OBJECTIVETo compare the cardiorespiratory factors and surgical conditions during total intravenous anesthesia for prolonged laparoscopic pelvic surgery with or without supplemental muscle relaxants.

METHODSForty female ASA I or II patients undergoing laparoscopic pelvic surgeries were randomized into two groups A and B, both with standardized anesthesia via a intravenous bolus injection of rocuronium (0.6 mg/kg). The patients in group B received continuous rocuronium infusion upon observation of one TOF twitch response with the T1 value maintained within 0-10% and rocuronium withdrawal at 20 to 30 min before the completion of the surgery. The patients in group A received no supplemental muscle relaxants. The cardiorespiratory parameters were measured during the operation. The respiratory system compliance (Ceff rs) was calculated as the quotient of the tidal volume (VT) and peak inspiratory pressure (PIP), and the operative conditions were graded by the operating gynecologist.

RESULTSThe cardiorespiratory parameters significant increased and Ceff rs decreased after pneumoperitoneum, but no significant differences were found between the two groups. The surgical conditions were also comparable between the two groups, but the duration of intubation and the operating time were significantly shorter in the group A.

CONCLUSIONPneumoperitoneum severely affects the cardiorespiratory parameters during laparoscopy, which can not be lessened by neuromuscular block agents. A single intubating dose of rocuronium can suffice the requirement of prolonged gynecologic laparoscopic surgery.

Androstanols ; administration & dosage ; Anesthesia, Intravenous ; Female ; Gynecologic Surgical Procedures ; Humans ; Laparoscopy ; methods ; Neuromuscular Nondepolarizing Agents ; administration & dosage

Mivacurium is mainly metabolized by plasma cholinesterase, whereas atracurium is removed by Hofman elimination. The purpose of this study was to compare the infusion rate of atracurium and mivacurium in maintaining surgical relaxation, and to compare their recovery indices between parturients and non-pregnant women. Muscle relaxation was maintained by the continuous infusion of relaxants to retain the first response of train-of-four (TOF) at 5% of control. When mivacurium was used, Bolus-T5 (duration from the end of mivacurium bolus injection to 5% single twitch recovery) was measured. After discontinuing the infusion, the recovery index was measured. The infusion rate of mivacurium, not atracurium, was significantly lower in parturients and Bolus-T5 of parturients was significantly longer than that of non-pregnant women. There was no significant difference in the recovery indices of both relaxants. The authors concluded that the infusion rate of mivacurium in maintaining muscle relaxation in parturients should be reduced compared to the rate in non-pregnant women and measuring Bolus-T5 may be helpful in determining the infusion rate to maintain muscle relaxation.
Adult ; Atracurium/therapeutic use ; Atracurium/administration & dosage* ; Cesarean Section* ; Comparative Study ; Female ; Human ; Injections, Intramuscular ; Isoquinolines/therapeutic use ; Isoquinolines/administration & dosage* ; Neuromuscular Nondepolarizing Agents/therapeutic use ; Neuromuscular Nondepolarizing Agents/administration & dosage* ; Pregnancy

d-tubocurarine is one of the non-depolarizing muscle relaxants which is most commonly used in clinical situations d-Tc is used as a selective muscle relaxant in hypertensive patients or patients for renal transplantation. The most common side effect of d-Tc is a dose-related fall in arterial pressure. Although the cause of the hypotension is still controversial, the two mechanism most frequently suggested are ganglionic block and histamine release. d-Tc is an active ganglionic blocking agent. Howver, because its potency at the neuromuscular junction is greater than at the ganglia, there is some doubt that a clinical concentration of d-Tc is sufficient to cause hypotension. histamine release may play a role in this blood pressure reduction. Indeed, decrease in blood pressure produced by d-Tc have been shown to be less when the muscle relaxant was preceded by and antihistamine. The amount of histamine release substance depends on plasma levels of the drug achieved and thus on the rapidity of intravenous administration of that drug. If d-Tc produces histamine release, then slow intravenous injection would be associated with minimal histamine release and a resulting attenuation of the typical blood pressure reduction that follows' this drugs injection. Therefore, we measured changes in mean arterial pressure(MAP) and heart rate in patients anesthetized with nitrous oxide-halothane during and after the intravenous injection of d-Tc at varying rates of administration. The results are as follows: 1) Group 1: Maximum reduction in MAP were present 3 minutes following d-Tc injection over 1 second (81+/- 3 torr). Comparative with control group (99+/-6 torr), significant reduction was revealed(18.1%). 2) Group 2: Decrease in MAP 3 minutes after administration of d-Tc over 90 seconds(11.1%) were intermediate between the other injection rates. 3) Group 2: Decrease in MAP 3 minutes after d-Tc administration was significantly less in patients receiving the drug over 180 seconds(5.1%). Heart rate did not change significantly after d-Tc injection regardless of the rate of administration.
Administration, Intravenous ; Arterial Pressure ; Blood Pressure* ; Ganglia ; Ganglion Cysts ; Heart Rate ; Histamine Release ; Humans ; Hypotension ; Injections, Intravenous ; Kidney Transplantation ; Neuromuscular Junction ; Neuromuscular Nondepolarizing Agents ; Plasma ; Tubocurarine*

OBJECTIVETo compare the dose requirements of continuous infusion of rocuronium and atracurium throughout orthotopic liver transplantation (OLT) in humans.

