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PEDIATRIC TOXICOLOGY. Badrinath Narayan, PEM Fellow Pediatric AHD, Aug 5 th 2014. PEDIATRIC TOXICOLOGY. Objectives Provide a general approach to the poisoned patient History, physical, investigations Introduce types of decontamination with indications/complications List “Pills that Kill”.
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PEDIATRIC TOXICOLOGY Badrinath Narayan, PEM Fellow Pediatric AHD, Aug 5th 2014
PEDIATRIC TOXICOLOGY • Objectives • Provide a general approach to the poisoned patient • History, physical, investigations • Introduce types of decontamination with indications/complications • List “Pills that Kill”
Poisoning • Poisoning • One of the most common medical emergencies • Exploratory behaviour • Child abuse • Environmental exposures • Suicide attempts • In utero toxicants • Pediatricians have a role in advocacy • Modes of exposure: • Ingestion, ocular exposure, topical exposure, envenomation, inhalation and transplacental exposure.
Approach • Brief window of opportunity to make critical diagnostic and management decisions • Prioritize critical assessment and simultaneous management interventions
14 year old female found unconscious in a park by friends The patient is brought into the trauma bay at BCCH ED What would you do?
Primary Survey - ABCDEFG Apply monitors - O2, HR, RR, cycling BP Obtain vitals: HR, RR, BP, O2 sat A – Maintain patency, assess reflexes, note GCS, have airway equipment ready B - Apply O2, consider ETCO2, ABG C – Assess perfusion, Get two large bore Ivs Disability (GCS, pupil size and reactivity), ? Signs of trauma DecontaminationDrug Treatment – dextrose, oxygen, narcan Bedside Glucose
Primary Survey • Pay special attention to: • Evidence of impaired airway protective reflexes • Many poisoned patients will vomit • Elective endotracheal intubation may be indicated at a lower threshold • Anticipate imminent respiratory failure • Cyanosis/apnea are late findings
Case • The patient has been stabilized • What would you ask?
History – known intoxicant Take standard AMPLE history plus: What was ingested, How much, When, Why? Obtain prescription bottles when possible, and be sure that bottles contain med listed Talk to patient’s family and friends in ED/contact home Ensure belongings are looked at to identify paraphernalia In a toddler think single pills, in an adolescent think co-ingestions!!
When to suspect? • Suspected but unknown intoxicant: • Acute onset of illness • Pica-prone age (1-5) • History of pica, ingestions • Current household “stress” • Significantly altered mental status • Family medications/recent illnesses • Social: grandparents visiting, holiday parties, other events
Case • On exam what things might you see to suggest a toxicological cause for the child’s presentation?
Physical • Vitals • GCS/mental status • Pupils, EOM, fundi • Mouth: corrosive lesions, odors, secretions • Respiratory: rate, chest excursion, air entry • CVS: rate, rhythm, perfusion • GI: motility, corrosive effects • Skin colour, burns, diaphorsis, piloerection, track marks • Bladder size
Removal of toxic substance Decontamination: Removal of a substance prior to entry into the circulation Elimination: Removal of a substance by enhanced excretion once it has entered the circulation
Approach to decontamination Get help -- Poison control centre 24-hour Line: 604-682-5050 or 1-800-567-8911 Healthcare professionals only line: 604-707-2787 or 1-866-298-5909 (outside the Lower Mainland) Monday to Friday from 9 am - 4 pm
Forms of Decontamination Topical flush aggressively (ocular or skin), remove contaminated clothing Dilution Ipecac (no longer recommended; AAP statement against it) Activated Charcoal Gastric Lavage – also fallen out of favour Whole Bowel Irrigation
Dilution • Indicated if toxin produces only simple irritation • Controversial for caustic agents • May be used in first few minutes • NOT for drugs – may increase absorption • Not if upper airway compromise • Water or milk • E.g. dish soap
Activated Charcoal • “Activation” increases surface area of particles • Toxins adsorb to activated charcoal decreasing amount adsorbed by the body • Some toxins are not well adsorbed – most small molecules • Iron, the alcohols, lithium, strong acids and alkali, sodium, chloride. • Dose: 10:1 charcoal to drug ratio. • For unknown ingestions dosing is based on ability to tolerate the agent: Children - 1 gram/kg of body weight.
