Propofol Infusion Syndrome

Propofol is an intravenous anesthetic that is commonly used for sedation in ICU. the elimination of propofol is not impaired by hepatic or renal dysfunction. Propofol has a large volume of distribution and is highly protein bound. During administration serum triglycerides should be monitored in all patients who receive propofol in doses > 50 mcg/kg/min for more than 2 days. If hypertriglyceride is detected, alternative should be considered. Unusual and potentially serious complications are associated with continous infusion of propofol for longer tnan 24 to 48 hours. These include progressive hyperglyceridaemia, pancreatitis, increased carbon dioxide production and excessive caloric load (the emulsion contains approcimately 1.1 kcal/ml, most of which derived from lipids).

Propofol Infusion Syndrome (PRIS): PRIS is a rare complication of propofol for longer than 24 to 48 hours. It is associated with high doses ( more than 4 mg/kg/hour of mone than 67 mcg/kg/min) and prolonged use (more than 48 hr). Characteristic of the syndrome include acute refractory bradycardia, severe metabolic acidosis, CVS collapse, rhabdomyolysis, hyperlipidaemia, renal failure and hepatomegaly. Mortality is high, more than 60% in a study. Risk factors:

• large doses and duration more than 48hrs


• younger age


• acute neurological injury


• low carbohydrate intake


• catecholamine and corticosteroid infusion

Clinical and lab findings:

• unexplained lactic acidosis


• increasing inotropic support


• Brugada like ECG abnormalities


• Green urine


• CVS collapse


• rhabdomyolysis, high CK, hyperkalaemia


• arrythmia/ heart block


• renal failure

Management:

1. high index of suspicion


2. discontinue infusion immediately


3. monitor for early warning signs: lactate, CK, urine myoglobin, ECG


4. standard cardiorespiratory support


5. consider pacing for bradycardia ( often resistant to high dose of CA )


6. adequate carbohydrate intake


7. ECMO: 2 case reports


8. haemoperfusion and haemodialysis are used with uproven benefit


9. carnitine supplementation: theoretical benefit