This study was originally undertaken to evaluate the analgesic efficacy of an intravenously
administered dose of ketorolac compared with intravenous morphine in the relief of acute,
postoperative pain in children admitted to the Intensive Care Unit. Using the urine and
plasma samples originally collected from patients in the morphine treatment group and which
were never analyzed, this proposal seeks to study the pharmacokinetics and metabolism of
intravenous morphine in critically-ill children along with its concentration-related efficacy
using prior measures of pain.