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Objective: To compare the dose requirements of continuous infusion of rocuronium and atracurium throughout orthotopic liver transplantation (OLT) in humans. Methods: Twenty male patients undergoing liver transplantation were randomly assigned to two comparable groups of 10 patients each to receive a continuous infusion of rocuronium or atracurium under intravenous balanced anesthesia. The response of adductor pollicis to train-of-four (TOF) stimulation of unlar nerve was monitored. The infusion rates of rocuronium and atracurium were adjusted to maintain T1/Tc ratio of 2%~10%. The total dose of each drug given during each of the three phases of OLT was recorded. Results: Rocuronium requirement, which were (0.468±0.167) mg/(kg·h) during the paleohepatic phase, decreased significantly during the anhepatic phase to (0.303±0.134) mg/(kg·h) and returned to the initial values at the neohepatic period ((0.429±0.130) mg/(kg·h)); whereas atracuruim requirements remained unchanged during orthotopic liver transplantation. Conclusions: This study showed that the exclusion of the liver from the circulation results in the significantly reduced requirement of rocuronium while the requirement of atracurium was not changed, which suggests that the liver is of major importance in the clearance of rocuronium. A continuous infusion of atracurium with constant rate can provide stable neuromuscular blockade during the three stages of OLT.

Duchenne muscular dystrophy is a hereditary disorder characterized by progressive muscle weakness and contracture, and special care during anesthesia is needed in these patients. Because inhalational anesthetics and succinylcholine can cause fatal results, intravenous anesthetics are commonly used. However, monitorings for the pediatric population are not otherwise specified. We report our experience of a 6 year-old boy that underwent muscle biopsy suspicious of muscle dystrophy under general anesthesia. The patient received midazolam, fentanyl, propofol and a small dose of rocuronium. He was monitored with bispectral index (BIS), acceleromyography (TOF). At the end of surgery, recovery of TOF ratio to 90% was evaluated, followed by injection of pyridostigmine and glycopyrrolate. When reversal of neuromuscular block was confirmed quantitatively and clinically, the patient was extubated and he experienced no complication.

Epinephrine promotes platelet aggregation through alpha 2 receptor-mediated mechanisms. In this study, the change in the platelet retention rate (PRR) was investigated before and after submucosal epinephrine injection with or without lidocaine in oral surgical patients during isoflurane-nitrous oxide anesthesia. Thirty-nine consenting patients participated in this study. Subjects were allocated in one of five groups depending on the solution injected, the diclofenac supplement, and the patients' age. PRR was measured immediately before and 5 min after epinephrine injection using a modified form of Saltzman's method. Injection of epinephrine with lidocaine deteriorated PRR, although epinephrine without lidocaine produced no PRR change. Epinephrine at doses used in routine dental practices may activate the platelet aggregating function. Dentists should keep in mind that epinephrine elicits both hemodynamic and platelet-activating effects. The latter may be of clinical importance in some situations.

Background:

Rapid and safe endotracheal intubation is of paramount importance in general anaesthesia. The aim of this study was to compare the intubating conditions of succinylcholine with rocuronium bromide and vecuronium bromide using “Timing principle”. The timing principle entails administration of a single bolus dose of nondepolarizing muscle relaxant, followed by an induction drug at the onset of clinical weakness.

Patients & Methods:

75 patients were divided into three groups of 25 each. Patients allocated to Groups A and B received rocuronium 0.6 mg kg-1 and vecuronium 0.12 mg kg-1 respectively. At the onset of clinical weakness (ptosis), anesthesia was induced with propofol 2.5 mg kg-1; intubation was accomplished after 60 seconds of induction agent in both groups. Patients in Group C received propofol 2.5mg kg-1 followed by succinylcholine 2mg kg-1 and their tracheas were intubated at 60s.Train of four count was assessed at adductor pollicis muscle using nerve stimulator at intubation and time to loss of TOF was observed. in group A and B. Intubating conditions were assessed according to a grading scale and haemodynamic variables were compared at 1,3 and 5 minutes after intubation.

