Toxicology Flashcards
Management of paracetamol overdose, immediate release
> 10g or 200mg/kg. > 30 g or 500mg/kg = massive.
Charcoal if < 2 hrs post IR and cooperative. Or < 4 hrs if > 30 g.
< 8 hrs - APAP and +/- NAC
8-24 hrs - NAC, APAP & LFTs. Below nomogram and normal ALT - then stop
> 24 hrs - NAC, APAP & LFTs. Below 10 mg/L and normal ALT - stop.
NAC 200 mg / kg for 4 hrs, then 100 mg/kg (double if 2x nomogram) over 16 hrs.
- APAP and LFT 2 hrs prior to cessation.
Management of slow release paracetamol overdose
< 10g / 200 mg/kg - 2 levels, 4 hrs appart, start NAC if either above the line.
> 10g / 200 mg/kg - start NAC. APAP 4 hrs post ingestion and 4 hrs later. Complete NAC. If >2x nomogram, then dobule NAC.
> 30g / 500 mg/kg - start double dose NAC with 4 & 8 hr APAP.
APAP and LFTs prior to cessation
Paracetamol overdose, liver transplant unit referral criteria (kings college)
PH < 7.3 SBP < 80 BSL < 4 INR > 3.5 at 48 hrs, or > 4 at any time Renal failure, Cr > 200 Encephalopathy Plt < 50
Toxic dose risk assessment for salicylates
150-300 mg/kg - symptomatic
> 300 mg/kg - acid base abn, AMS, seizures
> 500 mg/kg - potentially lethal
Toxic dose risk assessment for iron (and max dose / tablet)
> 60 mg/kg - symptomatic
120 mg/kg - potentially lethal
Max dose / tablet = 110 mg/kg
Toxic dose risk assessment for TCA poisoning
5-10 mg/kg drowsy, anticholinergic
>10 mg/kg major toxicity possible
> 30 mg/kg severe toxicity, cardiotoxicity and coma
QRS > 100 = seziures
QRS > 160 = VT
Risk assessment - Colchicine anticipate lethal effects if dose more than:
> 0.8 mg/kg
Risk assessment - Isoniazid anticipate lethal effects if dose more than:
10 g
Risk assessment - Ibuporfen anticipate multiorgan failure if dose more than:
300 mg/kg
Risk assessment - Potassium anticipate lethal effects if dose more than:
2.5 mmol/kg (40 tablets)
Management of salicylate poisoning
Resus:
- intubation for coma, respiratory insufficiency or seizures.
- hyperventilate
- C - IVT for dehydration, urine output 1-2 mls/kg/hr
- D: IV benzodiazepines for seizures
Decontam: charcoal if > 150 mg/kg up to 8 hrs, via NG
Elim:
- urinary alkalinisation (if symptomatic) 1-2 mEq/kg bicarb, then infusion. Aim pH 7.5. IDC.
- haemodialysis: cant alkalinise, severe toxicity or rising salicylate level
Dispos: ICU
Management of tricyclic poisoning
Resus:
- Intubation for GCS <12 or seziure.
- Hyperventilate, target pH 7.5-7.55
- C: arrhythmia: Sodium bicarb for wide QRS or arrhythmia
- C: Hypotension: IV fluid, noradrenaline and bicarb.
- D: IV benzos and bicarb for seizures
D: Charcoal when intubated
A: Sodium bicarb, until pH 7.55, then 3% saline or lignocaine.
D: ICU
Management of calcium channel blocker toxicity
Resus:
- Airway: intubate if shock
- Bradycardia: atropine, adrenaline, CALCIUM, HIET
- Hypotension: IV fluid, CALCIUM, adrenaline, noradrenaline, HIET
—> Pacing, ECMO.
Decontam: Whole bowel irrigation if early and asymptomatic. Once hypotensive not possible.
Antidote: HIET. 1 unit/kg rapid acting insulin, 50 mls 50% dextrose. Then infusion 0.5 unit/kg/hr, 250 mls/hr 10% dextrose . Target MAP 60-65.
D: ICU
Anticipate complications: heart block/bradycardia, hypotension, arrest, hypokalaemia/hypoglycaemia with HIET
B-blocker
R:
- A/B: intubate if shocked or to hyperventilate (propranolol)
- C: atropine, adrenaline, external pacing. IV fluid bolus
- Elect: replace K, replace mag
S
I: ECG - long PR, heart block, wide qrs, TDP
D: charcoal < 2 hrs
A: HIET, intralipid, isoprenaline. ECMO.
Digoxin
R: lethal - K> 5.5, ingestion > 10g or level > 15 nmol/L.
R:
- C: bradycardia/tachycardia. Arrest. Hypotension. VT —> Lignocaine 1mg/kg.
—> atropine, adrenaline, fluid, pacing.
- Electrolytes: hyperkalaemia (insulin, sodium bicarb).
S
I: ECG - tachy/brady, conduction abnormalities (AV block, wide QRS, AF), increased automaticity: AE/VE, SVT
D: < 1 hr charcoal
E
A: Digoxin immune fab fragment. 5 stable, 10 unstable, 20 arrest.
