Pillar[6]MaxQ functions as an in vivo sequestrant for rocuronium and vecuronium.

The binding affinity of pillar[6]MaxQ toward a panel of neuromuscular blockers and neurotransmitters was measured in phosphate buffered saline by isothermal titration calorimetry and 1H NMR spectroscopy. In vivo efficacy studies showed that P6MQ sequesters rocuronium and vecuronium and reverses their influence on the recovery of the train-of-four (TOF) ratio.

Efficacy of Atracurium-Vecuronium Combination in Patients Undergoing Laparoscopic Surgery: A Randomized Controlled Study.

INTRODUCTION: Deep neuromuscular blockade (d-NMB) is an essential requirement for carboperitoneum during laparoscopy surgery. However, sustaining d-NMB till the completion of surgery delays the reversal of the residual block. Therefore, there is a merit in exploring the effect of synergistic vecuronium-atracurium combination on the duration-of-action of d-NMB during "laparoscopic" surgery when we compare intubating bolus non-depolarizers (atracurium, vecuronium) administered alone. This study aims to evaluate whether the synergistic effect atracurium-vecuronium combination increases duration-of-action of d-NMB "laparoscopic" surgery settings. METHODS: Forty-eight patients (18-60 years, American Society of Anesthesiologists physical status- II/III, either sex) undergoing laparoscopic cholecystectomy were randomly allocated to receive vecuronium (vecuronium group, n = 16) or atracurium (atracurium group, n = 16) or vecuroniumatr-acurium combination (vecuronium-atracurium combination group, n = 16) and analyzed for the effects on the duration-of-action (primary objective); onset-of-action, reversibility, and quality of intubating conditions (secondary objectives) profile of neuromuscular blockade in patients undergoing laparoscopic cholecystectomy. RESULTS: Duration-of-action of neuromuscular blockade was significantly longer in patients who received atracurium-vecuronium combination (53.9 ± 9.7 minutes) versus atracurium-alone (41.1 ± 3.8 minutes) or vecuronium-alone (43.5 ± 9.2 minutes) (P = 0.000). No difference was found for the time to onset-of-action (vecuronium [198.1 ± 34.9 seconds], atracurium [188.5 ± 50.6 seconds], or atracurium-vecuronium combination [196.3 ± 46.3 seconds] [P = 0.829]); time for the reversal of muscle relaxation effect (vecuronium [559.9 ± 216.2 seconds], atracurium [584.7 ± 258.3 seconds], and atracurium-vecuronium combination [555.0 ± 205.4 seconds] [P = 0.925]); and quality-of-intubating conditions (vecuronium group [9.6 ± 1.3]; atracurium group [10.0 ± 0.0]; atracurium-vecuronium group [10.0 ± 0.0] [P = 0.182]). CONCLUSION: The synergistic effect of the atracurium-vecuronium combination leads to an increased duration-of-action of d-NMB during laparoscopic cholecystectomy without impacting onset-of-action, quality of intubating conditions, and reversal of muscle relaxant effect.

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.

Sugammadex, the Guardian of Deep Muscle Relaxation During Conventional and Robot-Assisted Laparoscopic Surgery: A Narrative Review.

High intra-abdominal pressure induced by artificial pneumoperitoneum can obviously impair respiratory and circulatory functions and has a negative effect on the prognosis of patients undergoing conventional and robot-assisted laparoscopic surgery. The application of deep neuromuscular blockade during the operation is reported to lower the intra-abdominal pressure and improve patients' outcome. However, concern lies in the risks of postoperative residual muscular paralysis with the use of deep neuromuscular blockade. Sugammadex, a specific antagonist for aminosteroids muscle relaxants, can effectively and rapidly reverse rocuronium and vecuronium induced neuromuscular blockade of different depths. Thus, sugammadex allows the ability to safeguard the application of deep neuromuscular blockade in laparoscopic operations and helps to alleviate the adverse complications associated with pneumoperitoneum. Here, we review the application of deep neuromuscular blockade in different laparoscopic surgeries and discuss the benefits and possible risks of sugammadex administration in the reversal of deep neuromuscular blockade in these operations.

