Continuous Infusion Of Vecuronium Research Articles

The use of sugammadex for the reversal of vecuronium-induced neuromuscular block following intracranial surgery.

Total intravenous anaesthesia with propofol and remifentanil is widely used in neuroanaesthesiology and enables the quick recovery and early neurological assessment of patients. The administration of muscle relaxants carries a risk of residual relaxation following surgery. The administration of a suitable dose of sugammadex reverses the neuromuscular block irrespective of its depth and has none of the side effects associated with acetylcholinesterase inhibitors. The aim of the present study was to evaluate the usefulness of sugammadex for the reversal of vecuronium-induced effects following intracranial surgery. The study involved 38 women who underwent supratentorial tumour removal. These women were randomly divided into two groups. Total intravenous anaesthesia with propofol and remifentanil using target-controlled infusion was administered according to the Schnider and Minto models, respectively. Endotracheal intubation was performed after the target concentrations of propofol and remifentanil reached 4 μg mL⁻¹ and 4 ng mL⁻¹, respectively. Vecuronium (100 μg kg⁻¹) was administered, and no response to TOF stimulation was observed. Relaxation was continued via the continuous infusion of vecuronium (0.8-1.2 μg kg⁻¹ min⁻¹) to provide a TOF of 2 throughout the surgery. In group I, neuromuscular conduction was restored with intravenous sugammadex (2 mg kg⁻¹), whereas in group II, no reversal agents were administered. The times of the return of spontaneous breathing, extubation, eye opening (both spontaneous and in response to a verbal command) were found to be longer in group II than group I. The use of sugammadex following craniotomy accelerates the achievement of optimal extubation conditions.

Reversal of Vecuronium-induced Neuromuscular Blockade with Sugammadex in a Child with Moebius Syndrome after Accidental Extubation

Sugammadex chemically encapsulates rocuronium and vecuronium, thereby rapidly terminating the neuromuscular blockade induced by these agents. Although the experience with the use of sugammadex in children under 2 years of age is limited, it may be considered in specific clinical contexts. We present a case where spontaneous efficient respiratory effort was resumed after reversal of vecuroniuminduced neuromuscular blockade with sugammadex in a child. A 21-month-old boy with a history of Moebius syndrome and obstructive sleep apnea needing night time noninvasive ventilation support was scheduled for adenotonsillectomy and bilateral myringotomy. Tracheal intubation was anticipated to be difficult and so it was performed using a videolaryngoscope. In the postoperative period the child remained intubated in the intensive care unit sedated and with a continuous infusion of vecuronium. On day 3 accidental extubation occurred. As it was considered an urgent situation, flumazenil, naloxone and sugammadex 2 mg.kg-1 were administered with rapid return of spontaneous respiration and consciousness, obviating the need of unnecessary airway manipulation and the inherent risks.

The effect of bispectral index monitoring on anaesthetic requirements in target-controlled infusion for lumbar microdiscectomy.

Target-controlled infusion (TCI) is used to maintain the desired concentration of a hypnotic drug in the plasma and brain. However, pharmacodynamic variability can cause problems with maintaining the adequate level of anaesthesia. The bispectral index (BIS) is one of only a few parameters that allow an assessment of the depth of anaesthesia. In the present study, we attempted to determine the optimal dosages of drugs used for total intravenous anaesthesia with TCI based on BIS-guided monitoring of depth of anaesthesia. The study was conducted in 60 ASA I patients undergoing elective surgery due to lumbar discopathy. The participants were divided into two groups of 30 individuals. The patients were premedicated with 15 mg oral midazolam. Group I was the control group; group II received BIS monitoring. Anaesthesia was induced with TCI propofol (4 mg mL⁻¹), fentanyl (2 mg kg⁻¹) and vecuronium (0.12 mg kg⁻¹) and maintained with TCI propofol, continuous infusion of vecuronium (0.03 mg kg⁻¹ h⁻¹) and fractionated doses of fentanyl. ECG, HR, MAP, SaO₂, ETCO₂, and the degree of neuromuscular blockade were monitored, specifically at the following time points: T₁ - before induction, T₂ - after induction, T₃ - after intubation, T₄ - after positioning of the patient, T₅-T₁₃ - every 5 min during surgery, T₁₄ - on completion of surgery, T₁₅ - before extubation, T₁₆ - after extubation. The study groups were comparable in terms of age, body weight, duration of anaesthesia and recovery time. The haemodynamic parameters, such as HR and MAP, did not differ significantly between the groups. In both groups, changes in the mean MAP values were observed between T₁ and T₂, T₂ and T₃, T₃ and T₄ as well as T₁₄and T₁₅. The total dose of fentanyl and the doses of propofol were lower in the group that received BIS monitoring. BIS monitoring reduces the doses of opioids and hypnotics used during total intravenous anaesthesia by TCI.

