Clinical pharmacology and efficacy of sugammadex in the reversal of neuromuscular blockade

Evaluation of Subetadex-α-methyl, a Polyanionic Cyclodextrin Scaffold, as a Medical Countermeasure against Fentanyl and Related Opioids

Subetadex-α-methyl (SBX-Me), a modified, polyanionic cyclodextrin scaffold, has been evaluated for its utilization as a medical countermeasure (MCM) to neutralize the effects of fentanyl and related opioids. Initial in vitro toxicity assays demonstrate that SBX-Me has a nontoxic profile, comparable to the FDA-approved cyclodextrin-based drug Sugammadex. Pharmacokinetic analysis showed rapid clearance of SBX-Me with an elimination half-life of ∼7.4 h and little accumulation in major organs. SBX-Me was also evaluated for its ability to counteract the effects of fentanyl, carfentanil, and remifentanil in rats. Recovery times in rats exposed to sublethal fentanyl doses were found to be shorter when treated with SBX-Me after opioid exposure. The recovery times were reduced from ∼35 to ∼17 min for fentanyl, ∼172 to ∼59 min for carfentanil, and ∼18 to ∼12 min for remifentanil. SBX-Me increased the elimination half-life for fentanyl and remifentanil from 5.37 to 6.42 h and 8.24 to 9.74 h, respectively. These data support SBX-Me as a solid platform from which further research can be launched for the development of a MCM against the effects of fentanyl and its analogs. Furthermore, the data suggests that SBX-Me and other analogs are attractive candidates as broad spectrum opioids targeting MCMs.

The Effect of Neuromuscular Blockade Reversal Agents on Postoperative Pulmonary Complications in Patients undergoing Femur Fracture Repair Surgery: A Retrospective Observational Study

BACKGROUND

Femoral fracture repair surgery under general anesthesia is associated with postoperative pulmonary complications (PPCs). However, information on PPCs caused by residual neuromuscular blockade following perioperative use of neuromuscular blockers is limited. This study aimed to identify the differences in the incidence of PPCs according to the type of neuromuscular blockade reversal agent used in femoral fracture repair surgery, as well as the risk factors for PPCs.

METHODS

We retrospectively analyzed the electronic medical records of 604 patients aged >18 years who underwent general anesthesia for femoral fracture repair surgery at a single university hospital between March 2017 and March 2022. Patients in whom sugammadex or anticholinesterase was used to reverse the neuromuscular block were subjected to propensity score matching. Multivariate logistic regression analysis was performed to identify risk factors for PPCs.

RESULTS

Among the 604 patients, 108 were matched in each group. The incidence rates of PPCs overall and in the anticholinesterase and sugammadex groups were 7.0%, 8.3%, and 5.6%, respectively, with no significant differences between the groups. Older age, higher ASA (American Society of Anesthesiologists) physical status, and lower preoperative oxygen saturation were risk factors, whereas emergency surgery was a preventive factor.

CONCLUSIONS

Our results demonstrated that the incidence of PPC did not differ significantly between sugammadex and anticholinesterase in patients undergoing femur fracture repair under general anesthesia. Identifying the risk factors and confirming complete recovery from neuromuscular blockade might be more important.

Rapid Sequence Intubation Experiences in the Pediatric Emergency Department

Aim: Patient selection and management of rapid sequence intubation application in the emergency department can be challenging for clinicians. In this study, we aimed to describe the demographic information, clinical characteristics and medical conditions of the patients who underwent rapid sequence intubation in the children's emergency department of our hospital and to present patient management strategies. Methods: Cases under the age of 18 who underwent rapid sequence intubation in the emergency department between January 2021 and January 2022 were retrospectively analyzed. Results: 11 patients were included in the study. The median age of the patients was 6 years (min-max 2-15), 7 of them were girls (63,6%). The median time from symptom onset to presentation was 120 minutes (min-max 15 minutes-2 weeks). RSI indications were trauma (n=5), mass (n=4), ventriculoperitoneal shunt dysfunction (n=1), refractory status epilepticus (n=1). All patients had focal neurological deficits on examination. The median value of Glasgow coma scale scores of the patients was 8 (min-max 4-15). The first neuroimaging method was cranial tomography in ten (90.9%) patients. Intracranial hemorrhage was present in 45.4% (5 patients) of the patients. No complications were observed in any of the patients during rapid sequence intubation application. One patient each died due to intracranial hemorrhage and shunt dysfunction. Neurological deficits (dysarthria, gait disturbance, hemiparesis, visual impairment) were detected in five patients during their first month follow-up. Conclusion: This retrospective study identified critically ill children who were admitted to the emergency department with acute neurological symptoms and underwent RSI to prevent increased intracranial pressure and further brain damage.

