A Review of Current Literature of Interest to the Office-Based Anesthesiologist

Remifentanil has been shown to be poorly soluble when added to propofol in high concentrations; however, the physiochemical properties of these admixtures have not been studied in clinically relevant concentrations or settings. This study examined remifentanil-propofol admixtures in commonly used concentrations while subjecting them to delivery through an extension line driven by a syringe pump. A solution of propofol 10 mg/mL combined with remifentanil 5 mcg/mL was run using a Paedfusor propofol target-controlled infusion model for 10- and 20-kg children for 57 minutes at a target plasma concentration of 3 mcg/mL. The solution was delivered through a 30-mL syringe, 180-cm minimum volume extension line, luer-lock cannula, interlink injection site, and 22-g intravenous (IV) cannula into sample pots. Samples were taken at the completion of the loading bolus, 1 minute and 2 minutes after completion of the loading bolus, and every 5 minutes thereafter. The remifentanil concentration in these samples was...