ACUTE POISONING - MANAGEMENT Ayman M. Kamaly, MD Professor of Anesthesiology Ain Shams

INTRODUCTION Acute poisoning is a common medical emergency in any country. The exact incidence of this problem in our country remains uncertain.

For effective management of an acutely poisoned victim, 5 steps are required: I. I. Resuscitation and initial stabilization II. II. Diagnosis of type of poison III. III. Nonspecific therapy IV. IV. Specific therapy V. V. Supportive care

I.Resuscitation and Initial Stabilization Initial management: ABCDs A Airway B Breathing C Circulation

Lessons from History... A young princess ate part of an apple given to her by a wicked witch

She was found comatose and unresponsive, as if in a deep sleep, Airway positioning and mouth to mouth ventilation were performed, and she was fully recovered.

Lessons: Best Antidote = Good Supportive Care Best Antidote = Good Supportive Care (Love’s first kiss) Airway Airway issues is a still the major cause of morbidity in toxicology as in other aspects of emergency.

Circulation = Plumbing Pump working? Pump working?  Inotrope Enough volume (is it primed)? Enough volume (is it primed)?  Hypovolemia?  IV fluid challenge Adequate resistance (no leaks)? Adequate resistance (no leaks)?  Inadequate vascular resistance?  Norepinephrine, phenylephrine

Initial management: ABCDs Treat problems as you find them!! A Airway, B Breathing, C Circulation, D Drugs, D Decontamination, D Detoxication, D Disability – GCS/AVPU and Pupils, DGLUCOSE. DON’T EVER FORGET GLUCOSE.

Don’t forget GLUCOSE A stroke is never a stroke until it’s had 50 of D50 “A stroke is never a stroke until it’s had 50 of D50” ??! Empiric administration of dextrose??! Check the blood sugar using a reliable bedside test ONLY80 Administer dextrose ONLY if the RBS is <80 mg/dl.

II.Diagnosis of Type of Toxin ? What? ? When? ? How much? (mg/kg) ? What else? ? Why? A) History Be a Detective

Collateral history – Paramedics – Family / friends – Notes !!! – Look in pockets – carefully!!! Look for Clues

B) Examination

Investigations All Patients – Glucose – Paracetamol & Salicylate As indicated – LFT – RFT, Lytes – Co-ag / INR – CK – ABG / VBG Urine toxicology screen

Investigations – Pinkish urine --->>> phenothiazine, – Chocolate colored --->>> met-hemoglobinaemia, – Oxalate crystals --->>> ethylene glycol, – Ketonuria (without metab. changes) --->>> Salicylate

Investigations Abdominal X-Ray (Radiopaque Toxins) – Chloral hydrate, iodides, – Heavy metals, iron, – Sustained release pills, – Solvents (Chloroform, CCL4)

Aim: Aim: – Reduce absorption – Reduce absorption of poison from the gut, – Increase excretion – Increase excretion of absorbed poison. III.Non-Specific Therapy

1) Emesis Ipecac Syrup of Ipecac Amount of recovered toxin is highly variable ONEhour Effective within ONE hour Contraindicated: – Comatose/Convulsing – Ingested corrosive or hydrocarbon* A. Reducing absorption

2) Gastric Lavage Lt Lat Position + head down to prevent aspiration & ↓ pushing lavage into duodenum. If unconscious  ETT 1-2hours Effective within 1-2 hours Contraindicated: – Strong corrosive or – Volatile hydrocarbons

3) Activated Charcoal Small particle size & enormous surface area, Bind most drugs & toxins, Dose: 1 g/kg Exceptions: – Iron, Lithium, Metals, – Methanol, Ethanol, Hydrocarbons, – DDT

Activated Charcoal (cont.) More effective than Ipecac, Gastric Lavage First choice for most Over Doses

4) Whole Bowel Irrigation Polyethylene glycol (2 L/hr) Isotonic soln. of Polyethylene glycol (2 L/hr) Not absorbed from intestine Not absorbed from intestine (  mechanical flush) Good for: – Iron, Lithium, – Sustained-release pills, – Foreign bodies, – Drug “packets”