METHODSTwenty 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.

RESULTSRocuronium 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.

CONCLUSIONSThis 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.

Adult ; Aged ; Androstanols ; administration & dosage ; pharmacokinetics ; Atracurium ; administration & dosage ; pharmacokinetics ; Humans ; Infusions, Intravenous ; Intraoperative Period ; Liver ; metabolism ; Liver Transplantation ; Male ; Middle Aged ; Neuromuscular Nondepolarizing Agents ; administration & dosage ; pharmacokinetics

OBJECTIVETo determine the half-effective dose (IED50) of rocuronium for intratracheal intubation in female patients of different ages by sequential experiments and evaluate the effect of age on IED50 of rocuronium.

METHODSForty ASA class I-II female patients undergoing elective surgery under general anesthesia were randomly divided (n = 20) into young patient group and elderly patient group. The intratracheal intubation dose was divided into 4 grades by geometric progression, namely 0.24, 0.29, 0.35, and 0.42 mg/kg in the young patient group and 0.22, 0.26, 0.31, and 0.37 mg/kg in the elderly group. The IED(50) and 95% confidence interval (95%CI) of rocuronium during intubation in both groups were determined by sequential experiments.

RESULTSThe IED50 was 0.284 mg/kg in the elderly patient group, which was 91% that of in the young patient group (0.312 mg/kg), showing significant difference between the two groups (P < 0.05).

CONCLUSIONThe IED50 of rocuronium is significantly lower in elderly female patients than in young female patients, suggesting the necessity of reducing the dose of rocuronium accordingly in anesthesia induction in elderly female patients.

Adolescent ; Adult ; Age Factors ; Aged ; Aged, 80 and over ; Androstanols ; administration & dosage ; Dose-Response Relationship, Drug ; Female ; Humans ; Intubation, Intratracheal ; Middle Aged ; Neuromuscular Nondepolarizing Agents ; administration & dosage ; Sex Factors

The neuromuscular and hem+odynamic effects of mivacurium 0.15 mg/kg and succinylcholine 1 mg/kg were compared in 26 adult patients (ASA I and II) during nitrous oxide-oxygen-propofol-fentanyl anesthesia. Neuromuscular block was monitored by recording the compound electromyogram of the hypothenar muscle resulting from supramaximal train-of-four stimuli applied to the ulnar nerve. Time to onset of over 95% block and duration to 25% recovery of control twitch after injection of mivacurium were significantly longer than for succinylcholine (201 +/- 37.6 vs 54 +/- 5.2 sec and 13.0 +/- 2.2 vs 8.4 +/- 2.1 min; mean +/- SD). Onset of mivacurium with priming technique was shortened (125 +/- 20.7 sec), but was also slower than that of succinylcholine. Although the recovery index during spontaneous recovery was significantly longer for mivacurium than for succinylcholine (6.9 +/- 1.3 vs 5.1 +/- 0.9 min), antagonism with neostigmine at 25% recovery of twitch height sufficiently facilitated the recovery index of mivacurium (4.5 +/- 1.0 min) to a level similar to that of succinylcholine with no statistical difference. The hemodynamic effects of mivacurium were few as compared to those of succinylcholine. In conclusion, mivacurium is considered to have additional advantages for short procedures when succinylcholine is undesirable.
Adult ; Anesthesia ; Female ; Fentanyl/administration & dosage ; Hemodynamics/*drug effects ; Humans ; Isoquinolines/*pharmacology ; Male ; Neuromuscular Junction/*drug effects ; Neuromuscular Nondepolarizing Agents/*pharmacology ; Nitrous Oxide/administration & dosage ; Propofol/administration & dosage ; Succinylcholine/*pharmacology

OBJECTIVETo define the ideal time window for intubation after rocuronium administration during target-controlled infusion (TCI) ofpropofol and sulfentanil.

METHODSOne hundred and twenty elective surgical patients (age range 18-55 years) were randomized into 4 groups (n=30) according to the intubation time after administration of the muscle relaxant. Patients with predicted difficult airway were excluded. General anesthesia was induced by TCI of propofol and sulfentanil. A senior anesthesiologist blinded for the randomization performed the intubations at 1, 2, 3, or 4 min after injection of rocuronium, and the vocal card visibility was evaluated upon full exposure of the vocal cord and the intubation conditions assessed according to Cooper's score.

RESULTSThe intubation conditions were excellent or good in all patients, but the vocal cord visibility at 2-4 min differed significantly from that at 1 min after rocuronium administration (P<0.01). Suppression of the neuromuscular function 1 min after rocuronium administration differed significantly from that at other time points (P<0.01).

CONCLUSIONThe condition of vocal cord can be more suitable for intubation at 2-4 min than at 1 min after rocuronium administration as the ideal time window for intubation during TCI of propofol and sulfentanil.

