BACKGROUND: This study compared the hemodynamic response and recovery profile of remifentanil-sevoflurane anesthesia for a pediatric tonsillectomy with that of remifentanil-propofol anesthesia. METHODS: Fifty healthy children (4-10 yr) undergoing a tonsillectomy were randomly assigned to one of two groups. Anesthesia was induced with remifentanil 1 mcg/kg over 1 min, propofol 2 mg/kg, and rocuronium 0.8 mg/kg. Anesthesia was maintained with remifentanil 0.25 mcg/kg/min and propofol 6 mg/kg/h, or remifentanil 0.25 mcg/kg/min and sevoflurane 1.0 vol%. The propofol and sevoflurane dose was kept unchanged, and remifentanil was titrated according to the hemodynamic response. The perioperative hemodynamics, recovery time, and side effects were assessed. RESULTS: Remifentanil-based anesthesia with propofol or sevoflurane resulted in stable hemodynamics, but sevoflurane was associated with a significantly lower systolic blood pressure. The recovery times were similar for spontaneous ventilation, extubation, eye opening, orientation, and full recovery in both groups. The incidence of side effects was similar in both groups. CONCLUSIONS: Remifentanil/sevoflurane is as equally effective as remifentanil/propofol in pediatric patients. The hemodynamic stability is appropriate and the recovery from anesthesia is rapid.
Anesthesia* ; Blood Pressure ; Child ; Hemodynamics ; Humans ; Incidence ; Propofol ; Tonsillectomy* ; Ventilation

BACKGROUND: Propofol is a good choice for elderly patents because it produces rapid onset and quick recovery with few side effects. Propofol produces dose-dependent cardiovascular depression. This effect is more pronounced in elderly patients during induction and can be minimized by a slow injection. The aim of this study was to determine the appropriate induction dose of propofol using a slower infusion rate for elderly patients to obtain desirable sedation and hypnotic conditions with minimal hemodynamic changes. METHODS: Thirty-nine patients aged over 70 years were assigned to receive a propofol infusion of either 1.5 mg/kg (n = 21, Group 1) or 2.0 mg/kg (n = 18, group 2). The infusion rate was 20 mg/kg/hr. The systolic and diastolic pressure, heart rate, BIS and modified observers assessment of the alertness/sedation scale (OAA/S) were measured before the induction (baseline), after the propofol infusion, as well as immediately, 3 and 5 minutes after intubation. RESULTS: The systolic pressure decreased significantly after the propofol infusion in both groups (group 1: 17%, group 2: 25%) but there were no significant differences between them. The BIS values after the propofol infusion and intubation were 67.1 +/- 12.6 and 62.3 +/- 12.7 in group 1, 49.6 +/- 11.1 and 51.7 +/- 11.7 in group 2, respectively which showed significant differences between the groups. CONCLUSIONS: When 2.0 mg/kg of propofol is administrated to elderly patients, a slower infusion rate is more appropriate for maintaining the desirable sedation and hypnotic conditions and cause no significant hemodynamic changes.
Aged* ; Blood Pressure ; Depression ; Heart Rate ; Hemodynamics* ; Humans ; Intubation ; Propofol*

BACKGROUND: Induction of anesthesia with propofol commonly associated with reduction in systemic arterial pressure, especially in elderly and high risk patients. This reduction is influenced by the dose and rate of propofol injection. The aim of this study was to examine the effect of different injection rate of propofol on vital signs, dose requirement and induction time during induction period. METHODS: Unpremedicated one hundred and twenty ASA physical status I and II patients aged 20~60 years scheduled for elective surgery were randomly allocated into one of four (150, 300, 600, 1200 ml/hr) groups according to speed of injection of propofol during induction period. Loss of verbal contact was taken as the end-point of induction. Vital signs, SpO2, dose requirement of propofol and induction time were checked. RESULTS: As the injection rate of propofol became slower, there were significant reduction in induction dose and increase in induction time (p<0.05). For example, induction dose and time were 1.82 mg/kg, 223 +/- 58 sec in 150 ml/hr group and 3.14 mg/kg, 50 +/- 11 sec in 1200 ml/hr group, respectively. Also, decrease in systolic and diastolic pressure were less marked at lower injection rates. CONCLUSIONS: Slower injection of propofol produces less vital sign changes and dose requirement for the induction of anesthesia.
Aged ; Anesthesia* ; Arterial Pressure ; Blood Pressure ; Humans ; Propofol* ; Vital Signs*

