Craven Flashcards
What does Mr Craven’s patient profile tell us?
Has a 30-pack year smoking history
Grew up in Glasgow, both parents were smokers
Works as a British Gas plumber, work has reduced hours these days
A huge fan of the Glasgow rangers
Had a chest infection recently and took amoxicillin
Took his wife to the cinema for their wedding anniversary
Enjoys fly fishing accompanied by his wife
What does Mr Craven talk about in the Case video?
Breathing gotten a lot worse over the last few days Can't get enough air in Chest feels tired, achy Having difficulty sleeping at night Last night had to get blue puffer out at least 4x during the night Coughing up more phlegm and sputum than normal - a few egg cup fulls a day Yellow green coloured sputum No blood in sputum No wheezing, 'rattling' No chest tightness No chest pain Diagnosed with COPD 3 years ago On a good day - 15 mins to shop Stairs - can manage a flight but but of breath getting to the top Claims he hasn't taken antibiotics or oral steroids from the GP in the last year No other medical problems Off food for last few days - soups Just him and his wife He's gonna be a grandpa (has a daughter) Swelling in both ankles Feeling flushed Waterworks and bowel movements okay No recent faints / unconsciousness Quit smoking when he got the COPD diagnosis Used to smoke a pack a day for 40 years On blue puffer and special combo inhaler No drug allergies
What does the doctor think Mr Craven has after taking his history?
Effective exacerbation of your COPD
What does the doctor want to do next?
Examine Mr Craven, listen to his chest, run some blood tests, get a chest x-ray (CXR), get an ECG, sputum analysis
Arterial blood gas test - O2 sats low at 87
What is Chronic Obstructive Pulmonary Disease (COPD)?
Name for a group of lung conditions that cause breathing difficulties:
Emphysema – damage to the air sacs in the lungs
Chronic bronchitis – long-term inflammation of the airways
What are the main symptoms of COPD?
Increasing breathlessness, particularly when active
Persistent chesty cough with phlegm – some people may dismiss this as just a “smoker’s cough”
Frequent chest infections
Persistent wheezing
When is it good to get medical advice?
Persistent COPD symptoms, esp. if 35+ and smoke / used to smoke
Why is it important not to ignore COPD symptoms?
Best to start treatment ASAP before lungs get significantly damaged
What are the causes of COPD?
Long term exposure to dust or harmful fumes
Smoking
Rare genetic problem = lungs more vulnerable to damage
All lead to inflamed, damaged and narrowed lungs (aKA COPD)
What are the treatments for COPD? Why are they important / useful?
Damage to lungs caused by COPD is permanent but treatment can help slow down the progression of the condition
Treatments include:
Stop smoking
Inhalers and medications - help breathing
Pulmonary rehabilitation - specialised exercise and education programme
Surgery / lung transplant
What else may be required by someone with COPD?
Social care and support
Need help for daily tasks
Or they may be a carer
How can you reduce the chance of developing COPD?
Avoid smoking
What did COPD used to be known as?
Chronic bronchitis and emphysema
Affects lung tubes, air tubes and the lung tissue itself
How is COPD defined clinically?
Coughing up mucus every day, for 3 months of the year, typically in the winter
What is the progression of COPD?
Persistent smoker’s cough
Coughing up phlegm / sputum / mucus
Breatlessness on exertion
How to diagnose suspected COPD?
CXR (chest x-ray)
Blow test - measures lung function compared to average
What are the typical treatments prescribed by the GP for COPD patients?
Inhaler to to open up air passages during spasms / coughing
Inhaler to reduce inflammation
Emergency supply of antibiotics = do not need to wait for prescription if they develop a chest infection
What are some other less common symptoms of COPD?
Weight loss
Tiredness
Swollen ankles from a build-up of fluid (oedema)
Chest pain and coughing up blood – although these are usually signs of another condition, such as a chest infection or possibly lung cancer
Only tend to happen with COPD reaches advanced stage
What other conditions cause similar symptoms to COPD?
How can you differentiate between them?
Asthma, bronchiectasis, anaemia, heart failure
Breathing test can help determine if you have COPD
What are the causes of COPD?
