Journal of Anesthesia最新文献

Purpose: We evaluated the electromyography (EMG)-based neuromuscular monitoring detectability of our novel stimulating electrode attachment method compared to the original Nihon-Kohden (Tokyo, Japan) attachment method.

Methods: This single-center randomized, double-blind, controlled pilot study enrolled 32 patients aged ≥ 18 years, undergoing scheduled laparoscopic surgery. The EMG electrode NM-345Y™ was attached to one forearm using the Nihon-Kohden method (Pattern N-K) and the other forearm using our novel method (Pattern Cross). The allocation to each attachment method was determined post-randomization. In Pattern Cross, the NM-345Y™ was attached such that the line connecting the anode and cathode crosses the ulnar nerve. Patients received 0.9 mg/kg rocuronium after calibration with the forearm in 90-degree supination. Following tracheal intubation, the forearm was positioned in 0-degree pronation. Intraoperatively, 0.2 mg/kg rocuronium was administered if the train-of-four (TOF) count one persisted for 1 min on either side. Post-surgery, the forearm position was returned to 90-degree supination, and rocuronium was antagonized with sugammadex. TOF and post-tetanic count (PTC) were simultaneously measured bilaterally every 15 s and 5 min, respectively, from post-calibration to tracheal extubation.

Results: The time to first PTC appearance was significantly shorter by 33 min in the Pattern Cross group than in the Pattern N-K group (95% Confidence interval: 1-66, p = 0.043). Following sugammadex administration, TOF ratios ≥ 0.9 were achieved in 72% of patients in the Pattern N-K group and 97% of those in the Pattern Cross group (p = 0.025).

Conclusions: Crossing the line connecting the anode and cathode with the ulnar nerve stabilizes EMG-based neuromuscular monitoring detectability.

Purpose: Inferior alveolar nerve (IAN) and lingual nerve (LN) blocks are commonly performed using the intraoral landmark techniques. However, these methods have a risk of unanticipated nerve and arterial injury or a higher failure rate. We developed a novel extraoral approach for the IAN and LN blocks, the "inferior alveolar nerve block mandibular angle approach (IANB-MA)," using ultrasound guidance. The mechanism of action of this nerve block was examined anatomically, and its clinical feasibility was reported.

Methods: We performed the IANB-MA on four cadavers using different dye volumes (2, 4, 6 and 8 mL). The ultrasound probe was placed on the lower edge of the mandibula of each cadaver, and the needle was advanced to the mandibular inner surface. Blue acrylic paint solution was injected, and its spread was evaluated by dissection.

Results: Our study showed that the medial pterygoid muscle fascia was stained in all cadavers. The dye reached the LN consistently, and the IAN was stained with higher volumes (6 mL and 8 mL). The pterygomandibular space was filled with 6 mL and 8 mL of the dye. The IANB-MA successfully reduced pain in three patients with trigeminal neuralgia, tongue or jaw pain.

Conclusions: The IANB-MA is a novel ultrasound-guided approach to the IAN and the LN. The clinical feasibility and effectiveness of this technique were confirmed in our patients. It may be a good alternative analgesic approach to other conventional approaches.

Purpose: This study aimed to estimate the median effective dose of intrathecal isobaric ropivacaine without opioid required for adequate cesarean delivery anesthesia after epidural labor analgesia.

Methods: Patients aged 20-40 years with American Society of Anesthesiology scores of I-II, body mass index ≤ 36, who underwent emergency cesarean delivery after failed vaginal delivery with epidural analgesia of a duration ≤ 6 h were included in the study. After removal of the epidural used for labor analgesia, a new combined spinal epidural was performed, and a dose of intrathecal isobaric ropivacaine without opioid was administered. The dose was determined using up-down methodology, with the starting patient's dose set to 12 mg. Adequate anesthesia, defined as a pinprick level no lower than T6 at 5 min after ropivacaine administration, resulted in the next patient receiving a dose of ropivacaine 1 mg higher, and inadequate anesthesia 1 mg lower. The primary outcome was the median (95% confidence interval (CI)) dose of spinal ropivacaine required for adequate cesarean delivery anesthesia.

Results: Of the 46 patients included in the study, 40 were analyzed. The median spinal ropivacaine dose was 8.11 mg (95% CI 7.29-8.93 mg) by the Dixon and Mood method and 8.06 mg (95% CI 6.93-9.00 mg) by isotonic regression. Two patients had high spinal anesthesia.

Conclusion: Our findings suggest that for 50% of patients undergoing cesarean delivery after failed vaginal delivery with epidural analgesia, an 8-mg spinal dose of isobaric ropivacaine without opioid provides an anesthesia level no lower than T6 at 5 min.

Purpose: Remimazolam is often used for perioperative sedation due to its rapid onset and offset. However, the possible association between remimazolam and postoperative delirium (POD) remains undetermined. The present study evaluated whether remimazolam increased the incidence of POD compared with dexmedetomidine in elderly patients undergoing orthopedic surgery of the lower extremities.

Methods: This retrospective study included patients aged ≥ 65 years who had undergone orthopedic surgery of the lower extremities under spinal anesthesia from January 2020 to November 2022 and were sedated with continuous intravenous infusion of dexmedetomidine or remimazolam. The incidence of POD was assessed through a validated comprehensive review process of each patient's medical records. The effect of remimazolam on the occurrence of POD compared with dexmedetomidine was evaluated by propensity score weighted multivariable logistic models.

Results: A total of 447 patients were included in the final analysis. The crude incidence of POD within 3 days after surgery was 7.5% (17/226) in the dexmedetomidine group and 11.8% (26/221) in the remimazolam group, increasing to 9.7% (22/226) and 15.8% (35/221), respectively (p = 0.073), within 5 days. The multivariable models showed that, compared with dexmedetomidine, intraoperative sedation with remimazolam significantly increased the occurrence of POD within 3 days (odds ratio [OR] 2.21, 95% confidence interval [CI] 1.31 to 3.82, p = 0.003) and 5 days (OR 2.10, 95% CI 1.32 to 3.40, p = 0.002).

Conclusion: Compared with dexmedetomidine, remimazolam infusion may be associated with a higher risk of POD in elderly patients undergoing orthopedic surgery of the lower extremities under spinal anesthesia.

Purpose: Ultrasound view of the interlaminar structure is likely to be associated with difficult spinal anesthesia (DSA), and a poor ultrasound view which cannot show the anterior and posterior complex predicts a difficult spinal technique. As our target site is the posterior complex, this study aimed to assess whether the ratio of posterior complex length to depth measured by ultrasound can predict DSA in cesarean delivery.

Methods: Four anesthesiologists with 1-2 years of experience located and marked the puncture interspace using a traditional surface landmark. Subsequently, the ultrasound examiner located and measured the marked interspace via an oblique parasagittal ultrasound scan. The anesthesiologists, who were blinded to the ultrasound results, performed spinal anesthesia using a 25-gauge Whitacre spinal needle. The total number of attempts, including skin punctures and needle passes, was recorded and the DSA was defined as 10 unsuccessful attempts. A multivariable logistic regression analysis was used to determine the independent predictors, and receiver operating characteristic curves were constructed to evaluate the performance of the ratio of posterior complex length to depth for predicting DSA.

Results: A total of 397 cesarean delivery parturients with successfully measured posterior complex were included in the analysis. DSA occurred in 64 parturients (16.1%). Reduced length [odds ratio (OR) = 0.010, 95% confidence interval (CI), 0.002-0.062, P < 0.001] and increased depth [OR = 6.127, 95% CI, 2.671-14.056, P < 0.001] of the posterior complex were independently predictive of DSA compared with body mass index, abdominal circumference, and palpable surface landmarks. The ratio of posterior complex length to depth for predicting DSA had an area under the curve of 0.86 (95% CI, 0.82-0.90). The optimal cutoff was 0.23, with a sensitivity of 86% (95% CI, 74-93%) and specificity of 72% (95% CI, 67-77%).

