A method to quickly calculate mixtures for epidural infusions.

Epidural solutions of local anesthetics and opioids, such as bupivaCaine and fentanyl, are commonly employed for intraoperative use, labor and delivery, and postoperative analgesia. Clinicians frequently need to assemble mixtures of different concentrations from individual components. Knowing the initial and final concentrations of local anesthetic and opioid, this method allows one to quickly calculate the amount of each drug to be mixed and diluted to the desired final volume. Given that the final volume of solution is V,,,, the initial concentration of local anesthetic is CLA-i,,itial, and the final concentration of local anesthetic is CLA.anal, the volume of local anesthetic to be drawn up is: