Cardiac Arrest Following Remimazolam-Induced Anaphylaxis: A Case Report

Remimazolam for procedural sedation in gastrointestinal endoscopy: real-life, single center observational study

BACKGROUND AND AIM

Remimazolam has proved to be a very promising sedative drug in randomized clinical trials for usage in a wide spectrum of patients, including critically ill ones. The purpose of our study was to verify efficacy and safety of remimazolam for procedural sedation during diagnostic and first level operative endoscopy in a real-world setting.

METHODS

This single centre prospective study evaluated sedation regimen with remimazolam for EGDS and fentanyl and remimazolam for colonoscopy in consecutive ASA 1-3 patients.

RESULTS

Seventy-one patients underwent 73 procedures (25 EGDS, 48 colonoscopies) with a total amount of 13.2 ± 8.7 mg and 10.2 ± 6.2 mg of remimazolam administered respectively. In 6 EGDS, rescue sedation with propofol was needed. Transient hypotension was frequent (37%) and no cases of hypoxia occurred. One case of suspected allergy (erythema of the trunk) without anaphylaxis was reported.

CONCLUSIONS

Procedural sedation can be applied with remimazolam without the use of propofol, obtaining effective sedation in colonoscopies while in EGDS remimazolam alone guarantees the result in a percentage of around 70-75% of cases.

Severe Anaphylaxis From Remimazolam in a Mastocytosis Cancer Patient: A Case Report

Remimazolam besylate is a novel, rapid-onset, ultra-short-acting benzodiazepine with an advantageous cardio-respiratory safety profile. To date, there have been few published reports of remimazolam-induced anaphylaxis, none of which are documented in patients with mast cell disease. We describe the case of a 77-year-old male with oncologic mastocytosis who developed anaphylaxis following remimazolam administration. Symptoms included shortness of breath, hypoxia, loss of consciousness, tachycardia, and hypotension. Resolution of symptoms was attained after the administration of flumazenil, dexamethasone, diphenhydramine, famotidine, and phenylephrine. Suspicion of an anaphylactic reaction was confirmed by elevated serum tryptase levels. This case report helps establish how to diagnose anaphylaxis in a mastocytosis patient.

Remimazolam-Induced Anaphylaxis and Cardiovascular Collapse: A Narrative Systematic Review of Eleven Cases

Background and Objectives: Remimazolam, a novel benzodiazepine, is used for procedural sedation and general anesthesia due to its rapid onset and short duration of action. However, remimazolam-induced anaphylaxis (RIA) is a rare but severe complication. This study aimed to analyze RIA characteristics, focusing on cardiovascular collapse, and provide guidelines for safe remimazolam use. Methods: This study conducted a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. Research articles retrieved from PubMed on 26 May 2023, using the keywords 'remimazolam AND anaphylaxis' were evaluated based on the inclusion criteria of being written in English and aligning with the World Allergy Organization criteria for anaphylaxis, while studies not meeting these criteria were excluded. All published articles up to the search date were included without any date restrictions. The review analyzed factors such as age, sex, type of anesthesia, remimazolam dose (bolus/continuous), allergic symptoms and sign, epinephrine use, serum tryptase levels, and skin prick tests. Results: Among eleven cases, the mean age was 55.6 ± 19.6 years, with 81.8% male. Hypotension (81.8%) was the most common symptom, followed by bradycardia (54.5%) and desaturation (36.4%). Two patients experienced cardiac arrest. Serum tryptase levels confirmed anaphylaxis in ten cases. Epinephrine was the primary treatment, with intravenous doses ranging from 0.1 mg to 0.3 mg. Conclusions: Vigilance is crucial when administering remimazolam, adhering to recommended dosages, and promptly treating RIA with epinephrine. Further research is needed to understand the risk factors and refine the management strategies. Guidelines for safe remimazolam use are proposed.

Remimazolam anaphylaxis in a patient not allergic to brotizolam: a case report and literature review

BACKGROUND

Remimazolam is a recently developed, ultrashort-acting benzodiazepine that is used as a general anesthetic. Some cases of remimazolam anaphylaxis have been reported, but its characteristics are not fully understood. We present an interesting case report and review of the literature to better understand remimazolam anaphylaxis.

