No abstract available.
Bone Plates* ; Spine*

BACKGROUND: Both propofol and ketamine are useful hypnotics for induction of anesthesia, and the combination of propofol and ketamine has been used for total intravenous anesthesia. The aim of this study was to evaluate the dose response of propofol, ketamine and combination of these drug, and determine possible interaction between two drugs in patients. METHODS: The effect of ketamine on the dose response curve for propofol was studied in unpremedicated 165 ASA physical status I or II patients who were scheduled for elective operation. As an endpoint of hypnosis, ability to open eyes on verbal command was checked. Dose response curves for propofol and ketamine were determined with a probit procedure and their type of pharmacologic interaction was determined by fractional and isobolographic analysis. RESULTS: At the hypnotic endpoint, the ED50s were 1.13 mg/kg propofol, 0.66 mg/kg ketamine, and the ED95s were 1.67 mg/kg propofol, 1.09 mg/kg ketamine. The type of interaction between two drugs for hypnosis was found to be additive and ketamine was 1.7 times potent than propofol as an equieffective dose of hypnosis. CONCLUSIONS: The type of interaction between propofol and ketamine for hypnosis was additive.
Anesthesia* ; Anesthesia, Intravenous ; Humans ; Hypnosis ; Hypnotics and Sedatives ; Ketamine* ; Propofol*

BACKGROUND: Total intravenous anesthesia (TIVA) is by definition a technique involving the induction and maintenance of the anesthetic state with intravenous drugs alone. In particular, propofol and opioid and muscle relaxants allow enhanced control of the state of anesthesia for the entire duration of the surgical procedure. We evaluated the clinical usefulness of TIVA with fixed fentanyl concentration 3 ng/ml using isoconcentration nomogram and titrated propofol for coronary artery bypass graft. METHODS: Anesthesia was induced using 1% propofol mixed with lidocaine 0.5 mg/kg and ephedrine 10 mg (150 ml/hr) until loss of consciousness in 19 patients undergoing coronary artery bypass graft. Infusion rate of propofol was adjusted in response to blood pressure and pulse rate. To achieve constant fentanyl concentration, infusion rate of fentanyl was changed timely according to isoconcentration nomogram. Infusion of propofol and fentanyl was discontinued 15 and 30 min before predictable end of surgery, respectively. Intraoperative hemodynamics, recovery profile and postoperative analgesic requirements were checked. RESULTS: Overall intraoperative hemodynamics including cardiac index and PCWP showed no significant changes compared with preinduction control value except during CPB period. Average flow rate of propofol and fentanyl was 3.4 0.2 mg/kg/hr and 2.8 0.4 g/kg/hr, respectively. Spontaneous eye opening time was 96.4 min after discontinuation of fentanyl. More than 80% (16/19) of patients did not require any analgesic during first postoperative 24hrs for pain relief. CONCLUSIONS: TIVA with propofol and fentanyl (3 ng/ml) could be a suitable and safe anesthetic technique for coronary artery bypass graft.
Anesthesia ; Anesthesia, Intravenous* ; Blood Pressure ; Coronary Artery Bypass* ; Coronary Vessels* ; Ephedrine ; Fentanyl ; Heart Rate ; Hemodynamics ; Humans ; Lidocaine ; Nomograms ; Propofol ; Transplants ; Unconsciousness

BACKGROUND: Propofol is useful agents for anesthesia induction and maintenance, but pain on injection and possible hypotension are a commonly encountered problems during induction. Meanwhile, ketamine has potent analgesic and sympathomimetic effect. Therefore, we evaluated the effect of ketamine pretreatment on injection pain and hemodynamic changes during induction with propofol. METHODS: Premedicated one hundred and twenty ASA physical status I or II patients scheduled for elective surgery were randomly allocated into one of four groups (group 1; propofol only, group 2, 3, 4; pretreatment with 25%, 50%, 75% dose of hypnotic ED50 of ketamine, respectively) groups. Intensity and frequency of injection pain, mean arterial pressure and pulse rate were checked for evaluation of ketamine pretreatment on injection pain and hemodynamic changes during induction with propofol. RESULTS: Incidence of pain on injection was significantly reduced in group 2,3 and 4 compared with group 1. Group 2 and 3 showed more stable hemodynamic changes than Group 1 and 4. CONCLUSIONS: 25-50% of hypnotic ED50 of ketamine (0.17-0.33 mg/kg) pretreatment reduced pain on injection and hemodynamic changes during propofol induction significantly.
Anesthesia* ; Arterial Pressure ; Heart Rate ; Hemodynamics* ; Humans ; Hypotension ; Incidence ; Ketamine* ; Propofol* ; Sympathomimetics

