respiratory 9-14 (s + p) Flashcards
1
Q
What is the main function of the respiratory system?
A
oxygenates blood by bringing it to close proximity of venous blood in pulmonary capillaries
2
Q
What are the basic physiological roles of the respiratory system?
(Hint - CAB)
A
- Control of airway tone by ANS (bronchomotor tone maintained by vagal nerves)
- Airflow of lungs (slows as cross-sectional area decreases)
- Breathing - mechanical (inspiration or expiration and control of respiration)
3
Q
What is respiratory failure?
Hint - not enough swapping and +/- as a result
A
- inadequate gas exchange in lungs
- resulting in hypoxia +/- hypercapnia (low O₂/CO₂)
4
Q
What is type 1 respiratory failure?
1 problem
A
- hypoxia (pO2 <8kPa)
- due to ventilation-perfusion mismatch
- most commonly normal ventilation but inadequate perfusion
5
Q
What is type 2 respiratory failure?
2 problems and something which affects the lungs
A
- hypoxia (pO2 <8kPa) and hypercapnia (pCO2 >6kPa)
- caused by a reduced lung SA or fatigue
6
Q
Which tests used in the diagnosis of an obstructive airway disease?
A
- spirometry + peak flow → method of assessing lung function by measuring volume of air patient can expel after a maximal inspiration
- arterial blood gas (ABG)
7
Q
What are spirometry and peak flow effective reliable in and what do they show?
A
- reliable method of distinguishing betw/ obstructive airways and restrictive disorders
- most effective way of determining disease severity in COPD
- subdivisions of lung volume
8
Q
What is the healthy range for pH and what is it called when we deviate from it?
A
- 7.35-7.45
- acidosis ←→ alkalosis
9
Q
What is the healthy range for pO2 and what is it called when we deviate from it?
(Hint - the upper limit is the most unlucky number)
A
- 10-13kPa
- hypoxia ←→ hyperoxia
10
Q
What is the healthy range for pCO2 and what is it called when we deviate from it?
(Hint - the upper limit is the number of sides of a hexagon)
A
- 4.5-6kPa
- hypocapnia ←→ hypercapnia
11
Q
What is the healthy range for HCO3?
A
22-26mmol/L
12
Q
What type of respiratory problem is it if there is a:
a) problem with CO₂
b) problem with HCO₃
A
a) respiratory
b) metabolic
13
Q
Case: An adult very stressed at work has come to A&E with acute shortness of breath and dizziness. ABG: • pH – 7.50 • pO₂ – 13 • pCO₂ – 3 • HCO₃ - 23
A
- pH – 7.50 alkalosis
- pO₂ – 13 normal pO₂
- pCO₂ – 3 low pCO₂
- HCO₃ – 23 normal HCO₃
Respiratory alkalosis!
14
Q
Case: An 85-year-old lady with a one week history of shortness of breath, cough with green sputum and temperature. PMH – COPD. ABG: • pH – 7.42 • pO2 – 7.5 • pCO2 – 4.9 • HCO3 - 24
A
- pH – 7.42 normal
- pO2 – 7.5 low pO2
- pCO2 – 4.9 normal
- HCO3 – 24 normal
Type 1 respiratory failure!
15
Q
Case: 69-year-old male with 2-day history worsening shortness of breath and cough. Heavy smoker. • pH - 7.22 • pO₂ – 7.2 • pCO₂ – 8.5 • HCO₃ - 26
A
• pH - 7.22 acidosis • pO2 – 7.2 low pO2 • pCO2 – 8.5 high pCO2 • HCO3 – 26 normal - type 2 respiratory failure/respiratory acidosis!
16
Q
What does the CXR of a asthmatic patient look like?
A
like a normal CXR - nothings shows up
17
Q
What does a COPD CXR look like?
Hint - the main vessels expands and Francis from MIC
A
- hyperinflated + hyperlucent lungs
- flattened diaphragm
- central pulmonary artery enlargement
- bullae
18
Q
What does a COPD CT scan look like?
A
- bronchial tubes damaged + expanded
- thickening of bronchial walls
- lots of white
(see notes for image)
19
Q
How do long and short-acting beta-2-adrenergic receptor agonists treat asthma/COPD? Give examples of them.
