ANTINOCICEPTIVE EFFECT OF PROPOFOL ON SOMATIC AND VISCERAL PAIN IN SUBHYPNOTIC DOSES

In this study we examined the effect of propofol on somatic and visceral pain in mice. A thermal method (tail immersion) and a chemical method (acetic-acid-induced writhing) were used to determine the antinociceptive effect of propofol. First we determined the dose-response relationships of propofol with a preliminary study. Then propofol was administered according to the results of the preliminary experiment. We used the subhypnotic and nonsedative doses of propofol in the experiments. This dose was lower than 10 mg/kg for mice according to our findings, and ED50 sedation for propofol was 33 mg/kg. Propofol retarded tail withdrawal latencies and decreased writhing numbers of mice in a dose-dependent manner in dosages of 10 and 5 mg/kg (P 0.05). These results suggest that propofol has an antinociceptive effect on visceral as well as on somatic pain when given in subhypnotic doses

Sedation for outpatient endometrial biopsy: Comparison of remifentanil-propofol and Alfentanil-propofol

The purpose of the study was to compare the clinical activity of remifentanil or alfentanil. under propofol sedation with regard to respiratory rate, sedation and recovery rate when used for outpatient endometrial. biopsy. Patients were randomized to receive intravenously either bolus remifentanil 0.4 mug/kg and propofol 1 mg/kg in the remifentanil group (n = 30), or bolus alfentanil 20 mug/kg and propofol 1 mg/kg in the alfentanil group (n = 30). Patients were monitored for heart rate, systolic and diastolic arterial pressure, peripheral O-2 saturation (SpO(2)), respiration rate, and Aldrete sedation score. Pulse oximetry was used to monitor heart rate and SpO(2) during endometrial biopsy. Apnoea was observed in five patients from the remifentanil group, and in three patients from the alfentanil group. The groups did not differ with regard to apnoea incidences. Times were recorded for orientation and Aldrete score > 8, and were similar between the two groups (13.20 +/- 3.64 min and 14.0 +/- 3.87 min in the remifentanil. group, 14.7 +/- 3.64 min and 15.9 +/- 3.15 min in the alfentanil group, respectively). The sedative and analgesic combination of remifentanil-propofol does not offer any advantages compared with a combination of alfentanil-propofol with regards to respiration and recovery during sedation for outpatient endometrial biopsy

Early recovery properties of sevoflurane and desflurane in patients undergoing total hip replacement surgery

Background. The pharmacokinetic properties of sevoflurane and desflurane differ from those of other volatile anesthetics. For example, both agents allow more rapid emergence than traditional volatile anesthetics. However, few direct comparisons of the 2 agents have been made

The direct depressant effects of desflurane and sevoflurane on spontaneous contractions of isolated gravid rat myometrium

Our purpose was to investigate the direct depressant effects of desflurane and sevoflurane at 0.5, 1 and 2 minimum alveolar concentrations (MAC) on spontaneous contractions of isolated gravid rat myometrium. Ten gravid, albino Wistar rats, weighing 240-310 g and at 19-20 days' gestation were used. Sixty myometrial strips were obtained from 10 rats, and randomly assigned into six groups of 10. After obtaining spontaneous myometrial contractions in de Jalon solution for 45 min, 0.5, 1 or 2 MAC of desflurane or sevoflurane were continuously bubbled in the bath for 15 min and myometrial contractions evaluated during the last 10 min. Desflurane 0.5 MAC did not affect duration or amplitude of spontaneous contractions, but frequency was significantly decreased (P < 0.05). Duration, amplitude and frequency were all significantly decreased by desflurane I and 2 MAC (P < 0.05). Sevoflurane did not affect duration, amplitude or frequency at 0.5 MAC, but amplitude and frequency were significantly decreased at I MAC and all were significantly decreased at 2 MAC (P < 0.05). The frequency of contractions was decreased 21.2% with 1 MAC desflurane versus 17.1% with I MAC sevoflurane. The amplitude and frequency of contractions were decreased 48.2% and 48.7% with 2 MAC desflurane versus 58.9% and 49.3% with 2 MAC sevoflurane, respectively. We suggest that due to tocolytic activity, desflurane and sevoflurane can be useful in non-obstetric surgery during pregnancy. (C) 2003 Elsevier Science Ltd. All rights reserved

A Comparison of 1 Minimum Alveolar Concentration Desflurane and 1 Minimum Alveolar Concentration Isoflurane Anesthesia in Patients Undergoing Craniotomy for Supratentorial Lesions