Mapping the current evidence on the anesthetic management of adult patients with neuromuscular disorders-a scoping review

PURPOSE

Patients with neuromuscular disorders (NMDs) are at increased risk of perioperative complications. The objective of this scoping review was to examine emerging evidence from published studies, case reports, and review articles on anesthetic management of patients with NMDs, following the methodological frame for scoping reviews.

SOURCES

We searched PubMed and EMBASE for articles published between 1 January 2000 and 14 July 2021.

PRINCIPAL FINDINGS

Three prospective and 21 retrospective studies on altered pharmacokinetics and pharmacodynamics of neuromuscular blocking agents (NMBA) in NMD patients were included. Furthermore, 168 case reports/series reporting 212 anesthetics in 197 patients were included. These studies showed that preanesthetic neuromuscular monitoring can be used for precise NMBA dosing in myasthenia gravis patients. Sugammadex was associated with fewer postoperative myasthenic crises. Perioperative complications were not associated with specific anesthetic agents. Case reports/series showed that in 32% (67/212) of anesthetics, at least one complication was reported. Unexpected intensive care unit admission was a frequently reported complication. Patients with a complicated disease course may have had a higher use of succinylcholine (unadjusted relative risk, 0.13; 95% confidence interval [CI], 0.20 to 0.86) and volatile anesthetics (adjusted odds ratio [OR], 0.38; 95% CI, 0.20 to 0.73; P = 0.004).

CONCLUSION

Evidence on the anesthetic management and perioperative complications of patients with NMDs is mainly based on small retrospective studies and case reports. Further clinical trials or large retrospective studies are required to investigate the choice of safe anesthetic agents. Main areas of interest are the potential benefits of neuromuscular monitoring and sugammadex and the risks possibly associated with volatile anesthetics and succinylcholine.

Choice of neuromuscular block reversal agent to reduce postoperative pulmonary complications

The definition of postoperative pulmonary complications (PPCs) is inconsistent in literature; however, PPCs include pulmonary abnormalities that adversely affect patient outcomes, such as respiratory failure, atelectasis, pneumonia, pleural effusion, and exacerbation of underlying lung conditions. Furthermore, although the incidence of PPCs varies according to its definition, surgery type, and patient population, they can lead to increased morbidity, mortality, duration of hospitalization, and medical costs; thus, efforts to identify and reduce the risk factors are important to improve patient outcomes. Among the risk factors for PPCs, residual neuromuscular block is a representative and preventable anesthesia-related risk factor that is affected by the choice of the reversal agent. However, it is not clear whether the chosen reversal agent, i.e., sugammadex, reduces PPCs better when compared to anticholinesterases. Additionally, the effects of the reversal agents on PPCs in high-risk patients, such as elderly patients, pediatric patients, those with end-stage renal disease, obesity, obstructive sleep apnea, or those undergoing specific surgeries, are diverse. To reduce the PPCs associated with the use of neuromuscular blocking agents, it is important to confirm complete reversal of the neuromuscular block under neuromuscular monitoring. Additionally, efforts to reduce the incidence of PPCs through interdisciplinary communication are required.

