Toxicology Pearls from the 2019 North American Congress of Clinical Toxicology

Today’s pearls are some of the high points from the recent NACCT conference tweeted out by Mike O’Brien @MikeEMPharmD

Timely toxicology tweets and treatment tips

1. Methylxanthine toxicity
   • Pearl: In patients with methylxanthine toxicity (e.g., caffeine, theophylline, etc) please consider esmolol to treat their tachycardia despite potential hypotension. Hypotension likely secondary to persistent tachycardia and t1/2 is so short it can easily be turned off
2. Clonidine overdose
   • Pearl: Transient hypertension following clonidine overdose likely due to peripheral alpha-2 stimulation. These supratherapeutic levels also lead to endorphin release, which is where naloxone may have a role for CNS depression.
3. Naloxone kinetics
   • Pearl: Naloxone failures may not always be what they appear. Did we wait long enough to see full effect? Was the dose adequate? The route matters.
   • Pearl: Additionally, consider the time interval evaluated when higher doses of naloxone are reported. As IN naloxone doesn’t peak as quickly as we’d like, patients may receive multiple doses in short periods of time.
4. Vaping induced lung injury
   • • Pearl:
       • With over 500 cases and 8 deaths, Vaping Associated Lung-Injury (VALI) is a growing epidemic in the US. CDC definition includes:
         • 1) Use of vape in last 90 days
         • 2) CXR with infiltrate or CT with GGOs
         • 3) Absence of pulminfx
         • 4) No other plausible diagnosis
       • Typical clinical features:
         • 1) Young (median 19 years old)
         • 2) Respiratory, GI, and constitutional symptoms
         • 3) Hypoxia (70% with O2 <94%)
         • 4) Leukocytosis
         • 5) Elevated EST/CRP
       • No clinically evaluated or evidence-based treatment recommendations. Many patients successfully received:
         • 1) Aggressive respiratory support (including ECMO)
         • 2) Steroids (methylprednisolone 125mg BID to 250mg q6h)
         • 3) Broad infx workup
         • 4) Early transfer to tertiary care center
5. Toxic alcohols
   • Pearl: The traditional recommendation of treating methanol or ethylene glycol poisonings when levels exceed 20 mg/dL is not evidence based. Consider using a threshold of 30 mg/dL for methanol and 60 mg/dL for ethylene glycol
   • Pearl: This method ensures formate levels remain <10 mmol/L as patients with these levels are asymptomatic. Also decreases use of an expensive and prolonged course of therapy

Mike’s Twitter handle is @MikeEMPharmD.

^#21