Objective The aim of this study was to investigate the optimum dosage of dexmedetomidine for prevention of postanesthetic shivering.Methods One-hundred thirty two ASA physical status I-II patients scheduled for elective laparoscopic total hysterectomy were enrolled in this randomised, placebo-controlled study. Patients were randomly allocated to receive dexmedetomidine in four groups: group S (0.9% normal saline), group D0.5 (dexmedetomidine 0.5 µg/kg), group D0.75 (dexmedetomidine 0.75 µg/kg), group D1.0 (dexmedetomidine 1.0 µg/kg). Time to extubation and tympanic temperature during and after operation were measured. Shivering was graded (0-3 scale) upon patients arrival to the PACU and every ten minutes thereafter up to forty minutes. Sedation and first rescue analgesic time at the PACU were evaluated.Results The incidence of shivering was significantly lower in group D0.75 and D1.0 than in group S (P < 0.05). There were significantly fewer patients with a shivering score of 2 or 3 in groups D0.75 and D1.0 than in group S (P < 0.05, P < 0.001). Extubation time was shorter in group S than in groups D0.75 and D1.0 (P < 0.05). Tympanic temperature at 40 minutes postoperatively in the recovery room was higher in group S than in the other dexmedetomidine groups (P < 0.05)Fewer patients required rescue analgesia in groups D0.75 and D1.0 than in group S (P < 0.001), and the time to rescue analgesia was longer in group D1.0 than in group S (P < 0.001). Modified Observer's Assessment of Alertness/Sedation (MOAA/S) at arrival in the PACU was lower in all dexmedetomidine groups than in group S (P < 0.05).Conclusions Our results suggest that dexmedetomidine 0.75 or 1.0 µg/kg provides effective prophylaxis against postoperative shivering as well as an analgesic effect. Though potential for intraoperative requirement for atropine, sedation in the immediate recovery period and delayed extubation time with dexmedetomidine was noted, there were no major clinical impacts on the overall recovery from anesthesia.

Background:Adjuvant perineural dexmedetomidine can be used to prolong the analgesic effect of interscalene brachial plexus block (ISB). We investigated the optimal dose of dexmedetomidine in ISB for postoperative analgesia in patients undergoing arthroscopic shoulder surgery.Methods:One hundred patients scheduled for elective shoulder arthroscopic surgery were enrolled in this randomized, double-blind study. Ultrasound-guided ISB was performed before general anesthesia using 22 mL of ropivacaine 0.5% combined with 1, 1.5, or 2 μg/kg of dexmedetomidine (group D1, D2, and D3, respectively) or with normal saline as a control (group R, n = 25 per group). The primary outcome was the duration of analgesia (DOA), numeric pain rating scale (NRS), and consumption of additional analgesics during 36 h after ISB. Secondary outcome included durations of motor and sensory block (DOM and DOS), hemodynamic variables and sedation and dyspnea scores.Results:Ninety-seven patients completed the study. The DOS, DOM, and DOA were significantly longer in the dexmedetomidine groups than in group R. The DOA was significantly longer in group D3 than in groups D1 (P = .026) and D2 (P = .039). The DOA was 808.13 ± 179.97, 1032.60 ± 288.14, 1042.04 ± 188.13, and 1223.96 ± 238.06 min in groups R, D1, D2, and D3, respectively. The NRS score was significantly higher in group R than in the dexmedetomidine groups 12 h after ISB (P < .001) and significantly lower in group D3 than in the other groups 18 h after ISB (P = .02). The incidence of hypotension was higher in groups D2 and D3 than in group R during surgery (P = .008 and P = .011, respectively). There were no significant differences in consumption of rescue analgesics, sedation, and dyspnea scores between the study groups.Conclusion:Perineural dexmedetomidine 2 μg/kg could be the optimal dose in ISB for arthroscopic shoulder surgery in that it provides an adequate DOA. However, this dose was associated with increased risk of hypotension.