Required dose of sugammadex or neostigmine for reversal of vecuronium-induced shallow residual neuromuscular block at a train-of-four ratio of 0.3

Residual shallow neuromuscular block (NMB) is potentially harmful and contributes to critical respiratory events. Evidence for the optimal dose of sugammadex required to reverse vecuronium‐induced shallow NMB is scarce. The aims of the present study were to find suitable doses of sugammadex and neostigmine to reverse a residual vecuronium‐induced NMB from a time of flight (TOF) ratio of 0.3–0.9 and evaluate their safety and efficacy. In total, 121 patients aged 18–65 years were randomly assigned to 11 groups to receive placebo, sugammadex (doses of 0.125, 0.25, 0.5, 1.0, or 2.0 mg/kg), or neostigmine (doses of 10, 25, 40, 55, or 70 μg/kg). The reversal time of sugammadex and neostigmine to antagonize a vecuronium‐induced shallow residual NMB (i.e., TOF ratio of 0.3) and related adverse reactions were recorded. Several statistical models were tested to find an appropriate statistical model to explore the suitable doses of sugammadex and neostigmine required to reverse a residual vecuronium‐induced NMB. Based on a monoexponential model with the response variable on a logarithmic scale, sugammadex 0.56 mg/kg may be sufficient to reverse vecuronium‐induced shallow residual NMB at a TOF ratio of 0.3 under anesthesia maintained with propofol. Neostigmine may not provide prompt and satisfactory antagonism as sugammadex, even in shallow NMB.

[Anesthesia for patients suffering from neuromuscular diseases]

Neuromuscular diseases (NMD) are a heterogeneous group of motor unit disorders. Common to all is the main clinical symptom of muscle weakness. Depending on entity and phenotype, a broad range of disorders of neuronal, junctional or myocytic structures occurs. In addition to a weakness of the skeletal musculature, NMD can also affect throat musculature, respiratory and heart muscles. The possible consequences are immobility, deformities, tendency to aspiration as well as respiratory and cardiac insufficiency. In the context of surgery and anesthesia, complications that can result from the underlying disease and its interaction with anesthesia must be anticipated and averted. This article describes along the treatment pathway how preoperative evaluation, choice of the anesthetic procedure and postoperative care can be effectively and safely tailored to the needs of patients with NMD. Concise and practical recommendations for carrying out anesthesia for the most important NMDs are presented as well as relevant external sources of practice recommendations.

Pathomechanisms and Clinical Implications of Myasthenic Syndromes Exacerbated and Induced by Medical Treatments

Myasthenic syndromes are typically characterized by muscle weakness and increased fatigability due to an impaired transmission at the neuromuscular junction (NMJ). Most cases are caused by acquired autoimmune conditions such as myasthenia gravis (MG), typically with antibodies against the acetylcholine receptor (AChR). Different drugs are among the major factors that may complicate pre-existing autoimmune myasthenic conditions by further impairing transmission at the NMJ. Some clinical observations are substantiated by experimental data, indicating that presynaptic, postsynaptic or more complex pathomechanisms at the NMJ may be involved, depending on the individual compound. Most robust data exist for the risks associated with some antibiotics (e.g., aminoglycosides, ketolides, fluoroquinolones) and cardiovascular medications (e.g., class Ia antiarrhythmics, beta blockers). Apart from primarily autoimmune-mediated disorders of the NMJ, de novo myasthenic manifestations may also be triggered by medical treatments that induce an autoimmune reaction. Most notably, there is growing evidence that the immune checkpoint inhibitors (ICI), a modern class of drugs to treat various malignancies, represent a relevant risk factor to develop severe and progressive medication-induced myasthenia via an immune-mediated mechanism. From a clinical perspective, it is of utmost importance for the treating physicians to be aware of such adverse treatment effects and their consequences. In this article, we aim to summarize existing evidence regarding the key molecular and immunological mechanisms as well as the clinical implications of medication-aggravated and medication-induced myasthenic syndromes.