Conclusion: The ratio of posterior complex length to depth measured by ultrasound demonstrated a considerable accuracy in predicting DSA for inexperienced anesthesiologists. A higher ratio at ultrasound is an indication to evaluate the optimal puncture body position and interspace in the clinic practice.

Clinical trial registration: ChiCTR2200065171 https://www.chictr.org.cn/showproj.html?proj=180855.

Background: Ketamine and fentanyl are commonly used for sedation and induction of anesthesia in critically ill patients. This study aimed to compare the hemodynamic effects of ketamine versus fentanyl bolus in patients with septic shock.

Methods: This randomized controlled trial included mechanically ventilated adults with septic shock receiving sedation. Patients were randomized to receive either 1 mg/kg ketamine bolus or 1 mcg/kg fentanyl bolus. Cardiac output (CO), stroke volume (SV), heart rate (HR), and mean arterial pressure (MAP) were measured at the baseline, 3, 6, 10, and 15 min after the intervention. Delta CO was calculated as the change in CO at each time point in relation to baseline measurement. The primary outcome was delta CO 6 min after administration of the study drug. Other outcomes included CO, SV, HR, and MAP.

Results: Eighty-six patients were analyzed. The median (quartiles) delta CO 6 min after drug injection was 71(37, 116)% in the ketamine group versus - 31(- 43, - 12)% in the fentanyl group, P value < 0.001. The CO, SV, HR, and MAP increased in the ketamine group and decreased in the fentanyl group in relation to the baseline reading; and all were higher in the ketamine group than the fentanyl group.

Conclusion: In patients with septic shock, ketamine bolus was associated with higher CO and SV compared to fentanyl bolus.

Clinical trial registration: Date of registration: 24/07/2023.

Clinicaltrials: gov Identifier: NCT05957302. URL: https://clinicaltrials.gov/study/NCT05957302 .

Background: Benzodiazepines are used in pediatric patients with congenital heart disease (CHD) because of their mild hemodynamic depressant effects. A novel short-acting benzodiazepine, remimazolam, is expected to be suitable for these patients. We examined the characteristics of remimazolam anesthesia in pediatric patients with CHD undergoing cardiac catheterization.

Methods: This single-center retrospective study included pediatric patients undergoing cardiac catheterization for CHD. The primary outcome was the remimazolam dose for loss of consciousness. Secondary outcomes included the mean maintenance remimazolam dose, recovery time from anesthesia, predicted remimazolam concentration at emergence, decrease in blood pressure and heart rate, vasopressor administration during anesthesia, electroencephalogram index (bispectral index: BIS or patient state index: PSI), and life-threatening adverse events.

Results: Thirty-nine patients, aged 2 months to 16 years, were included. Thirty-three patients received a median [interquartile] midazolam dose of 0.10 [0.10-0.10] mg.kg^-1 in the pre-anesthesia room. The remimazolam dose for loss of consciousness was 0.34 [0.26-0.45] mg.kg^-1. The mean maintenance dose was 1.0 [0.8-1.4] mg.kg^-1.h^-1. The recovery time was 15 [12-17] min. The predicted remimazolam concentration at emergence was 0.4-1.2 µg.ml^-1 in 3-6-year-old patients. Blood pressure and heart rate decreased by 30% in 15 and 6 patients, respectively. Vasopressors were administered as a bolus in 8 patients. The BIS or PSI did not fall ≤ 60 or ≤ 50, respectively, in 51% of patients before tracheal intubation. No life-threatening adverse events were reported.

Conclusions: Remimazolam is a good alternative anesthetic agent for pediatric patients undergoing cardiac catheterization for CHD.