poisoning ali alhaboob assisstant professor of pediatrics picu consultant n overview of pediatric...

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