Results:

Intubating conditions were either excellent(84% in group A,48% in group B and 88% in group C) or good (16% in group A, 48% in group B and 12 %in group C)and only 4% pt had poor intubating conditions in group B. Patients were interviewed postoperatively, and all were satisfied with the technique of induction of anesthesia.Rocuronium and Vecuronium are haemodynamically stable drugs as compared to Succinylcholine.

Conclusion:

Rocuronium 0.6 mg kg-1 provides good to excellent intubating conditions at 60 s comparable to succinylcholine after the induction of anesthesia using the timing principle.

Background

Several studies have demonstrated that ephedrine shortens the onset time of muscle relaxants, and it does so probably by increasing the cardiac output. However, elevation of the systemic blood pressure through α adrenergic stimulation via ephedrine may affect the onset of muscle relaxants during the induction of anesthesia. We investigated the effect of phenylephrine, which is a selective α-1 agonist, on the onset time of rocuronium and the intubating conditions in adults after the administration of propofol.

Methods

Sixty-four patients were randomly assigned to two groups. Phenylephrine (0.9 µg/kg) (P group) or the same volume of saline (S group) was injected before rocuronium (0.6 mg/kg) administration. Anesthesia was induced with fentanyl 2 µg/kg and propofol 2 mg/kg. The onset time was defined as the time from the end of rocuronium injection to the time when a single twitch height gets to 0% or the minimum level. A well-trained anesthesiologist who was 'blinded' to the treatment groups evaluated the intubating conditions. The mean arterial pressure and heart rate were recorded before induction, before intubation, immediately after intubation and 1 minute and 2 minutes after intubation.

Results

The onset time was 84 ± 18 sec in the P-group and 72 ± 14 sec in the S-group. There was no difference of the intubating conditions, the mean arterial pressure and the heart rate between the two groups.

Conclusions

A small dose of phenylephrine, which has a limited effect on blood pressure, delayed the onset time of rocuronium after the administration of propofol, and the vasoconstriction effect of phenylephrine may affect the prolongation of the rocuronium onset time at the induction of anesthesia with using propofol.

Background

We designed this double-blind, placebo-controlled study to compare the efficacy of remifentanil in reducing the pain of both propofol and rocuronium injection during rapid-sequence induction.

Methods

Ninety-five patients, scheduled for elective surgery under general anesthesia, were divided into 3 groups: saline (Group S, n = 31), remifentanil 1 µg/kg (Group R, n = 32), and lidocaine 1.5 mg/kg (Group L, n = 32) were administered after tourniquet application. The occlusion was released after 1 min and 5 ml of 1% propofol was injected over 10 s. Pain on propofol injection was evaluated by a 10-point verbal numeric rating scale (VNRS). The rest of the induction dose of propofol and 1 mg/kg of rocuronium, were injected. Pain on rocuronium injection was evaluated by a four-point score (FPS).

Results

The VNRS of propofol injection was as follows: R (0.78) = L (1.34) < S (4.26). The incidence of withdrawal response due to rocuronium was as follows: R (6.3%) < L (53.1%) < S (83.9%). The FPS of rocuronium injection was as follows: R (0.81) < L (1.78) < S (2.93).

Conclusions

Pretreatment with a bolus of remifentanil was effective in simultaneously reducing injection pain of propofol and rocuronium. In addition, remifentanil pretreatment was more effective in suppression of withdrawal response by rocuronium than lidocaine.

Aim:

The aims of present study were to compare the propofol and rocuronium with thiopentone and rocuronium in terms of clinically satisfactory intubating conditions and to co-relate intubating conditions with degree of paralysis in adductor pollicis muscle using train of four ratio (TOFR). The intubating conditions were evaluated after rocuronium bromide 0.6 mg kg-1 at 60 s.

Materials and Methods:

60 patients of ASA grades I-II of either sex, age 18-50 years, undergoing various elective surgical procedures were randomly divided into two groups, propofol rocuronium (PR group) and thiopentone rocuronium (TR group) of 30 patients in each. In the PR group, patients received propofol 2.5 mg kg-1 and rocuronium 0.6 mg kg-1; in TR group, patients received thiopentone 5 mg kg-1 and rocuronium 0.6 mg kg-1. In all patients the intubating conditions were evaluated by the observer at 60 s. TOFR was measured at the time of intubation by an assistant.