Vecuronium Requirements According to the Operative Phase During Living Donor Liver Transplantation Under Desflurane Anesthesia

The requirements of nondepolarizing neuromuscular blocking agent during liver transplantation show conflicting results. We sought to evaluate the requirements according to the operative phase and find extrahepatic factors that influence neuromuscular blocking agent requirements. We enrolled 35 patients undergoing living donor liver transplantation. Continuous infusion of vecuronium was adjusted every 15 minutes for consistent neuromuscular blockade aimed at T1/Tc of 0.10 monitored with a neuromuscular transmission module. We compared the mean infusion dose in each phase, and investigated whether it is correlated with preoperative Model for End-Stage Liver Disease (MELD) score, Child-Turcotte-Pugh (CTP) score, graft-recipient weight ratio (GRWR), or time to recovery of first twitch response to train-of-four (TOF) stimulation. There was a significant difference between vecuronium doses during each phase (P < .001): 0.48 ± 0.16 μg/kg/min, preanhepatic; 0.38 ± 0.14 μg/kg/min, anhepatic and 0.26 ± 0.07 μg/kg/min, neohepatic phase. There was a significant positive correlation between vecuronium infusion dose in the preanhepatic phase and CTP scores (P = .006, correlation coefficient = 0.465). There was also a significant negative correlation between the time to recovery of first twitch response of TOF stimulation and vecuronium infusion dose in the preanhepatic phase (P = .001, correlation coefficient = -0.546). The infusion dose during the preanhepatic phase was not associated with the MELD score, and that of neohapatic phase not with GRWR. The vecuronium infusion dose requirement during the anhepatic decreased compared with that in the preanhepatic phase. It further decreased during the neohepatic phase compared with the previous phases. Vecuronium infusion dose reduction is suggested especially during the neohepatic phase for early extubation. The dose during the preanhepatic phase is suggested to be determined considering the CTP score and the time to recovery of the TOF response.

Vecuronium requirement during liver transplantation under sevoflurane anesthesia

In liver transplantation patients under intravenous anesthesia, the vecuronium dose is known to be reduced, especially during the anhepatic phase. Volatile anesthetics potentiate a muscle relaxation effect of neuromuscular blocking agents, so the vecuronium dose is supposed to further decrease if sevoflurane is used during liver transplantation. The purpose of this study was to determine the appropriate dose of vecuronium at each phase of liver transplantation under sevoflurane anesthesia. Thirty-five patients scheduled for living donor liver transplantation because of liver cirrhosis were enrolled in this study. They were anesthetized with 1 MAC of sevoflurane and intermittent administration of fentanyl. Continuous infusion of vecuronium (0.5mg/ml) was used for muscle relaxation, which was adjusted every 15min for consistent muscle relaxation aimed at T1/Tc of 0.1 monitored by ulnar nerve stimulation. Vecuronium infusion was stopped after hepatic artery anastomosis was finished. The infusion rate of each operative phase-dissection, anhepatic, and neohepatic-was calculated and analyzed by one-way analysis of variance. The recovery time from train-of-four (TOF) count 1 to TOF ratio 25% was also measured. The vecuronium infusion rate of each operation phase for adequate muscle relaxation was as follows: 0.033±0.009mg/kg/h during dissection phase, 0.031±0.009mg/kg/h during anhepatic phase, and 0.026±0.006mg/kg/h during early neohepatic phase. There was a statistically significant difference between doses at each phase (P=0.033). The recovery time from TOF count 1 to TOF ratio 25% was 103±29min. The required vecuronium dose in all phases was less than the known dose in the anhepatic phase (0.036mg/kg/h) under midazolam-fentanyl anesthesia. In addition, the vecuronium infusion dose was not reduced in the anhepatic phase compared to the dissection phases.