Protective effects of beta-cyclodextrins vs. zearalenone-induced toxicity in HeLa cells and Tg(vtg1:mCherry) zebrafish embryos

Zearalenone is a xenoestrogenic mycotoxin produced by Fusarium species. High exposure with zearalenone induces reproductive disorders worldwide. Cyclodextrins are ring-shaped host molecules built up from glucose units. The apolar cavity of cyclodextrins can entrap so-called guest molecules. The formation of highly stable host-guest type complexes with cyclodextrins can decrease the biological effect of the guest molecule. Therefore, cyclodextrins may be suitable to decrease the toxicity of some xenobiotics even after the exposure. In this study, the protective effect of beta-cyclodextrins against zearalenone-induced toxicity was investigated in HeLa cells and zebrafish embryos. Fluorescence spectroscopic studies demonstrated the formation of stable complexes of zearalenone with sulfobutyl-, methyl-, and succinyl-methyl-substituted beta-cyclodextrins at pH 7.4 (K = 1.4-4.7 × 10⁴ L/mol). These chemically modified cyclodextrins considerably decreased or even abolished the zearalenone-induced loss of cell viability in HeLa cells and mortality in zebrafish embryos. Furthermore, the sublethal effects of zearalenone were also significantly alleviated by the co-treatment with beta-cyclodextrins. To test the estrogenic effect of the mycotoxin, a transgenic bioindicator zebrafish model (Tg(vtg1:mCherry)) was also applied. Our results suggest that the zearalenone-induced vitellogenin production is partly suppressed by the hepatotoxicity of zearalenone in zebrafish. This study demonstrates that the formation of stable zearalenone-cyclodextrin complexes can strongly decrease or even abolish the zearalenone-induced toxicity, both in vitro and in vivo. Therefore, cyclodextrins appear as promising new mycotoxin binders.

Novel steroidal 1,3,4-thiadiazines: Synthesis and biological evaluation in androgen receptor-positive prostate cancer 22Rv1 cells

A flexible approach to previously unknown spirofused and linked 1,3,4-thiadiazine derivatives of steroids with selective control of heterocyclization patterns is disclosed. (N-Arylcarbamoyl)spiroandrostene-17,6' [1,3,4]thiadiazines and (N-arylcarbamoyl)17-[1',3',4']thiadiazine-substituted androstenes, novel types of heterosteroids, were prepared from 16β,17β-epoxypregnenolone and 21-bromopregna-5,16-dien-20-one in good to high yields by the treatment with oxamic acid thiohydrazides. The synthesized compounds were screened for antiproliferative activity against the human androgen receptor-positive prostate cancer cell line 22Rv1. Most of (N-arylcarbamoyl)17-[1',3',4']thiadiazine-substituted androstenes exhibit better antiproliferative potency (IC₅₀ = 2.1-6.6 µM) than the antiandrogen bicalutamide. Compounds 7d with IC₅₀ = 3.0 μM and 7j with IC₅₀ = 2.1 μM proved to be the most active in the series under study. Lead synthesized compound 7j downregulates AR expression and activity in 22Rv1 cells. NF-κB activity is also blocked in 7j-treated 22Rv1 cells. Apoptosis is considered as a possible mechanism of 7j-induced cell death.

Myasthenia Gravis and Thymoma Surgery: A Clinical Update for the Cardiothoracic Anesthesiologist

Myasthenia gravis (MG) is a rare neuromuscular disorder characterized by skeletal muscle weakness. Patients with MG who have thymoma and thymic hyperplasia have indications for thymectomy. The perioperative care of patients with MG scheduled for thymus resection should be focused on optimizing their neuromuscular function, identifying factors related to postoperative mechanical ventilation, and avoiding of triggers associated with myasthenic or cholinergic crisis. Minimally invasive surgical techniques, use of regional analgesia, and avoidance or judicious administration of neuromuscular blocking drugs (NMBs) is recommended during the perioperative period. If NMBs are used, sugammadex appears to be the drug of choice to restore adequately the neuromuscular transmission. In patients with postoperative myasthenic crisis, plasma exchange or intravenous immune globulin and mechanical support is recommended.

Sugammadex-Induced Hypersensitivity Reaction in a Pediatric Patient

We report a case of a 3-year-old boy who administered sugammadex and developed an allergic reaction several minutes after the administration. He developed an increase in airway pressures and a decrease in peripheral oxygen saturation; auscultation revealed widespread wheezing in the lungs. He was successfully treated with immediate administration of methylprednisolone, pheniramine, and theophylline. We assumed an allergic reaction to sugammadex based on the clinical condition of the patient.