Results:

In the PR group the number of the patients placed in intubating conditions grades I, II, III and IV were 40%, 36.67%, 13.33% and 10% and their mean TOFR were 31.8±17.9%, 61.8±;14.6%, 61.7±27.9%, and 78.3±5.7% respectively. While in theTR group the number of patients placed in intubating condition grade I, II, and III were 60%, 26.67%, and 13.33% and their mean TOFR , 41.2±28.3%, 68.0±10.9% and 78.7±6.8%, respectively. There was no patient in grade lV in theTR group.

Conclusion:

The clinical intubating conditions and degree of paralysis of adductor pollicis muscle after rocuronium 0.6 mg kg-1 at 60 s in adults induced with propofol or thiopentone sodium are comparable.

Background

It was well-known that smoking affects the cardiovascular system, and remifentanil can suppress the sympathetic stimulations induced by tracheal intubation. The purpose of this study was to investigate whether there was any difference in the hemodynamic changes induced by tracheal intubation with using remifentanil between smokers and nonsmokers.

Methods

Eighty patients were enrolled: male smokers (MS), male nonsmokers (MN), female smokers (FS) and female nonsmokers (FN). Anesthesia was induced with diluted remifentanil (20 µg/ml) at a rate of 10 µg/kg/hr using an infusion pump, and 2 min later, midazolam 0.05 mg/kg and propofol 0.8 mg/kg were injected for achieving unconsciousness. Rocuronium 1 mg/kg was used for muscle relaxation, and tracheal intubation was performed 2 min after rocuronium injection. After tracheal intubation, the remifentanil was decreased to 2 µg/kg/hr. The mean arterial pressure (MAP) and heart rate (HR) were checked before induction, on unconsciousness, just before intubation, just after intubation and 1, 2 and 3 minutes after intubation, and these values were compared between the groups.

Results

In men, the MAP and HR just after intubation and at 1, 2 and 3 minutes after intubation in Group MS were significantly higher than those of Group MN (P < 0.05). For the women, the HR in both groups (the FS and FN groups) were increased just after intubation and 1, 2 and 3 minutes after intubation compared with that at the baseline, respectively, but there was no difference between the two groups.

Conclusions

There was a difference of the hemodynamic changes induced by tracheal intubation with using remifentanil between the male smokers and nonsmokers, but not in women.

Background

To analyze how lidocaine 40 mg mixed prevents injection pain of propofol affects the onset time of rocuronium, tracheal intubating conditions and intubation related hemodynamic changes.

Methods

This study consisted of 70 patients with an American Society of Anesthesiologists (ASA) physical status class 1 or 2 for general anesthesia. All the patients were randomly allocated into two groups: propofol 2 mg/kg plus normal saline 2 ml (Group C) and propofol 2 mg/kg plus 2% lidocaine 40 mg (Group L). Each group was administrated intravenously during induction and the patient was intubated 1 minute after an injection of 0.6 mg/kg of rocuronium. The time at disappearance of the first twitch and intubation scores were recorded. Also, blood pressure and heart rate were measured at the baseline, after intravenous injection of propofol, before intubation, and at 0, 1, 2, 3 and 5 minutes after intubation.

Results

There were no significant differences between group C and L (P > 0.05).

Conclusions

40 mg of lidocaine mixed with propofol to prevent injection pain did not affect the onset time of rocuronium, intubating conditions and intubation related hemodynamic changes.