Transcranial motor evoked potential monitoring during the surgical clipping of unruptured intracranial aneurysms

The aim of the present study was to evaluate the usefulness of transcranial motor evoked potential (MEP) monitoring and its impact on morbidity after surgical clipping of unruptured intracranial aneurysms. Motor outcomes were compared before and after the application of MEP monitoring for a one year period. A total intravenous anesthesia was induced and maintained with a continuous infusion of vecuronium. Muscle MEPs were elicited by constant voltage stimulation via subdermal needle electrodes placed at C3 and C4 positions. A more than 50% decrement of MEP amplitudes compared with baseline recordings was regarded as a warning sign and promptly indicated to the surgeon. Before the application of MEP monitoring, a new motor deficit was observed in 3 of 66 patients. However, in 98 patients operated under MEP monitoring, no new motor deficit was found except for one patient who manifested delayed hemiparesis 30 h after the operation owing to a cortical vein injury during craniotomy. MEPs deteriorated in 12 patients which were related to hypotension (n=1), temporary clipping (n=7), and permanent clipping (n=4), and recovered in all after prompt corrective measures. After surgical clipping of unruptured aneurysms, the absence of new motor deficits could be reliably anticipated by recovered MEPs as well as unchanged MEPs. Transcranial MEP monitoring is a simple, safe, and reliable tool for the prediction of postoperative motor functions. The ischemic complications can be reduced via prompt corrective measures taken on the basis of MEP changes during aneurysm surgery.

Rocuronium and Vecuronium Do Not Affect Mandibular Bone Marrow and Masseter Muscular Blood Flow in Rabbits

The goal of this study was to investigate the effect of rocuronium and vecuronium continuous infusion on oral tissue blood flow in rabbits. We used 8 male Japan White rabbits. The infusion rates of rocuronium were 7, 14, and 28 microg kg(-1) min(-1) for 20 minutes, in this order. After rocuronium was discontinued and body movement confirmed, continuous infusion of vecuronium was started. The infusion rates of vecuronium were 1.6, 3.2, and 6.4 microg kg(-1) min(-1) for 20 minutes, in this order. Observed variables were systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate, common carotid artery blood flow, tongue mucosal blood flow, oxygen partial pressure of the mandibular bone marrow, and oxygen partial pressure of the masseter muscle. Heart rate in both groups tended to decrease depending on the infusion rate. Common carotid artery blood flow in the rocuronium group was increased depending on the infusion rate. Tongue mucosal blood flow in the vecuronium group was decreased depending on the infusion rate. There were no differences in diastolic blood pressure, mean arterial pressure, oxygen partial pressure of the mandibular bone marrow, and oxygen partial pressure of the masseter muscle between the 2 groups. Systolic blood pressure in both groups showed no major change. Rocuronium and vecuronium did not change mandibular bone marrow and masseter muscular blood flows. Vecuronium decreased tongue mucosal blood flow depending on the infusion rate.

Influence of Hypothermia on Pharmacokinetics of Vecuronium in Rat Livers Investigated.

Influence of Hypothermia on Pharmacokinetics of Vecuronium in Rat Livers Investigated.Beaufort et al.(page 270)Beaufort et al. used an isolated perfused rat liver model with a fairly constant perfusion rate to elucidate the influence of hypothermia on the uptake of vecuronium in the intact organ. The researchers divided each perfusion experiment into three phases: (1) a 950-μg bolus of vecuronium was administered, followed by a continuous infusion of vecuronium throughout the experiment; (2) temperature was reduced to 28°C; and (3) temperature was restored to 38°C. In control experiments, temperature was kept constant throughout the perfusion procedure. Concentrations of vecuronium and its metabolites were measured in the perfusion medium, in bile collected from the livers, and in liver homogenate.The team found that hypothermia increased the amount of vecuronium in the perfusion medium and that, when normal temperatures were restored, this amount decreased. Although hypothermia reversibly reduced the net uptake of vecuronium to the liver, biliary excretion remained virtually intact. Hypothermia drastically reduced the biliary excretion rate of 3-desacetyl vecuronium in contrast to that of the parent compound. Researchers were able to measure metabolism of vecuronium in only one of three liver homogenate preparations, and they found in that case that hypothermia reduced the rate of conversion by a factor of 2. Pharmacokinetic analysis showed that the hypothermia-induced changes in the pharmacokinetics of vecuronium could be described adequately only by the combination of reduced hepatic net uptake and reduced metabolism. These results show the need for effective measurement of muscle relaxants during hypothermia to prevent overdosing.

