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THE SPIRAL CURRICULUM General Principles in the Emergency Management of the Acutely Poisoned Patient (one more time) Allan R. Dionisio MD What are the 6 principles in the approach to the poisoned patient? General Approach Emergency stabilization Clinical evaluation Decontamination Elimination of absorbed substance Administration of antidotes Supportive therapy and observation When should you not give oxygen to a poisoned patient? What is the IV fluid of choice in treating poisoned patients? Emergency Stabilization Maintain adequate airway Provide adequate oxygenation/ventilation Exceptions: watusi. paraquat Maintain adequate circulation Starting fluids: NSS in adults, 0.3 NaCl in children If a previously well patient has seizures, and he has no history of epilepsy, what medication can be given as a therapeutic trial apart from the usual anticonvulsants? Emergency Stabilization Treat convulsions Diazepam 5mg IV Do NOT mix with D5 containing solutions—the diazepam will crystalize Aspirate until you get blood, then inject the diazepam, then push with plain NSS Seizures of unknown origin--pyridoxine 80120mg/kg What is appropriate dose of naloxone in patients presenting with what appears to be a metabolic coma in the ER? Emergency Stabilization Treat coma D50-50 the single most common cause of decreased sensorium Hypoglycemia is LIFE-THREATENING! Naloxone 2mg IV (pedia 0.1 mg/kg) Textbooks will tell you to give 0.2mg IV—good for pure agonists but NOT EFFECTIVE for mixed agonist/antagonists Thiamine 100mg IV To treat or prevent Wenicke’s encephalopathy Emergency Stabilization Correct metabolic abnormalities Electrolytes Acid-base abnormalities General Approach Emergency stabilization Clinical evaluation Decontamination Elimination of absorbed substance Administration of antidotes Supportive therapy and observation Clinical Evaluation Time of exposure Most ingestions beyond 2 hours are not worth decontaminating Clinical effectiveness of gut decontamination appears to be insignificant beyond 1 hour postingestion Exceptions: meds that slow down gut motility- ex. Loperamide Slow release meds—ex. Verapamil SR Enteric coated preparations—ex. Enteric coated aspirin Clinical Evaluation Mode of exposure—tells you what to decontaminate Intake of other substances always keep co-ingestants in the back of your mind Look for incongruences between ssx and hx Circumstances prior to poisoning Get MULTIPLE testimonies Clinical Evaluation Current medications AND past medical history of patient and family Most suicidals get anything within reach Most children get anything within reach Any home remedies taken Milk makes lipophilic toxicants get absorbed faster (ex. Benzodiazepines) Egg yolk enhances watusi/firecraker absorption Aspiration pneumonia is frequent in kerosene/hydrocarbon ingestions given household emetics What toxicant can smell this way? Bitter almonds Fruity odor Oil of wintergreen Rotten eggs Garlic Mothballs Clinical Evaluation--Odors Bitter almonds--cyanide Fruity odor--DKA, isopropyl alcohol Oil of wintergreen--methylsalicylate Rotten eggs--sulfur dioxide, hydrogen sulfide, Garlic--arsenic, zinc phosphide, watusi Mothballs--camphor Clinical Evaluation--Colors Red skin— Gray gums— Green urine— Blue skin and lips— Cherry red lips— Clinical Evaluation--Colors Red skin—rifampicin, anticholinergics Gray gums—lead, mercury Green urine--formaldehyde Blue skin and lips—methemoglobin Cherry red lips—carbon monoxide LEAD OTHER TOXIC EFFECTS: Abdominal colic Gingival lines Pay attention to autonomic ssx 3 toxicants that can cause hypertension Clinical Evaluation--HPN C T S C A N cocaine theophylline sympathomimetics caffeine anticholinergics nicotine 3 toxicants where hypotension is the prominent effect Clinical Evaluation--Low BP C R A S H clonidine reserpine and other antihypertensives antidepressants sedative-hypnotics heroin and other opiates 3 toxicants that present primarily as bradycardia Clinical Evaluation--Bradycardia P A C E D propranolol and other beta blockers anticholinesterases clonidine, calcium channel blockers ethanol digitalis 3 toxicants that can cause mydriasis Clinical Evaluation--Mydriasis A antihistamines A antidepressants S sympathomimetics I isoniazid A anticholinergics 3 toxicants that present as miosis Clinical Evaluation--Miosis C O P S cholinergics, clonidine opiates, organophosphates phenothiazines, pilocarpine sedative-hypnotics Toxidrome Hot as a hare Dry as a bone Red as a beet Blind as a bat Mad as a hatter Toxidrome D diarrhea, diaphoresis U urinary incontinence M miosis, muscle fasciculations B bradycardia, bronchoconstriction E emesis L lacrimation S salivation Toxidrome Seizures Coma Acidosis Toxidrome Mixed metabolic acidosis and respiratory alkalosis in an unknown poisoning Tinnitus Tachycardia Lab exams 5-10ml heparinized blood 5-10 ml clotted blood 100 ml urine Gastric aspirate General Approach Emergency stabilization Clinical evaluation Decontamination Elimination of absorbed substance