Phentolamine mesylate accelerates recovery from oral soft tissue anesthesia in patients who have received local anesthetic injections containing a vasoconstrictor. The proposed mechanism is that phentolamine, an alpha-adrenergic antagonist, blocks the vasoconstriction associated with the epinephrine used in dental anesthetic formulations, thus enhancing the systemic absorption of the local anesthetic from the injection site. Assessments of the pharmacokinetics of lidocaine and phentolamine, and the impact of phentolamine on the pharmacokinetics of lidocaine with epinephrine were performed to characterize this potentially valuable strategy. The blood levels of phentolamine were determined following its administration intraorally and intravenously. Additionally, the effects of phentolamine mesylate on the pharmacokinetics of intraoral injections of lidocaine with epinephrine were evaluated. Sixteen subjects were enrolled in this phase 1 trial, each receiving 4 drug treatments: 1 cartridge lidocaine/epinephrine followed after 30 minutes by 1 cartridge phentolamine (1L1P), 1 cartridge phentolamine administered intravenously (1Piv), 4 cartridges lidocaine/epinephrine followed after 30 minutes by 2 cartridges phentolamine (4L2P), and 4 cartridges lidocaine/epinephrine followed by no phentolamine (4L). Pharmacokinetic parameters estimated for phentolamine, lidocaine, and epinephrine included peak plasma concentration (Cmax), time to peak plasma concentration (Tmax), area under the plasma concentration-time curve from 0 to the last time point (AUClast) or from time 0 to infinity (AUCinf), elimination half-life (t1/2), clearance (CL), and volume of distribution (Vd). The phentolamine Tmax occurred earlier following the intravenous administration of 1Piv (7 minutes than following its submucosal administration in treatment 1L1P (15 minutes) or 4L2P (11 minutes). The phentolamine t1/2, CL, and Vd values were similar for 1L1P, 1Piv, and 4L2P. The Tmax for lidocaine occurred later and the Cmax for lidocaine was slightly higher when comparing the 4L2P treatment and the 4L treatment. The phentolamine-induced delay of the lidocaine Tmax likely represents phentolamine's ability to accelerate the systemic absorption of lidocaine from oral tissues into the systemic circulation.

Background

Recent studies have questioned our previous understanding on the effect of nitrous oxide on muscle relaxants, since nitrous oxide has been shown to potentiate the action of bolus doses of mivacurium, rocuronium and vecuronium. This study was aimed to investigate the possible effect of nitrous oxide on the infusion requirements of cisatracurium.

Methods

70 ASA physical status I-III patients aged 18-75 years were enrolled in this randomized trial. The patients were undergoing elective surgery requiring general anesthesia with a duration of at least 90 minutes. Patients were randomized to receive propofol and remifentanil by target controlled infusion in combination with either a mixture of oxygen and nitrous oxide (Nitrous oxide/TIVA group) or oxygen in air (Air/TIVA group). A 0.1 mg/kg initial bolus of cisatracurium was administered before tracheal intubation, followed by a closed-loop computer controlled infusion of cisatracurium to produce and maintain a 90% neuromuscular block. Cumulative dose requirements of cisatracurium during the 90-min study period after bolus administration were measured and the asymptotic steady state rate of infusion to produce a constant 90% block was determined by applying nonlinear curve fitting to the data on the cumulative dose requirement during the study period.

Results

Controller performance, i.e. the ability of the controller to maintain neuromuscular block constant at the setpoint and patient characteristics were similar in both groups. The administration of nitrous oxide did not affect cisatracurium infusion requirements. The mean steady-state rates of infusion were 0.072 +/- 0.018 and 0.066 +/- 0.017 mg * kg-1 * h-1 in Air/TIVA and Nitrous oxide/TIVA groups, respectively.

Conclusions

Nitrous oxide does not affect the infusion requirements of cisatracurium.

Trial registration

ClinicalTrials.gov NCT01152905; European Clinical Trials Database at http://eudract.emea.eu.int/2006-006037-41.

Background

Withdrawal movement during rocuronium injection is a common, unresolved adverse effect. We aimed to investigate the effect of IV acetaminophen pretreatment on withdrawal movement during rocuronium injection.

Methods

This study enrolled 120 American Society of Anesthesiologists (ASA) I-II patients undergoing general anesthesia. They were randomly assigned to three treatment groups. After occluding venous drainage using a tourniquet on the upper arm, the saline group received 5 ml of 0.9% sodium chloride solution, the lidocaine group received 40 mg of lidocaine, and the acetaminophen group received 50 mg of acetaminophen. During injection of pretreatment drug, pain was assessed on a four-point scale. The tourniquet was released after 120 seconds and anesthesia was performed using thiopental sodium 5 mg/kg followed by rocuronium 0.6 mg/kg. The withdrawal movement was graded on a four-point scale in a double-blind manner.