Effect of hypothermia on the hepatic uptake and biliary excretion of vecuronium in the isolated perfused rat liver.

Hypothermia prolongs the time course of action of nondepolarizing muscle relaxants. It is not known whether this prolongation is caused by a reduced rate of extrahepatic distribution or elimination, liver uptake, metabolic clearance, or biliary excretion. Therefore, the authors studied the effects of hypothermia on the net hepatic uptake, metabolism, and biliary excretion of vecuronium in isolated perfused rat liver. Livers of Wistar rats were perfused with Krebs Ringer solution (1% albumin, 3.3% carbon dioxide in oxygen, pH 7.36-7.42, 38 degrees C). Each perfusion experiment (recirculatory perfusion system) was divided into three phases. In phase 1, a bolus dose of vecuronium (950 microg) was followed by a continuous infusion of vecuronium (63 microg/min) throughout the perfusion experiment. In phase 2, the temperature was reduced to 28 degrees C. In phase 3, temperature was restored. In controls, the temperature was kept constant throughout the perfusion. Concentrations of vecuronium and its metabolites were measured in perfusion medium, bile, and liver homogenate. Parameters of a multicompartmental liver model were fitted to the concentration patterns in perfusion medium and in bile. Hypothermia increased vecuronium concentrations in the perfusion medium from 4.0 microg/ml (range, 2.5-6.6) to 15.6 microg/ml (11.5-18.4 microg/ml; P = 0.018). Hypothermia reduced the biliary excretion rate of 3-desacetyl vecuronium from 18% (range, 6-37%) to 16% (range, 4-19%) of that of vecuronium (P = 0.018). Pharmacokinetic analysis confirmed that hypothermia reduced the rate constants of hepatic uptake and metabolism from 0.219 to 0.053 and from 0.059 to 0.030, respectively. Hypothermia significantly and reversibly reduced the net hepatic uptake of vecuronium. Hypothermia reduced the metabolism of vecuronium and the biliary excretion rate of 3-desacetyl vecuronium.

Comparison of Vecuronium and Meperidine on the Clinical and Metabolic Effects of Shivering After Hypothermic Cardiopulmonary Bypass

The use of vecuronium and meperidine on the clinical and metabolic effects of shivering in mechanically ventilated patients after hypothermic cardiopulmonary bypass (CPB) was compared. Twenty adult male patients undergoing cardiac surgery were randomized to meperidine, 25 to 75 mg (n = 10), or vecuronium, 0.1 microgram/kg (n = 10), for the treatment of shivering during postoperative rewarming. Vecuronium was continued as an infusion at 1.0 microgram/kg/min for 4 hours. Meperidine abolished shivering in 50% of patients with a 60% recurrence within 2 hours and did not correct acute respiratory acidosis when it occurred. Vecuronium uniformly abolished shivering, corrected acute respiratory acidosis, and improved mixed venous oxygen saturation (20% v 4%), decreased oxygen consumption (-32% v -7%) and decreased end-tidal carbon dioxide (-21% v -5%) significantly more than meperidine (p < 0.005). Meperidine administration caused a significant decline in systolic blood pressure (121.9 +/- 10.6 mmHg to 106.9 +/- 8.5 mmHg, p = < 0.02). The authors conclude that, during rewarming after hypothermic CPB, muscle relaxation with vecuronium reverses both the clinical and metabolic effects of shivering more reliably and effectively than repeated boluses of meperidine, and with greater hemodynamic stability. Control can be maintained by continuous infusion of vecuronium with concomitant sedation for up to 4 hours without prolonging intubation time.

