Recovery of memory retention after anesthesia with remimazolam: an exploratory, randomized, open, propofol-controlled, single-center clinical trial.

PURPOSE: Remimazolam, a newly developed ultra-short-acting benzodiazepine, provides early recovery of consciousness but its effects on memory recovery are unclear. This study examined memory recovery after emergence from general anesthesia using remimazolam. METHODS: Seventy-four patients undergoing breast surgery between October 2021 and March 2022 were enrolled and randomly assigned to receive propofol (control group) or remimazolam as general anesthetic during surgery. The primary endpoint was the number of posters patients remembered 24 h after surgery (among four posters shown after recovering from anesthesia) as an assessment of memory retention. The secondary endpoints were the recall of a numeric character patients had been shown just before anesthetic induction, as an assessment of retrograde amnesia 24 h after surgery. RESULTS: Sixty-six patients (propofol, 32; remimazolam, 34) were assessed. Patients in the remimazolam group remembered significantly fewer posters shown to them after surgery than those in the propofol group (0 [0 - 2] vs. 2 [1 - 3], p < 0.001). In the remimazolam group, the patients who received flumazenil remembered a higher number of posters than those who did not receive flumazenil (3 [1 - 4] vs. 0 [0 - 0], p < 0.001). All patients remembered all events that occurred during the preoperative period as well as the numeric character. CONCLUSION: Patients recovering from remimazolam anesthesia without receiving flumazenil do not remember events after regaining consciousness. IRB: Kyushu University School of Medicine Hospital Institutional Review Board (IRB) (approval number: 20212006). TRIAL REGISTRATION: This clinical trial was registered with the University Hospital Medical Information Network (UMIN) Center on September 28, 2021 (UMIN-CTR: UMIN000045593). IMPLICATION STATEMENT: Memory recovery is slower following emergence from remimazolam than from propofol anesthesia.

Comparison of Changes in Chest Wall Mechanics and Respiratory Timing Between Patient-Controlled Epidural Analgesia and Intravenous Patient-Controlled Analgesia After Laparoscopic Gastrectomy: A Randomized Controlled Trial.

BACKGROUND: Upper abdominal surgery is associated with postoperative diaphragmatic dysfunction. Whether patient-controlled epidural analgesia (PCEA) is superior to intravenous patient-controlled analgesia (IV-PCA) in preventing postoperative diaphragmatic dysfunction is still unclear in laparoscopic gastric surgery. METHODS: Sixteen patients undergoing laparoscopic gastrectomy randomly received either PCEA or IV-PCA. The primary outcomes were the change in chest wall mechanics and respiratory timing, measured by respiratory inductive plethysmography (Respitrace; Ambulatory Monitoring Inc., Ardsley, New York, United States) before and after surgery, and analyzed by a data acquisition system (PowerLab; ADInstruments, Dunedin, New Zealand). Inspiratory time (Ti), expiratory time (Te), total respiratory cycle time (Ttot), proportion of inspiratory time over total respiratory cycle time (Ti/Ttot), respiratory rate (RR), and abdominal contribution to tidal volume (AB/VT [%]) were calculated from the stored data. AB/VT, relative volume contribution of diaphragm to tidal breathing, represents an index of diaphragmatic function. Because the diaphragm is the main contributor to tidal volume, decreases in AB/VT indicate diaphragm dysfunction. Changes in outcomes over time between the two groups were analyzed using a linear mixed model, and two-sided p values < 0.05 were considered statistically significant. The secondary outcomes were postoperative pain score (visual analog scale (VAS)), bowel function recovery, and hospital stay duration. RESULTS: Postoperative AB/VT in the IV-PCA group was significantly decreased compared to preoperative levels. AB/VT in the PCEA group was significantly higher than the IV-PCA group on postoperative day (POD) 1. Change in AB/VT over time between the PCEA group and the IV-PCA group differed significantly (p = 0.01). A decrease of AB/VT during POD 1 to 3 was observed in the IV-PCA group but not in the PCEA group. As for respiratory timing, there were significant increases in RR with a reduction of Te and Ttot compared to preoperative levels on POD 1 in the PCEA group. There were significant decreases in RR and Ti/Ttot with an increase of Te and Ttot compared to preoperative levels on POD 1 in the IV-PCA group. There was a significant difference in the change of the Ttot over time between the two groups (p = 0.046). There were no significant differences in the changes of Te, Ti/Ttot, Ti, and RR over time between the two groups. There was no significant difference in VAS over time at rest and mobilization, recovery of bowel function, and hospital stay between the two groups. CONCLUSIONS: Continuous ropivacaine infusion with PCEA partially attenuated diaphragmatic dysfunction after laparoscopic gastrectomy, while pain relief by continuous intravenous administration of fentanyl could not attenuate diaphragmatic dysfunction. This suggests that PCEA might ameliorate postoperative diaphragmatic dysfunction after laparoscopic gastrectomy.