Results

The incidence of pain on pretreatment injection in saline, lidocaine, and acetaminophen groups was 7.7%, 5.1%, and 2.5%, respectively. The incidence of withdrawal movements was 77.5% in saline group, 32.5% in lidocaine group, and 37.5% in acetaminophen group (P < 0.05).

Conclusions

Acetaminophen and lidocaine reduced the incidence of withdrawal movement after rocuronium injection compared with saline.

Background

The aim of this study was to determine the clinical effective dose of rocuronium for tracheal intubation using a lightwand after induction with propofol, alfentanil, and a low concentration of sevoflurane.

Methods

Twenty-eight adults scheduled to undergo elective surgery lasting less than one hour were enrolled in this study. All patients received alfentanil (10 µg/kg) and propofol (1.5 mg/kg) for the induction of anesthesia. Tracheal intubation using a lightwand was attempted 3 minutes after administering rocuronium and mask ventilation with 2 vol% of sevoflurane. The initial rocuronium dose was 0.5 mg/kg. The rocuronium dose for consecutive patients, determined by Dixon's up-and-down method, was increased or decreased by 0.05 mg/kg according to the result of the previous patient. The mean arterial pressure and heart rate were recorded before induction, 1 min before intubation, 1 and 2 min after intubation.

Results

The 50% clinical effective dose (cED50) of rocuronium for tracheal intubation using a lightwand was 0.20 ± 0.05 mg/kg according to Dixon's up and down method. Isotonic regression revealed the cED50 and cED95 (95% confidence intervals) to be 0.20 mg/kg (0.10-0.3 mg/kg) and 0.35 mg/kg (0.16-0.49 mg/kg), respectively.

Conclusions

The cED50 and cED95 of rocuronium for tracheal intubation using the lightwand were 0.20 mg/kg and 0.35 mg/kg, respectively, after induction with alfentanil, propofol, and a low concentration of sevoflurane.

Purpose:

To compare the effects of intravenous infusion of ketamine and propofol anesthesia in children undergoing strabismus surgery.

Methods:

Sixty pediatric patients aged 4–11 years were enrolled for the study. Patients in Group K were infused ketamine 1–3 mg/kg/hr (n = 30) and patients in Group P were infused with propofol 6–9 mg/kg/hr (n = 30). After giving fentanyl 1 μg/kg and rocuronium bromide 0.5 mg/kg, patients were intubated.

Results:

The consumption of anesthetics (P = 0.0001) and antiemetics (P = 0.004), the incidence of oculocardiac reflex (P = 0.02) in Group K were significantly lower than in Group P. The recovery time (P = 0.008), postoperative agitation score (P = 0.005), Face Pain Scale (P = 0.001), Ramsay Sedation Score (P = 0.01) during awakening and at postoperative 30th min (P = 0.02) in Group K were significantly lower than in Group P. The postoperative agitation score during awakening was significantly lower than the preoperative values in Group K (P = 0.0001).

Conclusions:

The infusion of ketamine is more advantageous than the infusion of propofol in children for use in strabismus surgery.

Perioperative anaphylaxis is characterized by severe respiratory and cardiovascular manifestations. Correct management of anaphylaxis during anaesthesia requires a multidisciplinary approach with prompt recognition and treatment of the acute event by the attending anesthesiologist. A 34-year-old woman was scheduled to undergo endo venous laser therapy of varicose veins. She had no history of allergies and had never undergone general anesthesia. General anesthesia was induced with propofol and rocuronium bromide. Approximately three minutes after rocuronium administration, hypotension and tachycardia developed and angioedema around the eyelids and skin rashes and urticaria appeared. The patient received ephedrine and hydrocortisone with hydration. After achieving stable vital signs and symptom relief, surgery was performed without complications. A postoperative skin dermal test performed to identify the agent responsible revealed a positive skin test for rocuronium.

