Study of a Drug Called "Ketamine" and How Much is in the Bloodstream of Infants and Children Who Have Undergone Surgery. Ketamine is a standard-of- Care Medication Used in the Intensive Care Unit at Stanford for Sedation and Anesthesia.

Dosing of medications is based on the plasma level achieved with a given dose and how long
the medicine remains in the body. This study is called pharmacokinetics-that is, what the
body does to the medication. Ketamine is an intravenous medication used for anesthesia and
sedation in children. However the pharmacokinetics of Ketamine has not been systematically
studied. We propose to study the pharmacokinetics of ketamine in different age groups of
children ranging from infants to teenagers.