Administration of antidotes Supportive therapy and observation Elimination of Poison: External Decontamination Dermal: discard clothing; bathe with alkaline soap Eye: irrigate with free flowing water for 30 minutes Avoid neutralizing solutions in caustic exposures. Protect yourself! Correct dose of activated charcoal and sodium sulfate Elimination of Poison: Gastric Decontamination Insert NGT; Trendelenburg position Lavage with NSS Activated charcoal Adults: 100g in 200ml water Children: 1g/kg as a slurry Sodium sulfate Adults: 15g in 100ml water Children: 250mg/kg as 10% solution in water 2 toxicants where activated charcoal is not effective Elimination of Poison: Gastric Decontamination Contraindications to NGT/lavage Caustics, kerosene less than 1ml/kg, frank convulsions Charcoal Not effective for: alcohol, cyanide, iron, lithium, petroleum distillates Contraindicated in: watusi, caustics 2 contraindications for giving sodium sulfate Elimination of Poison: Gastric Decontamination Sodium sulfate is contraindicated in: caustics, ileus, electrolyte imbalance, patients with heart failure patients with kidney failure Alternative is sorbitol 1-2g/kg General Approach Emergency stabilization Clinical evaluation Decontamination Elimination of absorbed substance Administration of antidotes Supportive therapy and observation Elimination of Poison: Multiple Dose Activated Charcoal Adults: 50g in 150ml water retained in stomach q6h PO or per NGT x 48h Children: 0.5g/kg as a slurry q6h PO or per NGT x 48h Give sodium sulfate every morning to evacuate the charcoal. 3 toxicants where multiple dose charcoal is effective Elimination of Poison: Multiple Dose Activated Charcoal Salicylates Methamphetamine and ecstasy Diazepam and other benzodiazepines Phenobarbital Digoxin Elimination of Poison: Multiple Dose Activated Charcoal Carbamazepine Dapsone Phenobarbital Quinine theophylline Elimination of Poison: Multiple Dose Activated Charcoal Amitriptyline Dextropropoxyphene Digitoxin and digoxin Disopyramide Nadolol Phenylbutazone Phenytoin Piroxicam sotalol When do you alkalinize and when do you acidify the urine? Elimination of Poison: urine pH manipulation Alkalinize for weak acids: Salicylates, barbiturates, INH Acidify for weak bases: Amphetamines, phenytoin, theophylline How do you alkalinize and how do you acidify the urine? Elimination of Poison: urine pH manipulation To alkalinize--Sodium bicarbonate 1mEq/kg/dose until urine pH > 7.5 To acidify--Ascorbic acid 1g (pedia 20mg/kg) IV q6h until urine pH< 5.5 2 pharamacokinetic parameters that say dialysis is possible Elimination of Poison: Dialysis Low volume of distribution Low protein binding Toxin is dialysable Benefit outweighs risks of dialysis 3 dialysable toxicants Elimination of Poison: Dialysis Barbiturates Ethylene glycol INH Lithium Ethanol, methanol, isopropanol Salicylates General Approach Emergency stabilization Clinical evaluation Decontamination Elimination of absorbed substance Administration of antidotes Supportive therapy and observation Antidotes: Pyridoxine (Vit B6) Specific antidote for INH poisoning Give IV bolus dose equal to amount of INH ingested If dose of INH is not known, give 120mg/kg of pyridoxine and repeat as necessary to control seizures As much as 52g has been given safely Antidotes: Pyridoxine Maintain on 10mg/kg/d in 3dd x 6wks If Vit B1/B6 combination, do not give more than 1g of Vit B1 at any one bolus; repeat every 5 minutes until total required B6 is given What is atropine the antidote for? What are the atropinization parameters? Antidotes: Atropine Physiologic antidote for cholinesterase inibitors 1-2mg (pedia 0.01mg/kg) IV q15min until HR > 100 Pupils > 4mm Dry oral mucosa Hypoactive bowel sounds Antidotes: Atropine Once fully atropinized, gradually increase intervals--speed of downloading the dose depends on whether carbamate or organophosphate WOF: hyperpyrexia, tachyarrhythmias, hallucinations, flushing. Stop atropine and hydrate patient until symptoms wear off. What is the antidote for opiate overdose? What is the appropriate dose? Antidotes: Naloxone Specific antidote for opiate poisoning 2mg IV initially. Repeat q5min until awake or until max of 10mg total given Once awake, give 2/3 of the wake up dose as a drip every hour Antidote for benzodiazepine overdose Antidotes: Flumazenil Specific antidote for benzodiazepine overdose Anexate 0.5mg/5ml 0.1mg in 4ml D5W IV over 15 seconds q1min; max of 2mg Maintain on 0.1-0.2mg/hour as IV drip General Approach Emergency stabilization Clinical evaluation Decontamination Elimination of absorbed substance Administration of antidotes Supportive therapy and observation 80% of poisoned patients survive with aggressive supportive therapy alone. Your management is NOT COMPLETE unless you address the PSYCHOSOCIAL factors leading to the poisoning. For suicidals: Counseling Co-mgt with Psych Patients who attempt suicide deserve compassion, not ridicule or condemnation. For accidental poisoning TOXICOVIGILANCE (home, workplace, community) Thank you for listening.