A 33-year-old male patient with multiple sclerosis (MS) received an emergency laparotomy because of perforated appendicitis. He had been suffering from MS for 2 years and the symptoms of MS were paraplegia and urinary incontinence. Anesthesia was induced with propofol and remifentanil and maintained with nitrous oxide, sevoflurane and remifentanil. Rocuronium was used for tracheal intubation. Train of four ratio and bispectral index scale were also monitored for adequate muscle relaxation and anesthetic depth. The patient emerged from general anesthesia smoothly and was extubated without any complication. Postoperative exacerbation of MS symptoms did not appear. However, he was rehospitalized because deep vein thrombosis (DVT) occurred after discharge and he received heparinization immediately. Eventually, he was discharged after a full recovery from DVT. We report a safe anesthetic management of the patient with MS, with the use of sevoflurane and with no the aggravation of MS during postoperative period.

Steroidal neuromuscular blocking agents (NMBAs), such as rocuronium, are widely used in clinical anesthesia and emergency medicine to facilitate endotracheal intubation and artificial ventilation and to allow surgical access to body cavities. Reversal of neuromuscular blockade is important for the acceleration of patient recovery and prevention of postoperative residual neuromuscular blockade and reduces the incidence of severe morbidity and mortality associated with anesthesia management. Sugammadex is the first selective relaxant binding agent (SRBA) and has been designed to reverse the steroidal neuromuscular blocking drug rocuronium. Encapsulation of the rocuronium molecule by sugammadex results in a rapid decrease in free rocuronium in the plasma and subsequently at the nicotinic receptor at the motor endplate. After encapsulation, rocuronium is not available to bind to the nicotinic receptor in the neuromuscular junction. This promotes the liberation of acetylcholine receptors, and muscle activity reappears. This new concept of reversal of neuromuscular block induced by rocuronium (or vecuronium) led to impressive results in animal and phase 1 and 2 studies. Sugammadex is currently in phase 3 clinical studies and may be commercially available by 2008.

Background

Pain on injection of rocuronium is a common clinical problem. We compared the efficacy of lidocaine, ketorolac, and the 2 in combination as pretreatment for the prevention of rocuronium-induced withdrawal movement.

Methods

For this prospective, randomized, placebo-controlled, double-blind study a total of 140 patients were randomly allocated to one of 4 treatment groups to receive intravenously placebo (saline), lidocaine (20 mg), ketorolac (10 mg), or both (n = 35 for each group), with venous occlusion. The tourniquet was released after 2 min and anesthesia was performed using 5 mg/kg thiopental sodium followed by 0.6 mg/kg rocuronium. The withdrawal response was graded on a 4-point scale in a double-blind manner.

Results

The overall incidence of withdrawal movements after rocuronium was 34.3% with lidocaine (P = 0.001), 40% with ketorolac (P = 0.004), and 8.6% with both (P < 0.001), compared with 74.3% with placebo. There was a significantly lower incidence of withdrawal movements in patients receiving the lidocaine/ketorolac combination than in those receiving lidocaine or ketorolac alone (P = 0.009 and 0.002, respectively). The incidence of moderate to severe withdrawal movements was 14.3% with lidocaine, 17.2% with ketorolac, and 2.9% with lidocaine/ketorolac combination, as compared to 45.7% with the placebo. There was no significant difference in withdrawal movement between the lidocaine group and the ketorolac group.

Conclusions

Ketorolac pretreatment had an effect comparable to that of lidocaine in attenuating rocuronium-induced withdrawal movements and the lidocaine/ketorolac combination pretreatment, compared with lidocaine or ketorolac alone, effectively reduced withdrawal movements during rocuronium injection.

Background

We have investigated the possibility of rocuronium 0.6 mg/kg and timing principle application with the same dose for rapid sequence induction (RSI) in 65 children, aged 4-8 yr.

Methods

Sixty five patients were randomly assigned to one of two groups; Group A (n = 31, timing principle application) received rocuronium (0.6 mg/kg) followed by administration of propofol (2.5 mg/kg), and group B (n = 36) received rocuronium (0.6 mg/kg) after administration of propofol. Intubation was assessed at 60 seconds just after administration of last injectants. Intubating conditions (jaw relaxation, vocal cord movement, and response to tracheal intubation) were evaluated as excellent, good, fair and poor.

