Poisoning Ali Alhaboo Assisstant Professor of Pediatrics PICU consultant Overview of pediatric poisoning, diagnosis and treatment Summary of the most encountered poisoning Epidemiology Most of the toxic exposures have only minor or no effect on the child 85% - 90% of pediatric poisoning occurs in < 5 yrs of age (accidental) usually single agent 10% - 15% in older age, mainly adolescents (intensional) usually several agents 3-4% of PICU admission are because of toxic exposures ED referral recommendations Serious exposures Younger than 6 months History of previous toxic ingestion Questionable or unreliable history Routes of exposures in children Ingestion Inhalation Skin exposure Common agents Cosmetics and personal care product Cleaning substance: flash is more serious than Clorox because it melts the esophagus and destroys it. Plants Analgesics: Paracetamol is the commonest cause of poisoning in children ( high doses more than 200 mg/kg) Note: OCPs are not harmful. Less common but serious Fe supplements: 2nd most common in females. Antidepressants Anti-diabetics: causing severe hypoglycemia and LOC. Antihypertensive. Pesticides: organophosphates. Hydrocarbon History Identification of the toxic agent Age of the child. What has been done to the child. The time elapsed and the dose taken (if it was unknown consider it serious). The route of exposure Underlying medical problems The clinical effect (with few exceptions rapidity of symptoms progression correlates with severity of poisoning.e.g., acetaminophen) ? Trauma in addition to ingestion (change in LOC). Physical Exam Weight (determine ? mg/kg ingested) Vital signs Check odors from the breath, skin, hair, clothing Thorough exam for any abnormal finding General presentations suggestive of poisoning Severe vomiting, diarrhea Acutely disturbed consciousness Abnormal behavior Seizure unusual odor Shock Arrhythmias Metabolic acidosis Cyanosis Respiratory distress Clinical clues to the diagnosis of unknown poisoning Odor Skin Mucous membranes Temperature Blood pressure Pulse rate Respiration Pulmonary edema CNS GI system Odor Signs or symptom Poison Bitter almond Acetone Oil of wintergreen Garlic Alcohol Petroleum Cyanide Isopropyl alcohol, methanol, acetylsalicylic acid Methyl salicylate Arsenic, phosphorous, thallium, organophosphates Ethanol, methanol Petroleum distillates Skin Sign or symptom Cyanosis Red flush Sweating Dry Poison Methemoglobinemia secondary to nitrates, nitrites, phenacetin, benzocaine Carbon monoxide, cyanide, boric acid, anticholenergics Amphetamines, LSD, organophosphates, cocaine, barbiturates Anticholenergics Mucous membranes Signs or symptoms Dry Salvation Oral lesions Lacrimation Poison Anticholenergics Organophosphates, carbamates Corrosives, paraquat Caustics, organophosphates, irritant gases Temperature Signs or symptoms Hypothermia Hyperthermia Poison Sedatives hypnotics, ethanol, carbon monoxide, clonidine, phenothiazines, TCAs Anticholenergics, salicylates, phenothiazines, cocaine, TCAs, amphetamines, theophylline Blood Pressure Signs or symptoms Hypertension Hypotension Poison Sympathomimitics (especially phenylpropanolamine in overthe-counter cold remedies), organophosphates, amphetamine, phencyclidine, cocaine Antihypertensives, barbiturates, benzodiazepines, beta blockers, Ca++ channel blockers, clonidine, TCAs Pulse rate Signs or symptoms Bradycardia Tachycardia Arrhythmias Poison Digitalis, sedatives hypnotics, beta blockers, ethchlorvynol, opioids Antichlonergics, sympathomimetics, amphetamines, alcohol, aspirin, theophylline, cocaine, TCAs Anticholenergics, TCAs, organophosphates, digoxin, phenothiazines, betablockers, carbon monoxide, cyanide Respirations Signs or symptoms Depressed Tachypnea Kussmaul’s sign Wheezing Pneumonia Pulmonary edema Poisoning Alcohol, opioids, barbiturates, sedatives/hypnotics, TCAs, paralytic shelfish