Myoglobinemia and propofol infusion

Propofol infusion associated metabolic acidosis in patients undergoing neurosurgical anesthesia: a retrospective study

Objective

Propofol and volatile anesthesia have been associated with metabolic acidosis induced by increased lactate. This study was designed to evaluate changes in pH, base excess (BE), and lactate in response to different anesthetic agents and to characterize propofol infusion-associated lactic acidosis.

Methods

The medical records of patients undergoing neurosurgical anesthesia between January 2005 and September 2012 were examined. Patients were divided into 2 groups : those who received propofol (total intravenous anesthesia, TIVA) and those who received sevoflurane (balanced inhalation anesthesia, BIA) anesthesia. Propensity analysis was performed (1 : 1 match, n=47), and the characteristics of the patients who developed severe acidosis were recorded.

Results

In the matched TIVA and BIA groups, the incidence of metabolic acidosis (11% vs. 13%, p=1) and base excess (p>0.05) were similar. All patients in the TIVA group who developed severe acidosis did so within 4 hours of the initiation of propofol infusion, and these patients improved when propofol was discontinued.

Conclusions

The incidence of metabolic acidosis was similar during neurosurgical anesthesia with propofol or sevoflurane. In addition, severe acidosis associated with propofol infusion appears to be reversible when propofol is discontinued.

Analytic Reviews: Propofol Infusion Syndrome in the ICU

Propofol is an alkylphenol derivative named 2, 6, diisopropylphenol and is a potent intravenous short-acting hypnotic agent. It is commonly used as sedation, as well as an anesthetic agent in both pediatric and adult patient populations. There have been numerous case reports describing a constellation of findings including metabolic derangements and organ system failures known collectively as propofol infusion syndrome (PRIS). Although there is a high mortality associated with PRIS, the precise mechanism of action has yet to be determined. The best preventive measure for this syndrome is awareness and avoidance of clinical scenarios associated with development of PRIS. There is no established treatment for PRIS; care is primarily supportive in nature and may include the full array of advanced cardiopulmonary support, including extracorporeal membrane oxygenation (ECMO). This article reviews the reported cases of PRIS and describes the current understanding of the underlying pathophysiology and treatment options.

Propofol infusion syndrome in anaesthesia and intensive care medicine

PURPOSE OF REVIEW

Propofol infusion syndrome is a rare but often fatal syndrome, characterized by lactacidosis, lipaemic plasma and cardiac failure, associated with propofol infusion over prolonged periods of time. As propofol is used worldwide, knowledge of propofol infusion syndrome is essential for all anaesthesiologists and intensive care physicians. This review will provide an update on reported cases, and describe recent findings relevant to the pathophysiology and clinical presentation of propofol infusion syndrome.

RECENT FINDINGS

Case reports of propofol infusion syndrome have contributed new pathophysiological evidence. Reported cases of similar syndromes may represent initial propofol infusion syndrome, and may help to identify further risk factors such as low carbohydrate supply and early warning signs such as lactacidosis. Newly identified gene defects mimicking propofol infusion syndrome may elicit the underlying genetic susceptibility. Recommendations for the limitation of propofol use have been devised by various institutions.

SUMMARY

Propofol infusion syndrome must be kept in mind as a rare but highly lethal complication of propofol use, not necessarily confined to the prolonged use of propofol. Dose limitations must be adhered to, and early warning signs such as lactacidosis should lead to the immediate cessation of propofol infusion.