(Hint - short-acting: ST and long-acting: SF)
A
- long-acting cause SM relaxation, leading to dilation of bronchial passages
- short-acting i.e. salbutamol and terbutaline
- long-acting i.e. salmeterol and formoterol
20
Q
How are anticholinergic drugs used to treat asthma and COPD? Give examples of long and short-acting ones.
(Hint - short and long-acting have very similar names)
A
- block acetylcysteine in the central and peripheral nervous system
- inhibit parasympathetic system blocking involuntary SM in the lungs, GI tract, urinary tract, etc…
- short-acting: ipratropium bromide
- long-acting: tiotropium bromide
21
Q
How are steroids used to treat asthma/COPD and how can they be administered? Give examples for each form of administration.
A
- anti-inflammatory corticosteroid
- inhaled → i.e. beclometasone fluticasone
- combined therapy → i.e. seretide
- oral → i.e. prednisolone
- IV → i.e. hydrocortisone
22
Q
How are leukotriene receptor antagonists used to treat asthma/COPD and give an example of the one most-commonly used?
(Hint - Monty luke used)
A
- inhibit leukotrienes (IS compounds that cause inflammation) but less effective than steroids
- i.e. montelukast most commonly-used
23
Q
How are the main actions in theophylline used to treat asthma/COPD and why is it used less than other treatments?
A
- relaxing bronchial SM
- increasing heart muscle contractility and efficiency, HR, BP, renal blood flow
- someanti-inflammatory effects
- CNS stimulation mainly on the medullaryrespiratory centre
- numerous side effects, therefore less in use
24
Q
How do we assess whether oxygen should be used to treat asthma/COPD?
A
based on: - v. severe airflow obstruction - cyanosis - polycythaemia - peripheral oedema - raised jugular venous pressure - O2 saturations 92% or less OR - an ABG – pO2 <7.3kPa (<8kPa if secondary polycythaemia, nocturnal hypoxaemia, peripheral oedema or pulmonary hypertension)
25
In which 3 forms can oxygen be used to treat asthma/COPD and when do we use each one?
- Long-term oxygen therapy (LTOT) – used >15 hours/day
- Ambulatory oxygen therapy (AOT) – for patients wishing to leave the home on LTOT
- Short-burst oxygen therapy – little evidence for use; symptomatic relief of breathlessness i.e. for palliation
26
In what form do we have medication devices?
- inhalers
- spacers
- nebulisers
- oral
- IV
27
What is asthma?
inflammation of airways in lungs affecting the sensitivity of airway nerve endings so they are easily irritated
28
What happens during an asthma attack?
| Hint - think of it as an allergic reaction
- passage linings become swollen
| - this narrows the airways and reduces airflow in/out of the lungs
29
What are the symptoms of asthma and who does it affect?
| Hint - RCCW, why might someone clutching their chest?
- recurrent SOB attacks
- wheeze
- cough (usually nocturnal)
- chest tightness
(affects all ages, usually starting in childhood)
30
State the signs of asthma.
| Hint - RICTER PACT
- Recession in children
- Inability to complete sentences
- Confusion
- Tachycardia
- Exhaustion
- Reduced peak flow
- Polyphonic wheeze
- Audible wheeze
- Cyanosis
- Tachypnoea
31
How do we diagnose asthma?
- pulmonary function tests (peak expiratory flow and reversibility)
32
What are the the different types of acute asthma and how is each one classified?
- Moderate; PEF 50-75% best predicted, increasing symptoms, no features
- Acute severe; PEF 33-50% best/predicted; RR ≥25; HR ≥110/min, inability to complete sentences in one breath
- Life-threatening; PEF <33% best/predicted; SpO2 <92%; PaO2 <8kPa; normal PaCO2; symptoms: silent chest, cyanosis, poor respiratory effort, arrhythmia, exhaustion/altered conscious level
- Near-fatal; raised PaCO2 and/or requiring mechanical ventilation w/ raised inflation pressures
33
How is asthma acutely-identified?
| ABC
- Airway – patent (unobstructed)
- Breathing – raised RR, decreased O2 saturations, wheezing, use of accessory muscles, talking in full sentences, peak flow if possible
- Circulation – raised HR
34
How do we manage acute asthma via treatment?
