Remifentanil-induced pronociceptive effect and its prevention with pregabalin / 대한마취과학회지

BACKGROUND: Experimental and clinical studies have suggested that remifentanil probably causes acute tolerance or postinfusion hyperalgesia. This study was designed to confirm whether remifentanil given during propofol anesthesia induced postoperative pain sensitization, and we wanted to investigate whether pregabalin could prevent this pronociceptive effect. METHODS: Sixty patients who were scheduled for total abdominal hysterectomy were randomly allocated to receive (1) a placebo as premedication and an intraoperative saline infusion (control group), (2) a placebo as premedication and an intraoperative infusion of remifentanil at a rate of 3-4 ng/ml (remifentanil group), or (3) pregabalin 150 mg as premedication and an intraoperative infusion of remifentanil at a rate of 3-4 ng/ml (pregabalin-remifentanil group). Postoperative pain was controlled by titration of fentanyl in the postanesthetic care unit (PACU), followed by patient-controlled analgesia (PCA) with fentanyl. The patients were evaluated using the visual analogue scale (VAS) for pain scores at rest and after cough, consumption of fentanyl, sedation score and any side effects that were noted over the 48 h postoperative period. RESULTS: The fentanyl titration dose given in the PACU was significantly larger in the remifentanil group as compared with those of the other two groups. At rest, the VAS pain score in the remifentanil group at 2 h after arrival in the PACU was significantly higher than those in the other two groups. CONCLUSIONS: The results of this study show that remifentanil added to propofol anesthesia causes pain sensitization in the immediate postoperative period. Pretreatment with pregabalin prevents this pronociceptive effect and so this may be useful for the management of acute postoperative pain when remifentanil and propofol are used as anesthetics.

A Comparison of Remifentanil versus Fentanyl as an Adjuvant to Propofol Anesthesia for Ureteroscopic Lithotripsy / 대한마취과학회지

BACKGROUND: Remifentanil is a new member of fentanyl family and a short-acting, esterase-metabolized opioid.This study compared the perioperative characteristics of a remifentanil infusion with those of fentanyl bolus administration as an adjuvant to propofol infusion for the anesthetic management of patients undergoing ureteroscopic lithotripsy. METHODS: Eighty patients were randomly assigned to receive either remifentanil target controlled infusion (R group, effect-site concentration of 4.0 ng/ml for induction followed by 2.0 ng/ml) or fentanyl bolus (F group, 2.0microgram/kg before induction).All patients received propofol infusion as the part of the induction and maintenance.We investigated recovery profiles, adverse events and the ease of insertion of laryngeal mask airway (LMA) between the two groups.Heart rate (HR) and mean blood pressure (MBP) were also compared at baseline (T0), loss of consciousness (T1), insertion of LMA (T2), beginning and end of operation (T3, T4) and removal of LMA (T5). RESULTS: The time from the end of anesthesia to spontaneous respiration, eye opening and LMA removal were significantly shorter for patients receiving remifentanil than for those receiving fentanyl.HR at T3 and T4 were lower in the R group than in the F group.Aldrete recovery score, time to discharge from recovery ward, the ease of insertion of the LMA, MAP and adverse events did not differ significantly between the two groups. CONCLUSIONS: Target controlled infusion of remifentanil combined with propofol can significantly shorten the early recovery time than fentanyl bolus administration without increasing adverse events in patients undergoing ureteroscopic lithotripsy.