Effects Of Rocuronium Research Articles

Efficacy of Sugammadex for the Reversal of Moderate and Deep Rocuronium-induced Neuromuscular Block in Patients Pretreated with Intravenous Magnesium

Magnesium enhances the effect of rocuronium. Sugammadex reverses rocuronium-induced neuromuscular block. The authors investigated whether magnesium decreased the efficacy of sugammadex for the reversal of rocuronium-induced neuromuscular block. Thirty-two male patients were randomized in a double-blinded manner to receive magnesium sulfate (MgSO4) 60 mg/kg or placebo intravenously before induction of anesthesia with propofol, sufentanil, and rocuronium 0.6 mg/kg. Neuromuscular transmission was monitored using TOF-Watch SX acceleromyography (Organon Ltd., Dublin, Ireland). In 16 patients, sugammadex 2 mg/kg was administered intravenously at reappearance of the second twitch of the train-of-four (moderate block). In 16 further patients, sugammadex 4 mg/kg was administered intravenously at posttetanic count 1 to 2 (deep block). Primary endpoint was recovery time from injection of sugammadex to normalized train-of-four ratio 0.9. Secondary endpoint was recovery time to final T1. Average time for reversal of moderate block was 1.69 min (SD, 0.81) in patients pretreated with MgSO4 and 1.76 min (1.13) in those pretreated with placebo (P = 0.897). Average time for reversal of deep block was 1.77 min (0.83) in patients pretreated with MgSO4 and 1.98 min (0.58) in those pretreated with placebo (P = 0.572). Times to final T1 were longer compared with times to normalized train-of-four ratio 0.9, without any difference between patients pretreated with MgSO4 or placebo. Pretreatment with a single intravenous dose of MgSO4 60 mg/kg does not decrease the efficacy of recommended doses of sugammadex for the reversal of a moderate and deep neuromuscular block induced by an intubation dose of rocuronium.

Effect of rocuronium on transcranial muscle-evoked potentials restored by sugammadex in the patients with cervical myelopthy

Effect of rocuronium on transcranial muscle-evoked potentials restored by sugammadex in the patients with cervical myelopthy

Competitive Inhibition of the Nondepolarizing Muscle Relaxant Rocuronium on Nicotinic Acetylcholine Receptor Channels in the Rat Superior Cervical Ganglia

A number of case reports now indicate that rocuronium can induce a number of serious side effects. We hypothesized that these side effects might be mediated by the inhibition of nicotinic acetylcholine receptors (nAChRs) at superior cervical ganglion (SCG) neurons. Conventional patch clamp recordings were used to study the effects of rocuronium on nAChR currents from enzymatically dissociated rat SCG neurons. We found that ACh induced a peak transient inward current in rat SCG neurons. Additionally, rocuronium suppressed the peak ACh-evoked currents in rat SCG neurons in a concentration-dependent and competitive manner, and it increased the extent of desensitization of nAChRs. The inhibitory rate of rocuronium on nAChR currents did not change significantly at membrane potentials between -70 and -20 mV, suggesting that this inhibition was voltage independent. Lastly, rocuronium preapplication enhanced its inhibitory effect, indicating that this drug might prefer to act on the closed state of nAChR channels. In conclusion, rocuronium, at clinically relevant concentrations, directly inhibits nAChRs at the SCG by interacting with both opened and closed states. This inhibition is competitive, dose dependent, and voltage independent. Blockade of synaptic transmission in the sympathetic ganglia by rocuronium might have potentially inhibitory effects on the cardiovascular system.

Dexamethasone Produces Dose-Dependent Inhibition of Sugammadex Reversal in In Vitro Innervated Primary Human Muscle Cells

Corticosteroids are frequently used during anesthesia to provide substitution therapy in patients with adrenal insufficiency, as a first-line treatment of several life-threatening conditions, to prevent postoperative nausea and vomiting, and as a component of multimodal analgesia. For these last 2 indications, dexamethasone is most frequently used. Due to the structural resemblance between aminosteroid muscle relaxants and dexamethasone, concerns have been raised about possible corticosteroid inhibition in the reversal of neuromuscular block by sugammadex. We thus investigated the influence of dexamethasone on sugammadex reversal of rocuronium-induced neuromuscular block, which could be relevant in certain clinical situations. The unique co-culture model of human muscle cells innervated in vitro with rat embryonic spinal cord explants to form functional neuromuscular junctions was first used to explore the effects of 4 and 10 μM rocuronium on muscle contractions, as quantitatively evaluated by counting contraction units in contraction-positive explant co-cultures. Next, equimolar and 3-fold equimolar sugammadex was used to investigate the recovery of contractions from 4 and 10 μM rocuronium block. Finally, 1, 100, and 10 μM dexamethasone (normal, elevated, and high clinical levels) were used to evaluate any effects on the reversal of rocuronium-induced neuromuscular block by sugammadex. Seventy-eight explant co-cultures from 3 time-independent experiments were included, where the number of contractions increased to 10 days of co-culturing. Rocuronium showed a time-dependent effect on depth of neuromuscular block (4 μM rocuronium: baseline, 10, 20 minutes administration; P < 0.0001), while the dose-dependent effect was close to nominal statistical significance (4, 10 μM; P = 0.080). This was reversed by equimolar concentrations of sugammadex, with further and virtually complete recovery of contractions with 3-fold equimolar sugammadex (P < 0.0001). Dexamethasone diminished 10 μM sugammadex-induced recovery of contractions from rocuronium-induced neuromuscular block in a dose-dependent manner (P = 0.026) with a higher sugammadex concentration (30 μM) being close to statistically significantly improving recovery (P = 0.065). The highest concentration of dexamethasone decreased the recovery of contractions by equimolar sugammadex by 26%; this effect was more pronounced when 3-fold equimolar (30 μM) sugammadex was used for reversal (48%). This is the first report in which the effects of rocuronium and sugammadex interactions with dexamethasone have been studied in a highly accessible in vitro experimental model of functionally innervated human muscle cells. Sugammadex reverses rocuronium-induced neuromuscular block; however, concomitant addition of high dexamethasone concentrations diminishes the efficiency of sugammadex. Further studies are required to determine the clinical relevance of these interactions.

Effects of pretreatment with different neuromuscular blocking agents on facilitation of intubation with rocuronium: A prospective randomized comparative study.

Background and Aims:Priming principle refers to administration of a small dose of non-depolarising blocker, which when followed by a large intubating dose produces a relatively rapid and profound blockade to ensure suitable conditions for endotracheal intubation. We aimed to compare the effects of rocuronium, vecuronium, and atracurium as “pretreatment” drugs on intubating conditions with rocuronium facilitated endotracheal intubation.Methods:This double-blinded, randomised controlled prospective study was carried out at a tertiary health care hospital on patients undergoing surgical procedures under general anaesthesia. They were randomly allocated into three groups (n = 35) by computer generated randomisation chart to receive either rocuronium (0.06 mg/kg body weight) (Group A); vecuronium (0.01 mg/kg body weight) (Group B) or, atracurium (0.05 mg/kg body weight) (Group C), followed by intubating dose (0.6 mg/kg body weight) of rocuronium. The haemodynamic parameters and intubating conditions were studied and statistically analysed by ANOVA test and Student's t-test as applicable using statistical package for the social sciences 16.0 for windows (SPSS Inc., Chicago, IL, USA).Results:Excellent intubating conditions were noted in maximum number of patients in Group C (97.41%). No significant differences were observed in the systolic blood pressure in all the three groups at all-time intervals. The mean arterial pressure rose significantly from baseline value to maximum, at ‘0’ min in all the groups; however, no significant difference was observed amongst the groups (P > 0.05).Conclusion:Pretreatment with rocuronium bromide can facilitate endotracheal intubation in 60 s irrespective of non-depolarising muscle relaxants used for priming; however, it cannot attenuate haemodynamic changes associated with laryngoscopy and intubation.

The effect of rocuronium and sugammadex on neuromuscular blockade in a child with congenital myotonic dystrophy type 1

Myotonic dystrophy type 1 (MD1) is the commonest muscular dystrophy found in adults; however, it may present in the neonatal period with hypotonia, talipes, poor feeding, and respiratory failure. Inheritance is autosomal dominant with a defect in the DMPK gene found on the long arm of chromosome 19 with variable expansion of the cytosine-thymine-guanine (CTG) triplet repeat. A 14-month-old boy with congenital MD type 1 was scheduled for percutaneous endoscopic gastrostomy (PEG) insertion, orchidopexy, and division of tongue-tie. Following induction of anesthesia, acceleromyography was used to monitor neuromuscular function. This revealed a very rapid onset of profound neuromuscular block which lasted significantly longer than would be expected in a child without MD1. Sugammadex reversed the block rapidly. The anesthetic management of children with MD1 has been well described but not the acceleromyographic monitored use of rocuronium and its subsequent reversal with the new cyclodextrin sugammadex.

Effects of rocuronium and vecuronium on initial rundown of endplate potentials in the isolated phrenic nerve diaphragm preparation of rats.

Rocuronium and vecuronium, two non-depolarizing neuromuscular blockers, have been widely used in surgery procedures. However, their electrophysiological properties need to be more widely explored. We examined the effects of rocuronium and vecuronium on initial rundown of endplate potential amplitudes in the non-uniform stretched muscle preparation of the rat isolated phrenic nerve diaphragm. More specifically, the endplate potentials were recorded with one microelectrode from a single endplate. The effects of rocuronium or vecuronium each at 4 concentrations (0.5 ×, l ×, 2 ×, 4 × EC95; EC95 = concentration of the drug required to produce the inhibitory effect by 95%) on the amplitude of endplate potentials and its rundown were observed. Treatment of the isolated rat phrenic nerve-diaphragm preparation with rocuronium (2.5–20 μg/ml) or vecuronium (0.5–4 μg/ml) decreased the amplitude of endplate potentials and inhibited its rundown in a concentration-dependent manner. At the concentration (2.5 μg/ml for rocuronium and 0.5 μg/ml for vecuronium) that did not alter the endplate potential amplitude, the onset of reduced endplate potential rundown was 3 and 5 min after administration of rocuronium or vecuronium, respectively. The results suggest that rocuronium and vecuronium block the neuromuscular junction presynaptically and that rocuronium does it faster than vecuronium.

A survey of the current use of neuromuscular blocking drugs among the Middle Eastern anesthesiologists

Background:This survey aimed to assess the extent of practice of the Middle Eastern anesthesiologists in the use of neuromuscular blocking agents (NMB) in 2012.Methods:We distributed an electronic survey among 577 members of the Triple-M Middle Eastern Yahoo anesthesia group, enquiring about their practice in the use of neuromuscular blocking agents. Questions concerned the routine first choice use of NMB, choice for tracheal intubation, the use of neuromuscular monitoring (NMT), type of NMB used in difficult airway, frequency of using suxamethonium, cisatracurium, rocuronium and sugammadex, observed side effects of rocuronium, residual curarization, and the reversal of residual curarization of rocuronium.Results:A total of 71 responses from 22 Middle Eastern institutions were collected. Most of the Middle Eastern anesthesiologists were using cisatracurium and rocuronium frequently for tracheal intubation (39% and 35%, respectively). From the respondents, 2/3 were using suxamethonium for tracheal intubation in difficult airway, 1/3 were using rocuronium routinely and 17% have observed hypersensitivity reactions to rocuronium, 54% reported residual curarization from rocuronium, 78% were routinely using neostigmine to reverse the rocuronium, 21% used sugammadex occasionally, and 35% were using NMT routinely during the use of NMB.Conclusions:We believe that more could be done to increase the awareness of the Middle Eastern anesthesiologists about the high incidence of PROC (>20%) and the need for routine monitoring of neuromuscular function. This could be accomplished with by developing formal training programs and providing official guidelines.

Synergistic effect of sevoflurane and isoflurane on inhibition of the adult-type muscle nicotinic acetylcholine receptor by rocuronium

Inhaled anesthetics increase the incidence of postoperative residual neuromuscular blockade, and the mechanism is still unclear. We have investigated the synergistic effect of low-concentration inhaled anesthetics and rocuronium on inhibition of the inward current of the adult-type muscle nicotinic acetylcholine receptor (ε-nAChR). Adult-type mouse muscle ε-nAChR was expressed in HEK293 cells by liposome transfection. The inward current of the ε-nAChR was activated by use of 10μmol/L acetylcholine alone or in combination with different concentrations of sevoflurane, isoflurane, or rocuronium. The concentration-response curves of five cells were constructed, and the data yielded the 5, 25, and 50% inhibitory concentrations (IC5, IC25, and IC50, respectively) for single-drug application. Subsequently, the functional channels were perfused by adding 0.5IC5 of either sevoflurane or isoflurane (aqueous concentrations 140 and 100μmol/L, respectively) to the solution, followed by addition of IC5, IC25, or IC50 rocuronium. The amount of inhibition was calculated to quantify their synergistic effect. The inhibitory effect of rocuronium was enhanced by sevoflurane or isoflurane in a concentration-dependent manner. Sevoflurane or isoflurane (0.5IC5) with rocuronium at IC5, IC25, and IC50 synergistically inhibited the current amplitude of adult-type muscle ε-nAChR. When the IC5 of rocuronium was used, isoflurane had a stronger synergistic effect than sevoflurane (p<0.05). When rocuronium was applied at higher concentrations (IC25 and IC50), sevoflurane had an effect similar to that of isoflurane. For both inhaled anesthetics, the synergistic effect was more intense for rocuronium at IC5 than for rocuronium at IC25 or IC50. Residual-concentration sevoflurane or isoflurane has a strong synergistic effect with rocuronium at clinically relevant residual concentrations. A lower rocuronium concentration resulted in a stronger synergistic effect.

Effect of systemic lidocaine infusion on train-of-four ratios during recovery from general anesthesia

IntroductionIn spite of introduction of intermediate-acting neuromuscular blocking drugs (NMBDs), incidence of postoperative residual muscle weakness is still high. The aim of this trial is to study the effect of systemic lidocaine infusion on intraoperative consumption of rocuronium and TOF ratios at extubation and on arrival to postanesthesia care unit (PACU).MethodsForty-six ASA I–III patients aged 16–60 yr were randomly allocated into two groups: lidocaine (L) group (n = 23) and control (C) group (n = 23). After induction of standard endotracheal general anesthesia with fentanyl, propofol and rocuronium, patients of group L were given i.v. lidocaine bolus (1.5 mg kg−1) followed by continuous infusion (1.5 mg kg−1 h−1) till time of endotracheal extubation while patients in group C were given equal volumes of normal saline. Rocuronium was titrated based on clinical signs. On conclusion of surgery, neostigmine was given to reverse the effects of rocuronium if TOF count was two or more. Immediately before extubation, TOF ratio was measured and recorded and considered the primary outcome.ResultsThere were no significant differences between the two study groups regarding intraoperative fentanyl doses or core temperature at the end of surgery. End-tidal sevoflurane concentrations were significantly lower in group L than in group P (P < 0.01). The dose of rocuronium was significantly less in group L than in group C (P = 0.001). Train-of four ratios were significantly higher in group L than in group C either before extubation (P < 0.001) or on arrival to PACU (P = 0.001).ConclusionThe current study shows that intraoperative use of i.v. lidocaine infusion in generally anesthetized patients can result in higher TOF ratios at time of extubation and on arrival to PACU when rocuronium was given based on clinical signs.

Effects of sugammadex and rocuronium mast cell number and degranulation in rat liver

We investigated the effect of rocuronium- and sugammadex-induced mast cell increase and degranulation in rat portal triads. Forty-two rats, in six groups, received either rocuronium 1 mg.kg(-1); sugammadex 15 mg.kg(-1); sugammadex 100 mg.kg(-1); rocuronium 1 mg.kg(-1) and 5 min later, sugammadex 15 mg.kg(-1); rocuronium 1 mg.kg(-1) and 5 min later, sugammadex 100 mg.kg(-1); or isotonic saline. Total mast cell numbers were significantly higher with rocuronium only, than in all other groups (p<0.003), although in all active groups, the number was greater than the control. Total mast cell number was significantly higher with rocuronium and low-dose sugammadex compared with low-dose sugammadex only. The number of tryptase-positive mast cells with rocuronium only was significantly higher than in all other groups (p<0.003). Tryptase-positive mast cell numbers in both groups receiving both rocuronium and sugammadex were significantly higher compared with both groups receiving sugammadex only. Rocuronium increased mast cell numbers, and degranulation was mitigated by sugammadex. These results suggest that sugammadex may be beneficial in treatment of rocuronium-induced anaphylaxis.

The effect of rocuronium, sugammadex, and their combination on cardiac muscle and diaphragmatic skeletal muscle cells

Rocuronium has been associated with muscle weakness when administered in prolonged infusions. The effect of sugammadex and rocuronium together on muscle is unknown. In this study, we examined the effects of rocuronium and sugammadex, and the complex formed by these agents, on cardiac and diaphragmatic muscle cells. Forty-two Sprague-Dawley male rats were divided into six groups. Group I received only rocuronium at a dose of 1mg/kg and groups II and III received sugammadex alone at doses of 16 and 96mg/kg, respectively. Groups IV and V received 1mg/kg rocuronium plus 16mg/kg sugammadex and 1mg/kg rocuronium plus 96mg/kg sugammadex, respectively. Group six was the control group and received only 0.9% NaCl without any drug. Histopathological examination demonstrated that rocuronium and high doses of sugammadex accumulated in both cardiac and diaphragm muscle tissues. We also observed intense edema and degeneration in diaphragmatic and myocardial cells when the rocuronium-sugammadex complex was used. Rocuronium and sugammadex remain in the circulation for a long time and they may cause skeletal muscle myopathy, vacuolization, pyknotic nuclear clumps, and hypertrophy, and weaken the muscle fibers. Rocuronium, sugammadex, and rocuronium-sugammadex complexes cause histopathological changes and immunoreactivity to calcineurin in muscle cells.

Effect of rocuronium 0.3 mg/kg(ED95)for anesthesia induction on monitoring of recurrent laryngeal nerve in patlents undergoing thyroid surgery

Objective To investigate the effect of rocuronium 0.3 mg/kg(ED95)for anesthesia induclion on monitoring of recurrent laryngeal nerve in patients undergoing thyroid surgery.Methods Seventy-five patients,ASA Ⅰ or Ⅱ,aged 20-70 yr,weighing 50-85 kg,scheduled for thyroid surgery,were randomly divided into two groups:rocuronium group(groupⅠ,n=38)and sevoflurane group(group Ⅱ,n =37).Anesthesia was induced with midazolam 2 mg,propofol 2 mg/kg,sulfentanil 0.5 ug/kg.After loss of eyelash reflex,group Ⅰ received rocuronium 0.3 mg/kg(ED95)and was intubated with the electromyographic(EMG)endotracheal tube under glidescope al 2 min after rocuronium administration.Group Ⅱ received sevoflurane inhalation and was endotracheal intubated with EMG tube until end-tidal sevoflurane concentration achieved 4％.Anesthesia was maintained with inhalation of sevoflurane in both groups.SP,DP,and HR were monitored continuously through the surgery.Cooper's score and the success of attempt at endotracheal intubation were recorded.Recurrent laryngeal nerve evoked EMG was recorded by neuromonitoring and the amplitude of EMG responses was recorded at 5 min intervals from 30 min to 70 min of surgery duration.Results SP,DP and HR remained within normal range in both groups.The success rates of endotracheal intubation were 100％ in both groups,but the Cooper' s score of group Ⅰ was significantly higher than that of group Ⅱ(P ＜ 0.05).Compared with group Ⅱ,the amplitude of EMG respouses was significantly decreased in group Ⅰ(P ＜ 0.05).However,the EMG response in group Ⅰ was adequate for neuromonitoring of recurrent laryngeal nerve.Conclusion Rocuronium 0.3 mg/kg(ED95)for anesthesia induction can not only provide satisfied endotracheal intubation conditions,but also be adequate for monitoring of recurrent laryngeal nerve in patients undergoing thyroid surgery. Key words: Androstenols; Anesthesia,general; Intraoperalive complications

Comparison between the Effects of Rocuronium, Vecuronium, and Cisatracurium Using Train-of-Four and Clinical Tests in Elderly Patients

BackgroundPostoperative residual blockade, longer duration of action for neuromuscular blockade, and slower recovery were relatively common in elderly patients.ObjectivesWe aimed to investigate the safety of train-of-four ratio and clinical tests in the assessment of patient recovery, and to determine the effects of the rocuronium, vecuronium, and cisatracurium on intubation, extubation and recovery times in elderly patients undergoing abdominal surgery.Patients and MethodsAfter obtaining institutional approval and informed consent, 60 patients over 60 years old and undergoing elective abdominal operations were included in this double-blind, randomized clinical trial. Following a standard anesthesia induction, 0.6mg kg-1 rocuronium, 0.1mg kg-1 vecuronium, and 0.1mg kg-1 cisatracurium were administered to the patients in Group R, Group V, and Group C, respectively. Train-of-four (TOF) ratios were recorded at 10-minute intervals during and after the operation. Modified Aldrete Score (MAS) and clinical tests were recorded in the recovery room at 10-minute intervals. In addition, intubation and extubation times, duration of recovery room stay, and any complications were recorded.ResultsIntubation time was found to be shorter in Group R than that in Groups V and C (P ˂ 0.001). Times to positive visual disturbances and grip strength tests were shorter in Group C than that in Group V (P = 0.016 and P = 0.011, respectively). In Group R and group C, time to TOF ≥ 0.9 was significantly longer than all positive clinical test times except grip strength (P < 0.05).ConclusionsWe hold the opinion that cisatracurium is safer in elderly patients compared to other drugs. We also concluded that the usage of TOF ratio together with clinical tests is suitable for assessment of neuromuscular recovery in these patients.

Oral Mucosal Injection of a Local Anesthetic Solution Containing Epinephrine Enhances Muscle Relaxant Effects of Rocuronium

The purpose of this study was to examine how submucosal injection of a clinically relevant dose of a lidocaine hydrochloride solution containing epinephrine affects the muscle relaxant effects of rocuronium bromide. Sixteen patients scheduled for orthognathic surgery participated in this study. All patients were induced with fentanyl citrate, a target-controlled infusion of propofol and rocuronium bromide. Anesthesia was maintained by total intravenous anesthesia. After nasotracheal intubation, an infusion of rocuronium bromide was started at 7 µg/kg/min, and the infusion rate was then adjusted to maintain a train of four (TOF) ratio at 10 to 15%. The TOF ratio just prior to oral mucosal injection of a 1% lidocaine hydrochloride solution containing 10 µg/mL epinephrine (LE) was taken as the baseline. TOF ratio was observed for 20 minutes, with 1-minute intervals following the start of injection. Mean epinephrine dose was 85.6 ± 18.6 µg and mean infusion rate of rocuronium bromide was 6.3 ± 1.6 µg/kg/min. TOF ratio began to decrease 2 minutes after the injection of LE, reached the minimum value at 3.1 ± 3.6% 12 minutes after the injection, and then began to recover. We conclude that oral mucosal injection of LE enhances the muscle relaxant effects of rocuronium bromide.

Effects of sugammadex on immunoreactivity of calcineurin in rat testes cells after neuromuscular block: a pilot study

Reversal of neuromuscular blockage induced by steroidal neuromuscular blocking agents such as rocuronium can be achieved using normal dose of sugammadex, which has been shown to be very effective for such reversal. In this study, we determined the effects of sugammadex on calcineurin immunoreactivity by examining the histopathological and histochemical structure of rat testis cells after neuromuscular blockage. Moreover, the regional distribution levels of calcineurin immunopositive testes cells were investigated. Eighteen adult male, Sprague-Dawley rats were divided into one control and two study groups. Study groups 1 and 2 rats received sugammadex at doses of 16 and 96 mg kg(-1) i.v., respectively, after rocuronium treatment (mg kg(-1) i.v.). The control group received intravenous 0.9% NaCl 1 ml. i.v without any drug. Our study demonstrates that sugammadex is safe and effective for reversal of rocuronium effects in rats, as well as in other animals and humans. Furthermore, histopathological examination indicates that high levels of sugammadex-rocuronium complexes accumulate a little in testis tissue. We found that rocuronium-sugammadex complexes were remained in circulation for a long time resulting in a decrease in interstitial space, testis size, germ cell numbers and Leydig cell numbers. Calcineurin immunoreactivity was higher in the experimental groups than the control group due to increase of calcium level. The results suggest that sugammadex-rocuronium complexes are cause histopathological and immunohistochemical changes in testis interstitial tissues, as well as changes in sperm density and germ cell number.

Testing rocuronium-induced neuromuscular blockade at the stapedius muscle using stapedius reflex measurements

Neuromuscular monitoring prior to emergence from anaesthesia has been shown to be necessary to achieve adequate airway protection in order to decrease postoperative pulmonary complications. In the present study we hypothesized that stapedius reflex measurement allows the detection of residual neuromuscular blockade using the stapedius muscle following the administration of rocuronium. Parallel stapedius and acceleromyographic measurements were performed on 20 patients undergoing cholecystectomy. Acceleromyographic measurements were continuously performed during the course of anaesthesia, whereas the stapedius reflex was measured on different occasions: (1) after premedication but before anaesthesia induction, (2) after induction, but before administration of muscle relaxant, (3) after administration of muscle relaxant, (4) during the course of surgical anaesthesia at regular intervals, and (5) continuously performed during emergence from anaesthesia, until the stapedius reflex threshold returned to normal. The intensity of the sound energy at which the stapedius reflex is detectable was similar: 89.5 ± 9.9 dB(mean ± SD) after premedication and after anaesthetic induction. However, after administration of rocuronium, when the twitch height decreased to 5%, the stapedius reflex disappeared, indicating a total block of the stapedius muscle.During the recovery phase (twitch>10%) significantly higher sound energies compared to baseline values were necessary to evoke the reflex, indicating residual inhibition of the stapedius muscle. At the point where stapedius reflex threshold returned to normal the twitch height averaged about 50% showing low sensitivity of the tympanometry in detecting residual neuromuscular blockade. The neuromuscular effect of rocuronium on the stapedius muscle can be detected using stapedius reflex measurements. Due to its methodological limitation and low sensitivity, the method cannot be recommended for the monitoring of residual neuromuscular blockade.

Effect of rocuronium and cis-atracuriumon on contraction of isolated uterine smooth muscle in rat of labor stages

Effect of rocuronium and cis-atracuriumon on contraction of isolated uterine smooth muscle in rat of labor stages

High-resolution solid-state manometry of the effect of rocuronium on barrierpressure

The pressure in the lower esophageal sphincter (LES) is partly dependent on striated muscles derived from the crural portion of the diaphragm. The effect of neuromuscular blockade on the integrity of the esophagogastric junction is not well studied. We conducted a prospective interventional study to determine the effect of rocuronium on the barrier pressure (LES pressure - intragastric pressure) of the esophagogastric junction. We also studied the effect of positive pressure ventilation on the barrier pressure after neuromuscular blockade with rocuronium. Fourteen patients classified as American Society of Anesthesiologists classification system (ASA) I or II (aged 18-75 years) who presented for elective surgery (11 cholecystectomy, 3 inguinal hernia) participated in the study. Esophageal manometry was performed during anesthetization with propofol, fentanyl, and sevoflurane. The LES pressure was studied prior to anesthesia, after anesthesia induction during spontaneous breathing with laryngeal mask airway, after administration of rocuronium (0.6 mg/kg), and during positive pressure ventilation. Muscle relaxation with rocuronium showed no significant changes in barrier pressure when comparing the pressure immediately before rocuronium administration with the pressure obtained after rocuronium administration at the time point of 0% train-of-four (TOF). Conversion to positive pressure ventilation did not change the barrier pressure with inspiration or expiration. The greatest decrease in barrier pressure was measured after inducing anesthesia when comparing pressures during inspiration (P < 0.01). Neuromuscular blockade with rocuronium and conversion from spontaneous breathing to positive pressure ventilation does not decrease the barrier pressure during anesthesia induction.

Sugammadex, a Promising Reversal Drug. A Review of Clinical Trials

According to published data, sugammadex, rapidly reverses (2-5 min) shallow and profound NM block induced by rocuronium and vecuronium, without being connected with serious adverse events. It is accepted that in order to reverse shallow block, the suggested dose of sugammadex comes up to 2 mg/kg. Profound level of NM block demands 4 mg/kg in order to defy few responses at the post titanic count. Doses of sugammadex lower than 1 mg/kg may lead to rebound of rocuronium's effect. Higher doses of sugammadex (12 16 mg/g) are used in rescue reversal. In children and adolescents the 2 mg/kg dose is both effective and well tolerated, while, to date, data regarding infants are scarce. In patients with renal failure, 2 mg/kg of sugammadex resulted in a mean time to recovery of TOF ratio to 0.9 in 2 min, which was quicker than the time of reversal by acetylcholinesterase inhibitors. Investigations in cardiac patients undergoing noncardiac surgery suggest that 2 and 4 mg/kg of sugammadex are both safe and effective. Compared with neostigmine, sugammadex has no need to use muscarinic antagonists and therefore is not associated with variations in heart rate. Trials indicate that sugammadex acts faster than edrophonium and neostigmine. Sugammadex is a promising, well tolerated agent that enables fast reversal in different depths of NM block -shallow and profound- and in different patients populations. After completion of trial probation and settlement of issues concerning estimated cost and cost impact, it is believed to play a leading part in future anesthesiology.