Activated Charcoal • Timing • If not contraindicated there does not seem to be a reasonable time that is too late to give AC, especially with SR or DR products • Dogma used to be an hour but studies with respect to delayed gastric emptying have challenged this data Multiple-dose activated charcoal sustained-release products useful with drugs with low Vd, low protein binding, long half-life
Activated Charcoal Activated charcoal not useful with: P esticides H ydrocarbons A cids, Alkali, Alcohols I ron L ithium, Liquids S olvents
Activated Charcoal Contraindications absent gut motility or perforation if endoscopic visualization is required (e.g. caustic ingestions) loss of protective airway reflexes Complications fatal aspiration small bowel obstruction
Gastric Lavage Orogastric lavage with a large bore tube (36-40 F for adult; no smaller than 22-24 F for children) RARELY recommended – not been demonstrated to improve outcome, several risks Might be considered: VERY early or after very dangerous ingestions (colchicine, arsenic) Ensure airway protected Place patient in left lateral decubitus position with the head down Have suction available for secretions Place tube (tragus-nose-xyphoid) and confirm position Lavage until fluids clear
Whole Bowel Irrigation Whole bowel irrigation of the entire GI tract by instillation of large volumes of fluid Usually takes hours Has been used safely in children Most useful for substances with delayed absorption ( i.e. extended release ), not amenable to activated charcoal and with body stuffers/packers
Whole Bowel Irrigation Accomplished by orally taking (or through NG) large volumes of Nulytely (approved for children and adults), Colyte, or Golytely Adolescents: mininum of 1.5-2 L/hour Children: 25 mL/kg/h Give until rectal effluent is clear.
Whole Bowel Irrigation Contraindications: absent bowel sounds bowel obstruction or perforation unprotected compromised airway hemodynamic instability
Forms of Elimination Urine alkalinization - promotes excretion of salicylate, enhances clearance of some drugs Dialysis Charcoal Hemoperfusion
Dialysis Consider nephrology consult with dialysis if: S alicylates T heophylline U remia M ethanol B arbiturates L ithium E thylene Glycol
Antidotes • Avoid physostigmine if TCA ingestion present - has potential to worsen ventricular conduction defects and to lower seizure threshold.
Investigations Select tests only Help confirm diagnosis Help monitor Help identify “silent” killers Tox screens not useful in acute management
Investigations All symptomatic patients with unknown ingestion should get electrolytes, glucose, osmolarity, acetaminophen/ASA levels, blood gas, EKG All suicidal patients should get acetaminophen level (~1:500 patients without a history of APAP ingestion will have a potentially toxic blood level - NYPCC) and ASA level Other tests based on history, physical, level of suspicion CBC Specific drug levels Urinanalysis BHCG Calcium, liver function panel
Increased anion gap metabolic acidosis (Na – (Cl + HCO3) M ethanol (hx of alcohol abuse, methanol level), metformin U remia (BUN) DKA, AKA, SKA (hx; urine ketones) P araldehyde (distinctive odor) I soniazid (seizure; lactate level) Lactic acidosis Ethylene glycol(level) S alicylates/solvents (level)
Increased Osmolar gap (serum – calculated) “Two salts and a sticky BUN” Mannitol Alcohols Dye Glycerol Acetone Sorbitol
Pitfalls of osmolar gap • Cannot distinguish between type of toxic alcohol • Insensitive in late presentations • Not sufficiently sensitive to exclude small ingestion • Cannot rule out ingestion based on a normal OG
Radio-opaque drugs • Chloral Hydrate • Opioid packets (latex) • Iron and other heavy metals • Neuroleptics • Sustained release tablets/Salicylates
ECG • Findings include: • Toxicologictachcyardia/bradycardia • QRS widening • Prolonged QT (www.qtdrugs.org) • Findings can develop late so obtain serial ECGs
Case • A 2 year old girl is found playing with his grandmother’s pill box. Some pills may be missing and a powder residue is found in the child’s mouth. • What medications would most concern you if this child ate “just one pill”?
ONE PILL KILLERS Small dose toxins
Case • A 3 yo male presents to the ED comatose with a GCS of 6. He was found on the bathroom floor. Following stabilization, what is the most immediate course of action? • A. Head CT • B. ECG • C. Tox screen • D. Broad spectrum Abx