Efficacy of electrical stimulation on epidural anesthesia for cesarean section: a randomized controlled trial.

BACKGROUND: Loss of resistance (LOR) technique is a widely used method to identify the epidural space. However, cases of inadequate epidural anesthesia in cesarean section were frequently reported. Also, the success rate of epidural anesthesia with LOR technique varied depending on the proficiency of the practitioner. The purpose of this study was to assess the efficacy and safety of electrical stimulation to identify epidural spaces in cesarean section for novices or clinicians with recent gap in experience. METHODS: Pregnant women scheduled for elective cesarean section were randomly allocated to two groups. Groups were classified based on the methods used for identifying the epidural space: the LOR group (group L) and the LOR with epidural electrical stimulation group (group E). Clinicians with less than 10 epidural cesarean section experiences in the recent year performed epidural anesthesia for cesarean section. In the group E, a RegionalStim® conductive catheter was inserted through the Tuohy needle, and the guidewire passing through the catheter was connected to a peripheral nerve stimulator. The intensity of the stimulation was gradually increased from 0.25 mA to 1.5 mA until paresthesia was elicited and radiated. We assessed the success of epidural anesthesia (complete success, partial success or failure). Other clinical parameters including maternal satisfaction, time required for epidural anesthesia, neonatal Apgar scores, pain scores and adverse events were compared between the two groups. RESULTS: Except for 6 patients who withdrew consent, 54 patients were enrolled in this study (28 for the group L and 26 for the group E). The demographic data showed no difference between the two groups. There was no adverse event resulted from electrical stimulation. The group E showed higher rate of complete success, sensitivity in finding epidural space and maternal satisfaction compared to the group L (21/26 vs. 15/28, p = 0.034, 0.96 vs. 0.68, p = 0.012 and 4.04 vs. 3.39, p = 0.02, respectively). The other clinical parameters showed no differences between the two groups. CONCLUSION: In addition to the conventional LOR technique, identifying epidural spaces using electrical stimulation led to better outcomes without additional risks for novices as well as clinicians with recent gap in experience. TRIAL REGISTRATION: This study was retrospectively registered in the ClinicalTrials.gov Registry (NCT03443466) on February 23, 2018.

Comparison of the Analgesic Effect of Sufentanil versus Fentanyl in Intravenous Patient-Controlled Analgesia after Total Laparoscopic Hysterectomy: A Randomized, Double-blind, Prospective Study.

Background: Fentanyl is one of the most widely used opioids for intravenous patient-controlled analgesia (IV-PCA). Sufentanil, a fentanyl analog, is suitable for postoperative pain control because it has no active metabolites and shows a higher therapeutic index and lower frequency of respiratory suppression than fentanyl. This study aimed to compare the two opioids for postoperative pain relief on the basis of analgesic efficacy, adverse effects, and patient satisfaction. Methods: Sixty-four patients undergoing total laparoscopic hysterectomy were randomly allocated into a fentanyl group (n = 31) or a sufentanil group (n = 33). The patients received 50-µg fentanyl or 10-µg sufentanil before induction of anesthesia and 5 minutes after uterine incision during surgery in the fentanyl and sufentanil group, respectively. After arriving at the post-anesthesia care unit (PACU), verbal pain score (VPS) and sedation score were assessed. IV-PCA (fentanyl 1250 µg or sufentanil 250 µg with ondansetron 8 mg; total volume, 60 ml) was connected and continued for 48 h postoperatively. Postoperative pain was evaluated by using the numeric rating scale (NRS; at rest/during cough) at 6, 12, 24, 36, and 48 hours after surgery. The cumulative PCA consumption, patient satisfaction scores, and adverse effects were measured. Results: In the PACU, VPS was significantly higher and rescue fentanyl consumption was higher in the fentanyl group than in the sufentanil group, while the sedation score and adverse effects were comparable between the groups. No significant differences were observed in the NRS scores for pain (at rest/during cough) in the ward over 48 hours postoperatively, but the cumulative PCA consumption was significantly higher in the fentanyl group (47.4 ± 9.9 ml vs. 36.2 ± 14.6 ml, P = 0.01). There were no significant intergroup differences in patient satisfaction score and the incidence of adverse effects in the ward, except for a higher incidence of dry mouth in the fentanyl group. Conclusions: In comparison with fentanyl, sufentanil showed comparable analgesic efficacy and safety with less analgesic consumption (under a potency ratio of 1:5) in IV-PCA after total laparoscopic hysterectomy. Therefore, we suggest that sufentanil can be a useful alternative to fentanyl for IV-PCA.

A Comparison of Bispectral Index and Entropy During Sevoflurane Anesthesia Induction in Children with and without Diplegic Cerebral Palsy.

BACKGROUND: This study compared the correlation of bispectral index (BIS) or entropy with different sevoflurane concentrations between children with and without cerebral palsy (CP) during induction. METHODS: For eighty-two children (40 CP and 42 non-CP children), anesthesia was induced with sevoflurane. BIS and entropy (response entropy and state entropy (RE and SE)) were recorded before and after the induction of anesthesia at end-tidal sevoflurane concentrations of 1-3 vol%. The sedation status was assessed using an Observer's Assessment of Alertness/Sedation scale. The ability to predict awareness was estimated using the area under the receiver-operator characteristic curve (AUC) analysis. RESULTS: RE, SE and BIS values decreased continuously over the observed concentration range of sevoflurane in both groups. The SE values while awake and the RE, SE, BIS values at 3 vol% sevoflurane were lower in children with CP than in those without CP. The AUC of the BIS was significantly better than RE or SE in children without CP. The AUC of the BIS was not significantly higher than that of the RE or SE in children with CP. CONCLUSION: BIS seems better correlated than entropy with the clinical state of loss of response in children without CP, but not in those with CP.