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

OBJECTIVETo evaluate the residual paralysis after a single intubating dose of rocuronium and its effect of residual paralysis after a single dose of rocuronium on the postoperative pulmonary function of patients undergoing laparoscopic gynecological surgeries.

METHODSSixty American Society of Anesthesiologists (ASA) I - II patients undergoing laparoscopic gynecological surgeries were randomly divided into rocuronium (R) group (n = 30) and rocuronium + neostigmine (R + N) group (n = 30).All patients received midazolam (0.02 mg/kg), fentanyl (1 microg/kg), propofol(1.5-2 mg/kg), and rocuronium (0.6 mg/kg) to facilitate tracheal intubation and no more relaxant thereafter. Anesthesia was maintained with isoflurane and nitrous oxide in oxygen (N(2)O:O(2) = 1:1). At the end of the procedure, neuromuscular blockade was not reversed in R group, while antagonism was accomplished with neostigmine (0.04 mg/kg) and atropine (0.02 mg/kg) in R + N group. Immediately after tracheal extubation and on arrival in the PACU, the train-of-four (TOF) ratio at the adductor pollicis of all patients were measured using acceleromyography. Forced vital capacity (FVC), forced expiratory volume in one second (FEV(1)), and peak expiratory flow rate (PEFR) of all patients were measured using spirometry before surgery, after administration of midazolam and fentanyl, immediately after tracheal extubation, on arrival in the PACU, and after the TOF ratio recovered to 1.0. The TOF ratio and pulmonary function between two groups were compared.

RESULTSImmediately after tracheal extubation and on arrival in the PACU, the mean TOF ratio in R group was significantly lower than that in R + N group (P < 0.05). The mean time to achieve TOF ratio of 0.9 and 1.0 in R group was significantly longer than in R + N group (P < 0.05). Immediately after tracheal extubation and on arrival in the PACU, FVC, FEV(1), and PEFR were significantly lower in R group than in R + N group (P < 0.05). FVC, FEV(1), and PEFR after administration of midazolam and fentanyl and after TOF ratio recovered to 1.0 were significantly lower than the baseline values in all patients (P < 0.01).

CONCLUSIONSAfter a single intubating dose of rocuronium, residual paralysis exists in the majority of patients undergoing laparoscopic gynecological surgeries. The pulmonary function is impaired after the surgery, even after recovery of TOF ratio to 1.0.

Adolescent ; Adult ; Airway Extubation ; Androstanols ; administration & dosage ; adverse effects ; Female ; Gynecologic Surgical Procedures ; Humans ; Intubation, Intratracheal ; Laparoscopy ; Middle Aged ; Neuromuscular Nondepolarizing Agents ; administration & dosage ; adverse effects ; Paralysis ; chemically induced ; Postoperative Period ; Respiratory Function Tests ; Young Adult

OBJECTIVETo evaluate the effect of dexmedetomidine (Dex) on bispectral index (BIS) and auditory evoked potential index (AAI) during anesthesia with target controlled infusion (TCI) of propofol and remifentanyl.

METHODSThirty adult patients (ASA I approximate, equalsII) who were scheduled for elective thyroidectomy were monitored with BIS, AAI, ECG, blood pressure, end-tidal CO(2), and pulse oximeter before and during anesthesia. Anesthesia was induced by TCI with propofol 4 mg/L and remifentanyl 1 mu g/kg. After loss of consciousness the patients were intubated after rocuronium 0.6 mg/kg intravenous injection, remifentanyl was then infused at 0.2 microg/(kg x min)(-1) and propofol infusion (Ct) was titrated to maintain a BIS value at 50 +/- 3. At 10 min after stabilization of anesthesia the patients were randomly and double-blindly divided into 2 groups: Group D (n=15) received Dex 0.4 mu g/kg iv administered over 5 min and Group C (n=15) received equal volume of normal saline. Values of BIS, AAI, MAP, HR were recorded every 2 min within 20 min after the administration of the drugs.