poisoning Salicylates, amphetamines, carbon monoxide Methanol, ethylene glycol, salicylates Organophosphates Hydrocarbons Aspiration, salicylates, opioids, sympathomimetics CNS Sings or symptoms Seizures Fasciculation Hypertonus Myoclonus, rigidity Poison Camphor, carbon monoxide, cocaine, amphetamines, sympathomimetics, anticholenergic, aspirin, pesticides, organophosphates, lead, PCP, phenothiazines, INH, lithium, theophylline, TCAs Organophosphates Anticholenergics, phenothiazines Anticholenergics, phenothiazines, haloperidol CNS Sings or symptoms Poison Delirium/psychos Anticholenergics, is phenothiazines, sympathomimetics, alcohol, PCP, LSD, marijuana, cocaine, heroin, heavy metals Alcohol, anticholenergics, Coma sedative hypnotics, opioids, carbon monoxide, TCAs, salicylates, organophosphates Organophosphates, Weakness, carbamates, heavy metals paralysis EYE Signs or symptoms Miosis Mydriasis Blindness Nystagmus Poison Opioids, phenothiazines, organophosphates, benzodiazepines, barbiturates, mushrooms, PCP Antichlenergics, sympathomimitics (cocaine, amphetamines, LSD, PCP), TCA, methanol, glutethimide Methanol Diphenylydantoin, barbiturates, carbamazepine, PCP,carbon monoxide, glutethimide, ethanol GI Sings or symptoms Vomiting, diarrhea Poison Iron, phosphorous, heavy metals, lithium, mushroom, fluoride, organophosphates Toxidromes of Common Pediatric Poisonings Toxin Anticholenergi cs (atropine, scopolamine, TCAs, antihistamines, mushrooms) Cholenergics (organophosph ates and carbamate insecticides) Signs or symptoms Fever, flushed, warm, dry skin, dry mouth, mydriasis, tachycardia, arrhythmias, agitation, hallucinations, coma Salivation, lacrimation, sweating, bronchorrhea, emesis, diarrhea, miosis, bradycardia, bronchospasm with wheezing, confusion, weakness, fasciculations, coma Toxidromes of Common Pediatric Poisonings Toxin Opiates Narcotic withdrawal Signs or symptoms Hypothermia, hypoventilation, hypotension, bradycardia, miosis, coma Nausea, vomiting, diarrhea, abdominal pain, lacrimation, diaphoresis, mydriasis, tremor, irritability, delirium, seizure Toxidromes of Common Pediatric Poisonings Toxin Signs or symptoms Sedative/ hypnotics TCAs Hypothermia, hypoventilation, hypotension, tachycardia, coma Coma, convulsions, arrhythmias, anticholenergic manifestations Phenothiazines Hypotension, tachycardia, dystonia syndrome, oculogyric crisis, trismus, ataxia, coma, anticholenergic manifestations Toxidromes of Common Pediatric Poisonings Toxin Salicylates Iron Sympathomimetics (amphetamines, phenylpropanolamie , ephedrine, caffeine, cocaine, aminophylline) Signs or symptoms Fever, hyperpnea, vomiting, tinnitus, acidosis, seizure, lethargy, coma Hyperglycemia, shock, hemorrhagic diarrhea Tachycardia, arrhythmias, psychosis, hallucinations, nausea, vomiting, abdominal pain Laboratory tests Qualitative toxicology screening is rarely as helpful as Hx and PE in determining the cause Best done on urine and gastric aspirate samples Quantitative serum level of known drug is indicated when it can enable prediction of toxicity or determination of treatment ABGs with respiratory symptoms and to assess acid-base balance Blood glucose from 1st sample Liver and kidney function (metabolism&excretion) Serum electrolytes (anion gap, renal function) Serum osmolar gap CBC (anemia, hemolysis) DIC panel when suspected Routine Laboratory Tests That Can Suggest Poisoning - Decreased hemoglobin saturation with normal or increased PO2 - Elevated anion gap metabolic acidosis - Elevated osmolar gap - Hyperglycemia - Hypoglycemia - Hypocalcemia Agents causing methemoglobin (nitrates, nitrites, benzocaine) Methanol, ethanol, isopropyl alcohol, ethylene glycol, salicylates, isoniazid, paraldehyde, toluene, iron, phenformin, CO, cyanide Ethanol, methanol, isopropyl alcohol, ethylene glycol Salicylates, isoniazid, organophosphates, iron