The effect of neostigmine on twitch tension and muscle relaxant concentration during infusion of mivacurium or vecuronium.

An investigation suggested that neostigmine may not effectively antagonize mivacurium, presumably because neostigmine impairs mivacurium's metabolism. However, the effect of neostigmine on mivacurium's metabolism in vivo has not been reported. Therefore, the effect of neostigmine on neuromuscular function and plasma mivacurium concentrations during constant mivacurium infusion was determined. Mivacurium was infused in five patients to maintain 90% depression of adductor pollicis twitch tension, then 50 micrograms/kg intravenous neostigmine was administered without altering the mivacurium infusion. Peak twitch tension after neostigmine, plasma cholinesterase activity, and mivacurium concentrations before and after neostigmine were measured. Five additional patients were given 50 micrograms/kg neostigmine to antagonize block due to continuous infusions of vecuronium. Neostigmine produced less antagonism of mivacurium (39 +/- 11%) than of vecuronium (54 +/- 9%, P < 0.05). Neostigmine decreased plasma cholinesterase activity and increased plasma concentrations of the trans-trans and cis-trans stereoisomers of mivacurium (P < 0.05). Neostigmine is less effective at antagonizing the neuromuscular effect of mivacurium than that of vecuronium during constant infusion. Neostigmine increases plasma mivacurium concentrations, likely explaining its limited efficacy. Our results confirm that neostigmine impairs the metabolism of mivacurium in vivo and may explain the observation that neostigmine may not effectively antagonize mivacurium-induced block.

Comparison of vecuronium and meperidine on the clinical and metabolic effects of shivering after hypothermic cardiopulmonary bypass

The use of vecuronium and meperidine on the clinical and metabolic effects of shivering in mechanically ventilated patients after hypothermic cardiopulmonary bypass (CPB) was compared. Twenty adult male patients undergoing cardiac surgery were randomized to meperidine, 25 to 75 mg (n = 10), or vecuronium, 0.1 microgram/kg (n = 10), for the treatment of shivering during postoperative rewarming. Vecuronium was continued as an infusion at 1.0 microgram/kg/min for 4 hours. Meperidine abolished shivering in 50% of patients with a 60% recurrence within 2 hours and did not correct acute respiratory acidosis when it occurred. Vecuronium uniformly abolished shivering, corrected acute respiratory acidosis, and improved mixed venous oxygen saturation (20% v 4%), decreased oxygen consumption (-32% v -7%) and decreased end-tidal carbon dioxide (-21% v -5%) significantly more than meperidine (p < 0.005). Meperidine administration caused a significant decline in systolic blood pressure (121.9 +/- 10.6 mmHg to 106.9 +/- 8.5 mmHg, p = < 0.02). The authors conclude that, during rewarming after hypothermic CPB, muscle relaxation with vecuronium reverses both the clinical and metabolic effects of shivering more reliably and effectively than repeated boluses of meperidine, and with greater hemodynamic stability. Control can be maintained by continuous infusion of vecuronium with concomitant sedation for up to 4 hours without prolonging intubation time.

The Effect of Hypothermia on Adductor Pollicis Twitch Tension During Continuous Infusion of Vecuronium in Isoflurane-Anesthetized Humans

The effect of total body cooling on force of contraction of the adductor pollicis was determined during a constant rate infusion of vecuronium. Anesthesia was induced with thiopental and maintained with isoflurane/nitrous oxide in eight volunteers (study group) and seven surgical patients (control group). After train-of-four (TOF) stimulation of the ulnar nerve, we measured the amplitude of the first response (T1) in the train and the ratio of the fourth-to-first response (TOF ratio). Vecuronium was then administered as an intravenous (i.v.) bolus, 25 micrograms/kg, followed by continuous i.v. infusion, 25 micrograms.kg-1 x h-1; central body (core) temperature was maintained stable for 60 min, at the end of which T1 and TOF responses were constant. In the study group, core temperature was then reduced (using circulating-water blankets) by a mean of 2.6 degrees C, decreasing the T1 and TOF ratio, respectively, by 19% and 18% per degrees C reduction in adductor pollicis temperature. Normothermia was maintained in the control group for a mean of 111 min, with no significant change in T1 and TOF responses. We conclude that, during a constant-rate infusion of vecuronium, the magnitude of neuromuscular block increases significantly when adductor pollicis temperature decreases secondary to core cooling.

