an O2 spacer (2 puffs)
Systemic corticosteroids
Ipatropium bromide
Long term asthma tx?
Inhaled steroids
How is asthma linked to dentistry?
Anxiety = asthma
Inhaled allergens in practise
Knowledge before tx = emergency prep
Chronic use of bronchodilating inhalers and/or glucocorticoids = increase oral candidiasis
How to manage asthma?
ABC approach and monitoring
Salbutamol - how, spacer, how much
O2 - what rate, 15 litres per min for 4 hrs
Ambulance - if hypoxic, acute severe asthma or after initial therapy
In hospital:
- High flow O2
- Nebulisers - flow of O2 and add liquid of: salbutamol 5mg, ipratropium bromide 0.5mg
Prednisolone 40mg PO
= prevents late T cell response the next day
No response to nebulisers/life threatening:
- Mg
- Aminophylline - can cause arrhythmia
What is the BTS approach?
- SABA (salbutamol, terbutaline)
- Inhaled steroid (beclomethasone = brown inhaler)
- LABA (salmeterol)
- Antileukotrines
- Oral steroids (prednisolone)
How to treat asthma?
If PEF less than 75% = short acting bronchodilator
4 puffs via spacer then 2 puffs/2mins for up to 10 puffs
OR
salbutamol 5mg nebuliser (ideally by 6L/min O2)
Consider oral steroids and referral to GP
How to treat COPD?
If SOB/wheezy
- Salbutamol ventolin 5mg dose and ipratropium bromide 500mg via nebuliser (if not to hand = 4 puffs of short acting beta agonist via spacer)
If infective exacerbation - lower resp tract infec:
- Aminopenicillin
- Tetracycline
- Macrolide
How to give O2?
Initially: nasal cannulae 2-6L/min or simple face mask 5-10l/min
Pt not at risk of hypercapnic resp failure who have saturation <85% = reservoir mask at 10-15l/min
Recommended initial O2 saturation rate = 94-98%
