Young Soon Choi

Remifentanil-induced pronociceptive effect and its prevention with pregabalin

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.

The Effects of Postoperative Brachial Plexus Block Using MgSO4 on the Postoperative Pain after Upper Extremity Surgery

Background Although a brachial plexus block can be used to provide anesthesia and analgesia for upper extremity surgery, its effects using MgSO4 on postoperative pain management have not been reported. The aim of this study was to evaluate brachial plexus block using MgSO4 on postoperative analgesia. Methods Thirty-eight patients who were scheduled to undergo upper extremity surgery were randomly allocated into two groups: patients receiving axillary brachial plexus block with 0.2% ropivacaine 20 ml and normal saline 2 ml (group S) or 0.2% ropivacaine 20 ml and MgSO4 200 mg (group M). Before extubation, the blocks were done and patient controlled analgesia was started, and then, the patients were transported to a postanesthetic care unit. The postoperative visual analogue scale (VAS), opioid consumption, and side effects were recorded. Results The two groups were similar regarding the demographic variables and the duration of the surgery. No differences in VAS scores were observed between the two groups. There was no statistically significant difference in opioid consumption between the two groups. Nausea was observed in three patients for each group. Conclusions Axillary brachial plexus block using MgSO4 did not reduce the level of postoperative pain and opioid consumption.

A comparative study of emergence agitation between sevoflurane and propofol anesthesia in adults after closed reduction of nasal bone fracture

Background Emergence agitation is associated with increased morbidity and hospital costs. However, there have been few reports in the medical literature on the occurrence of emergence agitation in adults. The aim of this study was to compare emergence agitation between sevoflurane and propofol anesthesia in adults after closed reduction of nasal bone fracture. Methods Forty adults (ASA I-II, 20-60 yr) undergoing closed reduction of nasal bone fracture were randomly assigned to either sevoflurane or propofol group and anesthesia was maintained with sevoflurane or propofol. The bispectral index (BIS) was monitored and maintained within 40-60. At the end of surgery, patients were transported to the post anesthetic care unit (PACU) and agitation state scale was checked by Aonos four-point scale (AFPS). Emergence agitation was defined as and AFPS score of 3 or 4. Pain score were measured by numeric rating scale (NRS) on arrival and peak value at PACU. Results Nine (45.0%) patients in the sevoflurane group and 2 (10.0%) patients in the propofol group developed emergence agitation in the PACU (P = 0.031). There was no correlation between peak NRS and Aonos four-point scale. Conclusions Propofol may decrease incidence of emergence agitation compared to sevoflurane in adults undergoing closed reduction of nasal bone fracture.

The effects of lidocaine and fentanyl on airway irritability during inhalation induction with desflurane

BACKGROUND Inhalation induction with desflurane can cause airway irritability and sympathetic stimulation. The aim of this study was to investigate whether lidocaine and fentanyl could reduce these unwanted reactions. METHODS Seventy-five patients who had premedication with midazolam were randomly allocated to one of three groups to receive intravenous saline (S group), lidocaine 1.5 mg/kg (L group), fentanyl 1 microgram/kg (F group), respectively, before tidal volume induction with desflurane in oxygen and nitrous oxide. We recorded airway irritability such as cough, apnea, laryngospasm and excitatory movement and hemodynamic changes. RESULTS Airway irritability was not significantly different between the groups. In F group, mean blood pressure at LOC ver and LOC BIS and heart rate at LOC ver, LOC BIS and just before intubation were lower than those of S group (P < 0.05). Other results were not significantly different. CONCLUSIONS The results of the study showed that intravenous fentanyl and lidocaine had no beneficial effects to reduce airway irritability, but intravenous fentanyl could significantly reduce hemodynamic stimulation during inhalation induction with desflurane in the patients who were premedicated with midazolam.