Smoking - 9 out of 10 cases: harmful chemicals damage lining of lungs and airways
Passive smoking
Fumes and dust at work - damage lungs:
cadmium dust and fumes
grain and flour dust
silica dust
welding fumes
isocyanates
coal dust
Air Pollution
Exposure over a long period can affect how well the lungs work (inconclusive evidence)
Genetics
1 in 100 with COPD have tendency to develop a genetic condition called Alpha-1-antitrypsin deficiency. Alpha-1-antitrypsin = substance that protects your lungs
What might a GP do to confirm a diagnosis of COPD?
Ask about symptoms
Examine chest and listen to breath sounds
Ask about smoking history
Calculate BMI
Ask about family history of lung problems
Perform tests
What tests can help a GP confirm a diagnosis of COPD?
Spirometry - breathe into spirometer after inhaling a bronchodilator, record vol of air exhaled in 1st second and total vol of air exhaled. Compare results with baseline to check if lungs are obstructed
CXR (chest x-ray) - look for problems in the lungs that can cause similar symptoms to COPD e.g. cancer, chest infections
Blood test - show other conditions that can cause similar symptoms to COPD e.g. anaemia, polycythaemia. Sometimes done to look for alpha-1-antitrypsin deficiency
What are some further tests to determine severity of COPD?
Electrocardiogram (ECG) – a test that measures the electrical activity of the heart
Echocardiogram – an ultrasound scan of the heart
Peak flow test – a breathing test that measures how fast you can blow air out of your lungs, which can help rule out asthma
Blood oxygen test – a peg-like device is attached to your finger to measure the level of oxygen in your blood
CT scan – a detailed scan that can help identify any problems in your lungs
Phlegm sample – a sample of your phlegm (sputum) may be tested to check for signs of a chest infection
What are the available treatments for COPD?
Stop smoking
Inhalers - device delivers medicine directly into lungs whilst breathing
Tablets
Antibiotics
Pulmonary rehabilitation
Nebulised medicine - machine turns liquid medicine into mist and is breathed in through a mouth piece = larger dose delivered at a time
Roflumilast - new medication for flare ups to reduce inflammation
Long-term O2 therapy - >16hrs/day
Ambulatory oxygen therapy = blood O2 normal at rest, but falls on exertion
Non invasive ventilation = portable machine connected to mask to support lungs
Surgery
What are the different types of inhalers prescribed for COPD?
Short-acting bronchodilator inhalers - first treatment use:
Beta-2 agonist inhalers - e.g. salbutamol and terbutaline
Antimuscarinic inhalers e.g. ipratropium
Used up to 4x a day, only when feeling breathless
Long-acting bronchodilator inhalers - if symptoms persist throughout the day, use:
Beta-2 agonist inhalers e.g. salmeterol, formoterol and indacaterol
Antimuscarinic inhalers e.g. tiotropium, glycopyronium and aclidinium
Last up to 12 hours, should only be used 1-2x a day
Steroid inhalers - if still breathless or frequent exacerbations use:
corticosteroid medicines to reduce Inflammation in the airways
What so combination inhalers often include?
Steroid inhalers
Long-acting medicine
What are the different tablets prescribes for COPD?
Theophylline tablets - bronchodilator, reduces inflammation in the airways and relaxes the muscles lining them
Mucolytics - e.g. carbocisteine 3-4x a day = makes phlegm in the throat thinner and easier to cough up
Steroid tablet - for bad exacerbations to reduce inflammation = 5 day course though long term use = weight gain, mood swings, weakened bones (osteoporosis)
What is pulmonary rehabilitation?
Specialised programme of exercise and education: involving:
Physical exercise training tailored to your needs and ability – such as walking, cycling and strength exercises
Education about your condition for you and your family
Dietary advice
Psychological and emotional support
What are the side effects of Roflumilast?
Side effects of roflumilast include:
feeling and being sick
diarrhoea
reduced appetite
weight loss
headache
What are the surgical treatment options for COPD?
