Effect of Perioperative i.v. Low-dose S(+) Ketamine in Patients Undergoing Hemorrhoidectomy
Effect of Perioperative i.v. Low-dose S(+) Ketamine in Patients Undergoing Hemorrhoidectomy
The purpose of this study is to determine whether the use of perioperative intravenous S (+) ketamine reduces the amount and degree of postoperative pain.
Furthermore the purpose of this study is to determine whether the use of perioperative intravenous S (+) ketamine effects cognitive function in the early postoperative period.
The mechanism of development of postoperative pain is complex. Central and peripheral sensitization are playing an important role and this can lead to postoperative hypersensitization. Several studies have shown, that S (+) ketamine can be effective to reduce sensitization and postoperative pain. Ketamine (2-O-chlorophenyl-2-methylamino cyclohexanone) is a N-Methyl-D-Aspartat (NMDA) receptor antagonist. S (+) ketamine has a four times stronger affinity to the NMDA receptor compared to R (-) ketamine. The duration of action for S (+) ketamine is shorter than R (-) ketamine and it has fewer side-effects.
The purpose of this study is to compare the analgetic effect of pregabalin and placebo used in the perioperative period.
The hypothesis is that perioperative intravenous S (+) ketamine gives significant better analgesia than placebo without effecting cognitive function.
The study is including patients undergoing hemorrhoidectomy.
Inclusion Criteria:
Exclusion Criteria: