Occurrence of hemodynamic changes following administration of rocuronium in a dog presenting for an ophthalmic procedure.

A 10-year-old, neutered male, Golden Retriever dog presented for surgical correction of a descemetocele. Acepromazine (0.02 mg/kg) and methadone (0.5 mg/kg) were administered intramuscularly for sedation, propofol (2 mg/kg) and midazolam (0.2 mg/kg) were administered intravenously for anaesthetic induction and isoflurane in oxygen was utilised for anaesthetic maintenance. Rocuronium (0.5 mg/kg), a neuromuscular blocking agent, was administered intravenously to facilitate central positioning of the eye for surgery. Within 10 min of rocuronium administration, the dog became tachycardic and hypotensive. Hemodynamic aberrations did not resolve with initial interventions but were successfully mitigated with the administration of diphenhydramine (0.8 mg/kg) intravenously. The dog remained stable throughout the remainder of the procedure and experienced a smooth and uneventful recovery. While it is difficult to confirm that the hemodynamic changes observed in this clinical case resulted solely from administration of rocuronium, the observance of the cardiovascular changes, timing of events and response to therapy suggest that rocuronium elicited a histamine response that was successfully treated with diphenhydramine.

The Influence of Acid-Base Balance on Anesthetic Muscle Relaxants: A Comprehensive Review on Clinical Applications and Mechanisms.

Muscle relaxants have broad application in anesthesiology. They can be used for safe intubation, preparing the patient for surgery, or improving mechanical ventilation. Muscle relaxants can be classified based on their mechanism of action into depolarizing and non-depolarizing muscle relaxants and centrally acting muscle relaxants. Non-depolarizing neuromuscular blocking drugs (NMBDs) (eg, tubocurarine, atracurium, pipecuronium, mivacurium, pancuronium, rocuronium, vecuronium) act as competitive antagonists of nicotine receptors. By doing so, these drugs hinder the depolarizing effect of acetylcholine, thereby eliminating the potential stimulation of muscle fibers. Depolarizing drugs like succinylcholine and decamethonium induce an initial activation (depolarization) of the receptor followed by a sustained and steady blockade. These drugs do not act as competitive antagonists; instead, they function as more enduring agonists compared to acetylcholine itself. Many factors can influence the duration of action of these drugs. Among them, electrolyte disturbances and disruptions in acid-base balance can have an impact. Acidosis increases the potency of non-depolarizing muscle relaxants, while alkalosis induces resistance to their effects. In depolarizing drugs, acidosis and alkalosis produce opposite effects. The results of studies on the impact of acid-base balance disturbances on non-depolarizing relaxants have been conflicting. This work is based on the available literature and the authors' experience. This article aimed to review the use of anesthetic muscle relaxants in patients with acid-base disturbances.

The safety and efficacy of sugammadex for reversing neuromuscular blockade in younger children and infants.

INTRODUCTION: Sugammadex, a novel selective antagonist of non-depolarizing neuromuscular blocking agents, has been shown to rapidly and effectively reverse moderate and deep paralysis in adults and pediatric patients over age 2, improving patient recovery and reducing the risk of postoperative complications. AREAS COVERED: Since the use of sugammadex in patients under age 2 is not widely studied, we aim to provide an overview on the drug's application and potential use in infants and neonates. There is a limited but growing body of evidence for the safe, efficacious use of sugammadex in children under age 2. Relevant studies were identified from the most updated data including case reports, clinical trials, systematic reviews, and meta analyses. EXPERT OPINION: The results suggest that at a dose of 2 to 4 mg/kg of sugammadex can be safely used to rapidly and effectively reverse neuromuscular blockade in neonates and infants; it is non-inferior based on incidence of adverse events compared to neostigmine. Additionally, sugammadex doses between 8 and 16 mg/kg may be used as a rescue agent for infants during 'can't intubate, can't ventilate' crisis. Overall, sugammadex offers new value in the perioperative care of patients under age 2, with further studies warranted to better understand its application and full effect in the pediatric population.