Redistributional Hypothermia Prevention by Prewarming with Forced-Air: Exploratory, Open, Randomized, Clinical Trial of Efficacy.

Avoiding redistributional hypothermia that decreases core temperature by 0.5-1.5°C within the 1st hour of surgery is difficult. The efficacy of prewarming using a forced-air warming (FAW) device with a lower-body blanket on redistribution hypothermia during epidural procedures have not been investigated. After ethics approval, 113 patients undergoing laparoscopic surgery under general anesthesia combined with epidural anesthesia were enrolled. Intervention (prewarming) group patients who were warmed from operating room entry, including during epidural anesthesia, was compared with the control group that was warmed from just before surgery started. In total, 104 patients (52, control; 52, prewarming) were analyzed. In the prewarming group, compared to the control group, the core temperature 20 minutes after anesthesia induction (36.9 ± 0.4 vs. 37.1 ± 0.4°C, p < 0.02) was significantly higher. The core temperature was higher in the prewarming group than in the control group until 3 hours after the surgery. In the prewarming group, compared to the control group, the core temperature-time integral below baseline till 180 minutes after surgery start (65.1 ± 64.0 vs. 8.1 ± 18.6°C/min, p < 0.0001) or 30 minutes after anesthesia induction (5.3 ± 6.2 vs. 2.0 ± 4.7°C/min, p < 0.0001) were significantly smaller. Postoperative shivering was comparable between the groups. Prewarming during epidural catheter insertion with a FAW device could safely prevent a core temperature decrease induced by redistribution or heat loss without additional preparation, effort, space, or time requirements.

Comparison of the Occurrence of Postoperative Shivering Between Sevoflurane and Desflurane Anesthesia.

General anesthetic agents can change the shivering threshold. Sevoflurane and desflurane are widely used as inhalational anesthetics and have also been reported to lower the shivering threshold in a dose-dependent manner. Although the comparison of postoperative shivering (POS) between total intravenous anesthesia and inhalational anesthesia has been reported, there have been no reports on a direct comparison between sevoflurane and desflurane anesthesia and the occurrence of POS in open abdominal surgery. After obtaining approval from the Ethics Review Committee (2020-261), 683 adult patients who underwent open radical surgery for uterine, cervical, or pancreatic cancer under general anesthesia using inhalational anesthetics at Kyushu University hospital between December 2012 and March 2020 were included in this retrospective study. The odds ratio (OR) for the occurrence of POS between the two groups (sevoflurane and desflurane) was calculated. Multivariable-adjusted analysis was performed using possible factors affecting POS. Furthermore, propensity score (PS) matching was conducted using these factors. The multivariable-adjusted OR for the occurrence of shivering in the desflurane group (62 occurrences/356 patients) was 1.06 (95% confidence interval [CI]: 0.69-1.62, p = 0.79) compared with the sevoflurane group (77/327, reference). Similarly, after PS matching, the crude OR for the occurrence of shivering in the desflurane group (47/210) was 1.09 (95% CI: 0.68-1.75, p = 0.72) compared with the sevoflurane group (44/210, reference). Similar results were obtained in the stratified analysis by sex and age. The occurrence of POS is not different between sevoflurane and desflurane anesthesia.

Neurological sedative indicators during general anesthesia with remimazolam.

