Efficacy of S(+)-Ketamine Administered as a Continuous Infusion for the Control of Postoperative Pain

Efficacy of S(+)-Ketamine Administered as a Continuous Infusion for the Control of Postoperative Pain

Efficacy of S(+)-Ketamine Administered as a Continuous Infusion for the Control of Postoperative Pain: a Randomized Controlled Trial

Background: The use of low-dose continuous infusion of S(+)-ketamine combined with target-controlled intravenous anesthesia with remifentanil and propofol may be related to the control of postoperative pain and of opioid-induced hyperalgesia. The present study aimed to evaluate the efficacy of continuous infusion of S(+)-ketamine given intraoperatively in the control of postoperative pain compared to placebo.

Methods: This is a double-blind randomized controlled trial with 48 patients of both genders aged from 18 to 65 years who underwent videolaparoscopic cholecystectomy. After venipuncture, patients received intravenous parecoxib sodium (40 mg). Target-controlled intravenous anesthesia was induced with propofol and remifentanil associated with rocuronium and adjusted to maintain the bispectral index between 35 and 50. The S(+)-ketamine group (SG) group received a continuous infusion of S(+)-ketamine at a dose of 0.3mg.kg-1.h-1, while the placebo group (PG) received a continuous infusion of saline at the same dose. Postoperative analgesia was measured by a verbal numerical scale (VNS) from 0 to 10 during 12 hours and treated with morphine when VNS score was equal to or higher than 3 at a dose of 0.05 mg.kg-1 when the patient reported pain for the first time and at a dose of 0.025mg.kg-1 on subsequent occasions. Pain scores were recorded in the postoperative care unit (PACU) and at 4 and 12 hours after the end of the surgery The amount of morphine used during PACU stay, from PACU discharge to 4 hours after surgery, and from 4 to 12 hours after surgery, the overall dose of morphine used, and possible adverse effects were also assessed

Five minutes before surgery, patients in the SG group received an intravenous continuous infusion containing 0.3 mg.kg-1.h-1 of S(+)-ketamine

Inclusion Criteria: 18 Years to 65 Years ASA I and II Accepts healthy volunteers. Exclusion Criteria: alcohol or illicit drugs, H2 inhibitors, opioids, or calcium-channel blockers within the last 10 days chronic pain, myocardial ischemia, psychiatric diseases.

Joly V, Richebe P, Guignard B, Fletcher D, Maurette P, Sessler DI, Chauvin M. Remifentanil-induced postoperative hyperalgesia and its prevention with small-dose ketamine. Anesthesiology. 2005 Jul;103(1):147-55. doi: 10.1097/00000542-200507000-00022.

Untergehrer G, Jordan D, Eyl S, Schneider G. Effects of propofol, sevoflurane, remifentanil, and (S)-ketamine in subanesthetic concentrations on visceral and somatosensory pain-evoked potentials. Anesthesiology. 2013 Feb;118(2):308-17. doi: 10.1097/ALN.0b013e318279fb21.

Miziara LE, Simoni RF, Esteves LO, Cangiani LH, Grillo-Filho GF, Paula AG. Efficacy of Continuous S(+)-Ketamine Infusion for Postoperative Pain Control: A Randomized Placebo-Controlled Trial. Anesthesiol Res Pract. 2016;2016:6918327. doi: 10.1155/2016/6918327. Epub 2016 Feb 2.