Textbook Review - Differential Diagnosis Flashcards
A patient presents with gait disturbances, slurred speech and altered consciousness. Explain how to differentiate this with stroke and hypoglycemia?
- gait disturbances, slurred speech and altered consciousness are signs of hypoglycemia AND stroke
- Altered consciousness is uncommon in stroke and suggests a paramedic should look for metabolic and toxic causes (Hypoglycemia/alcohol/drugs).
- Altered consciousness will rarely occur in stroke when there is brain steam involvement, a massive cerebral haemorrhage or a sub-arachnoid haemorrhage.
- A BGL should be taken and this is an obvious differentiator.
Explain the symptoms you might expect in an episode of syncope?
- Hypotension
- Pale
- Sweaty
- Dizziness
- Visual Disturbances
- GENERALISED motor weakness.
How might you differentiate someone who has dizziness and motor weakness…between stroke and syncope?
- Motor weakness in those with syncope tends to be generalised rather than unilateral, as one would expect in stroke.
- Stroke patients tend to be hypertensive, as a result of the cushings reflex (which includes cushings triad). Therefore stroke patients are often hypertensive. Syncope patients by contrast are hypotensive.
- History of sudden loss of conciousness.
Cushings triad occurs in stroke .What are the 3 elements and what do they occur in response to?
- Cushings reflex/triad occurs in response to raising ICP. It is associated with both stroke and head injury.
- The triad includes hypertension, irregular breathing, and bradycardia
What symptoms are shared between stroke and sepsis? What are some differentiators?
Shared symptoms:
- Sepsis can produce altered conscious states.
- Abnormal speech
- Weakness
- Dizziness
Differentiation;
- Altered consciousness
What type of STEMI can sometimes involve the right ventricle? How often would this occur roughly?
What are two KEY management principles for managing this type of STEMI?
- Inferior infarcts are the STEMI most likely to have right ventricle involvement. This is because it involves the RCA (right coronary artery). It supplies almost all blood to the right ventricle, and 25-35% of blood to the left ventricle.
- Right ventricle involvement occurs in up to 40% of inferior STEMIs. The leads involved within an interior STEMI are II, III and aVf.
- Right ventricle infarcts are VERY preload sensitive due to poor RV contractility and hence the LV is poorly fed/has poor preload. For this reason you often see severe hypotension and nitrates that REDUCE preload are CONTRAINDICATED.
- Hypotension is often seen in RV STEMI. This is treated with fluid loading to increase preload and improve blood pressure.
What are signs on the ECG of right ventricle involvement in a STEMI.
- Always suspect RV involvement when it;s an inferior STEMI.
- ST elevation in V1 – the only standard ECG lead that looks directly at the right ventricle.
- ST elevation in lead III > lead II – because lead III is more “rightward facing” than lead II and hence more sensitive to the injury current produced by the right ventricle.
What are key risks associated with an inferior STEMI?
- Up to 20% of patients with inferior STEMI will develop significant bradycardia due to second- or third-degree AV block. These patients have an increased in-hospital mortality (>20%).
- If bradycardia occurs within 6 hours of the STEMI, bradycardia is likely due to the Bezhold-Jarish reflex. This reflex occurs when ischemic conditions irritate vagal receptors in the surface of the LV, initiating a parasympathetic response.
This stimulation commonly results in hypotension, as well as depressed automaticity of the SA node, inhibiting general conduction and prolonging AV nodal conduction and refractoriness. Up to 50% of patients may show signs of second or third degree heart block and this is a risk factor for arrhythmia.
What are the ECG signs of inferior STEMI?
- ST elevation in leads II, III and aVF
- Progressive development of Q waves in II, III and aVF
- Reciprocal ST depression in aVL (± lead I)
Explain the guiding practical principle regarding airway management in stroke?
Airways can become mechanically obstructed in stroke, due to hyper secretions and dysphagia (difficulty swallowing - poor motor control). These secretions can cause aspiration, and pnumonia is a common secondary injury associated with stroke.
Airway management has risks, firstly the consequences of failed intubation , secondly, the chance of an accidental oesophageal intubation.
Stroke patients often have a conscious status and hence, sedation would be required for an airway. This makes assessment of conciousness status, and symptoms more difficult to assess. It may also impact blood pressure (reducing CBF which is map - ICP).
Therefore the key is this:
- if the patient can maintain sp02 of 94% with oxygen, forgoe an airway.
- if below 94% after interventions, the consequences of cerebral hypoxia outweigh the risks associated with intubation.
A patient has a syncope episode, with onset of thunderclap headache. How differentiate between stroke and meningitis?
Meningitis is associated with gradual onset, as it is an infectious process. Patient would likely have felt lethargy, fever,weakness ect. Prior to episode. It is also associated with nuchal stiffness which is not a sign of stroke. Photo sensitivity is another sign,but that one can also be associated with stroke .
A patient becomes unconcious, wakes up with paresis How differentiate between stroke and siezure?
- Both stroke and a post ictal state can have similar symptoms.
- Search for a history of siezure before the loss of conciousness.
- Check for past history of siezure.
- Check for incontinence, which you might expect in siezure but not in stroke onset.
- An altered level of conciousness is UNCOMMON in stroke, unless it involves the brain stem.
What signs and symptoms are shared between a metabolic disorder and stroke?
How differentiate?
Metabolic disorder = Hypoglycemia.
One might expect signs such as:
- Dizziness
- Decreased level of consciousness
- Slurred speech
- Gait disturbance
- Occasionally uni, but more often bilateral weakness and or/ motor deficits.
Differentiate:
- Do a BGL is key
- General weakness that is not unilateral, is unlikely to be stoke.
- Loss of conciousness, is a rare occurance in stroke unless brain stem involvement.
What signs and symptoms are shared between a syncope and stroke?
syncope:
Shares symptoms of
- Altered mental status
- Dizziness
- Visual Disturbances
- Motor weakness
Differentiation:
- Pallor associated with syncope.
- Motor weakness is generalised rather than unilateral.
- Syncope more rare in stroke
- Hypotension rare in stroke, typically hypertension occurs.
- They respond to positioning the patient supine and IV fluids.
