PoisoningAli Alhaboob
Assisstant Professor of PediatricsPICU 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 Less common but serious
Cosmetics and personal care product
Cleaning substances
Plants Analgesics
Fe supplements Antidepressants Pesticides Hydrocarbon
History Identification of the toxic agent The time elapsed 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 Poison
Cyanosis
Red flush
Sweating
Dry
Methemoglobinemia secondary to nitrates, nitrites, phenacetin, benzocaine
Carbon monoxide, cyanide, boric acid, anticholenergics
Amphetamines, LSD, organophosphates, cocaine, barbiturates
Anticholenergics
Mucous membranes
Signs or symptoms Poison
Dry
Salvation
Oral lesions
Lacrimation
Anticholenergics
Organophosphates, carbamates
Corrosives, paraquat
Caustics, organophosphates, irritant gases
Temperature
Signs or symptoms Poison
Hypothermia
Hyperthermia
Sedatives hypnotics, ethanol, carbon monoxide, clonidine, phenothiazines, TCAs
Anticholenergics, salicylates, phenothiazines, cocaine, TCAs, amphetamines, theophylline
Blood Pressure
Signs or symptoms Poison Hypertension
Hypotension
Sympathomimitics (especially phenylpropanolamine in over-the-counter cold remedies), organophosphates, amphetamine, phencyclidine, cocaine
Antihypertensives, barbiturates, benzodiazepines, beta blockers, Ca++ channel blockers, clonidine, TCAs
Pulse rate Signs or symptoms Poison
Bradycardia
Tachycardia
Arrhythmias
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 Poisoning Depressed
Tachypnea
Kussmaul’s sign
Wheezing Pneumonia Pulmonary
edema
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 Poison Seizures
Fasciculation Hypertonus Myoclonus,
rigidity
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/psychosis
Coma
Weakness, paralysis
Anticholenergics, phenothiazines, sympathomimetics, alcohol, PCP, LSD, marijuana, cocaine, heroin, heavy metals
Alcohol, anticholenergics, sedative hypnotics, opioids, carbon monoxide, TCAs, salicylates, organophosphates
Organophosphates, carbamates, heavy metals
EYE
Signs or symptoms Poison Miosis
Mydriasis
Blindness Nystagmus
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 Poison
Vomiting, diarrhea
Iron, phosphorous, heavy metals, lithium, mushroom, fluoride, organophosphates
Toxidromes of Common Pediatric Poisonings
Toxin Signs or symptoms Anticholenergi
cs (atropine, scopolamine, TCAs, antihistamines, mushrooms)
Cholenergics (organophosphates and carbamate insecticides)
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 Signs or symptoms
Opiates
Narcotic withdrawal
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
Phenothiazines
Hypothermia, hypoventilation, hypotension, tachycardia, coma
Coma, convulsions, arrhythmias, anticholenergic manifestations
Hypotension, tachycardia, dystonia syndrome, oculogyric crisis, trismus, ataxia, coma, anticholenergic manifestations
Toxidromes of Common Pediatric Poisonings
Toxin Signs or symptoms Salicylates
Iron
Sympathomimetics (amphetamines, phenylpropanolamie, ephedrine, caffeine, cocaine, aminophylline)
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 hemoglobinsaturation with normalor increased PO2
Agents causing methemoglobin (nitrates,nitrites, benzocaine)
- Elevated anion gapmetabolic acidosis
Methanol, ethanol, isopropyl alcohol,ethylene glycol, salicylates, isoniazid,paraldehyde, toluene, iron, phenformin,CO, cyanide
- Elevated osmolar gap Ethanol, methanol, isopropyl alcohol,ethylene glycol
- Hyperglycemia Salicylates, isoniazid,organophosphates, iron
- Hypoglycemia Insulin, ethanol, isopropyl alcohol,isoniazid, phenfomin, acetaminophen,salicylates, oral hypoglycemic agents
- Hypocalcemia 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)
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 decontaminationEmesis-Syrup of Ipecac
Therapy Contraindications Dosage in < 1 yr 10
ml Young children 15
ml Adolescents,
adults 30 ml
may repeat once
Petroleum distillates Caustic agents Impaired
consciousness, seizures
Rapid coma-inducing agents
(e.g., propoxyphene, TCAs)
GI decontaminationLavage
Therapy Contraindications 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)
Corrosive caustic agents
Controversial in petroleum distillates ingestion
Stupor or coma unless airway is protected
GI decontamination Activated Charcoal
Therapy Contraindications
Administer in all cases after emesis
Dosage: - Children 1 g/kg - Adults 50-100 g
Corrosive agents: charcoal interfers with GI endoscopy
GI decontamination Cathartics
Therapy Contraindications
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
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 IndicationsAcetaminophen N-Acetylcysteine
(Mucomyst)Serum level in “probable”hepatotoxic range
Anticholenergics Physostigmine SVT with hemodynamiccompromise
Beta blockers Glucagon BradycardiaIsopreterenol,dopamine,epinephrine
Bradycardia
Benzodiazepines Flumazenil Symptomatic intoxication
Carbon monoxide O2 Level > 5-10%
Cyanide Amyl nitrite,sodium nitrite,sodium thiosulfate
Symptomatic intoxication
Digitalis Specific Fabantibodies
Specific Intoxications and Their AntidotesPoison Antidote IndicationsEthylene glycol Ethanol Osmolar gap and metabolic acidosis or
Serum level >20 mg/dl regardless ofsymptomatology
Iron salts Desferoxamine Symptomatic patientsSerum iron > 350 g/ml or > TIBCPositive deferoxamine challenge test
Isoniazid Pyridoxine(vit B6)
Methanol Ethanol Metabolic acidosis and elevatedosmolar gap regardless of symptoms
Methemoglobinemia producing agents
Methylene blue Symptomatic poisoningMethemoglobin level > 30-40 %
Narcotics Naloxane Symptomatic intoxication
Organophosphateinsecticides
AtropinePralidoxime
Cholenergic crisisFasciculation and weakness
Phenothiazines Diphenhydramine Symptomatic intoxication (oculogyriccrisis)
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 toxicityClinical manifestationsCommon Uncommon
Fever Sweating Nausea Vomiting Dehydration Hyperpnea Tinnitus Seizures Coma Coagulopathy
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