AbstractBackgroundA critical point in craniotomy is during opening of the dura and the subsequent potential for cerebral edema. Use of desflurane in neurosurgery may be beneficial because it facilitates early postoperative neurologic evaluation; however, data on the effect of desflurane on intracranial pressure in humans are limited. Isoflurane has been used extensively in neurosurgical patients.ObjectiveThis study compared 1 minimum alveolar concentration (MAC) desflurane with 1 MAC isoflurane in facilitating hemodynamic stability, brain relaxation, and postoperative recovery characteristics in patients who underwent craniotomy for supratentorial lesions.MethodsA total of 70 patients (aged 18–65 years), with American Society of Anesthesiologists (ASA) 1 or 2 physical status, who underwent craniotomy for supratentorial lesions, were enrolled in the study. For induction of anesthesia, fentanyl (2 μg/kg IV) and propofol (2 mg/kg IV) were administered. Endotracheal intubation was performed after administration of vecuronium (0.1 mg/kg IV) for total muscle relaxation. Before insertion of the skull pins, additional fentanyl (2 μg/kg IV) was administered. Patients were randomly allocated to 1 of 2 anesthetic regimens. For maintenance of anesthesia, 35 patients received 1 MAC of desflurane (group 1) and 35 patients received 1 MAC of isoflurane (group 2) within 50% oxygen in nitrous oxide. Intraoperatively, heart rate (HR) and mean arterial pressure (MAP) were measured and recorded before induction and 1 minute after induction, after endotracheal intubation, before skull pin insertion and 1 minute after skull pin insertion, before incision and 1 minute after incision, and before extubation and 1 minute after extubation. Also, HR and MAP were recorded at 30-minute intervals. Postoperatively, extubation time, eye opening time to verbal stimuli, orientation time, and time to reach an Aldrete postanesthetic recovery score of ≥8 were recorded. In addition, opioid consumption was calculated and recorded. Brain relaxation was evaluated according to a 4-step brain relaxation scoring scale. All outcomes of the study were assessed and recorded by an anesthesiologist blinded to the volatile anesthetic gases studied.ResultsNo significant difference in HR was observed between the 2 groups. Intraoperative MAP values in group 1 were higher than in group 2 (P < 0.05). No significant difference was found between these groups in brain relaxation and opioid consumption. Extubation time, eye opening time to verbal stimuli, and time to reach an Aldrete score of ≥8 were found to be significantly shorter in patients in group 1 compared with patients in group 2 (P < 0.05).ConclusionsIn patients who underwent craniotomy for supratentorial lesions, patients who received 1 MAC desflurane–based anesthesia had earlier postoperative cognitive recovery and postoperative neurologic examination compared with patients who received 1 MAC isoflurane–based anesthesia. The observed benefits of early recovery from anesthesia, however, should be considered with risks such as higher MAP in patients administered 1 MAC desflurane

The effectiveness of intramuscular Dexmedetomidine on hemodynamic responses during tracheal intubation and Anesthesia induction of hypertensive patients: A randomized, double-blind, placebo-controlled study

Background: Hypertensive patients are at risk for increased hemodynamic response to tracheal intubation. Sympatholytic drugs administered during the preinduction period may prevent adverse events

The effects of intravenous fentanyl and intravenous fentanyl combined with bupivacaine infiltration on the hemodynamic response to skull pin insertion

This study was conducted to compare the effects of intravenous fentanyl and intravenous fentanyl combined with bupivacaine infiltration on the hemodynamic response to skull pin insertion. 120 ASA I-II patients scheduled for elective craniotomy were included. The fentanyl group (group F, n - 60) received fentanyl during induction and prior to skull pin insertion (2 and 1 mug circle kg(-1), respectively). The fentanyl-bupivacaine group (group FB, n = 60) received the same doses of fentanyl as well as scalp infiltration with 0.25% bupivacaine. The heart rate (HR) was not significantly different between the groups. HR, at 5 minutes after skull pin insertion in the group F and at 1 and 5 minutes after skull pin insertion in group FB, significantly decreased in comparison to the baseline values (P < 0.05). In both groups, HR at 1 and 5 minutes after skull pin insertion was significantly lower than HR just before skull pin insertion (P < 0.05). In group FB, the mean arterial pressure (MAP) at 1 and 5 minutes after skull pin insertion were significantly lower than that in group F (P < 0.05). In group F, MAP at 1 minute after skull pin insertion was higher than that of just before skull pin insertion (P < 0.05),- however, MAP at 5 minutes after skull pin insertion was lower than that of just before skull pin insertion (P < 0.05). In group FB, MAP at 1 and 5 minutes after skull pin insertion was lower than that of just before skull pin insertion (P < 0.05). The hemodynamic response to skull pin insertion was effectively suppressed with both methods. Still, the addition of scalp infiltration to fentanyl did not provide any additional benefit. Administering an additional dose (I mug circle kg(-1)) of fentanyl just before skull pin insertion is recommended as a simple and effective option that requires no extra time