Bullectomy – remove pocket of air from one of the lungs, allowing the lungs to work better and make breathing more comfortable
Lung volume reduction surgery – an operation to remove a badly damaged section of lung to allow the healthier parts to work better and make breathing more comfortable
Lung transplant – an operation to remove and replace a damaged lung with a healthy lung from a donor
What should a patient living with COPD do?
Look after themselves
Take their prescribed medication and refer to info leaflets for flare ups
Stop smoking
Exercise regularly
Maintain a healthy weight - carrying extra weight makes breathlessness worse
Get vaccinated - COPD = strain on body = vulnerable to infections
Check weather - symptoms temperamental so prep in advance w/ extra medication
Watch what you breath - avoid dust, fumes, smoke, air freshners, strong smelling cleaning products, hairspray, perfume
Regular reviews and monitoring with care team
Practice breathing techniques - slow deep breaths
Talk to others - GP, local support group, counsellor, psychologist
Relationships - difficulty breathing = tired and depressed
Sex = strenous, sex life affected
Flying with COPD = take medications in hand luggage
Finance - entitled to statuatory sick day and employment & support allowance; carer entitled to carer’s allowance
End of life care - management plan based on your wishes (advance decisions made)
What are some co-morbidities (with COPD) that could contribute to Mr Craven’s current shortness of breath?
CVD - chronic heart failure, CAD, PAD, atrial fibrillation
Asthma
Anaemia
Anxiety / Depression - closely related to the risk of death
Respiratory infections
Cancer - oesophageal, pancreatic, breast, lung = also closely related to risk of death often due to COPD population being smokers
Hypertension
Diabetes
Chronic Renal Failure
Degenerative joint disease
Why are COPD exacerbations so serious?
Many patients die within 1 year of their first COPD exacerbation
Lung function decline Lessened physical activity Poor / declining mental Health Deterioration in quality of life Further COPD exacerbations Mortality
A chest x-ray is a mandatory investigation in anyone who presents to A&E with shortness of breath
What does Mr Craven’s chest x-ray show now, compared to before?
Hyperinflated lungs - clavicles raised, flat hemidiaphragm
Barrel chest?
Enlarged heart?
White fluffy cloud stuff in the right lung - pneumonia, (congestion + fluid build up in the lungs) or pleural effusion
Opacification in the lower lobe of the right lung = low bar pneumonia
Why does Mr Craven’s x-ray show an enlarged heart?
Enlarged heart - caused by pulmonary hypertension (raised BP in the pulmonary arteries) leading to cor pulmonale (i.e. right sided heart failure)
This is because the right side of the heart has to work harder to pump blood to the lungs due to the pulmonary hypertension
Why is there an increased RBC count in cor pulmonale?
Increased RBCs in cor pulmonale due to bone marrow compensates by producing more RBCs
How can you differentiate between pneumonia and pleural effusion?
Costophrenic angle up to the pleura outlining distinctive border, literally the bottom half of the lung is opaque
Loss of right hemidiaphragm in pneumonia and less distinct border in opacification - all over the lung especially at the borders (doesn’t collect at the bottom like pleural effusion)
What is Mr Craven’s diagnosis based on his x-ray and arterial blood gas?
Low pH - acidosis
Low O2
High CO2 - hypoxemia
Normal HCO3- / BE
Uncompensated respiratory acidosis with moderate hypoxemia
What is wrong with the ABG slip?
Doctor has not written FIO2 (fraction of inspired oxygen)
Write FIO2 = room air or being given oxygen?
What happens in hypoxemic respiratory failure?
Type I
Lack of oxygenation of the lung tissue
Lung tissue failure - oxygenation failure = V/Q mismatch - blood being delivered without oxygen in it
Inadequate O2 to meet matabolic needs
What happens in hypercapnic respiratory failure?
Type II
Pump failure - leading to increased CO2
Failure of lungs to eliminate CO2
Anything affecting the muscles - nerves, neuromuscular, cervical trauma, stroke at the PONS etc.
What are some possible causes of hypoxemic respiratory failure?
Pneumonia Pulmonary oedema Pulmonary fibrosis Pulmonary embolism 'ARDS Aspiration Lung collapse - retained secretions Asthma Pneumothorax
What are some possible causes of Type II respiratory failure?
