General management of poisoning involves stabilization, evaluation, gastrointestinal decontamination if recent, urinary alkalinization for some toxins, haemodialysis/haemoperfusion, lipid emulsion therapy, supportive care, and antidotes if available. Stabilization focuses on airway, breathing, circulation. Evaluation includes examination. Gastrointestinal decontamination includes activated charcoal orally or via tube for some toxins within 1 hour, or whole bowel irrigation for sustained release drugs. Urinary alkalinization enhances excretion of weak acids/bases. Haemodialysis/haemoperfusion effectively removes some toxins. Lipid emulsion therapy counters cardiac effects of some lipophilic drugs. Supportive care monitors until effects

1. GENERAL MANAGEMENT OF
POISONING

2. General management of poisoning can be done by:-
• Stabilization
• Evaluation
• Gastrointestinal decontamination
• Urinary alkalinisation
• Haemodialysis and haemoperfusion
• Lipid emulsion therapy
• Supportive care
• antidotes

3. Stabilisation & evaluation:-
• Assessment & correction of life threatening problems, if present.
• Attention must be paid to the air way, breathing, circulation,
depression of CNS.
• If patient is not in crisis i.e he is alert with normal speech &pulse,
proceed to a complete, thorough, & systemic examination.

4. Gastrointestinal decontamination:-
• Patients who have ingested potentially life –threatening quantities of
toxins may be considered for gastrointestinal decontamination if
poisoning has been recent.
• Induction of emesis is no longer used.

5. 1.Activated charcoal-
• Given orally as slurry, absorbs toxins in the bowel as a result of its large
surface area.
• If given sufficiently early, it can prevent absorption of an important
proportion of the ingested dose of toxin.
• Efficacy decreases with time & current guidelines do not advocate use
more than 1hour after overdose in most circumstances.
• However, use after a long interval may be reasonable when a delayed
release preparation has been taken or when gastric emptying is delayed.
• Some toxins do not bind to activated charcoal so it will not affect their
absorption.

6. • In patients with impaired swallowing or a reduced level of
consciousness, activated charcoal, even via nasogastric tube, carries a
risk of aspiration pneumonitis, which can be reduced by protecting
the airway with a cuffed endotracheal tube.
• Multiple doses of activated charcoal (50g 6 times daily in an adult)
may enhance the elimination of some drugs at any time after
poisoning.
• Recommended for serious poisoning with some substance.
• This interrupts enterohepatic circulation or reduces the concentration
of free drug in the gut lumen, to the extent the drug diffuses from the
blood bowel back to be absorbed on to the charcoal : so called gastro
intestinal dialysis.
• Laxative is generally given- to reduce the risk of constipation or
intestinal obstruction by charcoal briquette formation in the gut
lumen.

7. • Evidence suggests that single or multiple doses of activated charcoal
do not improve clinical outcomes after poisoning with pesticides or
oleander.
• Substances poorly absorbed by activated charcoal:-
MEDICINES
iron lithium
CHEMICALS
acid mercury
alkalis methanol
ethanol
ethylene glycol

8. 2.Gastric aspiration and lavage-
• It is infrequently indicated in acute poisoning.
• Not effective than activated charcoal.
• Complication are common especially aspiration.
• Use is justified for poisons which are not absorbed by
activated charcoal

9. 3.Whole bowel irrigation-
• Enhance the elimination of ingested packets of illicit drugs or slow
release tablets such as iron & lithium.
• Involves the administration of large quantities of osmotically balanced
Polyethylene glycol & electrolyte solution.
• Usually by a nasogastric tube, until the rectal effluent is clear.
• Contraindication- inadequate air way protection, haemodynamic
instability, gastrointestinal haemorrhage, obstruction or ileus.
• May precipitate nausea and vomiting, abdominal pain & electrolyte
disturbances.

10. Use of gastric decontamination methods:-
o single dose activated charcoal may be considered if a patient has
ingested a potentially toxic amount of a poison up to 1hour
previously.
multi dose activated charcoal – life threatening amount of
carbamazepine, dapsone, phenobarbital, quinine or theophylline.
o gastric lavage should not be employed routinely, if ever, in the
management of poisoned patients.

11. oWhole bowel irrigation should be considered for:
 poisoning with sustained – release or emetic coated drugs
 patients who have ingested substantial amounts of iron
 removal of ingested packets of illicit drugs.

