Propofol infusion syndrome (PRIS) is a rare but lethal complication. Which clinical scenario carries the HIGHEST risk for PRIS?

• A Single induction dose of propofol 2 mg/kg for a 30-minute procedure
• B TIVA with propofol 100 mcg/kg/min for a 4-hour elective laparoscopy
• C Propofol-based sedation for a 6-hour MRI in an ASA I paediatric patient
• D Prolonged ICU sedation with propofol >4 mg/kg/hr for more than 48 hours in a critically ill patient with high vasopressor requirements ✓

Explanation

Propofol infusion syndrome occurs with high doses (>4–5 mg/kg/hr) administered for prolonged periods (>48 hours), particularly in critically ill patients with concurrent high catecholamine/steroid requirements, head injury, or low carbohydrate intake. The syndrome is characterised by metabolic acidosis, rhabdomyolysis, hyperlipidaemia, cardiac dysfunction (right bundle branch block, ST changes), and renal failure. The pathophysiology involves impaired mitochondrial electron transport chain function and impaired fatty acid oxidation. Paediatric ICU patients are disproportionately at risk. Standard TIVA doses in the operating room are below the threshold.

Reference: Morgan & Mikhail's Clinical Anesthesiology, 6th ed.

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Written and medically reviewed by the StethoPrep medical team.