BACKGROUND: The effect site is the theoretical compartment in which a drug exerts its action and thus the concentration at this site is a direct determinant of a drug,s effect. This study was performed to compare effect site targeting with plasma targeting with regard to induction phenomena and vital sign changes using propofol target controlled infusion (TCI). METHODS: Forty patients were randomly assigned to one of two groups. Groups were defined as propofol administered via TCI to either a target plasma propofol concentration (group P) or to a target effect site (group E) propofol concentration. We used Master TCI for plasma targeting and a stelpump program for effect site targeting. The concentration targeted for all subjects was 5.7 microgram/ml. We compared the time to loss of consciousness, change of concentration, BP and pulse pressure between groups until the effect site concentration was reached at 5.7 microgram/ml. RESULTS: The median time to LOC in group P was 58.1 +/- 11.8 s and 35.8 +/- 7.9 s in group E (P <0.05). The mean time to achieve the effect site concentration of 5.7 microgram/ml was 18.5 +/- 0.1 min in group P and 3.6 +/- 0.1 min in group E (P < 0.05). Systolic and diastolic blood pressure showed significant changes in group E. CONCLUSIONS: We concluded that anesthetic induction time can be significantly reduced when the effect site concentration is targeted. However, we recommended effect site targeting in anesthesia induction with propofol TCI only in cases of healthy young patients because of possible undesirable hemodynamic changes.
Anesthesia ; Blood Pressure ; Hemodynamics ; Humans ; Plasma ; Propofol ; Unconsciousness ; Vital Signs

This study aimed to establish a new propofol target-controlled infusion (TCI) model in animals so as to study the general anesthetic mechanism at multi-levels in vivo. Twenty Japanese white rabbits were enrolled and propofol (10 mg/kg) was administrated intravenously. Artery blood samples were collected at various time points after injection, and plasma concentrations of propofol were measured. Pharmacokinetic modeling was performed using WinNonlin software. Propofol TCI within the acquired parameters integrated was conducted to achieve different anesthetic depths in rabbits, monitored by narcotrend. The pharmacodynamics was analyzed using a sigmoidal inhibitory maximal effect model for narcotrend index (NI) versus effect-site concentration. The results showed the pharmacokinetics of propofol in Japanese white rabbits was best described by a two-compartment model. The target plasma concentrations of propofol required at light anesthetic depth was 9.77±0.23 μg/mL, while 12.52±0.69 μg/mL at deep anesthetic depth. NI was 76.17±4.25 at light anesthetic depth, while 27.41±5.77 at deep anesthetic depth. The effect-site elimination rate constant (ke0) was 0.263/min, and the propofol dose required to achieve a 50% decrease in the NI value from baseline was 11.19 μg/mL (95% CI, 10.25-13.67). Our results established a new propofol TCI animal model and proved the model controlled the anesthetic depth accurately and stably in rabbits. The study provides a powerful method for exploring general anesthetic mechanisms at different anesthetic depths in vivo.
Anesthetics, Intravenous ; blood ; pharmacokinetics ; Animals ; Drug Monitoring ; Infusions, Intravenous ; Models, Statistical ; Propofol ; blood ; pharmacokinetics ; Rabbits ; Software

