Is intrathecal morphine of benefit to patients undergoing cardiac surgery

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed is whether intrathecal morphine is of benefit to patients undergoing cardiac surgery? Using the reported search 850 papers were identified. Ten papers represented the best evidence on the subject. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results and study comments and weaknesses were tabulated. The ten papers demonstrated that intrathecal morphine reduces postoperative pain scores, increases time to first IV morphine dose and reduces the overall postoperative IV morphine dose required, indicating its analgesic effect. Opioid-related complications remained comparable to controls, however, other benefits of reduced time to extubation, reduced ICU stay and improved postoperative lung function are variably reported with significant results found only in small retrospective studies. No spinal haematomas were reported, however, high-risk patients were excluded. We conclude that intrathecal morphine is an alternative method of pre-induction analgesia that benefits patients as less postoperative IV morphine is required, however, other benefits are less well reported.