Late severe acute asthma Neuromuscular diseases Flail chest injury Exhaustion Reduced respiratory drive - drug overdose, head injury COPD
What type of respiratory failure is Mr Craven in?
Type II
pH - low, = acidaemia
High PCO2 = respiratory acidosis
What organ tries to compensate for the respiratory failure in the lungs?
Kidneys try to compensate for the lungs
Metabolic alkalosis - increase blood pH to stabilise blood pH - regain blood pH balance
Response is a partial compensation
(with liver or kidney failure, lungs tend to try an compensate)
What is the initial management for Mr Craven’s shortness of breath?
Drug and non-drug
IV antibiotics - treat infection causing the pneumonia, look at previous cultures to deliver more specific antibiotic rather than broadspectrum
IV cortisone VS Systemic corticosteroids - improve inflammation
Anticholinergics - inhibit parasympathetic nerves, reduce airway tone and improve expiratory flow
Beta-2 agonists - smooth muscle relaxation, open up the airways e.g. IV salbutamol
Ventilation and oxygen - improve RR and hypoxemia
Sit up - release pressure against diaphragm
Respiratory physiotherapy - remove secretions clogging up the airways
Which ventilation method is to be used with Mr Craven?
CPAP or BIPAP?
CPAP - continuous positive airways pressure
NIV - non invasive ventilation AKA BiPAP
- bi-level positive airway pressure
BiPAP suitable for Mr Craven - has 2 pressure settings, one for inhalation and one for exhalation (compared to CPAP which only has one pressure)
This lessens the work for Mr Craven to breathe
Why is CPAP inappropriate for Mr Craven?
Continuous flow
Controlled flow - low, medium, high
Increases work required for exhalation to overcome continuous positive pressure
Why is BiPAP more suitable for Mr Craven?
Mr Craven has Type II = Pump failure
NIV - differing pressures depending on inspiratory and expiratory pressures
Higher pressure for inhalation than inhalation
Reduces the work of breathing
Mr Craven has an issue with his lungs. So why does he have swollen ankles?
Lack of O2 in blood =
Alveolar hypoxia
Hypoxic pulmonary vasoconstriction (high CO2 tension with elevated H+ concentration in the blood increases the extracellular Ca2+ influx, which is thought to be the main cause of vasoconstriction in the pulmonary circulation)
Increased pulmonary vascular resistance
Pulmonary hypertension
Right ventricular afterload is greater - needs to pump harder to compensate for pulmonary hypertension
Leads to right ventricular failure
Right heart muscle becomes enlarged and thickened and loses its ability to contract normally
Because of this, blood backs up in the veins of your body and fluid can leak into the surrounding tissues
Back flow of oedema into the peripheral system
Gravity causes the oedema to pool at the ankles and feet
How do you interpret an arterial blood gas (ABG) report?
- Look at pH and determine whether it is acidic, alkalotic, or normal
- Identify primary disturbance - respiratory or metabolic cause? Review pCO2 (respiratory) and HCO3- (metabolic)
- Is there a anion gap? (Base excess)
- Is there any compensation?
What causes respiratory acidosis?
Rise in CO2 level but patient cannot increase respiratory drive
Increased carbonic acid formation
Decreased pH
What causes respiratory alkalosis?
Hyperventilation
CO2 levels fall
Less carbonic acid formation
Increased pH
What is the buffering role of bicarbonate ions in the blood?
React with Hydrogen ions to form water and CO2
What is the role of the Kidneys in acid-base regulation?
Regulate reabsorption of bicarbonate ions esp. in PCT - to achieve bicarbonate homeostasis
Form bicarbonate ions through excretion of ammonia and monophosphate ions
Increase H+ excretion = higher pH
Bicarbonate ions (HCO3-) are kept within which range?
22-28 mmol/L
What is the importance of bicarbonate ions?
Marker of metabolic homeostasis
Low bicarb = metabolic acidosis
High bicarb = metabolic alkalosis
A metabolic acidosis is caused by?
Either increase in H+ or decrease in HCO3- (bicarb)
How can you differentiate between high H+ or low HCO3- causing the metabolic acidosis?
Calculate anion gap
How do you calculate the anion gap?
