8 - Poisoning, Metabolic and Temperature Changes Flashcards
At what point should hyperkalaemia be treated urgently?
- If >6.5 start treatment immediately
- If <6.5 do ECG first to see if any changes and decide how urgent treatment is
What are some symptoms of poisoning in general?
What are the signs of an aspirin (salicyclate) overdose?
- hyperventilation (centrally stimulates respiration)
- tinnitus
- lethargy
- sweating
- pyrexia*
- nausea/vomiting
- hyperglycaemia and hypoglycaemia
- seizures
- coma
What changes on ABG are there with salicyclate overdose?
Mixed respiratory alkalosis and metabolic acidosis
Early stimulation of the respiratory centre leads to a respiratory alkalosis whilst later the direct acid effects of salicylates (combined with acute renal failure) may lead to an acidosis.
In children metabolic acidosis tends to predominate.
When do you take bloods for salicyclate levels?
2 hours after ingestion then every 2 hours until a peak is reached
How should salicyclate overdose be managed?
- Activated charcoal if within 1 hour
- IV fluids
- Sodium bicarbonate
- Potassium replacement
- Cooling measuresif hyperthermia
- Haemodialysis: for severe salicylate poisoning with renal failure, severe metabolic acidosis or seizures.
- Psychological support
How does sodium bicarbonate help in salicyclate overdose?
Reduces transfer of salicylates into central nervous system and enhances urinary excretion of salicylates (otherwise known as urinary alkalinisation).
Plasma potassium should be corrected before starting sodium bicarbonate, as can potentiate hypokalaemia.
What are some complications of salicyclate overdose?
- Acute Respiratory Distress syndrome
- Sezirues
- Arrythmia
- Renal failure
- Drug induced hepatitis
What are the signs of a benzodiazepine overdose?
- Agitation
- Euphoria
- Blurred vision
- Slurred speech
- Ataxia
- Slate-grey cyanosis
What are the important investigations to do following a paracetamol overdose?
INR!!!!
How do you treat a beta blocker overdose?
Glucagon and Calcium replacement as hypocalcaemia
What are the signs of carbon monoxide poisoning?
Inebriation, coma, reduced reflexes, tachycardia, pulmonary oedema, shock, met acidosis, flushed cherry pink skin, headache
What are the antidotes for the following?
What are the features of a TCA overdose? e.g amitriptylline
LOW BLOOD PRESSURE
Early features (anticholinergic): dry mouth, dilated pupils, agitation, sinus tachycardia, blurred vision
Severe poisoning: arrhythmias, seizures, metabolic acidosis, coma
What are the ECG changes in a TCA overdose?
- Sinus tachycardia then
- Widening of QRS then
- Prolongation of QT interval
How is TCA overdose managed?
- Fluids for hypotension
- IV Bicarbonate
- Correction of acidosis, hypoxia, and electrolyte imbalance to help arrhythmias
- Benzos if seizures
How long between the ingestion of an overdose of TCAs and the symptoms?
1-2 hours
Who is always important to involve in an overdose?
Psychiatry!
What are some risk factors for hypothermia?
- Elderly
- Children
- General anaesthesia
- Homeless
- Dementia
- Long lie
- Alcohol/drug intoxication
- Hypothyroidism
- Poor nutrition
- Diabetes
- Stroke
- Parkinson’s
What are the signs of hypothermia?
- Shivering
- Slurred speech or mumbling
- Tachypnoea, tachycardia and hypertension (if mild)
- Respiratory depression, bradycardia and hypotension (if moderate)
- Drowsy
- Confusion
- Loss of consciousness
How can you prevent hypothermia?
- Avoid overexertion
- Stay dry
- Cover head and feet
- Avoid drinking alcohol in cold weather
How do we manage hypothermia in the hospital?
Passive
- Remove any wet/cold clothes
- Warm body with blankets
Active
- Warm IV fluids
- Forced warm air
Why should you try to avoid rapid re-warming?
Can lead to peripheral vasodilation and shock
What advice can you give to the community about managing hypothermia?
DUE TO RISK OF CARDIAC ARREST:
- Don’t put the person into a hot bath
- Don’t massage their limbs
- Don’t use heating lamps
- Don’t give them alcohol to drink
What are the ECG changes in hyperthermia?
- bradycardia
- ‘J’ wave (Osborne waves)
- first degree heart block
- long QT interval
- atrial and ventricular arrhythmias
What are the common causes of pyrexia?
- Infection
- Drug related
- Cancer
- Autoimmune
What are some investigations you can do if you have pyrexia of unknown origin?
What investigations should we do if someone has hypothermia?
- Rectal temperature
- 12 lead ECG
- FBC and U+Es: Hb and haematocrit can be elevated (due to haemoconcentration). Platelets and WBCs are low due to sequestration spleen. Monitor K as can go hypoK
-Blood glucose:stress hormones can cause hyperglycaemia
- ABG
- Coagulation factors