- give oxygen
- inhaler/nebulised salbutamol 5mg
- steroids (40mg prednisolone oral/100mg hydrocortisone IV)
- if no improvement, repeat nebulised salbutamol 5mg + ipratropium 500mcg
- try IV MgSO4 2g/20 mins
- if infection – antibiotics
- if life-threatening features/worrying ABG – ICU help
35
Case study:
• 18-year-old female diagnosed w/ asthma at 4 years old
• On salbutamol inhaler when required and has a beclomethasone inhaler that she uses twice a day
• For the past week, she has been using her salbutamol inhaler much more often than usual
• She has taken 3 days off university and is not improving
• You are the FY1 seeing her in A+E – what are you going to do?
- give oxygen
- inhaler/nebulised salbutamol 5mg
- steroids (40mg prednisolone oral/100mg hydrocortisone IV)
- if no improvement, repeat nebulised salbutamol 5mg + ipratropium 500mcg
- try IV MgSO4 2g/20 mins
- if infection – antibiotics
- if life-threatening features/worrying ABG – ICU help
36
Who does COPD affect?
- mainly affects those over 35 and smokers or ex-smokers
37
What are the symptoms and signs of COPD?
| Hint - FREWCN; sob, green stuff, wintry illness and no signs of another respiratory illness
- exertional breathlessness/SOB
- chronic cough
- regular sputum production
- frequent winter ‘bronchitis'
- wheeze
- no features of asthma
38
How do we diagnose COPD?
| Hint - CAFBP, immunology and weight included
- post-bronchodilator spirometry to assess severity (i.e. FEV >80% = mild, 50-79% moderate, 30-49% severe, <30% very severe)
- CXR
- full blood count (identify anaemia, polycythaemia)
- ABG
- BMI (usually higher risk of death when +/-)
39
How do we chronically manage COPD via medication?
| Hint - go from short-acting to long-acting to use more meds
- short-acting β2-agonist AND/OR short-acting anticholinergic
- if FEV1 ≥50% ADD long-acting β2-agonist OR long-acting anticholinergic
- if FEV1 <50% ADD inhaled corticosteroid in combination with long-acting β2-agonist OR try long-acting anticholinergic
- if still symptomatic try inhaled corticosteroid AND long-acting β2-agonist AND long-acting anticholinergic
- consider adding theophylline
40
How do we chronically manage COPD via other interventions?
- breathlessness and exercise limitation, smoking cessation, pulmonary rehabilitation, possible surgical intervention
- frequent exacerbations: antibiotics, increase treatment
- respiratory failure: LTOT, SBOT, AOT
- cor pulmonale: LTOT, diuretics
- abnormal BMI: dietitian input
- chronic cough: consider mucolytics
- anxiety and depression: screening and treatment as necessary
41
How do we identify acute COPD?
| ABC
- Airway – patent (unobstructed)
- Breathing – raised RR, decreased O2 saturations, wheezing, use of accessory muscles, talking in full sentences, chest signs
- Circulation – raised HR, low BP
42
How do we acutely manage COPD via medication?
- controlled oxygen
- inhaler/nebulised salbutamol 5mg
- steroids – 30mg prednisolone oral/100mg hydrocortisone IV
- no improvement, repeat nebulised salbutamol 5mg + ipratropium 500mcg
- if infection; antibiotics
- if life-threatening features/worrying ABG → ICU help
43
Case study
• 78-year-old man called Ron
• known COPD for 20 years, on inhalers only (2 different ones but cannot remember names)
• no home oxygen
• complaining of SOB and a worsening cough w/ green sputum
• you are asked to see him in A&E – what are you going to do?
- controlled oxygen
- inhaler/nebulised salbutamol 5mg
- steroids – 30mg prednisolone oral/100mg hydrocortisone IV
- no improvement, repeat nebulised salbutamol 5mg + ipratropium 500mcg
- if infection; antibiotics
- if life-threatening features/worrying ABG → ICU help
44
How is a peak flow meter used to find PEF and how can this be used?
1. attach a disposable mouthpiece to peak flow meter
2. slide reset lever in the slot to calibrate
3. hold apparatus horizontally and take a maximal inspiration and place the mouthpiece in the mouth gripping it with the teeth and sealing it with the lips
4. blow out as hard as possible
5. use the first as a practice and repeat the test twice; taken an average of the 3 for peak expiratory flow
6. use the nomogram provided to determine the predicted PEF for the subject
7. record results along with age and height of subject
8. collect a random sample of male/female results to complete the table and compare to average ranges.