- Either Na+ - HCO3- - Cl- = anion gap (8-16 mmol/L)
2. Or Na+ + K+ - HCO3- - Cl- = anion gap (12-20 mmol/L)
What causes a high anion gap?
Increase in unmeasured anions
Hydrogen ions reacting with the bicarbonate ions
Causes commonly by metabolic acidosis
What are common causes of high anion gap imetabolic acidosis?
Lactic acidosis
Ketoacidosis
Toxins
Renal failure
What happens in a normal anion gap metabolic acidosis?
What causes this?
Lost bicarbonate ions are replaced with chloride ions
Commonly due to: Diarrhoea
Renal tubular acidosis
What are the two methods of compensation?
Adjustments to ventilation
Adjustments to kidney absorption and excretion
What happens in metabolic acidosis to compensate?
Respiratory compensation usually begins within the first hour:
Ventilation increases driving off CO2
Reduces carbonic acid in blood
Increase pH
What are the compensatory mechanisms in metabolic alkalosis?
Hypoventilation
This is less pronounced
Rarely retains CO2 beyond 7.5 kPa
What is the compensatory mechanism for respiratory acidosis?
Kidneys attempt to retain more bicarb and excrete more H+ - to raise pH
Takes place over several days
Therefore more commonly seen in chronic respiratory diseases
What is ARDS?
Acute respiratory distress syndrome
What is the criteria for awake prone positioning?
In patients requiring and FiO2 > 28%
What does prone positioning do?
So why is it used in ARDS?
Decreases the pleural pressure gradients between dependent and non-dependent lung regions
Therefore used in ARDS to reduce:
Ventilation/perfusion mismatching
Hypoxaemia
Shunting (pulmonary shunt = passage of deoxygenated blood from the right side of the heart to the left without participation in gas exchange in the pulmonary capillaries
How does prone positioning help?
Gravitational effects
Conformational shape matching of the lung to chest cavity
Generates more homogenous lung aeration and strain distribution
Enhances recruitments of dorsal lung units
What is further contributing to incidence of COPD?
Environmental pollutants
What increases environmental pollutants in developing countries?
Use of biomass fuel for domestic energy
e.g. dung cakes, residues from crop, firewood
What leads to inefficient gas exchange in COPD?
Alveolar dead space
What does inefficient gas exchange lead to?
Ventilation perfusion mismatch
What does the body do to retain the V/Q ratio?
V/Q ratio is the amount of air that reaches your alveoli divided by the amount of blood flow in the capillaries in your lungs
Localised vasoconstriction in the affected lung areas that are not oxygenated well
What causes hypercapnia in COPD patients?
Patients have a reduced ability to exhale the carbon dioxide adequately
What does chronic CO2 elevation lead to?
Acid-base disorders and a shift of normal respiratory drive to hypoxic drive
Chemoreceptors develop tolerance to chronically elevated arterial carbon dioxide level
Shifts the normal acid-base balance toward acidic
What is the target O2 sats for COPD patients?
88% to 92%
What is the hasselbach equation?
pH = 6.1 + log − HCO3/0.03pCO2
What is the significance of COPD patients with renal failure and COPD exacerbation?
Kidneys are unable to reabsorb bicarbonate to compensate for chronic respiratory acidosis
Over time, mixed respiratory and metabolic acidosis sets in causing dangerously low levels of pH
The mortality rate is much higher
Why do you not want sats above 92% in COPD?
The failure of the hypoxic drive
Haldane effect: The increased partial pressure of oxygen in the blood displaces the carbon dioxide from hemoglobin and thereby increasing the CO2 level
The increased partial pressure of oxygen reverses the hypoxic vasoconstriction at the pulmonary artery level which leads to the blood going to areas of lungs with no ventilation. Increasing dead space and thus increasing acidosis
The increased amount of oxygen displaces nitrogen, which leads to atelectasis
How can hypercarpnia related complications be prevented?
Careful monitoring and proper management of COPD
Smoking cessation
Healthy lifestyle and regular exercise help prevent diseases that can worsen respiration
Side note:
Hypercapnia = hypercarbia = CO2 retention
they all mean the same thing