Insulin, ethanol, isopropyl alcohol, isoniazid, phenfomin, acetaminophen, salicylates, oral hypoglycemic agents Ethylene glycol, methanol - Oxalic acid crystalluria Ethylene glycol - Ketonuria Isopropyl alcohol, ethanol, salicylates Drugs with clinically useful serum level quantitation Acetaminophen Anticonvulsants Carbon monoxide Cholinesterase Digoxin Ethanol Ethylene glycol Heavy metals Iron Isopropanol Lead Lithium Methanol Methemoglobin Salicylate Theophylline Radiography indications If head trauma cannot be excluded (skull and cervical spine film, head CT if physical findings are suggestive) If child abuse is suspected (skeletal survey) If patient is having respiratory distress (CXRay) If radiopaque substance is suspected Common substances that are radiopaque (CHIPES) Chloral hydrate Heavy metals Iodine Phenothiazine Enteric coated and extended release medication Salt tablets (in Fe ingestion, serial films indicate movement and elemination) Steps of management First you have to start with ABC, if hypotensive repeat ABCs. Check the O2 saturation Glucocheck for hypoglycemia. If hypoglycemic give 5-10% dextrose (not higher than that because it might harm the vessel). Dose: 2-5 ml/Kg. Do toxicology screen. LFT, U/E, RFT, coagulation profile (PT is the first to be affected, if it was elevated give FFP or vitamin K) and albumin. Give antidote as early as possible if available. (N-acetylcesteine is the antidote for paracetamol. Desfuroxemine is the antidote for iron. Transfer the patient to the ICU, if there is no bed keep him in the ER. Treatment Airway: patency and protective mechanisms (if absent, use nonspecific antidote of D10W 2cc/kg and Naloxone 0.1mg/kg; if no response intubate. Breathing: clear secretions, give O2, continuous O2 saturation, ABGs, CXRay, treat wheezing and stridor, early controlled intubation prefered Circulation: frequent VS, continuous CR monitor, fluids for low BP, do baseline ECG, watch for arrythmias, PALS guidelines Neurologic status: frequent assessments, the most common cause to admit intoxication to PICU, use nonspecific antidotes, watch for seizures, rule out metabolic causes of seizure GI decontamination Emesis-Syrup of Ipecac Therapy Dosage in < 1 yr 10 ml Young children 15 ml Adolescents, adults 30 ml may repeat once Contraindications Petroleum distillates Caustic agents Impaired consciousness, seizures Rapid coma-inducing agents (e.g., propoxyphene, TCAs) We use lavage when the patient presents early and is stable. If late presentation where the drug has already passed to the duodenum use the activated charcoal( through a NG tube) where up to 1 million particles can adsorb to the medication. GI decontamination Therapy Lavage Large bore orogastric hose (28 Fr for young children, 36-40 Fr for adolescents) Left recumbent Trendelenburg’s position to reduce the risk of aspiration Lavage with saline or 1/2 NS until return is clear Most successful for toxins that delay gastric emptying (aspirin, iron, anticholinergics) and for those forming concretions (iron, salicylates, meprobamate) Contraindications Corrosive caustic agents Controversial in petroleum distillates ingestion Stupor or coma unless airway is protected GI decontamination Therapy Activated Charcoal Administer in all cases after emesis. It should be only given for conscious patients. Dosage: - Children 1 g/kg - Adults 50-100 g Contraindications Corrosive agents: charcoal interfers with GI endoscopy Most feared complication is aspiration leading to severe pneumonitis and ARDS GI decontamination Therapy Cathartics MgSO4 250 mg/kg/dose P.O.