Breathlessness and Cyanosis Flashcards
(39 cards)
Define the following:
a) dyspnoea
b) tachypnoea
c) hyperventilation
d) hyperpnoea
a) difficulty breathing
b)increased rate of breathing (can occur with anxiety but also can indicate lung disease and/or metabolic disease)
c) overbreathing resulting in decreased alveolar and arterial pCO2 (associated with increased resp rate)
d) increased level of ventilation (volume of air) as occurs with metabolic acidosis
What are the 2 key types of cause of sudden onset breathlessness
Pulmonary (pneumothorax; inhaled foreign body; anaphylaxis)
Cardiovascular (PE, MI)
Give 4 broad groups of causes that could underlie a breathlessness with a onset over hours
Give examples for each area
Pulmonary (acute bronchitis; pneumonia; asthma)
Cardiovascular (LVF; pericardial tamponade; high altitude)
Psychogenic (anxiety; panic attacks)
Metabolic (diabetic ketoacidosis; uraemia; poisons)
Name 3 poisons that could cause breathlessness with an onset over hours
salicylate
methyl alcohol
ethylene glycol
Name 3 poisons that could cause breathlessness with an onset over hours
salicylate
methyl alcohol
ethylene glycol
Give 5 broad groups of causes that could underlie a breathlessness with a onset over days to months
Give examples for each area
Pulmonary (TB; chronic bronchitis; emphysema; bronchiectasis; pleural effusion; interstitial lung disease)
Cardiovascular (heart failure; recurrent PE; pulmonary hypertension)
Neuromuscular (Myasthenia gravis; MND; myopathies)
Mechanical (chest wall and skeletal abnormalities; morbid obesity)
Metabolic (thyroid disease; anaemia)
What are the key things you need to ask about when taking a history of a breathless patient
Speed of onset
Associated symptoms
Medications
Past Hx
Which associated symptoms do you need to be aware of when assessing breathlessness in a Hx
Cough and sputum
Wheeze
Chest pain
Haemoptysis
Peripheral oedema
What are key things to look for when examining a breathless patient
cyanosis
oxygen saturations
PEF
chest sounds/ observations
What investigations do you want to do on a breathless patient
Radiology - CXR, thoracic CT
Respiratory function tests - PFTs, 6 MWT, CPET
Blood gas
What should blood pH be
7.35-7.45
What is the normal range for PO2 and PCO2 in the blood?
PO2= 11-15kPa
PCO2= 4.5-6kPa
What is the normal range of
a) [H+] and
b) [HCO3-] in the blood
a) 35-45nmol/L
b) 22-30mmol/L
What causes type 1 resp failure
acute hypoxaemia and diseases that damage lung tissue eg:
- pulmonary oedema
- pnuemonia
- idiopathic pulmonary fibrosis (+interstitial lung disease)
-asthma
What causes type 2 resp failure
give examples of when this occurs
ventilatory failure - when alveolar ventilation is insufficient to excrete the volume of CO2 produced by tissue metabolism
-COPD
-chest wall deformities
-respiratory muscle weakness (Guillan-Barre/ myasthenia gravis…)
-depression of respiratory centres (eg opiate overdose)
How could metabolic acidosis cause breathlessness
increased acid production and/or decreased elimination would mean the HCO3- buffer gets used up so has to compensate via hyperventilation causing PCO2 to fall
Give 3 causes of metabolic acidosis
Diabetic ketoacidosis
Renal failure
Lactic acidosis
What is lactic acidosis and what are the different types of lactic acidosis
acidosis from increased lactate production due to reduced tissue perfusion or reduced ability of cells to use O2
Type A: +tissue hypoxia (eg circulatory failure)
Type B: no tissue hypoxia (eg toxicity)
What tends to cause metabolic alkalosis
loss of acid or XS alkali administration leads to decreased [H+] with a small increase in PCO2 and [HCO3-]
What is base excess
calculated estimated of the non-respiratory influences on total buffering capacity
When is CRP raised
In bacterial infections and inflammatory disease - levels rapidly fall to baseline following resolution of injury/infection
Name a key autoimmune condition where CRP is not raised
SLE
What are 4 broad differential diagnoses for pulmonary infiltrates in asthmatic patients
Infection (look for cough, sputum, fever, pleuritic chest pain and bronchial breathing)
Inflammation
Haemorrhage (vasculitis in Churg-Strauss syndrome)
Malignancy
What should you look at on the imaging of a patient presenting with acute breathlessness
lung parenchyma (alveolar filling, interstitial thickening, airway disease)
pulmonary vascular (large vessel obstruction - PE)
cardiac causes (pleural oedema, pericardial effusion)
pleural problems (pneumothorax; haemothorax/ pleural effusion)
