Toxicology Flashcards
How is acute paracetamol overdose managed when less than 1 hour since time of ingestion?
- Activated charcoal
- Measure serum paracetamol level within 4-8 hours of ingestion
- Plot serum paracetamol level on normogram
- If UNDER normogram line - no medical rx required
- If OVER normogram line - Commence NAC infusion (usu. over 20 hours)
How is acute paracetamol overdose managed when between 1-8 hours since time of ingestion?
- Measure serum paracetamol level within 4-8 hours of ingestion
- Plot serum paracetamol level on normogram
- If UNDER normogram line - no medical rx required
- If OVER normogram line - Commence NAC infusion (usu. over 20 hours)
How is acute paracetamol overdose managed when more than 8 hours since time of ingestion?
- Commence NAC infusion immediately
- Measure serum paracetamol level and ALT
- Plot serum paracetamol level on normogram
- If UNDER normogram line/more than 24 h post OD and ALT normal - stop NAC. If UNDER normogram line/and ALT abnormal - continue NAC infusion until ALT normal
- If OVER normogram line, continue NAC infusion, and check ALT at end of infusion - if not normal, continue NAC, if normal, no further things to do.
How is paracetamol overdose treated when the time of ingestion is unknown?
Follow more than 8 hours scenario
- Commence NAC infusion immediately
- Measure serum paracetamol level and ALT
- Plot serum paracetamol level on normogram
- If UNDER normogram line/more than 24 h post OD and ALT normal - stop NAC. If UNDER normogram line/and ALT abnormal - continue NAC infusion until ALT normal
- If OVER normogram line, continue NAC infusion, and check ALT at end of infusion - if not normal, continue NAC, if normal, no further things to do.
How are multiple/”staggered” paracetamol overdoses treated?
Treat according to time of ingestion of first dose
What should be considered when administering NAC in a paracetamol overdose?
NAC anaphylactoid reactions are common!
Slow infusion + antihistamine if flushing, urticaria occurs
If significant anaphylactic reaction (angioedema, hypotension), cease infusion
List 6 signs of clinical envenomation
Muscle paralysis Coagulopathy Hypotension Rhabdomyolysis/renal failure Vomiting Abdo pain
What first aid measures should be instigated when dealing with a snake bite? (3)
- Pressure immobilisation bandaging - start distally, note location of bite (don’t wash venom) and mark bandage at this point so swabs can be taken later. +/- splint
- Keep patient still
- Call ambulance
What lab tests should be ordered for a suspected snake bite? (7)
- FBE for anaemia, thrombocytopaenia
- UEC
- Coag profile - INR, APTT, fibrinogen, fibrinogen degradation products, D-dimer
- CK for rhabdomyolysis
- Blood group and cross match
- Urinalysis for myoglobin
- Sample for venom detection kit
How is a sample for a snake venom detection kit taken?
Swab at the bite site (cute a window in bandage) and urine sample
What is the role of a snake venom detection kit?
Helps to indicate correct monovalent antivenom to use in an envenomed patient - does NOT help to determine whether or not a patient is envenomed
When should a bandage be removed (snakebite)?
Only once antivenom has been administered - clinical signs of improvement. Re-apply if patient’s condition worsens.
What test results do you see in venom-induced consumptive coagulopathy and which snakes can cause this? (3)
Immeasurably high INR and aPTT with an unmeasurable fibrinogen and positive D-dimer. Brown snakes, tiger snakes and taipans.
What does alcohol withdrawal look like? (3)
- CNS hyperactivity syndrome: tremor, sweating, anxiety and agitation and distractibility
- Tonic-clonic fits
- Severe: delirium tremens
What occurs in delirium tremens? (4)
Hyperactivity
Fluctuating confusion
Paranoid ideation
Visual hallucinations
