Case 9 Flashcards
What is partial pressure?
Pressure exerted by one of the gases in a mixture if it occupied the same value on its own.
Meaning of respiratory failure?
Failure of oxygenation and/or elimination of CO2
Definition of hypoxemia?
Low oxygen levels
Definition of hypercapnia?
High CO2 levels
Perfusion meaning?
Passage of fluid (norm. Blood) through circulatory system or tissues
Ventilation-perfusion mismatch meaning?
Imbalance in amount of air reaching alveoli and amount of blood circulating in the pulmonary capillaries (leading to low O2 conc)
What is ventilatory failure?
When respiratory system can’t effectively remove CO2 from body
What is type 1 respiratory failure?
Low levels of oxygen in blood
Ventilation-perfusion mismatch
What is type 2 respiratory failure?
Low blood oxygen levels (hypoxemia)
High blood CO2 levels (hypercapnia)
Due to ventilatory failure
What are acid base disturbances?
Changes in pH of blood
What is acidosis?
Increased acidity
What is alkalosis?
Decreased acidity
How does CO2 level impact acidity of blood?
High CO2 - more acidic, lower pH
How does HCO3 (Bicarbonate) level impact acidity of blood?
High HCO3 - less acidic (more alkaline), higher pH
What is respiratory acidosis?
Lungs don’t remove enough CO2
Increased acidity of blood
What is respiratory alkalosis?
Lungs remove excesssive CO2
Decreased acidity of blood
What is metabolic acidosis?
Excess of acid in blood or loss of bicarbonate
What is metabolic alkalosis?
Loss of acid in blood or excess of bicarbonate
Describe bicarbonate buffer system?
co2 + h2o <—> h2co3 <—> h+ + hco3-
H2CO3 — carbonic acid
HCO3- — bicarbonate
It maintains a constant blood pH
What is pH?
The measure of H+ ions
H+ conc is inverse to pH
More H+ ions, lower pH, more acidic
What is base excess?
Amount of excess base or acid in blood
What is asthma?
A collection of conditions characterised by inflammation and narrowing of airways. This leads to wheezing, shortness of breath, coughing and chest tightness. These are often triggered eg by exercise, respiratory infections, exposure to irritants.
How to diagnose asthma?
1)Spirometry tests (Lung function)
2)Bronchodilator reversibility test
3)Monitoring of peak flow
4)Exhaled nitric oxide (FeNO) - measures inflammation in airways
5)Methacholine challenge testing - can induce asthma symptoms
What is precision medicine?
Targeted treatment based on genetic, bio markers, phenotypic, or psychosocial characteristics
How is asthma treated currently?
Preventer(daily)
-Brown
-Inhaled glucocorticosteroids (anti inflammatory)
Reliever inhalers
-Blue
-Beta 2 agonist (bronchodilators)
What is typically used for prophylaxis treatment of asthma ( Preventer inhaler)
Inhaled gluco-corticosteroids
Anti inflammatory
What is typically found in reliever inhalers for asthma attacks?
Beta 2 agonist
Relaxation and dilation of airways
Triggers of asthma?
Allergens (eg common dust mites, mould spores, pollen)
Irritants (eg smoke, pollution, odours)
Respiratory infections
Physical activity
Weather
Causes of asthma?
Genetic factors
Environmental factors (early exposure to allergens or pollutants)
Respiratory infections
What is atopy, and how does it relate to asthma?
Atopy is a genetic predisposition to allergies, particularly in the context of asthma.
People with atopy and asthma experience heightened immune responses when exposed to allergens, leading to airway inflammation, wheezing, and bronchospasm. This increased sensitivity is a key factor in asthma, and treatments often aim to reduce inflammation and relax the airways.
How do beta agonists work to treat asthma?
Bronchodilators
Stimulate beta-2 adrenergic receptors, leading to bronchodilation
Side effects of bronchodilators?
Increased heart rate
Tremors
Potential desensitisation of beta receptors
How do steroids work to treat asthma?
Anti inflammatory
Reduce inflammation by inhibiting action of immune cells and decreasing production of inflammatory substances
Side effects of inhaled steroids?
Osteoporosis
Weight gain
Immune suppression
Definition of prophylaxis?
Treatment used for prevention of a disease
How is breathing controlled?
Controlled by brain stem - medulla and pons
The medullary respiratory centre has dorsal and ventral groups. These regulate basic rhythm and force of breathing
The pontine group (in the pons) fine tunes breathing patterns
How are oxygen and CO2 levels maintained in blood?
Chemoreceptors - carotid and aortic bodies
When levels are away for optimum, chemoreceptors signal to respiratory centres to adjust breathing.
What is spirometry?
A device which patients breath into which measures various lung volumes and capacities.
-Tidal volume
-Respiratory rate
-Vital Capacity
-Forced vital capacity
-Forced expiratory volume in 1 second
What is a peak flow monitor?
