#72 ICU Toxicology
On this week, Cyrus & Nick are joined again by intensivist extraordinaire, Dr. Adam Mora, for a long overdue episode on ICU Toxicology! Together, the three of us embark on a case-based journey covering some of the more common ICU toxidromes as well as some of the more unusual, but can't-miss diagnoses. This is a bit of a longer one but it's super high-yield and very practical for anyone who is studying for their boards and/or participating in the care of the critically ill! Thanks to our tag-team of sponsors for this episode: The Difficult Airway Course: Critical Care and our newest sponsor, Integration Health!
Overview
In this high-yield, case-based episode, we take a tour de toxidromes with returning guest Dr. Adam Mora (UT Southwestern, Intensivist with expertise in OB and Transgender Critical Care).
This is not a comprehensive tox textbook—but rather a practical ICU-focused framework to rapidly recognize and manage some of the most common (and deadly) toxicologic emergencies.
The ICU Approach to Toxicology
Across all cases, a few recurring themes:
Recognize patterns (toxidromes) quickly
Stabilize airway, breathing, circulation first
Don’t wait for confirmatory labs to start treatment
For any toxicology emergency consider: (Nick’s “5 what’s and a why”)
What drug?
What dose?
What route?
What time?
What else?
Why?
Remember that co-ingestions can muddle typical toxidrome patterns (e.g. co-ingestion of a stimulant and an anticholinergic)
CASE 1 — Opioid Toxicity
Presentation
Found unresponsive in bathroom
Pinpoint pupils, hypoventilation
Transient response to naloxone → re-sedation
Key Data
RR 6, SpO₂ 82%
ABG: pH 7.19 / CO₂ 78 → severe hypercapnic respiratory failure
Pupils: 1 mm
Diagnosis: Opioid toxidrome
CNS depression
Respiratory depression
Miosis (but may be absent with co-ingestion)
Teaching points:
Pupils matter—but aren’t perfect
Pinpoint pupils = classic
BUT:
Co-ingestions → normal pupils
Tramadol → atypical
Naloxone strategy
Goal: restore ventilation, NOT full wakefulness
Target: RR ≥ 10–12
Avoid overshooting → withdrawal
Escalation: Repeat boluses → then infusion
Infusion = typically ~2/3 of effective “wake-up dose” per hour
Avoid precipitated withdrawal
Use 0.04 mg incremental dosing
High-dose naloxone will cause vomiting, agitation, aspiration
Critical co-ingestions to consider
Xylazine (“Tranq”) → 🔥 HIGH-YIELD
Veterinary Alpha-2 agonist
“Temu Precedex”
Effects:
Profound sedation
Bradycardia
NO response to naloxone
Clues:
Necrotic skin ulcers → infection risk
Clonidine
Similar physiology
May need pressors (epi/norepi)
Intubation considerations
If intubated: Continue opioid-based sedation
Don’t “reverse then abandon”—you’re treating physiology