PURPOSE: Opioids may affect changes in the corrected QT interval (QTc) during anesthetic induction. This study examine whether a single bolus of remifentanil would prolong QTc after laryngeal mask airway (LMA) insertion during sevoflurane induction. MATERIALS AND METHODS: Forty women of American Society of Anesthesiologists physical status 1 (ASA PS1) undergoing gynecological surgery were studied. All patients were induced using three vital capacity inhalation inductions with 5% sevoflurane. Two minutes after induction, the inspiratory concentration of sevoflurane was reduced to 2%. Using double-blinded randomization, patients were allocated into one of two groups, receiving either saline (placebo group, n = 20) or 0.25 microg.kg-1 remifentanil (remifentanil group, n = 20) over a period of thirty seconds. Sixty seconds later, LMA insertion was performed. Recordings were taken with a 12-lead electrocardiogram at baseline, 2 min after induction and 1 and 3 min after LMA insertion. QTc was calculated by Bazett's formula. The mean arterial pressure (MAP) and heart rate (HR) were also measured at each time point. RESULTS: The QTc interval was significantly prolonged in the placebo group as compared to the remifentanil group at 1 min after LMA insertion (467.8 +/- 16.5 vs. 442.7 +/- 21.3 ms, p < 0.001). However, there was no significant difference in QTc at 3 min after LMA insertion between the two groups. MAP and HR were significantly higher in the placebo group (p < 0.001). CONCLUSION: A single bolus of remifentanil is safe method to attenuate prolonged QTc associated with insertion of LMA.
Adult ; Anesthetics, Inhalation/adverse effects/*pharmacology ; Anesthetics, Intravenous/administration & dosage/*pharmacology ; Electrocardiography/drug effects ; Female ; Gynecologic Surgical Procedures/adverse effects ; Heart Rate/*drug effects ; Humans ; Methyl Ethers/adverse effects/*pharmacology ; Middle Aged ; Piperidines/*pharmacology

The data obtained from present experiments demonstrated that among several inhalation anesthetics, ether was the most irritable, resulting in marked irregularity of respiratory movement, and halothane depressed respiratory rate more than the other. The pulse rate and blood pressure were decreased marked1y in ether and the halothane anesthesia. the rate of beat of the isolated atria was not greately altered after anesthesia with ether or trichlore-thylene, while it was reduced after chloroform or halothane inhalation. The response of isolated atria to exogeneous norepinephrine was most prominent in the atria isolated from halothane anesthetized rabbits. Myocardial catecholamine contents were reduced uniformly after anesthesia with each anesthetics and most significantly with the halothane inhalation. From the above results, it may be concluded that the increasing cardiac activity with general inhalation anesthetics is closely related to the quantitative changes of the endogenous myocardial catecholamine contents.
Anesthesia, Inhalation/adverse effects ; Anesthetics/*toxicity ; Animals ; Catecholamines/*metabolism ; Heart/*drug effects ; Myocardium/*metabolism ; Norepinephrine/*pharmacology ; Rabbits

PURPOSE: This study aims to investigate the most appropriate effect-site concentration of remifentanil to minimize cardiovascular changes during inhalation of high concentration desflurane. MATERIALS AND METHODS: Sixty-nine American Society of Anesthesiologists physical status class I patients aged 20-65 years were randomly allocated into one of three groups. Anesthesia was induced with etomidate and rocuronium. Remifentanil was infused at effect-site concentrations of 2, 4 and 6 ng/mL in groups R2, R4 and R6, respectively. After target concentrations of remifentanil were reached, desflurane was inhaled to maintain the end-tidal concentration of 1.7 minimum alveolar concentrations for 5 minutes (over-pressure paradigm). The systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR) and end-tidal concentration of desflurane were measured for 5 minutes. RESULTS: The end-tidal concentration of desflurane increased similarly in all groups. The SBP, DBP, MAP and HR within group R4 were not significantly different as compared with baseline values. However, measured parameters within group R2 increased significantly 1-3 minutes after desflurane inhalation. The MAP within group R6 decreased significantly at 1, 2, 4, and 5 minutes (p<0.05). There were significant differences in SBP, DBP, MAP and HR among the three groups 1-3 minutes after inhalation (p<0.05). The incidence of side effects such as hyper- or hypo-tension, and tachy- or brady-cardia in group R4 was 4.8% compared with 21.8% in group R2 and 15.0% in group R6. CONCLUSION: The most appropriate effect-site concentration of remifentanil for blunting hemodynamic responses by inhalation of high concentration desflurane is 4 ng/mL.
Adult ; Aged ; Androstanols/adverse effects/pharmacology ; Anesthetics/adverse effects/pharmacology ; Anesthetics, Inhalation/adverse effects/*pharmacology ; Blood Pressure/drug effects ; Etomidate/adverse effects/pharmacology ; Female ; Heart/*drug effects ; Heart Rate/drug effects ; Humans ; Isoflurane/adverse effects/*analogs & derivatives/pharmacology ; Male ; Middle Aged ; Piperidines/adverse effects/*therapeutic use ; Protective Agents/adverse effects/*therapeutic use