Adolescent ; Adult ; Androstanols ; administration & dosage ; Anesthetics, Intravenous ; administration & dosage ; Humans ; Infusions, Intravenous ; Intubation ; methods ; Middle Aged ; Neuromuscular Nondepolarizing Agents ; administration & dosage ; Propofol ; administration & dosage ; Single-Blind Method ; Sufentanil ; administration & dosage ; Time Factors ; Vocal Cords ; drug effects ; Young Adult

We have determined the infusion rates of rocuronium in the elderly and young adult patients during sevoflurane and nitrous oxide anesthesia. The correlation of some anthropometric predictors with infusion rate of rocuronium was also investigated for both elderly and young adult. Participating patients were assigned to one of two groups: 1) young adult patients aged 20 to 50 years (n = 30) ; 2) elderly patients aged over 65 years (n = 30). The anthropometric variables such as height, weight, ratio of weight to body surface area, subscapularis and suprailiac skin folds, body surface area, body mass index and % ideal body weight were evaluated as predictors for infusion rate. The infusion rate in elderly patients was significantly less compared with that in young adult patients (p < 0.05). In elderly patients, no anthropometric predictor was related to the infusion rate of rocuronium. This suggests that the infusion rate of rocuronium for an elderly patient needs to be individualized by monitoring neuromuscular transmission to avoid excessive dose.
Skinfold Thickness ; Neuromuscular Nondepolarizing Agents/*administration & dosage ; Middle Aged ; Male ; Infusions, Intravenous ; Humans ; Female ; Body Weight ; Body Surface Area ; Body Mass Index ; Body Height ; *Anthropometry ; Androstanols/*administration & dosage ; Aged ; Adult

PURPOSE: We investigated the effect of muscle relaxants (atracurium) on the outcomes of intermittent exotropia surgery under general anesthesia, with a focus on resection procedures. METHODS: Thirty four patients who underwent recession and resection (R&R) were divided into two groups: atracurium usage (group A, n=18) and no atracurium usage (group B, n=16). Patients were divided into two subgroups according to the amount of resection of the medial rectus (MR): less than 5 mm (group 1, n=13) or 5 mm and greater (group 2, n=21). Deviation angles were compared between groups and subgroups. Surgical outcome was defined as successful if distant deviation angles were equal to or less than 10 prism diopters. RESULTS: The overall postoperative deviation angles did not show statistically significant differences between groups A and B. However, in patients with larger MR resections (> or = 5 mm), the 1 week postoperative distant deviation was significantly larger in group A (1.8+/-2.6 PD) than in group B (-1.6+/-4.6 PD, p=0.048 by t-test). The overall undercorrection rate at 3 months postoperatively for group A was 16.7%, which was higher than that of group B (6.3%), and the difference was even larger in subgroups with larger MR resections (> or =5 mm): 18.2% in group A and 0% in group B. CONCLUSIONS: Patients who underwent R&R procedures under general anesthesia with a muscle relaxant tended to be less corrected than those without muscle relaxant, especially in the early postoperative period and with a larger MR resection equal to or greater than 5 mm. However, there was no significant difference in the later postoperative period.
Anesthesia, Inhalation ; Atracurium/*administration & dosage ; Child ; Child, Preschool ; Exotropia/*physiopathology/*surgery ; Female ; Humans ; Injections, Intravenous ; Male ; Muscle Relaxation ; Neuromuscular Nondepolarizing Agents/*administration & dosage ; Oculomotor Muscles/*physiopathology ; Ophthalmologic Surgical Procedures ; Treatment Outcome

OBJECTIVE: To determine the maximum dose of continuously infused mivacurium for intraoperative neuromonitoring and observe its adverse effects in thyroid surgery. METHODS: Twenty-eight patients undergoing thyroid surgery with intraoperative neuromonitoring received continuous infusion of mivacurium at the initial rate of 5.43 μg?kg?min, and the infusion rate for the next patient was adjusted based on the response of the previous patient according to the results of neurological monitoring. The depth of anesthesia was maintained with sevoflurane and remifentanil during the surgery. The LD50 and 95% of mivacurium were calculated using Brownlee's up-and-down sequential method. RESULTS: The LD50 of continuously infused mivacurium was 8.94 μg?kg?min (95% : 8.89- 8.99 μg?kg?min) during thyroid surgery, which did not affect neurological function monitoring. Transient chest skin redness occurred after induction in 9 patients (32.1%). None of the patients experienced intubation difficulties or showed intraoperative body motions during the surgery. CONCLUSIONS In patients undergoing thyroid surgery under anesthesia maintained by inhalation and intravenous infusion, the LD50 of mivacurium was 8.94 μg?kg?min (95% : 8.89-8.99 μg?kg?min) for continuous infusion, which does not cause serious adverse effects during the operation.
Anesthesia ; Anesthetics, Inhalation ; Anesthetics, Intravenous ; Humans ; Intraoperative Neurophysiological Monitoring ; methods ; Lethal Dose 50 ; Mivacurium ; administration & dosage ; adverse effects ; Neuromuscular Nondepolarizing Agents ; administration & dosage ; adverse effects ; Remifentanil ; Sevoflurane ; Thyroid Gland ; surgery