Neuroactive steroids, WIN-compounds and cholesterol share a common binding site on muscarinic acetylcholine receptors.

Endogenous neurosteroids and their synthetic analogues-neuroactive steroids-have been found to bind to muscarinic acetylcholine receptors and allosterically modulate acetylcholine binding and function. Using radioligand binding experiments we investigated their binding mode. We show that neuroactive steroids bind to two binding sites on muscarinic receptors. Their affinity for the high-affinity binding site is about 100 nM. Their affinity for the low-affinity binding site is about 10 µM. The high-affinity binding occurs at the same site as binding of steroid-based WIN-compounds that is different from the common allosteric binding site for alcuronium or gallamine that is located between the second and third extracellular loop of the receptor. This binding site is also different from the allosteric binding site for the structurally related aminosteroid-based myorelaxants pancuronium and rapacuronium. Membrane cholesterol competes with neurosteroids/neuroactive steroids binding to both high- and low-affinity binding site, indicating that both sites are oriented towards the cell membrane..

Actual versus ideal body weight dosing of sugammadex in morbidly obese patients offers faster reversal of rocuronium- or vecuronium-induced deep or moderate neuromuscular block: a randomized clinical trial.

BACKGROUND: This randomized, double-blind trial evaluated sugammadex-mediated recovery time from rocuronium- or vecuronium-induced moderate (M-) or deep (D-) neuromuscular block in morbidly obese adults dosed by actual (ABW) or ideal body weight (IBW). METHODS: Adults with BMI ≥40 kg/m2 were randomized to 1 of 5 groups: M-neuromuscular block, sugammadex 2 mg/kg ABW; M-neuromuscular block, sugammadex 2 mg/kg IBW; M-neuromuscular block, neostigmine 5 mg, and glycopyrrolate 1 mg; D-neuromuscular block, sugammadex 4 mg/kg ABW; or D-neuromuscular block, sugammadex 4 mg/kg IBW. Supramaximal train of four (TOF) stimulation of the ulnar nerve (TOF-watch SX®) monitored recovery. Primary endpoint was time to TOF ratio ≥ 0.9 for ABW and IBW groups pooled across neuromuscular blocking agent (NMBA)/blocking depth, analyzed by log-rank test stratified for agent and depth. Prespecified safety outcomes included treatment-emergent bradycardia, tachycardia, and other arrhythmias, and adjudicated hypersensitivity and anaphylaxis. RESULTS: Of 207 patients randomized, 188 received treatment (28% male, BMI 47 ± 5.1 kg/m2, age 48 ± 13 years). Recovery was 1.5 min faster with ABW vs IBW dosing. The sugammadex 2 mg/kg groups recovered 9-fold faster [time 0.11-fold, 95% CI 0.08 to 0.14] than the neostigmine group. ABW (5.3%) and IBW (2.7%) groups had similar incidences of recovery time > 10 min (95% CI of difference: - 4.8 to 11.0%); 84% for neostigmine group. Re-curarization occurred in one patient each in the 2 mg/kg IBW and neostigmine groups. Prespecified safety outcomes occurred with similar incidences. CONCLUSIONS: ABW-based sugammadex dosing yields faster reversal without re-curarization, supporting ABW-based sugammadex dosing in the morbidly obese, irrespective of the depth of neuromuscular block or NMBA used. TRIAL REGISTRATION: Registered on November 17, 2017, at ClinicalTrials.gov under number NCT03346070 .

In vitro alteration on erythrocytes mechanical properties by propofol, remifentanil and vecuronium.

Several studies report flow disturbance and microcirculation disorders upon anesthesia treatment. These alterations are often related to blood rheology changes. In this work, it was attempted to make a detailed description of the alterations in erythrocyte mechanical properties by the action of propofol, remifentanil, and vecuronium. For this, an in vitro study was performed on red blood cell samples from healthy donors incubated with solutions of propofol (4 µg/mL whole blood), remifentanil (10 ng/mL plasma), and vecuronium (0.15 µg/mL plasma). Erythrocyte viscoelastic parameters were determined by octuplicate using a Reómetro Eritrocitario. Also, a Wilcoxon signed rank-test with Yates correction for continuity was performed to analyze the overall alteration in the mechanical properties of erythrocytes. Statistical analysis showed that the three studied anesthetics changed the erythrocyte mechanical properties at different parts of the membrane. These results would imply an interaction of these anesthetics with the erythrocyte membrane. Finally, this could conduce to alterations in microcirculation.