BACKGROUND: The bispectral index (BIS) value during general anesthesia with the newly developed anesthetic remimazolam is reported to be relatively high; however, the reason for this and the appropriate indicator for assessing the sedation level during remimazolam anesthesia have not been determined. In this study, the level of sedation during general anesthesia with remimazolam was evaluated using several different indicators. METHODS: Thirty patients who underwent breast surgery under general anesthesia with remimazolam were included. BIS®, Sedline® and the pupil resting diameters were measured simultaneously. The intraoperative dose of remimazolam was adjusted to obtain a BIS in the range of 40-60; if a BIS < 60 could not be achieved, the intraoperative dose was increased up to the maximal dose of 2 mg/kg/h. RESULTS: The mean intraoperative BIS and patient state index (PSI) in all patients was 50.6 ± 9.1 and 43.0 ± 11.8, respectively. Five patients showed a mean intraoperative BIS > 60 and eight patients showed mean intraoperative PSI > 50. The mean intraoperative spectral edge frequency (SEF) of BIS® or Sedline® was 15.3 ± 2.5 Hz or 10.6 ± 3.0 Hz, each. The mean intraoperative resting pupil diameter was 1.7 ± 0.2 mm. There were no patients with awareness during anesthesia. CONCLUSIONS: Processed electroencephalograms (BIS and PSI), and SEF of BIS® were relatively high during anesthesia with remimazolam, but SEF of Sedline® or pupillary diameter could be a supportive indicator to confirm sedation level during remimazolam anesthesia.

Anesthetic management of cesarean section in a patient with Takayasu's arteritis: a case report.

BACKGROUND: Takayasu's arteritis (TA) is a chronic, progressive, inflammatory arteritis. We presented the case of cesarean section in a patient with TA. CASE PRESENTATION: A 31-year-old pregnant woman with TA underwent a planned cesarean section at 34 weeks of pregnancy. She had stenosis of the cerebral and coronary arteries and heart failure due to aortic regurgitation. Spinal anesthesia was performed. In addition to standard monitoring, arterial blood pressure in the dorsalis pedis artery and regional cerebral tissue oxygen saturation were monitored. Intraoperative arterial blood pressure was maintained using continuous infusion of noradrenaline with a careful intermittent bolus infusion of phenylephrine. All the procedures were successfully performed without significant complications. CONCLUSIONS: In a pregnant woman with TA, severe stenosis of the cerebral and coronary arteries, and heart failure due to valvular heart disease, careful anesthetic management by selecting catecholamines and assessing the perfusion pressure for critical organs is important.

Anesthetic Management Using Low Fraction of Inspiratory Oxygen for Living Donor Liver Transplantation in a Patient With Hepatopulmonary Syndrome Complicated by Interstitial Pneumonia: A Case Report.

BACKGROUND: Hepatopulmonary syndrome frequently complicates end-stage liver disease. It causes hypoxemia and requires oxygen administration. Additionally, interstitial pneumonia causes hypoxemia; however, it is known to be aggravated by high-concentration oxygen administration. CASE PRESENTATION: A 71-year-old woman with hepatopulmonary syndrome and interstitial pneumonia underwent living donor liver transplantation, requiring conflicting management in terms of the inspiratory oxygen concentration. We achieved a low intraoperative fraction of inspiratory oxygen by increasing the cardiac output with intravenous catecholamines. As a result, the transplanted liver functioned well postoperatively, and the patient was discharged without exacerbation of the interstitial pneumonia. CONCLUSION: We suggest that patients with hepatopulmonary syndrome complicated with interstitial pneumonia can undergo successful living donor liver transplantation without the use of high inspiratory oxygen concentration by using catecholamines to maintain a high mixed venous oxygen saturation.

Retrolaminar versus epidural block for postoperative analgesia after minor video-assisted thoracic surgery: a retrospective, matched, non-inferiority study.