CASE PRESENTATION

A 75-year-old man scheduled for robot-assisted gastrectomy was administered remimazolam for the induction of general anesthesia. After intubation, low end-expiratory CO2, high airway pressure and concurrent circulatory collapse were observed. Bronchoscopy revealed marked tracheal and bronchial edema, which we diagnosed as anaphylaxis. The patient suffered cardiac arrest after bronchoscopy but recovered immediately with intravenous adrenaline administration and chest compressions. We performed skin prick tests for the drugs used during induction except for remimazolam, considering the high risk of systemic adverse reactions to remimazolam. We diagnosed remimazolam anaphylaxis because the skin prick test results for the other drugs used during anesthesia were negative, and these drugs could have been used without allergic reactions during the subsequent surgery. Furthermore, this patient had experienced severe anaphylactic-like reactions when he underwent cardiac surgery a year earlier, in which midazolam had been used, but it was not thought to be the allergen at that time. Based on these findings, cross-reactivity to remimazolam and midazolam was suspected. However, the patient had previously received another benzodiazepine, brotizolam, to which he was not allergic, suggesting that cross-reactivity of remimazolam may vary among benzodiazepines. In this article, we reviewed the 11 cases of remimazolam anaphylaxis that have been described in the literature.

CONCLUSIONS

Remimazolam is an ultrashort-acting sedative; however, it can cause life-threatening anaphylaxis. In addition, its cross-reactivity with other benzodiazepines is not fully understood. To increase the safety of this drug, further research and more experience in its use are needed.

The Use of Remimazolam During Awake Craniotomy for Seizure Foci Resection in Adolescents: A Case Series

Remimazolam is a novel benzodiazepine with sedative, anxiolytic, and amnestic properties similar to midazolam. Metabolism by tissue esterases results in a short clinical half-life of 5 - 10 min and a limited context sensitive half-life. We present initial retrospective clinical experience with the use of remimazolam as an intraoperative adjunct to sedation during awake craniotomy in a cohort of three adolescent patients. A remimazolam infusion was added to a combination of dexmedetomidine and remifentanil to deepen the level of sedation during surgical incision, craniotomy, duraplasty, and surgical dissection for exposure of the seizure foci. The remimazolam infusion was discontinued 30 min prior to the planned awake assessments and electrophysiology testing. The patients emerged calmly and were able to follow commands for intraoperative testing. Our anecdotal experience supports the efficacy of remimazolam for awake craniotomy and tumor resection using a standard asleep-awake-asleep technique. We noted adequate sedation, maintenance of spontaneous respiration, rapid awakening, and no limitations to intraoperative neuromonitoring or awake assessment in our three patients.

Anesthesia Management Using Remimazolam for Lower Limb Amputation in a Patient With Septic Shock Due to Necrotizing Fasciitis

We report a case of a patient with necrotizing fasciitis and septic shock caused by streptococcal toxic shock syndrome, who was anesthetized and managed with remimazolam. The patient, a woman in her 40s, was admitted to the ICU with a diagnosis of necrotizing fasciitis of the right lower extremity and septic shock and was scheduled for above-the-knee amputation under general anesthesia. She was anesthetized with remimazolam for sedation and fentanyl and remifentanil for analgesia. Intraoperatively, we were able to maintain hemodynamic stability with similar or only slightly higher doses of circulatory agonists during admission. In the present case, remimazolam, an ultrashort-acting benzodiazepine, was safely used to provide anesthesia to a patient in septic shock due to necrotizing fasciitis, who was receiving high doses of vasopressor agents for cardiovascular support, as it was necessary to select an anesthetic drug that would cause minimal circulatory depression.

Remimazolam and serious adverse events: A scoping review

Remimazolam is anticipated to be an interesting anaesthetic and sedative. It combines the pharmacodynamic properties of midazolam with pharmacokinetic properties similar to remifentanil. However, worrisome case reports of anaphylaxis, delayed emergence and re-sedation have emerged recently and necessitate further investigation.PubMed (including MEDLINE) and EMBASE were searched for all studies reporting serious adverse events where remimazolam was administered for sedation or anaesthesia.Thirty-six case reports and 73 trials were identified, involving a total of 6740 patients who received remimazolam. Hypotension was reported in 911 cases, delayed emergence in 68 cases, anaphylaxis in 10 cases and re-sedation in 8 cases. The incidence of hypotension seems to be lower compared with other anaesthetics, even in high-risk patients.Delayed emergence might be related to the metabolism of remimazolam through carboxylesterase 1 (CES1), a tissue esterase predominant in the liver. There is significant interindividual variation, and it is inhibited by flavonoids, fatty acids and alcohol. Individual benzodiazepine sensitivity has also been reported. A higher BMI, older age and low plasma albumin concentration are risk factors for delayed emergence. Anaphylaxis might be related to a non-IgE-mediated effect of the excipient dextran-40 or a partially IgE-mediated reaction to remimazolam itself. Resedation has been reported after flumazenil reversal and is explained by the specific pharmacokinetic properties of flumazenil and remimazolam. Reversal by flumazenil should be reserved for and used carefully in patients with delayed emergence.