Involvement of the basal nucleus of Meynert on regional cerebral cortical vasodilation associated with masticatory muscle activity in rats.

We examined the neural mechanisms for increases in regional cerebral blood flow (rCBF) in the neocortex associated with mastication, focusing on the cortical vasodilative system derived from the nucleus basalis of Meynert (NBM). In pentobarbital-anesthetized rats, parietal cortical rCBF was recorded simultaneously with electromyogram (EMG) of jaw muscles, local field potentials of frontal cortex, multi-unit activity of NBM neurons, and systemic mean arterial pressure (MAP). When spontaneous rhythmic EMG activity was observed with cortical desynchronization, an increase in NBM activity and a marked rCBF increase independent of MAP changes were observed. A similar rCBF increase was elicited by repetitive electrical stimulation of unilateral cortical masticatory areas. The magnitude of rCBF increase was partially attenuated by administration of the GABAergic agonist muscimol into the NBM. The rCBF increase persisted after immobilization with systemic muscle relaxant (vecuronium). rCBF did not change when jaw muscle activity was induced by electrical stimulation of the pyramidal tract. The results suggest that activation of NBM vasodilator neurons contributes at least in part to the rCBF increase associated with masticatory muscle activity, and that the NBM activation is induced by central commands from the motor cortex, independently of feedback from brainstem central pattern generator or contracting muscles.

Context-sensitive recovery of neuromuscular function from vecuronium in dogs: Effects of dose and dosing protocol.

Recovery of neuromuscular function is a gradual phenomenon whereby function progresses from absent to normal. The speed of spontaneous recovery can be used to predict the time when neuromuscular function is expected to be restored. However, the speed of recovery might be affected by the dose of the neuromuscular blocker administered, and by the dosing regimen of that dose. The effects of both factors on the speed of spontaneous recovery from vecuronium were evaluated. Seven dogs were anesthetized three times and the train-of-four (TOF) ratio was measured with acceleromyography. Vecuronium was administered at 0.1 mg/kg, 0.2 mg/kg, or 0.1 mg/kg followed by two doses of 0.05 mg/kg was administered each time. In the divided-dose treatment group, aliquots were administered on return of the first twitch (T1) of the TOF from the previous dose. The duration of surgical block, from injection to return of T1, was longest for the divided-dose protocol, intermediate for 0.2 mg/kg single bolus, and shortest for 0.1 mg/kg (P < 0.0001). The recovery period, from return of T1 to a TOF ratio ≥0.9, was longer for 0.2 mg/kg administered as a single bolus than for the other two groups (P = 0.007). Doubling the dose of a single bolus of vecuronium extended the time of surgical block and prolonged the duration of the recovery period. However, dividing that dose into smaller aliquots extended the period of surgical block while shortening the recovery period. Hence, the spontaneous reappearance of T1 should not be used in isolation to predict the time to complete recovery of neuromuscular function.

Entamoeba histolytica L220 induces the in vitro activation of macrophages and neutrophils and is modulated by neurotransmitters.

The neuroimmunoregulation of inflammation has been well characterized. Entamoeba histolytica provokes an inflammatory response in the host in which macrophages and neutrophils are the first line of defense. The aim of this study was to analyze the effect of the 220 kDa lectin of Entamoeba histolytica on stimulation of human macrophages and neutrophils, especially the secretion of cytokines and the relation of these to neurotransmitters. Human cells were interacted with L220, epinephrine, nicotine, esmolol and vecuronium bromide. The concentrations of IL-1ß, IFN-γ, TNF-α and IL-10 were determined by ELISA at, 4 h of interaction. L220 has a cytokine stimulating function of macrophages and neutrophils for secretion of IL-1ß, and IL-10 only by macrophages, which was modulated by the effect of vecuronium on cholinergic receptors in this immune cells.