RESULTSBefore anesthesia the BIS index was 90 +/- 2 in Group D and 92 +/- 2 in Group C, AAI was 81 +/- 1 in Group D and 78 +/- 1 in Group C. In anesthesia with target controlled infusion of propofol, BIS index showed a significant decrease with the i.v. administration of Dex 0.4 microg/kg, while AAI remained unchanged. In Group C, both of BIS and AAI remained unchanged after saline injection.

CONCLUSIONDuring propofol and remifentanyl anesthesia, after the administration of Dex, BIS value demonstrates a predominant decrease, whereas AAI shows no changes.

Adrenergic alpha-Agonists ; administration & dosage ; Adult ; Androstanols ; administration & dosage ; Anesthetics, Combined ; administration & dosage ; Anesthetics, Intravenous ; administration & dosage ; Dexmedetomidine ; administration & dosage ; pharmacology ; Double-Blind Method ; Evoked Potentials, Auditory ; drug effects ; Female ; Humans ; Infusions, Intravenous ; methods ; Male ; Medetomidine ; pharmacology ; Middle Aged ; Monitoring, Intraoperative ; methods ; Neuromuscular Nondepolarizing Agents ; administration & dosage ; Piperidines ; administration & dosage ; pharmacology ; Propofol ; administration & dosage ; pharmacology ; Thyroidectomy

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

BACKGROUNDThere are few studies to assess whether the effect-site concentration of propofol can predict anesthetic depth during the target-controlled infusion (TCI) induction in elderly patients. This study aimed to evaluate the relationship between effect-site concentration of propofol and depth of anesthesia during the TCI induction in elderly patients.

METHODSNinety patients (60 - 80 years) with an American Society of Anesthesiologists (ASA) physical status of 1 - 3, undergoing scheduled abdominal and thoracic surgery under general anesthesia were randomly allocated into one of three groups, Group S1, S2 and S3 (30 patients in each group). The patients in Group S1 received propofol with a target plasma concentration of 4.0 microg/ml; patients in Group S2 received propofol with an initial target plasma concentrations of 2.0 microg/ml that was raised to 4.0 microg/ml 3 minutes later; patients in Group S3 received an infused scheme of 3 steps; starting from a target plasma concentration of 2.0 microg/ml that was increased stepwised by 1 microg/ml until a target plasma concentration of 4.0 microg/ml was achieved, the interval between the two steps was 3 minutes. When an Observer's Assessment of Alertness/Sedation (OAA/S) score of 1 was achieved, remifentanil (effect-site concentration (Ce) of 4.0 ng/ml) and rocuronium 0.9 mg/kg were administered. Tracheal intubation was started 2 minutes after rocuronium injection. Changes of propofol Ce, blood pressure (BP), heart rate (HR), and bispectral index (BIS) were recorded.

RESULTSWhen an OAA/S score of 1 was achieved, Ce of propofol were (1.7 +/- 0.4) microg/ml, (1.9 +/- 0.3) microg/ml, (1.9 +/- 0.4) microg/ml and the BIS values were 64 +/- 5, 65 +/- 8, and 62 +/- 8 in Groups S1, S2 and S3. Before intubation, Ce of propofol was (2.8 +/- 0.2) microg/ml, (2.8 +/- 0.3) microg/ml, (2.7 +/- 0.3) microg/ml, and the BIS values were 48 +/- 7, 51 +/- 7, and 47 +/- 5 in Groups S1, S2 and S3. By linear regression analysis, a significant correlation between Ce of propofol and BIS values was found (r = -0.580, P < 0.01). Systolic blood pressure (SBP) before intubation was significantly lower in Group S1 than in Groups S2 and S3. SBP and HR after intubation in the three groups were significantly increased when compared with pre-intubation values, but they did not exceed baseline values.