The effects of electroacupuncture (EA) on the minimum alveolar concentration (MAC) and on the cardiovascular system were evaluated with dogs under isoflurane anesthesia. Eight healthy male beagles were randomly assigned to six study groups (five heads/group) with washout intervals of 7 ~ 31 days between experiments for recovery and anesthetic clearance. MAC of isoflurane and cardiovascular parameters were determined after EA at nonacupoint and and at acupoints LI-4, SP-6, ST-36 and TH-8. Electroacupuncture for 30 minutes at LI-4, SP-6, ST-36 and TH-8 acupoints lowered the MAC of isoflurane by 17.5 +/- 3.1%, 21.3 +/- 8.0%, 20.5 +/- 8.2% and 15.6 +/- 3.1%, respectively (p < 0.05). However, electrical stimulation of nonacupoint did not induce a significant change in MAC of isoflurane. In the cardiovascular system, the ST-36 group did not induce any significant change in cardiovascular parameters. In the TH-8 group, the mean and diastolic arterial pressure and the systemic vascular resistance were decreased. In the LI-4 group, cardiac output and cardiac index decreased after EA. These results indicate that EA at LI-4, SP-6 and ST-36 have advantages in isoflurane anesthesia in terms of reducing the dose of anesthetics and minimizing cardiovascular side effects.
Anesthesia, Inhalation/adverse effects/*veterinary ; Anesthetics, Inhalation/*pharmacokinetics/pharmacology ; Animals ; Blood Pressure/drug effects ; Cardiac Output ; Dogs/*metabolism/physiology ; Electroacupuncture/*veterinary ; Heart Rate/drug effects ; Isoflurane/*pharmacokinetics/pharmacology ; Male ; Pulmonary Alveoli/*metabolism ; Pulmonary Wedge Pressure/drug effects ; Random Allocation ; Vascular Resistance/drug effects

OBJECTIVEAnesthetic isoflurane plus surgery has been reported to induce cognitive impairment. The underlying mechanism and targeted intervention remain largely to be determined. Ginsenoside Rb1 was reported to be neuroprotective. We therefore set out to determine whether ginsenoside Rb1 can attenuate isoflurane/surgery-induced cognitive dysfunction via inhibiting neuroinflammation and oxidative stress.

METHODSFive-months-old C57BL/6J female mice were treated with 1.4% isoflurane plus abdominal surgery for two hours. Sixty mg/kg ginsenoside Rb1 were given intraperitoneally from 7 days before surgery. Cognition of the mice were assessed by Barnes Maze. Levels of postsynaptic density-95 and synaptophysin in mice hippocampus were measured by Western blot. Levels of reactive oxygen species, tumor necrosis factor-α and interleukin-6 in mice hippocampus were measured by ELISA.

RESULTSHere we show for the first time that the ginsenoside Rb1 treatment attenuated the isoflurane/surgery-induced cognitive impairment. Moreover, ginsenoside Rb1 attenuated the isoflurane/surgery-induced synapse dysfunction. Finally, ginsenoside Rb1 mitigated the isoflurane/surgery-induced elevation levels of reactive oxygen species, tumor necrosis factor-α and interleukin-6 in the mice hippocampus.

CONCLUSIONThese results suggest that ginsenoside Rb1 may attenuate the isoflurane/surgery-induced cognitive impairment by inhibiting neuroinflammation and oxidative stress pending future studies.

Anesthetics, Inhalation ; adverse effects ; Animals ; Cognition ; Cognitive Dysfunction ; etiology ; prevention & control ; Female ; Ginsenosides ; pharmacology ; Hippocampus ; drug effects ; Inflammation ; etiology ; prevention & control ; Isoflurane ; adverse effects ; Medicine, Chinese Traditional ; Mice ; Mice, Inbred C57BL ; Oxidative Stress ; Postoperative Complications ; etiology ; prevention & control ; Random Allocation ; Surgical Procedures, Operative ; adverse effects ; Synapses ; metabolism