Week 2 Flashcards
What is DPLD? What part of the lung does it effect?
Diffuse parenchymal lung disease, it is an umbrella term for conditions that affect the interstitium of lungs causing fibrosis, lack of compliance,
Give an example of a condition that could cause dpld?
Extrinsic allergic alveolitis
Infection
Amiodarone (antiarrythmic drug)
Sarcoidosis
Heart failure
How can DPLD present?
With finger clubbing, cough but no wheeze Breathless on exertion Inspiratory lung crackles Central cyanosis if hypoxic Pulmonary fibrosis
How do you treat DPLD?
Avoidance of trigger
Treat underlying cause
Corticoid steroids to suppress immune system
Drugs to prevent further deposition of collaen like pirfenidone and nintedanib
What are the locations of the respiratory centres?
Ventral and dorsal neurones in the botzinger complex within the medulla
Pneumotaxic centre in pons
What do the ventral neurones control?
Upon excessive stimulation of the dorsal neurones they cause the activation of the internal intercostal muscle and abdominal muscle to carry out active expiration
What do the dorsal neurones control?
Firing of these neurones cause the contraction of the inspiratory muscles, diaphragm and the external intercostal muscles.
What occurs when the dorsal neurones stop firing?
Passive expiration
What is the term for brief expiration
Apneusis
How can the pneumotaxic centre modify the rate of inspiration
By inhibiting the dorsal neurones firing
What is the main function of the peripheral chemoreceptors
To sense oxygen saturations and H+ ion concentrations. If metabolic acidosis will undergo hyperventilation
What is the main function of the central chemoreceptors?
Sense arterial Co2 and Hydrogen ions in the brain
Why is there increased respiratory rate during exercise?
Joint receptors activated causing increase in resp
Accumulation of CO2 and H+
Adrenaline acting on beta 2 adrenoceptors
What is the term for increased RBC production?
Polycthaemia
What is the function of 2,3 BPG production in RBC’s
O2 easier offloaded to tissues
What is the negative predictive value for a test?
The % of people who have a negative test who actually dont have the disease. True negative vs false negative
What is the positive predictive value?
% of people who have a positive test for a disease who actually have the disease
What is the normal proportion for a lung volume test of FEV1/FVC
75%
What happens to the FEV1/FVC ratio is asthma and Copd
Is reduced
What happens to the FVC in asthma and COPD
Athma fvc the same
Copd fvc reduced
Describe the inflammatory cascade in asthma
Eosinophillic inflammation
Th2 activation
Cytokines
Twitchy smooth muscle
What are the two main classes of drugs for airflow obstruction diseases?
Preventers; antiinflammatory
Relievers; bronchodilators
Name some anti-inflammatory drug classes
Steroids Cromones Leukotriene receptor antagonists Anti-ige Anti-IL5 PDE4 inhibitors
Name some bronchodilator drug classes
Beta agonists
Muscarinic receptor antagonists
What are the two drugs in the corticosteroid antiinflammatory class?
Inhaled; beclomethasone
Oral; predinisalone
What is the main drug used in the cromones anti-inflammatory class? What is its function
Sodium cromoglycate- a mast cell stabiliser
Name the drug in Leukotriene receptor antagonists, how does this work? What drug is it used in conjuction with?
Monteleukast orally taken
Inhibits receptor on eosinophils that leukotrienes bind
ICS
Name an anti-ige medication and an anti-il5 and their modes of action
Anti ige- inhibits TH2 response that attracts eosinophils. OmaliZUMAB
Anti-il5- inhibits the IL-5 that acts on eosinophils. mepoliZUMAB or resliZUMAB
What is a PDE4 drug, what condition does it treat, what is it prescribed with?
Roflumilast, COPD, prescribed with a LABA or LAMA
Name muscarinic receptor antagonists long and short acting
Short acting- ipratropium
Long acting - tiatropium
What do methylxanthines treat? What is prescribed for an acute attack Vs management
COPD and asthma
Theophylline for maintenance
Aminophylline for acute attacks (A for A)
Describe how activation of muscarinic M3 receptors cause bronchial smooth muscle contraction
Acetylcholine acts on M3 receptors to activate a G protein that activates the phospholipase C pathway causing an influx in calcium ions that allow contraction of the smooth muscle
Name some causes of respiratory acidosis
Choking
Bronchopneumonia
COAD (chronic obstructive airway disease)
Name some causes for respiratory alkalosis
Mechanical Hyperventilation
Hysterical hyperventilation
Raised intracranial pressure (stimulating respiratory centres driving ventilation)
What are some causes for metabolic acidosis
Impaired H+ excretion (renal failure)
Increased H+ production from ingestion
Loss of HCO3-
What are some causes for metabolic alkalosis
Vomiting (loosing H+ ions)
Alkali ingestion
Potassium deficiency
What is involved in respiratory alkalosis
Loss of CO2
What is involved in metabolic acidosis
Increased presence of H+ ions
In healthy individuals what is the range of SaO2 saturations?
94-98%
What is type 1 resp failure?
Where there is lack of oxygen
What is type 2 resp failure?
When lack of oxygen and too muchco2
What is VQ mismatching
When ventilation and perfusion are not the same due to infarct, poor diffusion
What is the haldane effect?
That when haemoglobin is empty from o2, co2 will bind to it
What is the bohr effect
As acidity and co2 concentration increases, haemoglobins affinity for oxygen decreases
What two vitamins are required for the maturation of RBCs
B12 and folate
What is the maximum volume of air that can be expired in a single breath following maximum inspiration ?
Vital capacity
What is equivalent to inspiratory reserve volume plus tidal volume, plus expiratory reserve volume?
Vital capacity
What is the volume of air in the lungs following passive normal expiration?
The functional residual capacity