Sugammadex use in pediatric patients with stage IV-V chronic kidney disease in a quaternary referral hospital: a case series.

BACKGROUND: Sugammadex is a pharmacologic agent that provides rapid reversal of neuromuscular blockade via encapsulation of the neuromuscular blocking agent (NMBA). The sugammadex-NMBA complex is primarily cleared through glomerular filtration from the kidney, raising the possibility that alterations in renal function could affect its elimination. In pediatric patients, the benefits of sugammadex have led to widespread utilization; however, there is limited information on its application in pediatric renal impairment. This study examined sugammadex use and postoperative outcomes in pediatric patients with severe chronic renal impairment at our quaternary pediatric referral hospital. METHODS: After IRB approval, we performed a retrospective analysis in pediatric patients with stage IV and V chronic kidney disease who received sugammadex from January 2017 to March 2022. Postoperative outcomes studied included new or increased respiratory requirement, unplanned intensive care unit (ICU) admission, postoperative pneumonia, anaphylaxis, and death within 48 h postoperatively, unplanned deferral of intraoperative extubation, and repeat administrations of NMBA reversal after leaving the operating room. RESULTS: The final cohort included 17 patients ranging from 8 months to 16 years old. One patient required new postoperative noninvasive ventilation on postoperative day 2, which was credited to hypervolemia. Another patient had bronchospasm intraoperatively resolving with medication, which could not definitively be associated sugammadex administration. There were no instances of deferred extubation, unplanned ICU or need for supplemental oxygen after tracheal extubation identified. CONCLUSION: No adverse effects directly attributable to sugammadex in pediatric patients with severe renal impairment were detected. There may be a role for utilization of sugammadex for neuromuscular reversal in this population.

A new pharmacological approach for tracheal intubation?

Anaesthesia induced with remimazolam and a fentanyl-series opioid can be reversed with flumazenil and naloxone. Concomitant paralysis with rocuronium can facilitate tracheal intubation whilst being reversible with sugammadex. Together, this combination might offer full reversibility of a 'routine' or a 'rapid-sequence' induction anaesthesia. Whether this is useful, or even safe, requires careful evaluation.

Shortened time to neuromuscular recovery with lower doses of rocuronium in elderly patients.

INTRODUCTION: The effect of neuromuscular blocking agents may be reversed by administration of neostigmine, when two twitches are present using train-of-four (TOF) stimulation. However, in elderly patients, limited data are available about when to administer neostigmine. We hypothesised that time to two twitches after TOF (TOF-2) was shorter after rocuronium 0.6 mg/kg than after rocuronium 0.9 mg/kg. Also, we hypothesised that time to TOF-2 would be shorter after rocuronium 0.3 mg/kg than after rocuronium 0.6 mg/kg. METHODS: This was a secondary analysis of 50 elderly patients > 80 years; 16 patients received rocuronium 0.6 mg/kg, another 16 patients received rocuronium 0.9 mg/kg; and, finally, 18 patients received rocuronium 0.3 mg/kg. Patients received total intravenous anaesthesia, and neuromuscular block was monitored with acceleromyography. RESULTS: Time to TOF-2 was shorter after rocuronium 0.6 mg/kg than after rocuronium 0.9 mg/kg: 37 min. versus 59 min. (difference: 22 min. (95% confidence intervals (CI): 10 to 33 min.), p = 0.0007). Time to TOF-2 after rocuronium 0.3 mg/kg was shorter than after rocuronium 0.6 mg/kg: 19 min. versus 37 min. (difference: 18 min. (95% CI: 11 to 25 min.), p = 0.00006). However, only 33% of the patients receiving 0.3 mg/kg obtained full effect i.e. TOF-0. CONCLUSION: Time to TOF-2 was shorter after rocuronium 0.6 mg/kg than after 0.9 mg/kg and shorter after rocuronium 0.3 mg/kg than after 0.6 mg/kg. FUNDING: This work was supported by departmental sources. TRIAL REGISTRATION: This study was a secondary analysis of two clinical trials. CLINICALTRIALS: gov (NCT04512313), (NCT03857750).

Effect of tetanic stimulation prior to train-of-four monitoring on the time to muscle response stabilization with neuromuscular blockade with rocuronium in patients aged 60 to 80 years: A prospective randomized controlled trial.

PURPOSE: To determine the effect of tetanic stimulation on the time to achieve stabilization of the T1 height, by acceleromyography train-of-four (TOF) ratio monitoring, in patients aged 60 to 80 years. METHODS: Randomized, prospective, single-blind, controlled trial in patients aged 60 to 80 years undergoing elective surgery under general anesthesia in two university hospitals in Brazil between December 2019 and March 2022. This trial was performed in accordance with the principles of the Helsinki Declaration and the guidelines for good clinical research practice in pharmacodynamic studies of neuromuscular blocking agents II. Participants were randomly allocated by computer-generated numbers to receive tetanic stimulation (intervention group, n = 25) or not receive tetanic stimulation (control group, n = 25) to achieve T1 height stabilization on TOF ratio monitoring. The primary endpoint was to evaluate the effect of tetanic stimulation on the time to achieve stabilization of the T1 height. We also evaluated the effect on the onset time of rocuronium and time to recover from neuromuscular blockade with a single dose of rocuronium 0.6 mg.kg-1 with spontaneous recovery. RESULTS: There was no statistically significant difference between the groups in the time to T1 height stabilization (intervention: 4.3 [2.0-8.0] min; control: 5.8 [2.0-10.5] min; p = 0.202), onset time of the neuromuscular blocking agent (intervention: 1.9 [±0.7] min; control: 2.2 [±1.0] min; p = 0.219), or neuromuscular blockade recovery times to normalized TOF values of 0.7 (intervention: 106.1 [±37.2] min; control: 91.7 [±27.5] min; p = 0.295), 0.8 (intervention: 114.3 [±40.1] min; control: 97.8 [±28.9] min; p = 0.225), 0.9 (intervention: 126.5 [±44.0] min; control: 106.9 [±30.6] min; p = 0.153), and 1.0 (intervention: 138.3 [±43.4] min; control: 123.8 [±43.5] min; p = 0.425). CONCLUSION: The results of this study suggest that the recommendation to use tetanic stimulation to shorten the time to T1 height stabilization in neuromuscular monitoring did not alter the stabilization time of the T1 twitch or the pharmacodynamics of neuromuscular blockade with rocuronium in patients aged 60 to 80 years.

A Practical Dosing Algorithm for Deep Neuromuscular Blockade during Total Intravenous Anesthesia: ROCURITHM.

BACKGROUND: The number of trials investigating the effects of deep neuromuscular blockade (NMB) on surgical conditions and patient outcomes is steadily increasing. Consensus on which surgical procedures benefit from deep NMB (a posttetanic count [PTC] of 1 to 2) and how to implement it has not been reached. The European Society of Anaesthesiology and Intensive Care does not advise routine application but recommends use of deep NMB to improve surgical conditions on indication. This study investigates the optimal dosing strategy to reach and maintain adequate deep NMB during total intravenous anesthesia. METHODS: Data from three trials investigating deep NMB during laparoscopic surgery with total intravenous anesthesia (n = 424) were pooled to analyze the required rocuronium dose, when to start continuous infusion, and how to adjust. The resulting algorithm was validated (n = 32) and compared to the success rate in ongoing studies in which the algorithm was not used (n = 180). RESULTS: The mean rocuronium dose based on actual bodyweight for PTC 1 to 2 was (mean ± SD) 1.0 ± 0.27 mg · kg-1 ·h-1 in the trials, in which mean duration of surgery was 116 min. An induction dose of 0.6 mg ·kg-1 led to a PTC of 1 to 5 in a quarter of patients after a mean of 11 min. The remaining patients were equally divided over too shallow (additional bolus and direct start of continuous infusion) or too deep; a 15-min wait after PTC of 0 for return of PTC to 1 or higher. Using the proposed algorithm, a mean 76% of all 5-min measurements throughout surgery were on target PTC 1 to 2 in the validation cohort. The algorithm performed significantly better than anesthesiology residents without the algorithm, even after a learning curve from 0 to 20 patients (42% on target, P ≤ 0.001, Cohen's d = 1.4 [95% CI, 0.9 to 1.8]) to 81 to 100 patients (61% on target, P ≤ 0.05, Cohen's d = 0.7 [95% CI, 0.1 to 1.2]). CONCLUSIONS: This study proposes a dosing algorithm for deep NMB with rocuronium in patients receiving total intravenous anesthesia.

Comparing Neuromuscular Blockade Measurement Between Upper Arm (TOF Cuff®) and Eyelid (TOF Scan®) Using Mivacurium during General Anesthesia.

BACKGROUND Mivacurium is a non-depolarizing neuromuscular blocking agent. TOF-Cuff® is a device that monitors intraoperative neuromuscular blockade and blood pressure. TOF-Scan® measures muscle relaxation status of an anaesthetized patient. This study included 36 patients aged 18 to 75 years presenting for elective surgery, to compare neuromuscular blockade measured using the TOF-Cuff of the upper arm and the TOF-Scan of the facial corrugator supercilii muscle during general anesthesia and following administration of mivacurium. MATERIAL AND METHODS Train-of-four (TOF) values were obtained every 30 s before intubation and successively every 5 min until extubation. RESULTS The median onset time for TOF-Cuff was longer than for TOF-Scan (210 s vs 90 s, P<0.00001). Multiplying the time to relaxation (according to TOF-Scan) by 1 to 8, respectively, provided concordance with the TOF-Cuff result for the following cumulative percentages of patients: 5.5%, 38.9%, 58.3%, 77.8%, 83.3%, 86.1%, 88.9%, and 91.7%. Analogue values for time to recovery from the last dose were 11.1%, 63.9%, 83.3%, 86.1%, 86.1%, 88.9%, 88.9%, and 91.7%. The proportion of patients who still had TOFratio=0 in the assessment performed at min 15 did not differ significantly between these 2 methods (P=0.088). Both TOF-Scan and TOF-Cuff showed a false-negative result in patients with clinical symptoms of preterm recovery; the numerical difference favored TOF-Cuff (1.6% vs 2.1%) but without statistical significance (P=0.2235). CONCLUSIONS When measurement on the limb is not possible, TOF-Scan on the eyelid can be an alternative for TOF-Cuff on the upper arm, if the time to relaxation is multiplied by at least 8, which is enough for 90% of patients.

Comparison between conventional-dose and high-dose rocuronium use in general anesthesia for Cesarean section.

Background: There have been few studies comparing the effects of high- and low-dose rocuronium during cesarean section by directly measuring the concentration. Therefore, we conducted a study to examine the blood concentrations and clinical effects of both doses of rocuronium on mothers and fetuses. Methods: Eighteen patients were randomly assigned to two groups: C Group (0.6 mg/kg), and H Group, (1.0 mg/kg). The primary outcome was the comparison of umbilical vein rocuronium concentration between two groups. We assessed ease of intubation, time from rocuronium administration to some TOF points, post-anesthesia care unit (PACU) stay time, infused remifentanil dose, maternal rocuronium concentration, and Apgar scores. Results: No differences were observed in demographic data, ease of intubation, PACU stay time, 1 min Apgar scores, umbilical venous blood gas analysis between both groups. However, the time from rocuronium administration to T3 disappearance was shorter (p=0.009) and time to T1 and T2 reappearance were longer (p=0.003, p=0.009) in H group than that in C group. The administered remifentanil dose (p=0.042) was lower in the H group than in the C group. Rocuronium concentrations in the umbilical vein (p=0.004) and maternal vein before cord clamping (p=0.002) and at discharge (p<0.001) were also found to be higher in the H group than in the C group. Conclusions: We observed no prolongation of PACU stay, and no differences in Apgar scores in H group compared to C group. It suggests that 1.0 mg/kg of rocuronium has no negative effects on the fetus and mother in cesarean section.

Onset time, duration of action, and intubating conditions after mivacurium in elderly and younger patients.

BACKGROUND: The neuromuscular blocking agent mivacurium can be used during anesthesia to facilitate tracheal intubation. Data on onset time, duration of action, and effect on intubating conditions in patients 80 years and older are however limited. We hypothesized that onset time and duration of action of mivacurium would be longer in elderly patients than in younger adults. METHODS: This prospective observational study included 35 elderly (≥80 years) and 35 younger (18-40 years) patients. Induction of anesthesia comprised fentanyl 1-3 µg kg-1 and propofol 1.5-2.5 mg kg-1 and propofol and remifentanil for maintenance. Acceleromyography was used for monitoring neuromuscular blockade. The primary outcome was onset time defined as time from injection of mivacurium 0.2 mg kg-1 to a train-of-four (TOF) count of zero. Other outcomes included duration of action (time to TOF ratio ≥0.9), intubating conditions using the Fuchs-Buder scale and the intubating difficulty scale (IDS), and occurrence of hoarseness and sore throat postoperatively. RESULTS: No difference was found in onset time comparing elderly with younger patients; 219 s (SD 45) versus 203 s (SD 74) (difference: 16 s (95% CI: -45 to 14), p = .30). Duration of action was significantly longer in elderly patients compared with younger patients; 52 min (SD 17) versus 30 min (SD 8) (difference: 22 min [95% CI: 15 to 28], p < .001). No difference was found in the proportion of excellent intubating conditions (Fuchs-Buder); 31/35 (89%) versus 26/35 (74%) (p = .12) or IDS score (p = .13). A larger proportion of younger patients reported sore throat 24 h postoperatively; 34% versus 0%, p = .0002. No difference was found in hoarseness. CONCLUSION: No difference in onset time of mivacurium 0.2 mg kg-1 was found comparing elderly and younger patients. However, elderly patients had significantly longer duration of action. No difference was found in intubating conditions.

Comparison of rocuronium priming vs. standard rapid sequence intubation technique in emergency department patients requiring intubation.

OBJECTIVE: In our study, we aimed to compare the effect of standard rapid sequence intubation protocol and the application of rocuronium priming technique on the procedure time and hemodynamic profile. METHODS: Patients who applied to the emergency department and needed rapid sequence intubation were included in our study, which we conducted with a randomized controlled design. Randomization in the study was made according to the order of arrival of the cases. Rapid sequence intubation was performed in the standard group. In the priming group, 10% of the rocuronium dose was administered approximately 3 min before the induction agent. Intubation time, amount of drug used, vital signs, and end-tidal CO2 level before and after intubation used to confirm intubation were recorded. RESULTS: A total of 52 patients were included in the study, of which 26 patients were included in the standard group and 26 patients in the priming group. While intubation time was 121.2±21.9 s in the standard group, it was calculated as 68.4±11.6 s in the priming group (p<0.001). While the mean arterial pressure was 58.3±26.6 mmHg in the standard group after intubation, it was 80.6±21.1 mmHg in the priming group (p=0.002). CONCLUSION: It was observed that priming with rocuronium shortened the intubation time and preserved the hemodynamic profile better. CLINICAL TRIAL REGISTRATION NUMBER: NCT05343702.