We aimed to compare fentanyl, remifentanil and dexmedetomidine with respect to hemodynamic stability, postoperative pain control and achievement of sedation at the postanesthetic care unit (PACU). In this randomized double-blind study, 90 consecutive total laparoscopic hysterectomy patients scheduled for elective surgery were randomly assigned to receive fentanyl (1.0 µg/kg) over 1 minute followed by a 0.4 µg/kg/hr infusion (FK group, n = 30), or remifentanil (1.0 µg/kg) over 1 minute followed by a 0.08 µg/kg/min infusion (RK group, n = 30), or dexmedetomidine (1 µg/kg) over 10 minutes followed by a 0.5 µg/kg/hr infusion (DK group, n = 30) initiating at the end of main procedures of the operation to the time in the PACU. A single dose of intravenous ketorolac (30 mg) was given to all patients at the end of surgery. We respectively evaluated the pain VAS scores, the modified OAA/S scores, the BIS, the vital signs and the perioperative side effects to compare the efficacy of fentanyl, remifentanil and dexmedetomidine. Compared with other groups, the modified OAA/S scores were significantly lower in DK group at 0, 5 and 10 minutes after arrival at the PACU (P < 0.05), whereas the pain VAS and BIS were not significantly different from other groups. The blood pressure and heart rate in the DK group were significantly lower than those of other groups at the PACU (P < 0.05). DK group, at sedative doses, had the better postoperative hemodynamic stability than RK group or FK group and demonstrated a similar effect of pain control as RK group and FK group with patient awareness during sedation in the PACU. (World Health Organization registry, KCT0001524).

Acute unilateral parotid gland swelling after general anesthesia, anesthesia mumps is rare and when occurred, it is associated with the patient's position and with long-lasting surgery. The exact mechanism or etiology has not been fully established but stasis of gland secretion, blockage of Stensen's duct by direct compression, or retrograde flow of air by increased the oral cavity pressure are suspicious reasons. We experienced a case of soft tissue swelling in the left preauricular and submandibular regions in a 40-year-old female patient after short-lasting, hysteroscopic myomectomy performed in the lithotomy position with no suspicious predisposing factor. It is required to pay attention on the fact that even with the usual face mask ventilation can lead to the development of anesthesia mumps.

Background Most depth of anesthesia (DOA) monitors rely on the temporal characteristics of a single-channel electroencephalogram (EEG) and cannot provide spatial or connectivity information. Phase lag entropy (PLE) reflects DOA by calculating diverse connectivity from temporal patterns of phase relationships. The aim of this study was to compare the performance of PLE and bispectral index (BIS) monitors for assessing DOA during anesthesia induction, nerve integrity monitoring (NIM), and anesthesia emergence. Methods Thirty-five patients undergoing elective thyroid surgery with recurrent laryngeal nerve NIM received propofol and remifentanil via target-controlled infusion. After applying PLE and BIS monitors, propofol infusion was initiated at a calculated effect site concentration (Ce) of 2 µg/mL and then increased in 1-µg/mL Ce increments. After propofol Ce reached 5 μg/mL, a remifentanil infusion was begun, and anesthesia induction was considered complete. During NIM, PLE and BIS values were compared at a specific time points from platysma muscle exposure to subcutaneous tissue closure. PLE and BIS values were recorded continuously from preanesthetic state to full recovery of orientation; bias and limits of agreement between monitors were calculated. Results PLE and BIS values decreased progressively with increasing propofol Ce during anesthetic induction and increased by stages during emergence. The prediction probabilities of PLE and BIS for detecting propofol Ce changes were 0.750 and 0.756, respectively, during induction and 0.749 and 0.746, respectively, during emergence. No aberrant PLE or BIS values occurred during NIM. Correlation coefficients for BIS and PLE were 0.98 and 0.92 during induction and emergence, respectively. PLE values were significantly higher than BIS values at full recovery of orientation. Estimated bias between monitors was −4.16 ± 8.7, and 95% limits of agreement were −21.21 to 12.89. Conclusion PLE is a reasonable alternative to BIS for evaluating consciousness and DOA during general anesthesia and during NIM. Trial Registration Clinical Research Information Service Identifier: KCT0003490

