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July 27, 2026

Propofol Infusion Syndrome

Propofol Infusion Syndrome

Disclaimer: This article is intended solely for informational and educational purposes only. It does not constitute medical advice.

Propofol is one of the most widely used intravenous anesthetic agents due to its favorable pharmacokinetic profile, rapid onset of action, and generally low impact on hemodynamic stability compared to other agents.1 Although propofol use is broadly considered safe, prolonged or high-dose administration has been associated with the development of propofol infusion syndrome, a rare but potentially life-threatening complication. Initially described in pediatric patients, propofol infusion syndrome is characterized by severe metabolic acidosis and refractory bradycardia progressing to cardiac arrest.2

The clinical presentation of this condition is often multisystemic, with cardiovascular compromise, metabolic disturbances, and skeletal muscle injury occurring in combination. Because these manifestations are nonspecific and can overlap with the effects of critical illness, early recognition requires a high index of suspicion, particularly in patients receiving prolonged or high-dose propofol infusions. Subsequent reports have identified the syndrome in adults as well, often presenting with a broader range of clinical manifestations, such as rhabdomyolysis, acute kidney injury, cardiac dysfunction, hyperkalemia, and hepatic abnormalities.

Despite increasing recognition of propofol infusion syndrome, its pathophysiology remains incompletely understood, and the absence of a universally accepted diagnostic definition has contributed to ongoing uncertainty regarding its true incidence and clinical spectrum. As reported cases have evolved to include adults receiving propofol within recommended dosing limits, there is a growing need to better characterize the syndrome in contemporary clinical medicine.3

Cardiac and skeletal muscle injury are hallmark features of the disorder, as evidenced by marked elevations in creatine kinase, troponin I, and myoglobinuria, alongside histological findings of extensive myocyte necrosis. Experimental studies suggest that propofol exerts direct toxic effects on cardiac and skeletal muscle by impairing mitochondrial function. Specifically, propofol inhibits oxidative phosphorylation, disrupts electron transport chain activity (particularly at complexes II and IV), reduces oxygen utilization, impairs calcium channel function, and decreases β-adrenergic receptor responsiveness.4 Together, these effects reduce ATP production and myocardial contractility, contributing to the refractory cardiac failure commonly observed in advanced presentations of the condition.2,5

Propofol inhibits carnitine palmitoyltransferase I, preventing long-chain fatty acids from entering the mitochondria, while simultaneously disrupting β-oxidation and electron transport, limiting the utilization of medium- and short-chain fatty acids.6 The resulting energy deficit is particularly detrimental in critically ill patients with high metabolic demands, leading to bodily dysfunction and tissue necrosis. Accumulation of unused free fatty acids may also promote cardiac arrhythmias.2

The accumulation of toxic fatty acid intermediates compromises ATP production and exacerbates metabolic acidosis. These metabolic disturbances resemble those observed in inherited mitochondrial disorders, where defects in fatty acid oxidation can lead to rhabdomyolysis, cardiac dysfunction, and hepatic injury during periods of metabolic stress. Consequently, patients with underlying mitochondrial fatty acid oxidation disorders may be particularly susceptible to developing propofol infusion syndrome and should generally avoid prolonged propofol exposure.5

The risk of propofol infusion syndrome increases with higher propofol doses and prolonged infusion duration, although no definitive dose threshold guarantees safety.3 Current recommendations emphasize minimizing propofol exposure by using the lowest effective infusion rate, incorporating multimodal sedation, and considering alternative sedatives when propofol requirements escalate or metabolic abnormalities develop. Patients with suspected mitochondrial dysfunction, cardiovascular instability requiring high-dose vasopressors, or prolonged low-carbohydrate intake may be at increased risk and warrant additional caution.3 Overall, while propofol infusion syndrome remains a fairly uncommon complication, its high mortality underscores the importance of prompt recognition, careful risk assessment, and preventive strategies to optimize patient safety during prolonged propofol therapy.

References

  1. Ho KM, Ng JY. The use of propofol for medium and long-term sedation in critically ill adult patients: a meta-analysis. Intensive Care Medicine. 2008;34(11):1969-1979. https://doi.org/10.1007/s00134-008-1186-5
  1. Vasile B, Rasulo F, Candiani A, Latronico N. The pathophysiology of propofol infusion syndrome: a simple name for a complex syndrome. Intensive Care Medicine. 2003;29(9):1417-1425. https://doi.org/10.1007/s00134-003-1905-x
  1. Hemphill S, McMenamin L, Bellamy MC, Hopkins PM. Propofol infusion syndrome: a structured literature review and analysis of published case reports. British Journal of Anaesthesia. 2019;122(4):448-459. https://doi.org/10.1016/j.bja.2018.12.025
  1. Branca D, Roberti MS, Lorenzin P, Vincenti E, Scutari G. Influence of the anesthetic 2,6-diisopropylphenol on the oxidative phosphorylation of isolated rat liver mitochondria. Biochemical Pharmacology. 1991;42(1):87-90. https://doi.org/10.1016/0006-2952(91)90684-w
  1. Kam PCA, Cardone D. Propofol infusion syndrome. Anaesthesia. 2007;62(7):690-701. https://doi.org/10.1111/j.1365-2044.2007.05055.x
  1. Wolf A, Weir P, Segar P, Stone J, Shield J. Impaired fatty acid oxidation in propofol infusion syndrome. The Lancet. 2001;357(9256):606-607. https://doi.org/10.1016/s0140-6736(00)04064-2