Principles of Managing the Poisoned or Overdosed Patient Dr. Seyed Reza Mousavi Assistant professor of MUMS

Most Commonly Reported Exposures in Adolescents and Adults, 2004 1. Analgesics 2. Sedatives, hypnotics, antipsychotics 3. Cleaning substances 4. Antidepressants 5. Bites and envenomation 6. Cardiovascular drugs 7. Alcohols 8. Pesticides 9. Food products, food poisoning 10. Cosmetics and personal care products

The common cause of acute poisoning

Get vital sign and tests H Head to toes examination I ACLS guideline Modified A Airway Antidote B Breathing Behavioral control C Circulation Coma antidotes D Drug Drug elimination E Evaluation Exposure F Fluid management G Get vital sign and tests H Head to toes examination I Initiate consultation Advanced Cardiac Life Support (ACLS)

Assessment of the Poisoned Patient Initial assessment involves obtaining: A detailed history of the time and route of exposure The substance or substances involved The estimated amount of toxin taken Prehospital or emergency department interventions

Toxidromes A toxic syndrome, or “toxidrome,” is a set of characteristic signs and symptoms associated with a certain category of poisons. The 4 most common toxidromes are narcotic, sympathomimetic, cholinergic, and anticholinergic.

Anticholinergic Cholinergic Sympathomimetic Narcotic Flushing Salivation Hypertension Hypoventilation Tachycardia Lacrimation Bradycardia Mydriasis Urination Tremor Decreased mental status Dry skin Defecation Excitation Hypotension Urinary retention Gastrointestinal upset Seizures Hypothermia Psychosis Emesis Diaphoresis Miosis Bronchorrhea

Laboratory Evaluation Serum glucose Electrolyte levels Blood gas analysis and anion gap calculation Renal and hepatic function tests Toxicologic screen tests

Toxicological Tests urine blood Qualitative (present/absent) Quantitative (drug levels) Drugs with a large volume of distribution Drugs with a small volume of distribution Salicylates phenotiazine TCA Barbiturates Benzodiazepines Morphine, Tramadol, Methadone Cannabis, PCP Amphetamine, Methamphetamine, MDMA Cocaine Paraquat Arsenic,Talium Acetaminophen Iron Lithium Digoxin Theophylline Phenobarbital Methanol, Ethylene glycol Lead Carboxyhemoglobin Cholinesterase RBC PCP: Phencyclidine, angel dust

Other Diagnostic Studies Abdominal X Ray: Enteric-coated pills Lead paint chips Button batteries The drug-filled condoms of “body packers.” Iron tablet

ECG: cause Abnormal Normal (milliseconds) B blocker Ca channel blocker Digoxin PR prolongation 120 - 200 The PR Interval Cyclic antidepressants, Quinidine, Phenothiazines, Amantadine, Diphenhydramine, Carbamazepine, Cocaine A widening of the QRS complex 60 - 120 The QRS Complex Cocaine, Adrenergic agonists, Ergot alkaloids ST elevation The ST Segment QTc prolongation >440 The QT Interval

Management of the Poisoned Patient When caring for any poisoned patient, 3 basic patient goals should be kept in mind: Limit absorption Enhance elimination Manage the complications

The extent to which any one of these goals can be accomplished depends on: The substance involved The route of contamination The time since exposure The amount of toxin taken

Limit Absorption Administration of Ipecac Syrup Gastric lavage Activated charcoal(1 g/kg) + Sorbitol(1 ml/kg) Whole bowel irrigation (500 mL - 2000 mL /h)

Gastric lavage Indications include: 1) symptomatic patients who present within 1 hour of ingestion of a toxic substance 2) symptomatic patients who have ingested an agent that slows gastrointestinal motility 3)patients who have ingested a sustained-release Medication 4) Patients who have ingested massive or life- threatening amounts of a substance

Activated charcoal Ingested Substances Not Well Adsorbed by Activated Charcoal: Heavy metals Cyanide Iron Potassium Hydrocarbons Organic solvents Caustic agents Alcohols

Activated charcoal + sorbitol Indications include: 1) Patients who have ingested a potentially toxic amount of a poison

whole bowel irrigation This is done by administration of large doses of polyethylene glycol electrolyte solutions (500 mL - 2000 mL /h) Indications include: 1) Iron bezoars 2) Sustained-release or Enteric-coated medications 3) Ingested packets of illicit drugs

Enhance Elimination Hemodialysis Multiple-dose activated chrcoal Urinary Alkalinization

Hemodialysis

Hemodialysis Mechanism of action: Toxicants diffuse through a semipermeable membrane down a concentration gradient from blood to dialysate. This procedure eliminates those poisons with: Low molecular weight(< 500 daltons) Limited protein binding Small volume of distribution(< 1 L/kg)

Hemodialysis…

Hemodialysis… Indications: Ethanol, Methanol(>25 mg/dl), Ethylene glycol (>25 mg/dl) Bromide Chloral hydrate Lithium(>4mEq/L), Potassium Procainamide Quinidine Salicylate (>100 mg/dl) Theophyline (>90 μg/ml) Phenobarbital(>100 mg/dl)

Hemodialysis… Indications: Severe intoxication with a substance normally eliminated by the kidney in the setting of renal failure. Severe acidosis where the patient is unresponsive to therapy.

Hemodialysis… Adverse effects: Hypotension Fluid & electrolyte disturbance Seizure

Hemodialysis… Pitfalls: Ethanol & Femopizole eliminated with hemodialysis. Blood level of toxicants may rebound after termination of dialysis. Hemodialysis cannot be performed in severely hypotensive patients.

Multiple-dose activated chrcoal

Multiple-dose activated chrcoal… Mechanism of action: Repeated administration of activated charcoal interrupting enterohepatic recirculation and gasterointestinal dialysis The suggested dose is 0.5 g/kg every 2 to 4 hours, at least thrice. Most effective for drugs that: Undergo substantial enterohepatic recirculation Small volume of distribution(< 1 L/kg) Limited protein binding Which are adsorbed by activated charcoal Repeated administration of activated charcoal may enhance of the toxicant by adsorbing drug or metabolite that is secreted in bile(interrupting enterohepatic recirculation). Toxicant may diffuse across the intestinal wall down the concentration gradiant from mesenteric vasculature into the gasterointestinal lumen, where it can adsorbed by activated charcoal(gasterointestinal dialysis)

Multiple-dose activated chrcoal… Indications: Theophilne Phenobarbital Phenytoin Valporate Carbamazepine Quinine Dapson Cardiac glycosides

Urinary Alkalinization

Urinary Alkalinization… Mechanism of action: Sodium bicarbonate is administrated to raise the urine pH above 7.5 Drugs in which the parent compound is a weak acid undergo significant urinary excertion because ionized forms do not readily cross cell membranes.

Urinary Alkalinization… Indications: Urinary alkilazation should be used for mild to moderate intoxication only. Salicylate Phenobarbital Methotroxate Rhabdomyolysis

Urinary Alkalinization… Contraindication: Renal failure Adverse effects: Volume overload Alkalosis Hypokalemia hypomagnesemia

Manage Complications A decreasing level of consciousness Careful airway protection Seizures Benzodiazepines High temperature Benzodiazepines

Antidote Administration Naloxone Opioid toxicity Oxygen Carbon monoxide poisoning N-acetylcysteine Acetaminophen Dextrose Hypoglycemic drug Ethanol Methanol & Ethylene glycol Glucagon B-blocker Amyl nitrate Cyanide Atropine Organophosphate BAL, Penicillamine, EDTA Heavy metal Antivenins Snake bite & Scorpion sting

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