Association between reversal agents (sugammadex vs. neostigmine) for neuromuscular block and postoperative pulmonary complications: A retrospective analysis.

AIMS: Residual neuromuscular blockade has been linked to pulmonary complications in the postoperative period. This study aimed to determine whether sugammadex was associated with a lower risk of postoperative pulmonary complications (PPCs) compared with neostigmine. METHODS: This retrospective cohort study was conducted in a tertiary academic medical center. Patients ≥18 year of age undergoing noncardiac surgical procedures with general anesthesia and mechanical ventilation were enrolled between January 2019 and September 2021. We identified all patients receiving rocuronium and reversal with neostigmine or sugammadex via electronic medical record review. The primary endpoint was a composite of PPCs (including pneumonia, atelectasis, respiratory failure, pulmonary embolism, pleural effusion, or pneumothorax). The incidence of PPCs was compared using propensity score analysis. RESULTS: A total of 1786 patients were included in this study. Among these patients, 976 (54.6%) received neostigmine, and 810 (45.4%) received sugammadex. In the whole sample, PPCs occurred in 81 (4.54%) subjects (7.04% sugammadex vs. 2.46% neostigmine). Baseline covariates were well balanced between groups after overlap weighting. Patients in the sugammadex group had similar risk (overlap weighting OR: 0.75; 95% CI: 0.40 to 1.41) compared to neostigmine. The sensitivity analysis showed consistent results. In subgroup analysis, the interaction P-value for the reversal agents stratified by surgery duration was 0.011. CONCLUSION: There was no significant difference in the rate of PPCs when the neuromuscular blockade was reversed with sugammadex compared to neostigmine. Patients undergoing prolonged surgery may benefit from sugammadex, which needs to be further investigated.

Unraveling the molecular dynamics of sugammadex-rocuronium complexation: A blueprint for cyclodextrin drug design.

Sugammadex, marketed as Bridion™, is an approved cyclodextrin (CD) based drug for the reversal of neuromuscular blockade in adults undergoing surgery. Sugammadex forms an inclusion complex with the neuromuscular blocking agent (NMBA) rocuronium, allowing rapid reversal of muscle paralysis. In silico methods have been developed for studying CD inclusion complexes, aimed at accurately predicting their structural, energetic, dynamic, and kinetic properties, as well as binding constants. Here, a computational study aimed at characterizing the sugammadex-rocuronium system from the perspective of docking calculations, free molecular dynamics (MD) simulations, and biased metadynamics simulations with potential of mean force (PMF) calculations is presented. The aim is to provide detailed information about this system, as well as to use it as a model system for validation of the methods. This method predicts results in line with experimental evidence for both the optimal structure and the quantitative value for the binding constant. Interestingly, there is a less profound preference for the orientation than might be assumed based on electrostatic interactions, suggesting that both orientations may exist in solution. These results show that this technology can efficiently analyze CD inclusion complexes and could be used to facilitate the development and optimization of novel applications for CDs.

A compressomyograph train of four monitoring device.

The monitoring of the neuromuscular blockade is critical for patient's safety during and after surgery. The monitoring of neuromuscular blockade often requires the use of Train of Four (TOF) technique. During a TOF test two electrodes are attached to the ulnar nerve, and a series of four electric pulses are applied. The electrical stimulation causes the thumb to twitch, and the amount of twitch varies depending on the amount of neuromuscular blockade in patient's system. Current medical devices used to assist anesthesiologists to perform TOF monitoring often require free hand movement and do not provide accurate or reliable results. The goal of this work is to design, prototype and test a new medical device that provides reliable TOF results when thumb movement is restricted. A medical device that uses a pressurized catheter balloon to detect the response thumb twitch of the TOF test is created. An analytical model, numerical study, and mechanical finger testing were employed to create an optimum design. The design is tested through a pilot human subjects study. No significant correlation is reported with subjects' properties, including hand size.