Dose Requirements of Vecuronium, Pancuronium, and Atracurium During Orthotopic Liver Transplantation

To further elucidate the role of the liver in the clearance of vecuronium, atracurium, and pancuronium, 30 patients undergoing orthotopic liver transplantation were randomly assigned to three comparable groups to receive a continuous infusion of vecuronium, atracurium, or pancuronium. The evoked integrated compound action potential of the hypothenar eminence in response to train-of-four ulnar nerve stimulation was measured and recorded. Anesthesia was induced with 3-5 mg/kg of thiopental, 50 micrograms/kg of midazolam, and 1-5 micrograms/kg of fentanyl IV and was maintained with continuous infusions of midazolam and fentanyl while the lungs were ventilated with an air-oxygen mixture. The infusion rates of vecuronium, atracurium, and pancuronium were adjusted to achieve a T1/Tc ratio of between 0.02 and 0.10 (T1 = height of first twitch, Tc = height of control twitch). Vecuronium and pancuronium requirements, which were 0.072 +/- 0.022 and 0.042 +/- 0.015 mg.kg-1.h-1 (mean +/- standard deviation) respectively during the dissection phase, decreased significantly during the anhepatic phase to 0.036 +/- 0.021 and 0.018 +/- 0.012 mg.kg-1.h-1 and returned toward the initial values in the postreperfusion phase (0.055 +/- 0.018 and 0.032 +/- 0.012 mg.kg.-1.h-1); whereas atracurium requirements remained unchanged during the three phases (0.667 +/- 0.199, 0.567 +/- 0.142, and 0.692 +/- 0.254 mg.kg-1.h-1). These data suggest that the liver has an important role in the elimination of vecuronium and pancuronium, whereas the elimination of atracurium is unaltered during exclusion of the liver from the circulation.

Train of Four Hysteresis During Computer Assisted Continuous Infusion of Vecuronium

Train of Four Hysteresis During Computer Assisted Continuous Infusion of Vecuronium

The Cost of Continuous Infusions of Vecuronium in Critically Ill Patients

The Cost of Continuous Infusions of Vecuronium in Critically Ill Patients

The Cost of Continuous Infusions of Vecuronium in Critically Ill Patients

The Cost of Continuous Infusions of Vecuronium in Critically Ill Patients

Continuous infusion of vecuronium in children.

The average dose of vecuronium required in children continuous infusion to attain a steady state block of 90% was determined. The electromyographic (EMG) response and mechanical response to supramaximal stimulation of the ulnar never recorded simultaneously, were significantly correlated in four children. The steady-state infusion rate requirement of vecuronium was 1.4 +/- 0.03 micro g/kg/min during 2% enflurane anesthesia and 3.1 +/- 0.03 micro g/kg/min during 1% halothane anesthesia. The spontaneous recovery time to 25% of the control by EMG during halothane and enflurane anesthesia was 12.6 +/- 1.1 and 10.3 +/- 1.5 min, respectively, after termination of the infusion. There was no cumulative effect after prolonged vecuronium infusion.

A simple method for monitoring muscular relaxation during continuous infusion of vecuronium.

There is considerable individual variation in the dose of vecuronium required for the maintenance of surgical relaxation. Therefore to provide uninterrupted relaxation without overdosage it is advisable to regulate the IV infusion of vecuronium on the basis of appropriate monitoring. Monitoring with mechanomyography (MMG) or electromyography requires costly equipment and is too complex for routine clinical use. Visual observation of the adductor pollicis muscle contracting against zero resistance is not suitable for the reliable assessment of the degree of neuromuscular (NM) block. For clinical purposes satisfactory monitoring can be achieved with the simple device (Myoscan) described. The reliability of the Myoscan was tested in 30 patients by simultaneous monitoring of the force of contraction of the adductor pollicis on one side with the Myoscan and on the contralateral side with the MMG. Retrospective analysis of the MMG indicated that the conduct of anaesthesia would have been virtually the same if it would have been based on MMG monitoring.