Comparison of Different Muscle-Relaxant Anesthetics on Growth, Migration and Invasion of Gastric Cancer Cells.

BACKGROUND/AIM: Muscle relaxants, also known as neuromuscular blocking agents, can block nerve impulses to the muscles and are always used in surgery for general anesthesia. However, the effect of muscle-relaxant anesthetics on cell activity in gastric cancer is currently unknown. The present study aimed to examine and compare the role of three different muscle-relaxant anesthetics in gastric cancer cells. MATERIALS AND METHODS: Gastric cancer cells (SGC7901 and BGC 823) were treated with a different dose of muscle-relaxant anesthetics, Rocuronium bromide (Rb), Vecuronium bromide (Vb) and Cisatracurium Besilate (CB). Using in vitro models, the effects on gastric cancer cell invasion, growth and migration of various anesthetics were subsequently investigated. RESULTS: We found that Rb increased the growth, invasion and migration of gastric cancer cells SGC7901 and BGC823. However, Vb and CB, as relatively mitigative anesthetics, did not significantly affect gastric cancer cell malignant phenotype at their regular blood concentration. CONCLUSION: Our results are important in selecting the type and dose of anesthetic used for surgery of gastric cancer patients. An understanding of the effect of muscle-relaxant anesthetics and their impact on tumor metastasis is critical, since it provides insight into the appropriate anesthetic strategy that could improve long-term survival in some patients with gastric cancer.

Influences of cisatracurium besylate and vecuronium bromide on muscle relaxant effects and electromyography of tracheal intubation under general anesthesia.

OBJECTIVE: To observe the influences of atracurium besylate and vecuronium bromide on muscle relaxant effects and electromyography of patients with tracheal intubation under general anesthesia in thyroid surgery. PATIENTS AND METHODS: 120 patients treated with thyroid surgery were randomly divided into group A and group V. Patients in group A were administered with cisatracurium besylate combined with propofol and fentanyl for induction of tracheal intubation under general anesthesia. Patients in group V were administered with 0.10 mg/kg vecuronium bromide combined with propofol and fentanyl for induction of tracheal intubation under general anesthesia. Then, the amplitude in electromyography was observed 30-70 min after I.V. muscle relaxant medicine to record the time for patients to reach 0% TW convulsion in abductor pollicis muscle and to observe the muscle relaxant effects. RESULTS: There was no statistical difference in the time to reach 0% TW in two groups (p>0.05). After 30 min of injection of muscle relaxants, EMG positive rate and TW value in group A were significantly higher than those in group V (p<0.05). After 50-70 min of injection of muscle relaxants, EMG positive rate of patients in two groups was up to 100%, and EMG amplitude in group A was significantly higher than that in group V (p<0.05). The time of taking muscle relaxant effects in group A was significantly faster than that in group V (p<0.05), while the recovery time of autonomous respiration and the time of autonomous body activity in group A were slightly lower than those in group V (p>0.05). There was no statistical difference in the time of eye-opening of both groups (p>0.05). MAP and HR of patients in both groups showed no statistical difference before and after injection (p>0.05). CONCLUSIONS: Average EMG amplitude and the positive rate of effective EMG amplitude of cisatracurium besylate are all higher than those of vecuronium bromide. With faster effects and shorter action time, cisatracurium besylate is more suitable in thyroid surgery IONM (intraoperative neurophysiological monitoring).

Neuromuscular blockade and inspiratory breath hold during stereotactic body radiation therapy for treatment of heart base tumors in four dogs.