Background: Pressure-controlled ventilation volume-guaranteed (PCV-VG) is being increasingly used for ventilation during general anesthesia. Carbon dioxide (CO2) pneumoperitoneum in the Trendelenburg position is routinely used during robot-assisted laparoscopic gynecologic surgery. Here, we hypothesized that PCV-VG would reduce peak inspiratory pressure (Ppeak), compared to volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV). Methods: In total, 60 patients were enrolled in this study and randomly assigned to receive VCV, PCV, or PCV-VG. Hemodynamic variables, respiratory variables, and arterial blood gases were measured in the supine position 15 minutes after the induction of anesthesia (T0), 30 and 60 minutes after CO2 pneumoperitoneum and Trendelenburg positioning (T1 and T2, respectively), and 15 minutes after placement in the supine position at the end of anesthesia (T3). Results: The Ppeak was higher in the VCV group than in the PCV and PCV-VG groups (p=0.011). Mean inspiratory pressure (Pmean) was higher in the PCV and PCV-VG groups than in the VCV group (p<0.001). Dynamic lung compliance (Cdyn) was lower in the VCV group than in the PCV and PCV-VG groups (p=0.001). Conclusion: Compared to VCV, PCV and PCV-VG provided lower Ppeak, higher Pmean, and improved Cdyn, without significant differences in hemodynamic variables or arterial blood gas results during robot-assisted laparoscopic gynecologic surgery with Trendelenburg position.

Background: Immobilization with cervical spine worsens endotracheal intubation condition. Though various intubation devices have been demonstrated to perform well in oral endotracheal intubation, limited information is available concerning nasotracheal intubation (NTI) in patients with cervical spine immobilization. The present study compared the performance of the C-MAC D-Blade videolaryngoscope with the McCoy laryngoscope for NTI in patients with simulated cervical spine injuries. Methods: This was a prospective, randomized, controlled, study done in a tertiary hospital. Ninety-five patients requiring NTI were included in data analysis: McCoy group (group M, n = 47) or C-MAC D-Blade videolaryngoscope group (group C, n = 48). A Philadelphia neck collar was applied before anesthetic induction to immobilize the cervical spine. Single experienced anesthesiologist performed NTI. The primary outcome was duration of intubation divided by three steps: nose to oropharynx; oropharynx into glottic inlet; and glottic inlet to trachea. Secondary outcomes included glottic view as percentage of glottis opening (POGO) score and Cormack-Lehance (CL) grade, modified nasal intubation-difficulty scale (NIDS) rating, hemodynamic changes before and after intubation, and complications.Results: Total intubation duration was significantly shorter in group C (39.5 ± 11.4 s) compared to group M (48.1 ± 13.9 s). Group C required significantly less time for glottic visualization and endotracheal tube placement in the trachea. More patients in group C had CL grade I and higher POGO scores (P < 0.001, for both measures). No difficulty in NTI (modified NIDS = 0) was more in group C than group M. Hemodynamic changes and incidence of complications were comparable between groups.(Continued on next page)

Objective: To investigate the optimal dose of dexmedetomidine for attenuating the haemodynamic response during emergence from anaesthesia. Methods: Patients undergoing laparoscopic total hysterectomy were randomly allocated to receive 0.9% normal saline (control group) or dexmedetomidine (0.5 mg/kg, 0.75 mg/kg or 1.0 mg/kg 30 min) before extubation. Heart rate, systolic and diastolic arterial pressure and extubation time were measured before drug administration, immediately after the end of drug administration, 10 min after the end of drug administration, immediately after extubation and 5 min after extubation. Results: A total of 120 patients were included in the study (30 per group). Systolic and diastolic arterial pressure and heart rate after drug administration were significantly lower in all three dexmedetomidine groups compared with controls. Extubation times in the 0.75 and 1.0 mg/kg dexmedetomidine groups were significantly longer than in the control group. Conclusion: Intravenous infusion of 0.5 mg/kg dexmedetomidine 30 min before the end of surgery attenuated the haemodynamic responses during emergence without prolonging the extubation time. Dexmedetomidine doses higher than 0.5 mg/kg did not exert additional positive effects on cardiovascular responses, but did significantly prolong the extubation time.