BACKGROUND: Because of wide individual variations in response to sedative and the level of sedation desired by different patients, inadequate sedation is frequent during surgery. Patient-controlled sedation is a logical extension of patient-controlled analgesia to find and maintain their own steady-state of sedation by self-administration of sedatives during surgery. The purpose of this study was to evaluate the feasibility of patient-controlled sedation compared with anesthesiologist-controlled sedation during surgical spinal anesthesia. METHODS: Unpremedicated forty adult patients who received spinal anesthesia for lower extremity surgery were randomly allocated into two groups (n=20 for each group). After selection of target state of sedation according to sedation scale, patient-controlled sedation (PCS) group self-administered 0.5 mg (1 ml) intravenous midazolam in increments using a Walkmed PCA infusor and anesthesiologist- controlled sedation (ACS) group administered by the anesthesiologist as the same manner to achieve previously selected sedation state. Sedation score, vital signs, SpO2 were checked 5, 10, 20, 30, 40min after start of drug injection. RESULTS: The sedation scores patient desired were 4.4 +/- 0.8 in PCS group and 4.3 +/- 0.7 in ACS group. These scores were achieved 20min after start of injection in PCS group and 40 min in ACS grou p (p<0.05). Degree of satisfaction was higher in PCS group compared with ACS group (1.5 +/- 0.6 vs 2.1 +/- 0.8, p<0.05). No complications were detected in two groups. CONCLUSIONS: PCS using midazolam was better than ACS in terms of early achievement of sedation state patient desired and degree of satisfaction.
Adult ; Analgesia, Patient-Controlled ; Anesthesia, Spinal ; Humans ; Hypnotics and Sedatives ; Infusion Pumps ; Logic ; Lower Extremity ; Midazolam* ; Passive Cutaneous Anaphylaxis ; Vital Signs

BACKGROUND: Etomidate is a rapid-acting sedative/hypnotic agent with little or no cardiovascular effect and a high therapeutic index. For this reason, etomidate has been used as an anesthetic induction and maintenance agent in patients with poor cardiovascular reserve. Bispectral index (BIS), a parameter derived from electroencephalography (EEG), has been proposed as a measure of anesthetic effect and is shown to correlate with increasing sedation and loss of consciousness. To establish its utility for this purpose, it is important to determine the correlation among BIS, measured drug concentration, and increasing levels of sedation. This study was designed to evaluate this relation for etomidate. METHODS: Eighteen adult patients scheduled for elective surgery, ASA physical status I or II, were included. Etomidate was administerd until loss of consciousness (loss of verbal contact) using syringe pump with a constant rate (150 ml/h) and patients were observed until regaining consciousness as decided by prompt verbal response on command of "open your eyes". A BIS was monitored, arterial blood samples were obtained for analysis of drug concentration, and the patients were evaluated for level of sedation by the responsiveness portion of the modified observer's assessment of alertness/sedation (OAA/S) scale. RESULTS: The BIS (r = 0.86) correlated significantly with the OAA/S more than the etomidate plasma concentration (r = 0.57). The BIS values, OAA/S, and blood concentrations were 50, 1.26, and 1337 ng/ml at induction and 75, 4.6, and 236 ng/ml at awakening, respectively. CONCLUSIONS: We concluded that the BIS accurately predicted level of sedation with etomidate during anesthesia induction, but the correlation between blood concentration and level of sedation was less strong.
Adult ; Anesthesia* ; Anesthetics ; Consciousness ; Electroencephalography ; Etomidate* ; Humans ; Plasma ; Syringes ; Unconsciousness

BACKGROUND: We can usually see the yawning at induction of anesthesia, however, it has not been studied as such an indicator of anesthesia. The yawning is one means of changing arousal level, and a sign or marker that such a change is occurring, although its functions are not well understood. The purpose of the present study was to evaluate the yawning whether it could be used as an indicator of induction of anesthesia, using its property as a marker of changed arousal level. METHODS: In 60 adult patients, group 1 was done propofol target controlled infusion (TCI) with Stelpump software, while group 2 was done thiopental TCI similarly. Clinical indicators of induction of anesthesia were measured as follows: loss of verbal control (LOV), loss of eyelash reflex (LOE), the yawning. In addition, the occurrence of apnea (OOA) were measured, too. We assessed the hypnosis levels of indicators of induction of anesthesia including the yawning and demonstrate their effect site concentrations and elapsed time. Furthermore, we compared the incidences of yawning and apnea between both groups. RESULTS: Clinical indicators of induction occurred in the order of LOV > LOE > the yawning >> OOA in both groups. With respect to BIS, the yawning showed the lowest BIS and the highest effect site concentrations except OOA in both groups. The incidence of the yawning in group 2 was higher than in group 1 (about 82 vs 63%). On the contrary, the incidence of apnea in group 1 was higher than in group 2 (about 79 vs 53%). CONCLUSIONS: As far as the yawning could be shown, we could observe, it approximated most closely to their clinical impression of the 'true' induction in terms of the hypnosis level and its effect site concentration.
Adult ; Anesthesia* ; Apnea ; Arousal ; Humans ; Hypnosis ; Incidence ; Propofol ; Reflex ; Thiopental ; Yawning*