CASE DESCRIPTION 4 dogs were examined because of pleural effusion and ventricular tachycardia, coughing and supraventricular tachycardia, appendicular osteosarcoma, and syncopal episodes. CLINICAL FINDINGS In all 4 dogs, a heart base tumor was identified by means of thoracic CT. TREATMENT AND OUTCOME In all 4 dogs, the heart base tumors were treated by means of stereotactic body radiation therapy. Dogs were anesthetized, and neuromuscular blockade was achieved with atracurium or vecuronium. A circle rebreathing system with 15 m (50 feet) of anesthetic tubing coursing through the vault wall was used to connect the patient to the anesthesia machine, which was located in the control room. After a brief period of hyperventilation, an inspiratory breath was held at 20 cm H2O for the duration of beam delivery. Each beam delivery lasted between 30 and 100 seconds. Immediately following the breath hold, assisted ventilation was resumed. Mean treatment delivery time for each patient was 26 minutes; mean total anesthesia time was 89 minutes. All patients recovered without complications. There was no evidence of hemoglobin desaturation or hypercapnia during the anesthetic procedure. CLINICAL RELEVANCE The technique allowed for control of the respiration cycle from outside the radiation vault and a short overall treatment time. No adverse effects were encountered. This procedure should be considered when delivering radiation to structures within the thoracic cavity.

The effects of intravenous anesthetics on QT interval during anesthetic induction with sevoflurane.

PURPOSE: Sevoflurane is known to prolong the QT interval. This study aimed to determine the effect of the interaction between intravenous anesthetics and sevoflurane on the QT interval. METHODS: The study included 48 patients who underwent lumbar spine surgery. Patients received 3 µg/kg fentanyl and were then randomly allocated to either Group T, in which they received 5 mg/kg thiamylal, or Group P, in which they received 1.5 mg/kg propofol, at 2 min after administration of fentanyl injection for anesthetic induction. Vecuronium (1.5 mg/kg) and sevoflurane (3 % inhaled concentration) were administered immediately after loss of consciousness and tracheal intubation was performed 3 min after vecuronium injection. Heart rate (HR), mean arterial pressure (MAP), bispectral index score (BIS), and the heart rate-corrected QT (QTc) interval on a 12-lead electrocardiogram were recorded immediately before fentanyl administration (T1), 2 min after fentanyl injection (T2), immediately before intubation (T3), and 2 min after intubation (T4). RESULTS: There were no significant differences between the two groups in baseline patient characteristics. BIS and MAP significantly decreased after anesthesia induction in both groups. At T3, MAP in Group T was higher than in Group P, while HR had reduced in both groups. The QTc interval was prolonged after anesthesia induction in Group T, but did not change at any time point in Group P. The QTc interval after anesthesia induction in Group T was longer than in Group P. CONCLUSION: We concluded that an injection of propofol could counteract QTc interval prolongation associated with sevoflurane anesthesia induction.

Sonographic optic nerve sheath diameter as a surrogate measure for intracranial pressure in anesthetized patients in the Trendelenburg position.

BACKGROUND: It remains to be elucidated whether the Trendelenburg position increases intracranial pressure (ICP). ICP can be evaluated by measuring the sonographic optic nerve sheath diameter (ONSD). We investigated the effect of the isolated Trendelenburg position on ONSD in patients undergoing robot-assisted laparoscopic radical prostatectomy. Additionally, we evaluated the effect of the Trendelenburg position combined with pneumoperitoneum on ONSD. METHODS: Twenty-one patients scheduled for robot-assisted laparoscopic radical prostatectomy were enrolled. Sonographic ONSDs and hemodynamic parameters were measured at specific time points: in the supine position after induction of anesthesia, 3 min after the steep Trendelenburg position (35° incline), 3 min after the steep Trendelenburg position combined with pneumoperitoneum, and in the supine position after desufflation of the pneumoperitoneum. RESULTS: The ONSD 3 min after the steep Trendelenburg position was significantly higher than that of the supine position after induction of anesthesia (5.1 ± 0.3 mm vs. 4.5 ± 0.4 mm). In addition, the ONSD 3 min after the steep Trendelenburg position combined with pneumoperitoneum was higher than that of the supine position after induction of anesthesia (4.9 ± 0.4 mm vs. 4.5 ± 0.4 mm). The ONSD in the supine position after desufflation of the pneumoperitoneum was similar to that in the supine position after induction of anesthesia. CONCLUSIONS: Use of the isolated steep Trendelenburg position, for even a short duration, increased the sonographic ONSD, providing a better understanding of the effect of only a transient steep Trendelenburg position on ONSD as a surrogate measure for ICP.

