Impact of proficiency in the transcatheter aortic valve implantation procedure on clinical outcomes: a single center retrospective study.

BACKGROUND: We used transcatheter aortic valve implantation (TAVI) procedure time to investigate the association between surgical team maturity and outcome. METHODS: Among patients who underwent TAVI between October 2015 and November 2019, those who had Sapien™ implanted with the transfemoral artery approach were included in the analysis. We used TAVI procedure time and surgery number to draw a learning curve. Then, we divided the patients into two groups before and after the number of cases where the sigmoid curve reaches a plateau. We compared the two groups regarding the surveyed factors and investigated the correlation between the TAVI procedure time and survey factors. RESULTS: Ninety-nine of 149 patients were analysed. The sigmoid curve had an inflection point in 23.2 cases and reached a plateau in 43.0 cases. Patients in the Late group had a shorter operating time, less contrast media, less radiation exposure, and less myocardial escape enzymes than the Early group. Surgical procedure time showed the strongest correlation with the surgical case number. CONCLUSION: The number of cases required for surgeon proficiency for isolated Sapien™ valve implantation was 43. This number may serve as a guideline for switching the anesthesia management of TAVI from general to local anesthesia.

Anesthetic management with remimazolam for a patient with hereditary angioedema:a case report.

BACKGROUND: Hereditary angioedema (HAE), a genetic disorder caused by C1-inhibitor deficiency or dysfunction, may cause mucosal edema in the upper airway during tracheal intubation and extubation. CASE REPORT: A 57-year-old man with HAE and a history of laryngeal edema, scheduled to undergo cervical laminoplasty under general anesthesia. General anesthesia was induced by continuous injection of remimazolam and remifentanil, during which manual mask ventilation and intubation were performed without difficulty. The patient was extubated under deep anesthesia. After emergence from general anesthesia, he had no significant upper airway edema and was treated with a C1-inhibitor seven hours post-surgery because of slight tongue swelling. No additional airway edema was observed, and the patient was discharged from the intensive care unit the following day. CONCLUSIONS: Deep anesthesia tracheal extubation with remimazolam may be effective in preventing upper airway edema during anesthetic management in patients with HAE. J. Med. Invest. 71 : 184-186, February, 2024.

Effects of Remimazolam on Intracellular Calcium Dynamics in Myotubes Derived from Patients with Malignant Hyperthermia and Functional Analysis of Type 1 Ryanodine Receptor Gene Variants.

Remimazolam is a novel general anesthetic and its safety in patients with malignant hyperthermia (MH) is unknown. We used myotubes derived from the skeletal muscle of patients with MH to examine the response to ryanodine receptor 1 (RYR1) agonist and remimazolam in MH-susceptible patients. Patients underwent muscle biopsy for the Ca2+-induced Ca2+ release (CICR) rate test, a diagnostic tool for MH in Japan. Ten patients had myotubes obtained from skeletal muscle cultures, and the genes associated with malignant hyperthermia in these patients were analyzed. The EC50 of caffeine, cresol, and remimazolam to induce intracellular calcium concentration change were compared between myotubes from CICR-negative genetic test patients and myotubes from other patients. Eight of the ten were CICR-positive, five of whom had RYR1 causative gene mutations or variants. Two patients had CICR-negative genetic tests, and as expected had the highest EC50 (the concentration of a drug that gives a half-maximal response) in response to caffeine, 4CmC and remimazolam. Three patients had a positive CICR but no known variants in RYR1 or CACNA1S (voltage-gated calcium channel subunit alpha1S). Myotubes in these patients had significantly lower EC50s for all agents than myotubes in CICR-negative patients. When myotubes from a patient who was CICR-negative and had no gene variant were used as a control, myotubes from CICR-positive patients were more hyper-responsive than controls to all stimulants used. The EC50 for remimazolam was lowest for myotubes from CICR-positive, RYR1-mutant patients, at 206 µM (corresponding to 123 µg/mL). The concentration was more than 80-times higher than the clinical concentration. RYR1 gene variants in R4645Q and W5020G were shown to be causative gene mutations for MH. Intracellular calcium in myotubes from MH patients are elevated at high concentrations of remimazolam but not at clinically used concentrations of remimazolam. Remimazolam appears to be safe to use in patients with MH.

Remimazolam-based anesthesia with flumazenil allows faster emergence than propofol-based anesthesia in older patients undergoing spinal surgery: A randomized controlled trial.