BACKGROUND: Determination of blood concentration is essential for the pharmacokinetic/pharmacodynamic (PK/PD) study of intravenous anesthetic agents. Knibbe's method is a rapid, simple, and reliable method to quantify propofol in low-volume samples. The aim of this study was to qualify Knibbe's method by calculating the performance error in propofol target-controlled infusion (TCI). METHODS: With ethics commitee approval and informed consent, thirty ASA 1 or 2 adult patients undergoing orthopedic surgery participated in this study. All patients were premedicated with atropine 0.5 mg IM and received general anesthesia with propofol TCI (Master TCI) supplemented by 67% N2O and 33% O2. Anesthesia was induced by propofol TCI with a target concentration of 6 microgram/ml and maintained around 3-5 microgram/ml according to bispectral index (40-50). In the middle of surgery, the target concentration was increased to 6 microgram/ml and maintained until the effect concentration matched the target concentration. Three min after equilibration, 3 ml of blood was taken from the radial artery to analyse blood concentration using HPLC with the fluorescence detection method described by Knibbe et al. Using this method, the performance error for the 1 6 microgram/ml of predicted propofol concentration in whole blood was calculated according to the following formula: measured concentration-predicted concentration/predicted concentration x 100. RESULTS: The performance errors at each concentration were -12.86, -13.61, -2.95,7.94,9.22, and 13.85% for 1-6 microgram/ml of predicted propofol concentration, respectively. CONCLUSIONS: Knibbe's method for determination of plasma propofol concentration showed itself to be accurate accuracy in that there was a relatively low performance error in the concentration range of 1 6 microgram/ml, which is considered the usual concentration range for clinical practice.
Adult ; Anesthesia ; Anesthesia, General ; Anesthetics ; Atropine ; Chromatography, High Pressure Liquid ; Ethics ; Fluorescence ; Humans ; Informed Consent ; Orthopedics ; Plasma ; Propofol* ; Radial Artery

BACKGROUND: Clonidine has been shown to increase the duration of anesthesia and analgesia when mixed with the local anesthetic used to perform a regional block, but it has side effects such as hypotension, excessive sedation when used large amounts. The aim of this study was to determine the minimal effective dose of clonidine increasing anesthesia and analgesia time without any significant side effects after brachial plexus block. METHODS: One-hundred and twenty patients scheduled for upper extremity surgery, ASA physical status I and II, were randomly allocated into six groups(n=20 for each group) including group A(no clonidine) and group B-F(clonidine 0.25~1.25 mcg/kg at interval of 0.25 mcg/kg for each group). A parascalene brachial plexus block was performed with admixture of 20ml of 2% lidocaine and 20ml of 0.5% bupivacaine with or without clonidine. Duration of anesthesia and analgesia, also side effects were checked for each clonidine group and compared with group A. RESULTS: Duration of anesthesia increased significantly in group E(442+/-137 min) and F(472+/-143 min), and duration of analgesia increased significantly in group D(466+/-140 min), E(540+/-144 min) and F(561+/-196 min) compared with group A. More rapid onset time is noted in group C, D, E, and F. There were no differences in vital signs among groups. Sedative effect was evident in group D, E, and F, especially 60 minute after injection of drug, and the onset and duration of sedation depended on dosage. CONCLUSIONS: Minimal effective dose of clonidine for increasing anesthesia and analgesia time without any significant side effects was 1.0 mcg/kg.
Analgesia ; Anesthesia and Analgesia* ; Anesthesia* ; Anesthetics, Local* ; Brachial Plexus* ; Bupivacaine ; Clonidine* ; Humans ; Hypnotics and Sedatives ; Hypotension ; Lidocaine ; Upper Extremity ; Vital Signs

BACKGROUND: Propofol is a useful induction agent, but it can cause hypotention and bradycardia. Meanwhile, ephedrine has alpha-vasoconstriction and beta-cardiac stimulant effect. The purpose of this study was to assess the hemodynamic effects of adding various doses of ephedrine to propofol to obtund adverse hemodynamic response and to determine the optimal dose. METHODS: Unpremedicated 120 ASA physical status I adult patients (20~50yrs) scheduled for elective surgery were randomly allocated into four groups according to the doses of ephedrine added to propofol (1%, 20 ml). Group 1 (control group) was given propofol alone and 10, 15 and 20 mg of ephedrine was added to propofol in Group 2, 3 and 4, respectively (n=30 for each group). Propofol was loaded at 150 ml/hr using a syringe pump and no response to verbal command was ascertained as the end-point of induction. Vital signs and SpO2 were checked every 1 min during the induction period. RESULTS: In group 1, there was a significant decrease in both systolic and diastolic pressure prior to intubation. Group 2 and 3 showed relatively stable hemodynamic changes and significant systolic or diastolic changes occured only in the pre or post 1 min periods of intubation. But, in pulse rate, group 3 showed significant change 1 and 2 min after intubation, in contrary to group 2. Group 4 showed significant changes in systolic and diastolic pressure 1 and 2 min after intubation, and in pulse rate throughout the postintubation period. CONCLUSIONS: Ephedrine 10mg may be safely employed to reduce the hemodynamic changes during induction preiod with propofol.
Adult ; Anesthesia* ; Blood Pressure ; Bradycardia ; Ephedrine* ; Heart Rate ; Hemodynamics* ; Humans ; Intubation ; Propofol* ; Syringes ; Vital Signs