Toxic ingestions: prevention and work-up!

PREVENTION

Discuss safe storage of medications and household products at the 4-month-old and 6-month-old well child visits

  • Upcoming developmental milestones increase the risk of accidental ingestions!
    • increasing mobility: crawling around 9mo, cruising by 12mo, walking alone by 15mo
    • oral exploratory behavior: mouthing objects starting around 4-6mo
    • maturing pincer grasp: early pincer grasp at 9mo, mature pincer grasp and finger feeding around 12mo

Prioritize safety when prescribing meds!

Resources: 


HISTORY & EXAM

History

  • identify the substance(s)
    • ask caregivers to take a picture or bring the container itself
    • always consider coingestion 
    • if unwitnessed, review comprehensive home medication list
  • dose strength and type of release (e.g. immediate release, extended release)
  • possible amount
  • timing of ingestion
  • subsequent symptoms

Exam

  • vital signs are vital!
  • cardiopulmonary
  • abdominal
  • neurologic
  • mucous membranes and skin

Ask yourself: Does the clinical picture suggest a toxidrome? Do we need an antidote?


WORK-UP

  • ABCs, fingerstick glucose
  • Consider giving dextrose, naloxone, activated charcoal
  • CRM, IV access, urine collection
  • Studies: 
    • ECG
    • urine drug screen
    • drug levels (acetaminophen, salicylate)
    • EtOH level
    • CMP
    • maybe: blood gas, serum osm, imaging, comprehensive drug screen

HYPOGLYCEMIA

Kids have ↑risk of hypoglycemia because of higher baseline rate of glucose utilization and limited supply of gluconeogenic precursors (especially alanine) from ↓muscle mass reserve.

Toxicologic DDx of hypoglycemia = “HOBBIES”

  • H = oral Hypoglycemics 
  • O = Other (e.g. litchi fruit?!)
  • BB = Beta-blockers
  • I = Insulin
  • E = Ethanol
  • S = Salicylates


NALOXONE

FDA indication: known or suspected opioid overdose (i.e. respiratory depression or CNS depression) in adults or pediatric patients of all ages

  • Administration: IV, IM, IN
    • IV/IM: 0.1 mg/kg/dose if <5yo or <20kg; 2 mg/dose if ≥5yo or ≥20kg
    • IN: 4 mg/dose for any age and any weight

Narcan = naloxone nasal spray


ACTIVATED CHARCOAL

MOA: charcoal powder (aqueous solution) is incredibly porous and absorptive 

  • most effective if given within 1 hour of ingestion
  • works best for anticholinergics, ASA, acetaminophen, and TCAs
  • poor efficacy with liquids or metals (e.g. iron)

CI: depressed mental status, unprotected airway, risk of aspiration


ECG: QRS & QT

QRS

  • You may have been taught that the normal QRS duration is less than 3 small boxes (i.e. <120 msec), which is technically accurate but not precise. Normal QRS width = 70-100 msec, and varies by age!
  • Broad complexes (QRS >100 msec) may be either ventricular in origin or due to aberrant conduction (e.g. BBB, hyperkalemia)
  • Drugs associated with QRS widening: antiarrhythmics (Ia/Ic), bupivacaine, bupropion, carbamazepine, cocaine, diphenhydramine, lamotrigine, TCAs, etc

QT

  • Measure the QT interval in either lead II, V5, or V6
    • Measure several successive beats and use the maximum interval
  • QT interval shortens at faster HR and lengthens at slower HR
    • Corrected QT interval (QTc) estimates QT interval at a standard HR of 60 bpm
    • QTc = QT / √(RR interval)
  • MANY drugs are associated with QT prolongation: antiarrhythmics (Ia/Ic/III), antipsychotics, fluoroquinolones, macrolides, methadone, ondansetron, SSRI/SNRIs, etc

TOXICOLOGY SCREENING

  • Urine drug screen is an immunoassay (qualitative); comprehensive drug screen (CDS) is chromatography (quantitative)
    • At our hospital, both tests check the same 10 drugs/classes but only utox has thresholds to flag positive (see table below)

  • Notes on the above table:
    • detection times for barbiturates and BZD vary widely because of short- and long-acting formulations (e.g. phenobarbital, diazepam)
    • detection times for cannabinoid vary widely based on frequency of use
    • *opiates include morphine, codeine, heroin, hydrocodone
    • **oxycodone includes oxycontin, percocet, roxicodone

POISON CONTROL CENTER (PCC)

Hotline: 1-800-222-1222 (routes calls based on the caller’s area code)

  • Someone calls every 15 seconds!
  • Toxicologist = pharmacist or registered nurse

In 2018, PCC received 2.1 million calls nationwide!

  • 5,217 calls from Rhode Island (33% from healthcare facilities)
    • 151 exposures to opioids (2.9%), 6 exposures to e-cigarettes (0.1%)

According to the PCC, what are the most common ingestions/exposures in Rhode Island? 


“ONE PILL CAN KILL”

Common drugs and household items can be fatal in small children, including calcium channel blockers, TCAs, antimalarials, sulfonylureas, and opioids. 

Check out this great ACEP blog post from Brown EM physician Rebecca Karb!


OPIOIDS & THE CEREBELLUM

Recent case reports describe malignant cerebellar edema (MCE) following unintentional opioid exposure in children. 

  • MOA: direct neurotoxicity mediated by cerebellar opioid receptors with ischemia secondary to respiratory arrest aggravating the injury
  • MCE and increased ICP can mimic the pinpoint pupils and suppression of brainstem reflexes seen in traditional opioid overdose
  • MCE may progress to tonsillar herniation, obstructive hydrocephalus, and direct damage to the brainstem itself, thus early neuroimaging is critical!

*Blog post based on Med-Peds Forum talk by Matt Lorenz, MP Core Faculty