1)Forced Alkaline Diuresis Principle: Principle: Renal tubular epith is impermeable to ionized (+) molecules. If the urinary pH is changed so as to produce more of ionized form, it is trapped in the tubular fluid & is excreted in the urine. Useful in: – Salicylates, – Phenobarbital, – Lithium B. Increasing Excretion

Forced Alkaline Diuresis (Cont.) Method: Method: – D5% - ½ NS + bicarbonate mEq/L to produce a urine output of 3-6 ml/kg/hr & a urine pH – Diuretics are often needed to maintain high urine flows. – KCl is added to prevent ↓K +, Contraindications: Contraindications: – Shock, – Hypotension, CHF, – Renal failure

2) Multiple-Doses Activated Charcoal 1 g/kg/1-4 hrs To maintain intestinal toxin conc. near-zero (Gastrointestinal Dialysis). Indicated in toxins with : – Long ½ life, Digoxin, Phenobarbitals, Theophylline – Enterohepatic circulation ( Digoxin, Phenobarbitals, Theophylline), – Sustained-release preparations, – Massive toxin dose to be effectively adsorbed by single charcoal dose

3) Dialysis (Peritoneal/Hemo) H 2 O soluble & Low MW For H 2 O soluble & Low MW compounds. Useful in: – Ethanol, Methanol, – Salicylates, – Theophylline, – Ethylene glycol, – Phenobarbital – Lithium

IV.Specific Therapy

Try to maintain functions of CNS, CVS, Renal, … Care for coma, seizures, hypotension, arrhythmias, hypoxia, … V.Supportive Therapy

Cutaneous, Ocular Exposure to toxins could be through routes other than ingestion (Cutaneous, Ocular) NOT available for every toxin Antidotes are NOT available for every toxin

However; when Antidote is Present the effect is Dramatic However; when Antidote is Present the effect is Dramatic

clean !! The 1 st sample of gastric lavage should be collected in “clean” container (Contamination !!). sealed Container should be sealed using a glue paper before sending for toxicological screening. Legal Aspects

After sealing Blood & Urine collection tubes and bottles, pt’s information should be written on the labels & the juncture between the cap & the bottle. !! POLICE should be informed !!

Clinical Scenarios

Paracetamol Very common: 40% poisons admissions Often asymptomatic Can be lethal – deaths/year 4 hours Check blood level at 4 hours Two treatment lines normal and high risk

Prescott Nomogram

Paracetamol metabolism Metabolised by: – Glucuronidation (60%), – Sulphation (35%) – Oxidation (10%) by Cytochrome p450 produces NAPQI (toxic  hepatocellular necrosis) glutathione NAPQI detoxified by conjugation with glutathione.

High Risk pt. Increased oxidation pathway (enzyme induction) – Chronic alcohol use – Drugs Reduces glutathione stores – Malnutrition – Eating disorders – Chronic liver disease

N-Acetylcysteine 8hours Most effective within 8 hours Precursor for glutathione production !! Can cause anaphylactoid reactions !! Consider starting before paracetamol result if: – Presenting > 8 hrs & > 150mg/kg taken – Other accompanying overdose.

Patient 1 20 year old woman who takes a handful of paracetamol tablets No drug history No alcohol use Fit and well Blood level is 80mg/L after 4 hrs.

No need to treat Patient is not high risk Level at 4 hours is below even the high risk line

Patient 2 70 year old man Takes 20 paracetamol 6 hours before presenting Alcoholic No drug history Blood level 100mg/L

Treat High risk patient Level above the high risk line

Patient 3 17 year old epileptic 25 tab Panadol 2 hours before attendance Taking carbamazepine Blood level at 4 hours is 120mg/L

Treat High risk patient Level above the high risk line

Patient 4 35 year old man who presents after taking 24 paracetamol over a period of 24 hours No drug history Fit and well Blood level 20mg/L

Treat Staggered overdoses are difficult Level is above the treat-line in context to time Need to monitor Liver function, clotting and renal function May need discussing with Liver Unit if abnormal

Some Famous Historic Poisonings

Thank You.. !!