CONCLUSIONSDuring the TCI induction, Ce of propofol with (1.9 +/- 0.3) microg/ml may make the elderly patients unconscious. When remifentanil with a Ce of 4.0 ng/ml is added a Ce of propofol with (2.8 +/- 0.3) microg/ml is suitable for intubation. The Ce of propofol has a close correlation with the BIS values. Also, a two-step TCI technique seems to be a more suitable method of anesthesia induction in elderly patients compared with the no-stepwise TCI technique and three-step TCI technique.

Aged ; Aged, 80 and over ; Androstanols ; therapeutic use ; Anesthesia, General ; methods ; Anesthesia, Intravenous ; methods ; Anesthetics, Intravenous ; administration & dosage ; pharmacokinetics ; therapeutic use ; Awareness ; physiology ; Female ; Humans ; Infusions, Intravenous ; methods ; Intubation, Intratracheal ; Linear Models ; Male ; Middle Aged ; Neuromuscular Nondepolarizing Agents ; therapeutic use ; Piperidines ; therapeutic use ; Propofol ; administration & dosage ; pharmacokinetics ; therapeutic use

PURPOSE: This study was performed to find out the effects of lidocaine or 8.4% sodium bicarbonate mixed with rocuronium on mean arterial pressure, heart rate and withdrawal movement. METHODS: Data collection was performed from December 15, 2006 through May 31, 2007. Seventy-five patients with American Society Anesthesiologist (ASA) physical status I & II, under general anesthesia, were randomly assigned to 1 of 3 groups: R group (RG) received rocuronium 0.6 mg/kg; RL group (RLG), rocuronium 0.6 mg/kg mixed with 2 mL of 2% lidocaine; RS group (RSG), rocuronium 0.6 mg/kg with the same volume of 8.4% sodium bicarbonate. Mean arterial pressure, heart rate and withdrawal movement were observed from its injection until 5 min after endotracheal intubation. RESULTS: The incidence of withdrawal movement with its corresponding injections was 72%, 40% and 4% in RG, RLG and RSG, respectively (p<.001). Score of withdrawal movement was the lowest in RSG of all groups (p<.001). While mean arterial pressure (p=.011) in RSG decreased significantly, and heart rate (p=.003) in RG increased more with its injection than before induction of anesthesia. CONCLUSION: Administration of the equivalent volume of 8.4% sodium bicarbonate with rocuronium is more effective than that of lidocaine with rocuronium compared with rocuronium only, in preventing withdrawal movement and in stabilizing mean arterial pressure and heart rate.
Adult ; Androstanols/administration & dosage/*adverse effects ; Anesthetics, Local/administration & dosage/*therapeutic use ; Blood Pressure/*drug effects ; Female ; Heart Rate/*drug effects ; Humans ; Injections, Intravenous ; Lidocaine/administration & dosage/*therapeutic use ; Male ; Middle Aged ; Neuromuscular Nondepolarizing Agents/administration & dosage/*adverse effects ; Pain/*prevention & control ; Sodium Bicarbonate/*administration & dosage

The purpose of this study was to determine the effectiveness of antihistamine therapy for withdrawal movements caused by rocuronium injection. One hundred seventy one ASA I-II adults undergoing elective surgery were randomly assigned to one of two groups. Patients in the control group (Group C) were premedicated with 2 mL normal saline, and those in the antihistamine group (Group A) were pre-medicated with 2 mL (45.5 mg) pheniramine maleate. After the administration of thiopental sodium 5 mg/kg, rocuronium 0.6 mg/kg was injected. Withdrawal movements were assessed using a four-grade scale. The administration of antihistamine reveals lower grade of withdrawal movement after rocuronium injection.
Adult ; Androstanols/*administration & dosage/adverse effects ; Anesthetics, Intravenous/administration & dosage ; Double-Blind Method ; Female ; Histamine H1 Antagonists/*pharmacology ; Humans ; Incidence ; Injections, Intravenous ; Male ; Middle Aged ; Movement/drug effects/physiology ; Neuromuscular Nondepolarizing Agents/*administration & dosage/adverse effects ; Pain/chemically induced ; Pain Measurement ; Pheniramine/*pharmacology ; Thiopental/administration & dosage

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

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

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