Neuromuscular blocking effects of vecuronium in dogs with autosomal-recessive centronuclear myopathy.

OBJECTIVE: To evaluate the potency of vecuronium and duration of vecuronium-induced neuromuscular blockade in dogs with centronuclear myopathy (CNM). ANIMALS: 6 Labrador Retrievers with autosomal-recessive CNM and 5 age- and weight-matched control dogs. PROCEDURES: Dogs were anesthetized on 2 occasions (1-week interval) with propofol, dexmedetomidine, and isoflurane. Neuromuscular function was monitored with acceleromyography and train-of-four (TOF) stimulation. In an initial experiment, potency of vecuronium was evaluated by a cumulative-dose method, where 2 submaximal doses of vecuronium (10 µg/kg each) were administered IV sequentially. For the TOF's first twitch (T1), baseline twitch amplitude and maximal posttreatment depression of twitch amplitude were measured. In the second experiment, dogs received vecuronium (50 µg/kg, IV) and the time of spontaneous recovery to a TOF ratio (ie, amplitude of TOF's fourth twitch divided by amplitude of T1) ≥ 0.9 and recovery index (interval between return of T1 amplitude to 25% and 75% of baseline) were measured. RESULTS: Depression of T1 after each submaximal dose of vecuronium was not different between groups. Median time to a TOF ratio ≥ 0.9 was 76.7 minutes (interquartile range [IQR; 25th to 75th percentile], 66.7 to 99.4 minutes) for dogs with CNM and 75.0 minutes (IQR, 47.8 to 96.5 minutes) for controls. Median recovery index was 18.0 minutes (IQR, 9.7 to 23.5 minutes) for dogs with CNM and 20.2 minutes (IQR, 8 to 25.1 minutes) for controls. CONCLUSIONS AND CLINICAL RELEVANCE: For the study dogs, neither potency nor duration of vecuronium-induced neuromuscular blockade was altered by CNM. Vecuronium can be used to induce neuromuscular blockade in dogs with autosomal-recessive CNM.

Bispectral index and lower margin amplitude of the amplitude-integrated electroencephalogram in neonates.

BACKGROUND: The lower margin amplitude (LMA) of the amplitude-integrated electroencephalogram (aEEG) is suppressed in neonates during deep sedation, a feature that is attributed to the bispectral index (BIS) in adults. OBJECTIVE: We compare the BIS and the LMA of the aEEG in neonates. METHODS: Thirty neurologically healthy neonates between 37 and 44 weeks postmenstrual age were included in this study. Twenty patients received sedoanalgesic therapy for various reasons. BIS and aEEG recordings were performed simultaneously. The digital data were imported in the numerical software environment Matlab®. The LMA of the aEEG was computed on a 1-min time scale and synchronized with the BIS data. The correlation between the time-dependent variables BIS and LMA was estimated using the Spearman rank correlation index. RESULTS: The median correlation between BIS and LMA was 0.3. Inclusion of recordings of high signal quality only into analysis improved the median correlation index to 0.6. CONCLUSIONS: We found a light-to-moderate correlation between BIS and LMA in our study cohort and a good correlation in the subgroup with high signal quality.

Real-time monitoring of cerebral blood flow by laser speckle contrast imaging after cardiac arrest in rat.

Cardiac arrest (CA) results in global brain ischemia. To explore the role of cerebral blood flow (CBF) during ischemia, laser speckle contrast imaging (LSCI), a full-field high-resolution optical imaging technique, was used for real-time monitoring of the fluctuations of CBF in a rat model of asphyxial-CA. The temporal changes of CBF were characterized and the relationship between CBF and mean arterial pressure (MAP) was evaluated. Asphyxial-CA led to transient CBF dysregulation, manifested by changes in CBF velocity were significantly impacted by MAP. Hyperemia is aligned with a bolus injection of vecuronium, the first two minutes of asphyxia, the time of epinephrine injection and cardiopulmonary resuscitation, and then lasted for 13 min after the return of spontaneous respiratory (ROSC), followed by hypoperfusion about 55-70% of baseline level no later than 40 min after ROSC. Interestingly, we found that the velocity of venule blood flow increased more than that of the arteriole blood flow during the hyperemia (176% vs 120%). Our study, for the first time, shows real-time CBF changes during and immediately after asphyxial-CA, with high spatial and temporal resolution images. The quantified cerebro-vascular response during the different phases of recovery after CA may underlie the mechanism of injury and recovery after brain ischemia. The study provides a new technique to study the neurovascular coupling and metabolic regulation of CBF after CA.