Patients blow into it and it measures peak flow
What is tidal volume?
Amount of air breathed in/out during normal breathing
What is respiratory rate?
Breaths per minute
What is vital capacity?
Maximum amount of air a person can exhale after maximal inhalation. (Vital capacity = tidal volume + inspiratory reserve volume + expiratory reserve volume)
What is forced vital capacity?
Maximum amount of air forcefully exhaled after a deep breath (but not maximum inhalation)
What is forced expiratory volume in 1 second (FEV1)?
Volume of air expelled in first second during FVC test
What is peak flow?
Maximum speed of air leaving lungs due to forced expiration
What is inspiratory reserve volume?
Additional volume of air that can be inhaled after normal inhalation
What is expiratory reserve volume?
The additional volume of air that can be exhaled forcefully after normal exhalation.
Why is it bad if no breathing sounds can be heard when listening to chest?
Airways get tight so airflow is low - no breathing sounds
What are adrenoreceptors?
Respond to neurotransmitters and are part of sympathetic nervous system.
What are beta-agonists?
Stimulate beta adrenoreceptors
What are beta-blockers?
Block the beta adrenoreceptors
Where are beta-1 adrenoreceptors located?
Heart
What are the effects of beta-1 adrenoreceptors?
Increase heart rate and force of contraction
Where are beta-2 adrenoreceptors located?
Bronchial smooth muscle
Blood vessels and skeletal muscle
What are the effects of beta-2 adrenoreceptors?
Cause bronchodilation, vasodilation and relaxation of uterine muscle
Function of selective beta-2 agonists?
Used to treat asthma (bronchodilation)
These target lungs but don’t affect heart
Function of non-selective beta agonists?
Stimulates both heart and lungs (beta-1 and beta-2)
This can have unwanted effects on heart
Function of non-selective beta blockers?
Blocks both heart and lung receptors (beta-1 and beta-2)
This can worsen asthma and cause broncho-constriction
What is agonism?
Drug activates receptor
(Causing biological response)
What is antagonism?
Drug binds to receptor and prevents normal function (inhibits or blocks)
What is a full agonist?
Maximum possible response from target
What is partial agonist?
Activates target and creates a sub maximal response from target
What is a inverse agonist?
Induces opposite effect of the agonist
(Eg decreases activity of receptor below normal level)
What is a competitive antagonist?
Binds to receptor, blocking it
What is a non-competitive antagonist?
Binds to a different site on target, making it less responsive to agonist.
What are interleukins?
A type of cytokine which modulate growth, differentiation, and activation during inflammatory and immune responses.
What is a psycho-somatic illness?
When symptoms are thought to be mainly caused by psychological factors
Describe how behavioural theories can impact treatment adherence/non adherence ?
People are more likely to adhere to treatment when:
- They believe they’re at risk
- They understand seriousness
- They see benefits
- They find adherence easy
- What they and others think
- Feeling confident
- Personal, behavioural and environmental factors
What is motivational interviewing?
Collaborative conversation style for eliciting and strengthening a persons motivation and commitment to change
What is OARS for motivational interviewing?
O - open questions
A - positive affirmations
R - reflections
S - summaries
Describe the PICO framework for defining research questions?
Population - who will results apply to
Intervention - what are we trusting (drug/device/treatment). or E - exposure depending on experiment
Control/Comparator - what are we comparing to (placebo/alternative/standard care)
Outcome - how are we measuring outcome (quality of life/ symptoms/ survival etc)
Function and Structure of nose and nasal cavity?
Contains ciliated and goblet cells to produce mucus
It filters, humidifies and warms incoming air
Function and structure of pharynx (throat)?
Connects nasal cavity and mouth to larynx and eosophagus
Function of larynx (voice box)?
Connects vocal cords
Connects pharynx to trachea
Function and structure of trachea (wind pipe)?
Conducts air from larynx to bronchi
Cartilaginous tube
Contains ciliated cells and mucus producing goblet cells
Function and structure of bronchi and bronchioles?
Bronchi divide into bronchioles
Lined with smooth muscle, ciliated cells and goblet (mucus producing) cells
Function and structure of alveoli?
Tiny air sacs where as exchange occurs
Single epithelial cell thick walls
What is in upper respiratory tract?
Nose and nasal cavity
Pharynx
Larynx
What is in lower respiratory tract?
Trachea
Bronchi
Bronchioles
Alveoli
Function of upper respiratory tract?
Filters, warms and humidifies incoming air
Ciliated cells trap and remove unwanted pathogens and particles
Function of lower respiratory tract?
Conducts air to alveoli for gas exchange
Ciliated cells and mucus production protect lower airways, preventing airways and facilitating debris removal
What are true ribs?
Ribs 1-7
Directly attached to sternum via costal cartilage
What are false ribs?
Ribs 8-10
Indirectly connect to sternum either by sharing costal cartilage or not at all
What are floating ribs?
Ribs 11-12
Do not connect to sternum
