ABSTRACT
BACKGROUND: We investigated the effects of the combined administration of nefopam, a N-methyl-D-aspartate receptor antagonist and low dose remifentanil, on early postoperative pain and analgesic requirement. METHODS: Fifty patients scheduled to undergo mastoidectomy and tympanoplasty were randomized to be given either nefopam 40 mg mixed with normal saline 100 ml (Group N) or an equal amount of normal saline (Group C) before anesthesia induction. Anesthesia was maintained with 5-6 vol% desflurane and remifentanil 0.05-0.15 microg/kg/min during the surgery. Postoperative pain was controlled by titration of ketorolac in the postanesthesia care unit (PACU) and ward. We evaluated the intraoperative remifentanil dose, recovery profiles, ketorolac demand in the PACU and ward, numeric rating scale (NRS) for pain at time intervals of every 10 min for 1 h in the PACU, 6, 12, 18 and 24 h in a ward, as well as the time to first analgesic requirement in the PACU and ward. RESULTS: Ketorolac demand and NRS in the PACU were significantly lower in Group N than Group C (P = 0.002, P = 0.005, respectively). The time to first analgesic requirement in the PACU in Group N were significantly longer than Group C (P = 0.046). There were no significant differences in intraoperative remifentanil dose, ketorolac demand, NRS, and the time to first analgesic requirement in the ward between the groups. CONCLUSIONS: Nefopam administration combined with low dose remifentanil infusion reduces pain and analgesic consumption during the immediate postoperative period in patients undergoing middle ear surgery under desflurane anesthesia.
Subject(s)
Humans , Anesthesia , Ear, Middle , Ketorolac , N-Methylaspartate , Nefopam , Pain, Postoperative , Postoperative Period , TympanoplastyABSTRACT
BACKGROUND: Remifentanil is a useful and relatively safe opioid, but acute tolerance to it frequently develops, as patients who have received remifentanil based anesthesia often suffer postoperative hyperalgesia.This study investigated whether a small dose of ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, can attenuate postoperative pain suffered with remifentanil anesthesia. METHODS: 32 patients who were scheduled to undergo laparoscopic cholecystectomy were randomly assigned to two groups: a ketamine group (group K) and a control group (group C).All patients were given remifentanil by target controlled infusion (TCI) to the effect site (concentrations:4.0-6.0 ng/ml).Just before incision patients in group K received 0.15 mg/kg ketamine intravenously and patients in group C received the same volume, but only of normal saline.Pain scores measured by Numerical Rating Scale (NRS) and additional use of analgesics were immediately recorded by a blinded investigator at the post-anesthesia care unit (PACU) and general ward up to 24 hours after surgery. RESULTS: The average NRS scores upon arrival to PACU, 5, 10, 15 and 30 min in PACU, and 5 hours after discharge from PACU were significantly lower in group K than group C.The frequency of additional analgesics use was also significantly lower in group K. CONCLUSIONS: It is suggested that a small dose of ketamine attenuates the postoperative pain felt with remifentanil anesthesia. This finding also suggests that ketamine may decrease the possible acute tolerance developed with remifentanil anesthesia.
Subject(s)
Humans , Analgesics , Anesthesia , Cholecystectomy, Laparoscopic , Hyperalgesia , Ketamine , N-Methylaspartate , Pain, Postoperative , Patients' Rooms , Piperidines , Research PersonnelABSTRACT
AIM: To observe the effects of ketamine on preventing the increase of postoperative morphine requirement induced by fentanyl.METHODS: Sixty women undergoing total abdominal hysterectomy by spinal anaesthesia were assigned to 4 groups consisting of placebo(normal saline,C),fentanyl(3 bolus of 1 ?g/kg,at 15 min intervals,F),ketamine(infusion of 15 ?g?kg-1?min-1 ketamine from the skin incision until 20 min before the end of the surgery,K),ketamine and fentanyl(infusion of 15 ?g?kg-1?min-1 ketamine from the skin incision until 20 min before the end of the surgery plus 3 bolus of 1 ?g/kg fentanyl,at 15-min intervals,FK).The cumulative morphine consumption,pain score,and adverse effects(nausea, vomiting,hallucination,dizziness and itching) were recorded at 1,3,6,12,24,48 h postoperatively.RESULTS: There were no significant differences in age,weight,duration of surgery and the post-operative sensory block time.The cumulative morphine consumption in group F was significantly higher than those in group C at 3,6,12 h postoperatively(P