Respiratory Flashcards
(100 cards)
What is the difference between type 1 and 2 respiratory failure? Give an example of each
T1: Hypoxemic + normocapnic
[Failure to Oxygenate] (“One for Oygenate”) e.g. Altitude, fibrosis, asthma.
T2: Hypoxemic + Hypercapnic
[Failure to Ventilate] e.g. Neuromuscular disorder, COPD, Obesity, Opiates.
What is the treatment for acute T1 respiratory failure?
Increase FiO2 via Oxygen (100%)
Increase mean airway pressure via CPAP (keeps alveoli open and maximises SA)
What is the treatment for Type 2 respiratory failure?
BiPAP to increase respiration rate (greater ventilation).
2 = Bi
Where is the VQ ratio lowest?
Lung bases
Perfusion increases dramatically in the bases due to gravity.
Where are the lungs best ventilated?
The apex
(Perfusion is relatively low in the apex thereofre V/Q ratio remains pretty high)
NB: TB tends to grow in the apex due to high level of ventilation.
What are the lobes of the lungs?
Right: Superior/Middle/Inferior
Left: Superior/Inferior
What neurotransmitters are at the pre and post synapses of the sympathetic nerves and parasympathetic nerves?
Sympathetic: [Short pre / Long post]
Pre = Acetylcholine @ Nictoninic receptors
Post = Noradrenaline @ Beta-adrenergic receptors.
[Therefore: Beta-adrenergic agonist –> bronchodilation]
Parasympathetic: [Long pre / Short post]
Pre = Acetylcholine @ Nicotinic
Post = Acetylcholine @ Muscarinic receptors
[Therefore: Muscarinic antagonist –> Bronchodilation]
What effect does sympathetic innervation have on the lungs?
Bronchodilation
What effect does parasympathetic innervation have on the lungs?
Bronchoconstriction
What causes smooth muscles to relax in the lungs following sympathetic stimulation?
Raised CAMP
Protein Kinase A inhibits Myosin Light Chain Kinase –> relaxation.
What causes smooth muscles in the lungs to constrict following parasympathetic innervation?
Raised Phospholipase C enzyme –> Protein Kinase C (C for calcium!) –> rasied intracellular calcium –> raised Myosin Light Chain Kinase –> Smooth muscle contraction
What type of B-adrenergic receptors are found in the lungs?
B2
[B1 = Heart]
What type of muscarinic receptors are found in the lungs?
M3
[M1 salivary glands / M2 Heart]
What is asthma?
Reversible airway obstruction caused by bronchospasm
True or false, asthma is typically worse at night?
True
{It is not known why. Possibly due to airways cooling, or circadian hormonal changes]
What is the test to determine if asthma is eosinophilic?
FeNO test.
Nitric Oxide level check as eosinophils produce NO.
How do you test the reversibility of asthma? What level is diagnostic?
Peak flow before and after B2 agonist e.g. salbutamol.
12% improvement = diagnostic.
What is the treatment for an acute asthma attack?
Nebulised salbutamol (SABA) Ipratropium bromide (SAMA) Oxygen Hydrocortisone [+Aminophylline IV]
[NB: MgSO4 IV bolus is a potent bronchodilator and can be used in severe attacks]
Give an example of a SABA, SAMA, LABA, LAMA and preventer
SABA: Salbutamol LABA: Salmeterol SAMA: Ipratropium bromide LAMA: Tiotropium Preventer: Beclomethasone
Give a cause of lobar collapse
Mucus plugs
Foreign body
Tumour
What is atelectasis?
Collapse or closure of part of a lung/lobe.
Can be obstructvie e.g. tumour or mucus plug or non-obstructive e.g. due to air pressure or general anaesthesia.
What is the difference between pneumothorax and atelectasis?
Pneumothorax is a collapse of a whole lung. Drain this.
Atelectasis is a collapse of part of the lung. Don’t drain this.
What is poiseuille’s law?
Resistance in a tube is inversely proportional to the 4th power of the radius.
Doubling the radius decreases resistance 16 times.
Which type of cell makes up 90% of the SA of the lungs and is responsible for gas exchange?
Type 1 pneumocytes
Squamous epithelium
10% of the cells