Results

Excellent intubation conditions were obtained in 87% in group A and 61% in group B. However, clinically acceptable intubation conditions which means excellent and good did not show any significant difference as 100% (group A) and 99% (group B).

Conclusions

In cases of pediatiric patients undergoing elective surgery, RSI was possible irrespective of the use of timing principle.

Background

Neostigmine augments clindamycin-induced neuromuscular block and antagonizes rocuronium-induced neuromuscular block; however, it remains unclear whether neostigmine enhances the neuromuscular blocking (NMB) that is caused by combinations of rocuronium and clindamycin. The intent of this study was to determine whether neostigmine potentiates the muscle relaxation that is induced by combinations of rocuronium and clindamycin and to estimate whether both clindamycin and rocuronium have synergistic actions on NMB.

Methods

Forty-one left phrenic nerve-hemidiaphragms (from male Sprague-Dawley rats, 150-250 g) were mounted in Krebs solution. Three consecutive single twitches (ST, 0.1 Hz) and one tetanic tension (50 Hz for 1.9 s) were obtained for each increase in concentration of rocuronium or clindamycin. The concentrations of rocuronium were cumulatively increased until an 80% to 90% reduction in ST was attained in the Krebs solutions pre-treated with 0 (n = 5), 0.1 (n = 1), 0.25 (n = 1), 0.5 (n = 4), or 1.0 (n = 1) mM clindamycin or with 0 (n = 4), 0.1 (n = 1), 0.5 (n = 5), 1.0 (n = 5), or 2.0 (n = 4) mM clindamycin in combination with 250 nM neostigmine, and so were the concentrations of clindamycin in the Krebs solutions pre-treated with 0 (n = 6) or 250 nM (n = 6) neostigmine.

Results

Clindamycin increased the potency of rocuronium for ST and tetanic fade, irrespective of the presence of neostigmine. Neostigmine shifted the concentration-response curve of rocuronium to the right in the presence or absence of clindamycin. The interaction between rocuronium and clindamycin was synergistic when clindamycin concentrations were in excess of 0.5 mM, irrespective of the presence of neostigmine.

Conclusions

Neostigmine may partially antagonize the neuromuscular block that is induced by a combination of clindamycin and rocuronium. Clinicians are advised to be aware that clindamycin synergistically increases the degree of rocuronium-induced neuromuscular block, even when neostigmine is present.

This study was undertaken to investigate whether plain lidocaine, 3% plain mepivacaine and 3% prilocaine with felypressin were suitable epinephrine-free local anesthetic solutions for use in periodontal ligament anesthesia as alternatives to lidocaine with 1:80,000 epinephrine. Two hundred and seven patients received one of the four test solutions via a periodontal ligament injection and the success rate of anesthesia was confirmed using an electric pulp stimulator. Although neither mepivacaine nor prilocaine were as effective as lidocaine with epinephrine, the success rates of these three solutions were not statistically different. A single periodontal ligament injection of any of the solutions tested resulted in a low incidence of anesthesia. The success rate of lidocaine without epinephrine was consistently poor.

Background

Inexperienced anesthesiologists are frequently unclear as to whether to stimulate the ulnar or median nerve to monitor the adductor pollicis. The primary purpose of this study was to determine whether monitoring the adductor pollicis by positioning the stimulating electrodes over the median nerve is an acceptable alternative to applying electrodes over the ulnar nerve.

Methods

In 20 patients anesthetized with propofol and remifentanil, one pair of stimulating electrodes was positioned over the ulnar nerve. A second pair was placed over the median nerve on the other hand. The acceleromyographic response was monitored on both hands. Rocuronium 0.6 mg/kg was administered. Single twitch (ST) and train-of-four (TOF) stimulations were applied alternatively to both sites.

Results

None of the patients showed a twitch response at either site after injection of rocuronium. There were no differences in the mean supramaximal threshold, mean initial TOF ratio, or mean initial ST ratio between the two sites. Bland-Altman analysis revealed a bias (limit of agreement) in the TOF and ST ratios over the median nerve of 7% (± 31%) and 26% (± 73%), respectively, as compared with the ulnar nerve. The median nerve TOF ratio was overestimated by 16.2%, as compared with that of the ulnar nerve value, and the median nerve ST ratio was overestimated by 72.9%, as compared to that of the ulnar nerve.