VISUAL ABSTRACT

http://links.lww.com/EJA/A864 .

Remimazolam Anaphylaxis during Induction of General Anesthesia Confirmed by Provocation Test-A Case Report and Literature Review

Background: Remimazolam besylate, a newly developed drug, is linked to various anaphylaxis cases. We present a case of remimazolam anaphylaxis confirmed using a provocation test. Case: A 51-year-old female patient was scheduled for humeral pinning. General anesthesia was induced using remimazolam, rocuronium, and remifentanil. After tracheal intubation, the patient experienced decreased blood pressure, increased heart rate, and a systemic rash. Epinephrine was administered repeatedly, and the patient's vital signs stabilized. Acute phase tryptase levels were within normal limits. After four weeks, intradermal test results were negative. When remimazolam was administered intravenously for the provocation test, facial swelling, flushing, and coughing occurred, which improved with epinephrine. The culprit drug was identified as remimazolam using a provocation test. Conclusions: When anaphylaxis occurs during anesthesia induction, remimazolam should not be ruled out as the causative drug. If the skin test result for remimazolam is negative, a provocation test should be considered. The provocation test should be initiated cautiously at a low dose under careful patient monitoring.

Remimazolam versus propofol in combination with esketamine for surgical abortion: A double-blind randomized controlled trial

Remimazolam is a new benzodiazepine with a short half-life, good efficacy, and safety profiles in general anesthesia. Combining esketamine with propofol (P + E) could reduce propofol consumption and injection pain. It is, however, unclear if a low dose of remimazolam co-administrated with esketamine (R + E) is comparable to the increasingly used P + E for surgical abortion with general anesthetic. We conducted a double-blind randomized controlled trial to compare the efficacy and safety of R + E and P + E. Two hundred patients scheduled for a surgical abortion were randomized to receive remimazolam 0.3 mg/kg plus esketamine 0.3 mg/kg (R + E), and propofol 2 mg/kg plus esketamine 0.3 mg/kg (P + E). Sedative effectiveness was evaluated by measuring the time to lose consciousness (LOC), recovery time, and successful sedation rate. Safety was assessed by hemodynamics and adverse events during and postoperation. The time to LOC and recovery time in R + E was 5 s shorter and 1 min longer than that in P + E, respectively (both p < 0.001). Success sedation rate did not differ between groups (p = 0.73). Bradycardia incidence and injection site pain were less frequent in the R + E group than that in the P + E group. More rash was observed in the R + E group compared with the P + E group (32% vs. 5%, p < 0.001), but all were mild (only chest rash) and resolved subsequently. Low dose of remimazolam when combined with esketamine has favorable profiles with rapid onset and recovery, but mild hemodynamic side effects and adverse events. It can be used as an alternative for surgical abortion with general anesthetic.

Laryngeal edema following remimazolam-induced anaphylaxis: a rare clinical manifestation

Background

Remimazolam is an ultra-short-acting intravenous benzodiazepine, which has been used as sedative/anesthetic in procedural sedation and anesthesia. Although peri-operative anaphylaxis due to remimazolam has been reported recently, the spectrum of the allergic reactions is still not fully known.

Case presentation

We describe a case of anaphylaxis following remimazolam administration in a male patient undergoing colonoscopy under procedural sedation. The patient presented complex clinical signs including airway changes, skin symptoms, gastrointestinal manifestations and hemodynamic fluctuations. Different from other reported cases, laryngeal edema was the initial and main clinical feature of remimiazolam-induced anaphylaxis.

Conclusions

Remimazolam-induced anaphylaxis has a rapid onset and complex clinical features. This case reminds anesthesiologists should be particularly alert to the unknown adverse reactions of new anesthetics.