Propofol
Propofol — Intravenous Sedative-Hypnotic Agent
🧬 Mechanism of Action & Target Pathway
GABA-A Receptor Positive Allosteric Modulation & NMDA Inhibition
- Binds to GABA-A receptor beta-subunits, enhancing GABA-mediated chloride channel opening.
- Causes neuronal membrane hyperpolarization and central nervous system depression.
- Decreases Cerebral Metabolic Rate of Oxygen ($CMRO_2$), Cerebral Blood Flow (CBF), and Intracranial Pressure (ICP).
Pharmacokinetics & Pharmacodynamics (PK/PD) — Propofol
receptor occupancy⚖️ ICU Clinical Reasoning
Why I Choose It (Indications & Strengths)
- ✓A commonly used non-benzodiazepine sedative for mechanically ventilated adults; PADIS favors propofol or dexmedetomidine over benzodiazepines for routine sedation when clinically appropriate.
- ✓Rapid onset and relatively rapid early offset can facilitate neurologic assessment and spontaneous-awakening strategies, although recovery slows after prolonged/high-dose infusion because of redistribution and context-sensitive kinetics.
- ✓Potent anti-seizure activity and reduction of Intracranial Pressure (ICP).
Why I Don't (Limitations & Gaps)
- ✕Propofol Infusion Syndrome (PRIS): rare but potentially lethal metabolic acidosis, rhabdomyolysis, hyperkalemia, Brugada-like ECG changes and cardiac failure; risk increases with prolonged high-dose exposure and severe critical illness, but no single dose-duration threshold is perfectly safe.
- ✕Profound systemic vasodilation and myocardial depression (severe hypotension in hypovolemia/sepsis).
- ✕Provides no intrinsic analgesia; assess and treat pain separately rather than automatically pairing every propofol infusion with an opioid.
💉 Dosing & Administration Protocols
Current U.S. label for adult ICU sedation: when indicated, start 5 mcg/kg/min, increase by 5–10 mcg/kg/min at intervals of at least 5 minutes to effect, and use the minimum effective maintenance rate. Most adults require 5–50 mcg/kg/min, although higher rates may sometimes be needed; administration should not exceed 4 mg/kg/hour (~67 mcg/kg/min) unless benefits outweigh risks.
Renal Function Dosing
| CrCl Range | Dose Adjustment |
|---|---|
| Any CrCl | No renal dose adjustment required. |
Dialytic Clearance (HD / CRRT)
🩺 Organ Failure Considerations
Current labeling does not require a specific renal dose-adjustment algorithm; titrate to sedation and hemodynamic response.
Current labeling does not provide a fixed hepatic dose-adjustment algorithm; titrate carefully because critical illness, age and comorbidity can alter dose requirements.
⚠️ Toxicity & Safety Warnings
Major Warnings
- 🚨Propofol Infusion Syndrome (PRIS): Severe metabolic acidosis, rhabdomyolysis, hyperkalemia, hepatomegaly, cardiac failure.
- 🚨Hypertriglyceridemia and acute pancreatitis.
- 🚨Microbial-contamination risk: strict aseptic technique is required; current U.S. labeling requires completion/discard of product and dedicated tubing within 12 hours after vial spiking/opening.
🔄 Bedside Drug Interactions
| Interacting Drug | Mechanism | Clinical Consequence | Mandatory ICU Action |
|---|---|---|---|
| Opioids / Benzodiazepines | Synergistic CNS and respiratory depression | Profound hypotension and apnea | Reduce propofol dose when combining with opioids. |
📊 Monitoring & TDM Protocols
Required Monitoring Parameters
- ▪ Sedation depth with a validated scale at a frequency appropriate to the clinical state and local protocol
- ▪ Arterial blood pressure continuously
- ▪ Serum triglycerides during prolonged or high-dose infusion according to local protocol/risk
- ▪ CPK, Lactate, and ABG for PRIS screening
Evidence Status
CurrentLast Medically Reviewed
2026-08-28
Evidence Checked Through
2026-08-28
📚 Evidence Traceability & Guideline Citations
"SCCM PADIS guidelines recommend non-benzodiazepine sedatives (Propofol or Dexmedetomidine) over benzodiazepines."
🩺 Bedside Patient Scenarios
ICU Sedation and Daily Awakening Trial
Scenario: Intubated ARDS patient requiring light sedation (RASS -1).
Rationale: Propofol can facilitate wake-up assessment because of its pharmacokinetic profile, but SAT timing and eligibility depend on sedation indication, ventilator synchrony, neurologic status and hemodynamic stability.
🎯 Exam Traps & Board Misconceptions
Propofol is not an analgesic. Assess and treat pain independently—often with an opioid when appropriate—rather than automatically pairing every propofol infusion with an opioid.
Continue Learning
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