BACKGROUND: The role of thoracic epidural analgesia (TEA) for postoperative analgesia after video-assisted thoracic surgery (VATS) is still controversial. Some studies have reported the efficacy of ultrasound-guided retrolaminar block (RLB) for the postoperative management of pain after chest wall surgery. The purpose of this study was to compare the postoperative analgesic efficacy and adverse effects of ultrasound-guided RLB with those of TEA in patients undergoing minor VATS procedures. METHODS: A total of 192 relevant records of patients were enrolled in this study. We reviewed electronic medical records of patients undergoing minor VATS procedures under general anesthesia. The primary outcome was the median differences in the numerical rating scale (NRS) scores during rest between the groups at the morning of postoperative day 1 (POD 1m). A propensity-matched analysis incorporating preoperative variables was used to compare the efficacy of postoperative analgesia in two groups. RESULTS: Overall, 94 patients were identified for analysis. Propensity score matching resulted in 47 patients in each group. There were no significant differences in the NRS scores between the two groups. The median differences in NRS scores during rest between the two groups at POD 1m were under 1, which indicates non-inferiority of RLB. There were no significant differences in the incidence of adverse effects and rescue dose of analgesic consumption between the two groups. CONCLUSIONS: The analgesic effects of continuous ultrasound-guided RLB were non inferior to those of TEA for minor VATS procedures.

The effect of remimazolam on postoperative memory retention and delayed regeneration in breast surgery patients: Rationale and design of an exploratory, randomized, open, propofol-controlled, single-center clinical trial: A study protocol.

BACKGROUND: Remimazolam, a benzodiazepine ultra-short-acting sedative, has been used in general anesthesia since August 2020. It is used in awake surgeries that require awakening the patient in the middle of the surgery because of its rapid awakening effect as well as antagonistic interactions. If remimazolam has associated anterograde amnesia similar to benzodiazepines, it will have a positive effect on preventing psychological trauma. However, to our knowledge, the effect of remimazolam on anterograde amnesia has not been previously examined. METHODS/DESIGN: The aim of this exploratory, open, propofol-controlled, single-center, randomized clinical trial is to examine the effect of remimazolam on postoperative memory retention and delayed regeneration. Seventy patients undergoing breast surgery will be included in the study. The patients will be randomly assigned to receive propofol or remimazolam as sedatives during surgery. The primary endpoint is the number of posters patients remember 24 hours after surgery (among 4 posters shown after awakening from anesthesia) as an assessment of anterograde amnesia. Secondary endpoints are retrograde amnesia, dose of analgesic given from the time the patient returns to the ward until 24 hours after surgery, immediate postoperative pain numerical rating scale scores, and pain numerical rating scale scores 24 hours after leaving the operating room. Recruitment will take place between October 2021 and March 2022 to achieve the target sample size. DISCUSSION: To our knowledge, this is the first trial designed to examine the effects of remimazolam on postoperative memory retention and delayed regeneration in patients undergoing breast surgery. TRIAL REGISTRATION: This clinical trial was registered at the University Hospital Medical Information Network (UMIN) Center on September 28, 2021 (UMIN-CTR: UMIN000045593).

[Continuous infusion of low-dose remifentanil for palliation of pain with epidural catheterization].

BACKGROUND: To prospectively determine the safety and effectiveness of continuous infusion of low-dose remifentanil for the reduction of pain in patients for epidural catheterization. METHODS: This study was approved by the institutional review board. Written informed consent was obtained. Fifty two patients (27 men, 25 women, age range 16-96 years, mean age 68 years) were given continuous infusion of various rates of application (none, 0.02, 0.05, and 0.07 microg x kg -1 x hr-1) of remifentanil. Blood pressure, heart rate, pulse oximetry oxygen saturation and respiratory rate were recorded during the procedure of epidural catheterization. Pain score was measured with the visual analogue scale (VAS), and complications including muscle stiffness, nausea and vomiting, and depressed level of consciousness were monitored. RESULTS: Every rate of application, pulse oximetry oxygen saturation and systemic blood pressure were decreased but the reduction was not marked. The muscle stiffness, nausea and vomiting, and depressed level of consciousness were not observed in all the cases. No other serious complications were observed. CONCLUSIONS: Continuous infusion of low-dose remifentanil is a safe and effective method for palliation of pain in epidural catheterization.