Conclusions

The ulnar and median nerves cannot be used interchangeably for accurate neuromuscular monitoring.

The purpose of this study is to evaluate, with the electric pulp tester, the anesthetic efficacy of the periodontal ligament injection using 2% lidocaine with 1:100,000 epinephrine and saline in human mandibular premolars. The periodontal ligament injection using 2% lidocaine with 1:100,000 epinephrine was found to be an effective technique for anesthetizing mandibular first premolars. However, the duration of profound pulpal anesthesia was approximately 10 minutes. The periodontal ligament injection using sterile saline was not an effective technique for anesthesia. Teeth mesial and distal to the injected tooth may also become anesthetized with this injection technique. The initial needle penetration and injection of the anesthetic solution in clinically healthy teeth were only mildly discomforting. No increase in tooth mobility was observed 45 minutes after the periodontal ligament injection. No clinically observable pulpal or periodontal damage was seen at 3 weeks after the injection.

The purpose of this study was to measure the degree of anesthesia obtained with 2.2% lidocaine hydrocarbonate, 2.2% lidocaine hydrocarbonate with 1:100,000 epinephrine, and 2% lidocaine hydrochloride with 1:100,000 epinephrine for inferior alveolar nerve block. Using a repeated-measures design, 30 subjects randomly received an inferior alveolar injection of each solution over the course of three successive appointments. The first molar, first premolar, lateral incisor, and contralateral canine (control) were blindly tested with an Analytic Technology pulp tester at 3-min cycles for 60 min. Anesthetic success was defined as no subject response to the maximum output (80 reading) of the pulp tester within 16 min and maintenance of this reading for the remainder of the testing period. Although subjects felt numb subjectively, anesthetic success as defined here ranged from 3% to 10% for the plain lidocaine hydrocarbonate; for the lidocaine hydrocarbonate and lidocaine hydrochloride solutions with epinephrine, success ranged from 37% to 63%. We conclude that 2.2% lidocaine hydrocarbonate without vasoconstrictor is not as effective as the other two preparations for inferior alveolar nerve block. The 2.2% lidocaine hydrocarbonate with epinephrine and 2%.

OBJECTIVE

The aim of this prospective, randomized study was to evaluate the hemodynamic and analgesic effects of ketamine by comparing it with propofol starting at the induction of anesthesia until the end of sternotomy in patients undergoing coronary artery bypass grafting surgery.

INTRODUCTION

Anesthetic induction and maintenance may induce myocardial ischemia in patients with coronary artery disease. A primary goal in the anesthesia of patients undergoing coronary artery bypass grafting surgery is both the attenuation of sympathetic responses to noxious stimuli and the prevention of hypotension.

METHODS

Thirty patients undergoing coronary artery bypass grafting surgery were randomized to receive either ketamine 2 mg.kg−1 (Group K) or propofol 0.5 mg.kg−1 (Group P) during induction of anesthesia. Patients also received standardized doses of midazolam, fentanyl, and rocuronium in the induction sequence. The duration of anesthesia from induction to skin incision and sternotomy, as well as the supplemental doses of fentanyl and sevoflurane, were recorded. Heart rate, mean arterial pressure, central venous pressure, pulmonary arterial pressure, pulmonary capillary wedge pressure, cardiac index, systemic and pulmonary vascular resistance indices, stroke work index, and left and right ventricular stroke work indices were obtained before induction of anesthesia; one minute after induction; one, three, five, and ten minutes after intubation; one minute after skin incision; and at one minute after sternotomy.

RESULTS

There were significant changes in the measured and calculated hemodynamic variables when compared to their values before induction. One minute after induction, mean arterial pressure and the systemic vascular resistance index decreased significantly in group P (p<0.01).

CONCLUSION

There were no differences between groups in the consumption of sevoflurane or in the use of additional fentanyl. The combination of ketamine, midazolam, and fentanyl for the induction of anesthesia provided better hemodynamic stability during induction and until the end of sternotomy in patients undergoing coronary artery bypass grafting surgery.