Haemodynamic differences between pancuronium and vecuronium in an experimental pig model.

OBJECTIVE: To compare baseline cardiovascular function in anesthetised pigs using either pancuronium or vecuronium as a neuromuscular blocker. STUDY DESIGN: Retrospective, non-randomized comparison. ANIMALS: Norwegian Land Race pigs (Sus scrofa domesticus) weighing mean 42 ± SD 3 kg. METHODS: One hundred and sixteen animals from four different research protocols premedicated with identical doses of ketamine, diazepam, atropine and isoflurane, and anaesthetised with pentobarbital, fentanyl, midazolam and N(2)O were arranged into three uniform groups with respect to neuromuscular blocking agent: pancuronium bolus of 0.063 mg kg(-1) followed by 0.14 mg kg(-1) hour(-1) (n = 54), low-dose vecuronium 0.4 mg kg(-1) /0.2 mg kg(-1) hour(-1) (n = 29) and high-dose vecuronium 0.6 mg kg(-1) /0.3 mg kg(-1) hour(-1) (n = 33). RESULTS: The majority of cardiovascular parameters demonstrated no significant differences between groups. For heart rate, there was an overall group difference, p = 0.036. Dromotropy was low in the pancuronium group, with an increased normalised PR-interval compared to the high-dose vecuronium group, median 0.200 interquartile range (0.190, 0.215) versus 0.182 (0.166, 0.199), p < 0.05. Left ventricular compliance was increased in pancuronium-treated animals, demonstrated as a reduction in the nonlinear end-diastolic pressure volume relationship ß compared to both vecuronium groups, 0.021 (0.016, 0.025) versus 0.031 (0.025, 0.046) and 0.031 (0.022, 0.048), p < 0.05. The linear end-diastolic pressure volume relationship EDPVR(lin) was reduced as well in the pancuronium group, compared to the low-dose vecuronium group, 0.131 (0.116, 0.169) versus 0.181 (0.148, 0.247), p < 0.05. CONCLUSIONS: There are only minor haemodynamic differences when using pancuronium compared to vecuronium in the fentanyl-pentobarbital-midazolam-N(2)O anesthetised domestic pigs. Furthermore, increasing doses of vecuronium have minimal haemodynamic effects. CLINICAL RELEVANCE: Experimental studies in pigs using either pancuronium or vecuronium as a neuromuscular blocking agent are comparable with regard to cardiac and haemodynamic performance.

Biophysical study on the interaction of an anesthetic, vecuronium bromide with human serum albumin using spectroscopic and calorimetric methods.

The interactions between an anesthetic, vecuronium bromide (VB) and human serum albumin (HSA) have been investigated systematically by steady-state/time-resolved fluorescence, circular dichroism (CD), UV-vis absorption, Fourier transform infrared spectroscopy (FTIR), mass spectroscopy and differential scanning calorimetry (DSC) methods under physiological conditions. The fluorescence quenching observed is attributed to the formation of a complex between HSA and VB, and the reverse temperature effect of the fluorescence quenching has been found and discussed. Fluorescence analysis has proved that there is one classical binding site on HSA for VB with a relative weak binding constant of 1.07 × 10(4)M(-1) at 298 K. The primary binding pattern is determined by hydrogen bonding or van der Waals forces occurring in site I of HSA with ΔG°=-2.30 × 10(4)J mol(-1), ΔS°=-233 J mol(-1)K(-1) and ΔH°=-9.23 × 10(4)J mol(-1) at 298 K. VB could slightly change the secondary structure and induce unfolding of the polypeptides of protein. The DSC results provide quantitative information on the effect of VB on the stability of serum albumin. It is shown that VB can efficiently bind with HSA and be transported to the focuses needed.