(max dose 30 g) in 10%-20% solution Sorbitol magnesium citrate Repeat above doses every 2-4 hrs until passage of charcoal stained stools Contraindications Avoid MgSO4 in renal failure Enhanced elimination Forced diuresis by administering 2-3 times the maintenance fluid to achieve U.O = 2-5 cc/kg/hr (contraindicated in pulmonary or cerebral edema and renal failure) Urinary alkalinization to eleiminate weak acids(salicylates, barbiturates and methotrexate), can be achieved by adding NaHCO3 to the IV fluids, the goal is urine pH of 7-8 Serum alkalinization in TCAs toxicity Hemodialysis in low molecular weight substances with low volume of distribution and low binding to plasma proteins Hemoperfusion, protein binding is not a limitation Antidotal Therapy Only a small proportion of poisoned patients are amenable to antidotal therapy Only a few poisoning is antidotal therapy urgent (e.g., CO, cyanide, organophosphate and opioid intoxication) Specific Intoxications and Their Antidotes Poison Antidote Indications Acetaminophen N-Acetylcysteine (Mucomyst) Serum level in “probable” hepatotoxic range Anticholenergics Physostigmine SVT with hemodynamic compromise Beta blockers Glucagon Isopreterenol, dopamine, epinephrine Flumazenil Bradycardia Bradycardia Benzodiazepines Symptomatic intoxication Carbon monoxide O2 Level > 5-10% Cyanide Amyl nitrite, sodium nitrite, sodium thiosulfate Symptomatic intoxication Digitalis Specific Fab antibodies Specific Intoxications and Their Antidotes Poison Antidote Indications Ethylene glycol Ethanol Osmolar gap and metabolic acidosis or Serum level >20 mg/dl regardless of symptomatology Iron salts Desferoxamine Symptomatic patients Serum iron > 350 g/ml or > TIBC Positive deferoxamine challenge test Isoniazid Pyridoxine (vit B6) Methanol Ethanol Metabolic acidosis and elevated osmolar gap regardless of symptoms Methemoglobinemi Methylene blue a producing agents Symptomatic poisoning Methemoglobin level > 30-40 % Narcotics Naloxane Symptomatic intoxication Organophosphate insecticides Atropine Pralidoxime Cholenergic crisis Fasciculation and weakness Phenothiazines Diphenhydramine Symptomatic intoxication (oculogyric crisis) Acetaminophen (paracetamol) poisoning Nausea, vomiting and malaise for 24 hrs Improvement for 24-48 hrs Hepatic dysfunction after 72 hrs (AST is the earliest and most sensitive) Death may occur from fulminant hepatic failue Toxicity likely with ingestion of > 150 mg/kg Rumack-Matthew nomogram defines the risk of hepatic damage in acute intoxication (level at 4 hrs post ingestion) Acetaminophen (paracetamol) poisoning management GI decontamination Activated charcoal within 4 hrs of ingestion Antidote N-acetylcysteine is most effective if given within 8 hrs of ingestion, total of 17 doses, P.O or IV (However, NAC should be given even with > 24hrs presentation) NAC should be given if serum acetaminophen level is either in the “possible” or “probable” hepatotoxic range Salicylate toxicity Clinical manifestations Common Fever Sweating Nausea Vomiting Dehydration Hyperpnea Tinnitus Seizures Coma Coagulopathy Uncommon Respiratory depression Pulmonary edema SIADH Hemolysis Renal failure Hepatotoxicity Cerebral edema Laboratory findings in salicylate toxicity Metabolic acidosis Respiratory alkalosis Mixed (resp alkalosis &metabolic acidosis) Hyperglycemia, Hypoglycemia Hypernatremia, hyponatremia Hypokalemia Hypocalcemia Prolonged PT Ketouria Prediction of acute salicylate toxicity Ingested dose can predict the severity < 150 mg/kg toxicity not expected (asymptomatic) 150-300 mg/kg toxicity mild to moderate (mild to moderate hyperpnea, lethargy or excitability) 300-500 mg/kg severe toxicity (severe hyperpnea, coma or semicoma, sometimes with convulsions) Management of salicylate toxicity GI decontamination Correct dehydration and force diuresis Urine alkalinization and acidosis correction with IV NaHCO3 Monitor electrolytes, glucose, calcium Vit K for hemorrhagic diathesis Decrease fever with external cooling Hemodialysis for severe intoxication (Dome nomogram), severe acidosis unresponsive to NaHCO3, renal failure, pulmonary edema and severe CNS manifestation