BACKGROUND: Remimazolam is a novel, ultrashort-acting benzodiazepine that can be antagonized by flumazenil. This study aimed to determine whether remimazolam-based anesthesia with flumazenil provides a more rapid emergence than propofol-based anesthesia in older patients undergoing spinal surgery. METHODS: This was a prospective, single-blind, randomized controlled trial. Forty-four patients > 75 years old who had undergone spinal surgery were enrolled in this study. They were randomly assigned to the remimazolam or propofol group (1:1) using a computer randomization system stratified by age and body weight. For anesthesia induction and maintenance, remifentanil was administered at a defined dose in both groups, and remimazolam or propofol was adjusted to maintain the bispectral index or state entropy monitoring within 40-60. All anesthetics were discontinued simultaneously after the postoperative X-ray and 0.5 mg flumazenil was administered to the remimazolam group. The primary outcome was extubation time after discontinuing anesthesia, and the secondary outcomes were time to eye opening, obeying commands, and achieving a white fast-track score (WFTS) of 12. RESULTS: Thirty-nine patients were finally analyzed: remimazolam group (n = 20), propofol group (n = 19). There were no significant differences in intraoperative variables, such as operative time, anesthesia time, and patient background, between the 2 groups. Extubation times were significantly shorter in the remimazolam group than in the propofol group (4 vs 8 minutes, P < .001). The time to eye opening, obeying commands, and achieving a WFTS of 12 were significantly shorter in the remimazolam group (P < .001, for all comparisons). CONCLUSION: Remimazolam-based anesthesia with flumazenil resulted in a faster emergence than propofol-based anesthesia in older patients undergoing spinal surgery.

Rapid Dantrolene Administration with Body Temperature Monitoring Is Associated with Decreased Mortality in Japanese Malignant Hyperthermia Events.

Purpose: Malignant hyperthermia (MH) is a rare genetic disorder but one of the most severe complications of general anesthesia. The mortality rate of MH has dropped from 70% in the 1960s to 15% because of dantrolene, the only currently accepted specific treatment for MH. In this study, we retrospectively identified the optimal dantrolene administration conditions to reduce MH mortality further. Methods: Our database performed a retrospective analysis of patients with MH clinical grading scale (CGS) grade 5 (very likely) or 6 (almost certain) between 1995 and 2020. We examined whether dantrolene administration affected mortality and compared the clinical variables associated with improved prognosis. Furthermore, a multivariable logistic regression analysis was used to identify specific variables associated with improved prognosis. Results: 128 patients met the inclusion criteria. 115 patients were administered dantrolene; 104 survived, and 11 died. The mortality rate of patients who were not administered dantrolene was 30.8%, which was significantly higher than those of patients who were administered dantrolene (P = 0.047). Among patients administered dantrolene, the interval from the first sign of MH to the start of dantrolene administration was significantly longer in the deceased than in the survivors (100 min vs. 45.0 min, P < 0.001), and the temperature at the start of dantrolene administration was also significantly higher in the deceased (41.6°C vs. 39.1°C, P < 0.001). There was no significant difference in the rate of increase in temperature between the two, but there was a substantial difference in the maximum temperature (P < 0.001). The multivariable analysis also showed that the patient's temperature at dantrolene administration and interval from the first MH sign to dantrolene administration was significantly associated with improved prognosis. Conclusions: Dantrolene should be given as rapidly as possible once MH has been diagnosed. Beginning treatment at a more normal body temperature can prevent critical elevations associated with a worse prognosis.

Remimazolam Requires Less Vasopressor Support during Induction and Maintenance of General Anesthesia in Patients with Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement: A Retrospective Analysis from a Single Center.

Introduction: We compared the hemodynamics during general anesthesia with remimazolam and conventional anesthetics in patients with severe aortic stenosis (AS). Methods: This was a retrospective single-center analysis. We reviewed the records of 42 patients who underwent transcatheter aortic valve implantation with a transfemoral artery approach under general anesthesia from January to December 2020. Patients were divided into three groups based on the general anesthetic used for (induction/maintenance) remimazolam/remimazolam (Group R/R), propofol/sevoflurane (Group P/S), and midazolam/propofol (Group M/P). Vasopressor use (ephedrine, phenylephrine, and noradrenaline) was compared among the groups. Results: The number of patients in each group was 15 (Group R/R), 13 (Group P/S), and 14 (Group M/P), with no significant difference in background characteristics and intraoperative vital signs. For anesthesia induction, doses of ephedrine and phenylephrine used were significantly lower in Group R/R (ephedrine [mg]: Group R/R 2 [0-4] vs. Group P/S 8 [8-12], P < 0.001, Group R/R vs. Group M/P 5 [0-15], P = 0.39; phenylephrine (mg): Group R/R 0 [0-0.08] vs. Group P/S 0.15 [0.10-0.20], P = 0.03, Group M/P 0.21 [0.04-0.40], P = 0.08). For anesthesia maintenance, the noradrenaline dose used was low in the Group R/R (noradrenaline [µg/kg/min]: Group R/R 0.019 [0.015-0.039], Group P/S 0.042 [0.035-0.045], P = 0.02, Group M/P 0.048 [0.040-0.059], P < 0.01). Conclusion: In patients with severe AS, induction and maintenance of anesthesia with remimazolam resulted in less overall vasopressor use than conventional general anesthetics.