12. Urinary alkalinisation:-
• Urinary excretion of weak acids and bases is affected by urinary PH,
which changes the extent to which they are ionized.
• Highly ionized molecules pass poorly through the lipid membranes &
therefore little tubular reabsorption occurs &urinary excretion is
increased.
• If the urine is alkalinized (PH>7.5) by the administration of sodium
bicarbonate, weak acids (eg: salicylates, methotrexate) are highly
ionized, resulting in enhanced urinary excretion.

13. • Urinary alkalinisation is currently recommended for patients with
clinically significant salicylate poisoning when the criteria for
haemodialysis are not met.
• Complications- alkalaemia, hypokalaemia, occasionally alkalotic
tetany.
• Hypocalcaemia may occur but is rare.

14. Haemodialysis and haemoperfusion:-
• Enhance the elimination of poisons - have small volume of
distribution &a long half life after overdose.
• Appropriate when poisoning is sufficiently severe to justify invasive
elimination methods.
• The toxin must be small enough to cross the dialysis membrane –
haemodialysis or must bind to activated charcoal – haemoperfusion.
• Haemodialysis may also correct acid – base balance & metabolic
disturbances associated with poisoning.

15. • Poisons effectively eliminated by haemodialysis:-
ethylene glycol salicylates
isopropanol sodium valproate
methanol lithium
• Poisons effectively eliminated by haemoperfusion:-
Theophylline phenobarbital
phenytoin amobarbital
carbamazepine

16. Lipid emulsion therapy:-
• Lipid rescue is used for management of poisoning with lipid soluble
agents, such as local anaesthetics, tricyclic antidepressants, calcium
channel blockers & lipid- soluble beta blockers propranolol.
• It involves intravenous infusion of 20% lipid emulsion at an initial dose
of 1.5mL/Kg/min , followed by a continuous infusion of
0.25mL/Kg/min until there is clinical improvement.
• The elevated myocardial concentration of free fatty acids induced by
intralipid administration may also have beneficial effects on
myocardial metabolism &performance by counteracting the inhibition
of myocardial fatty acid oxidation produced by local anaesthetics.

17. • This reverses cardiac depression by enabling increased ATP synthesis
&energy production.
• Animal studies have suggested efficacy and case reports of use in
human poisoning have also been encouraging, with recovery of
circulatory collapse reported in cases where other treatment
modalities have been unsuccessful.
• No controlled trails of this technique have been performed, however,
&as a result, its efficacy remains uncertain.

18. Supportive care:-
• For most poisons, antidotes and methods to accelerate elimination
are inappropriate, unavailable or incompletely effective.
• Outcome is dependent on appropriate nursing and care, & on
treatment of complications.
• Patient should be monitored carefully until the effects of any toxins
have dissipated.

19. EXAMPLES OF CAUSATIVE AGENTS MANAGEMENT
coma Sedative agents Appropriate airway protection &
ventilatory support
Pressure area& bladder care
Identification & treatment of
aspiration pneumonia
seizures NSAIDs
Anticonvulsants
TCAs
theophylline
Appropriate airway& ventilatory
support
IV benzodiazepine (eg: diazepam
10-20mg, lorazepam 2-4mg)
Correction of hypoxia, acid base &
metabolic abnormalities
Acute dystonias Typical antipsychotics
metoclopramide
Procyclidine, benzatropine or
diazepam

20. EXAMPLES OF CAUSATIVE AGENTS MANAGEMENT
HYPOTENSION
Due to vasodilations
Due to myocardial suppression
Vasodilator antihypertensives
Anticholinergic agents
TCAs
Beta blockers
Calcium channel blockers
TCAs
IV fluids
Vasopressors
Optimisation of volume status
Inotropic agents
VENTRICULAR TACHYCARDIA
Monomorphic, associated with QRS
prolongation
Torsades de pointes, associated
with QTc prolongation
Sodium channel blockers
Anti arrhythmic drugs(quinidine,
amiodarone, sotalol)
Antimalarials
Organophosphate insecticides
Antipsychotic agents
Antidepressants
Antibiotics(erythromycin)
Correction of electrolyte& acid
base abnormalities &hypoxia
Sodium bicarbonate
Magnesium sulphate,2g Iv over 1-
2mins, repeated if necessary

21. Antidote:-
• Antidotes are available for some poisons.
• Examples- By specific antagonism –isoprenaline for beta blockers
chelation- desferrioxamine for iron
reduction –methylene for dapsone