OBJECTIVE: A rapid and selective method has been developed for the determination of propofol in blood by gas chromatography-mass spectrometry (GC-MS). METHODS: The blood was extrasted with the solution of internal standard, the extracted residue was analyzed by gas chromatography-mass spectrometry using selected-ion monitoring mode. RESULTS: The linear range was 0.1-10 microg/mL. The coefficient(R2) was 0.993 1. The detection limit was 0.05 microg/mL. CONCLUSION The method is simple and rapid, offering superior sensitivity and selectivity for propofol. The method can be used successfully during clinical and forensic toxicology.
Anesthetics, Intravenous/blood* ; Gas Chromatography-Mass Spectrometry/methods* ; Humans ; Propofol/blood* ; Reproducibility of Results ; Sensitivity and Specificity

BACKGROUND: We performed a prospective, randomized, and controlled trial to evaluate the effect of an intravenous fentanyl and propofol on the variation in BIS level associated tracheal suction. METHODS: Thirty ICU patients intubated or tracheostomized were randomly allocated to control and experimental groups. Control group was received saline and experimental groups were received propofol with or without fentanyl intravenously prior to tracheal suction. And then we monitored BIS index, blood pressure, heart rate and SpO2 before, during and after tracheal suction. RESULTS: BIS index was significantly lower in propofol plus fentanyl group than others during experiment (P < 0.05). Heart rate and blood pressure in propofol plus fentanyl group also less increased than those in control or propofol group during tracheal suction (P < 0.05). CONCLUSIONS: These results suggest that co-administration of propofol and fentanyl has more effective than propofol alone in sedation and analgesia of ICU patients during tracheal suction.
Analgesia ; Blood Pressure ; Fentanyl* ; Heart Rate ; Humans ; Propofol* ; Prospective Studies ; Suction*

BACKGROUND: Many pathophysiologic alterations in patients with major burns can cause changes in the response of propofol. The aim of this study is to determine the appropriate induction dose of propofol using a slow infusion rate for major burn patients to obtain desirable sedation and hypnotic conditions with minimal hemodynamic changes. METHODS: 45 adults with major burns and who were electively scheduled for escharectomy less than a week after injury were recruited. For induction with propofol, the patients were randomly allocated to one of two groups (group 1: 1.5 mg/kg, n = 20 and group 2: 2.0 mg/kg, n = 25). The infusion rate was 20 mg/kg/hr. The systolic and diastolic blood pressure (SBP, DBP), the heart rate, the bispectral index and the modified observers' assessment of the alertness/sedation scale (OAA/S) were measured before the induction and after the propofol infusion, as well as immediately, 3 and 5 minutes after intubation. RESULTS: The SBP and DBP were significantly decreased after the propofol infusion in both group, but there were no significant differences between the two groups. The BIS values after the propofol infusion and intubation were 44.2 +/- 16.1 and 43.5 +/- 13.8 in group 1, and 45.6 +/- 10.3 and 46.5 +/- 11.4 in group 2, respectively, and there were no differences between the 2 groups. CONCLUSIONS: When propofol is administrated to major burn patients, an induction dose of 1.5 mg/kg is appropriate and a slow infusion rate of 20 mg/kg/hr is safe for maintaining the desired hypnotic conditions and this dose and rate cause no significant hemodynamic problems.
Adult ; Blood Pressure ; Burns ; Consciousness Monitors ; Heart Rate ; Hemodynamics ; Humans ; Intubation ; Propofol

BACKGROUND: Because the propofol TCI software commands the syringe pump to deliver a rapid infusion at a rate of 1200 ml/hr until the pharmacokinetic model predicts that the selected target concentration has been reached, the hemodynamic changes are predicted. To this change, several methods could be considered and the fentanyl injection is one of them. METHODS: Sixty adult patients scheduled for orthopedic surgery were randomly alldegrees Cated into four groups according to amount of fentanyl injected during induction period(group 1: no fentanyl, group 2: 0.75 microgram/kg, group 3: 1.5 microgram/kg, group 4: 3.0 microgram/kg). Target plasma concentration of propofol was selected as 4.0 microgram/ml and this concentration was achieved using modification of Prys-Roberts method. We evaluated the hemodynamic effect of various doses of fentanyl that injected at Vdpeak effect time and determined the optimal dose of fentanyl during propofol induction using TCI mode. RESULTS: Induction dose(range: 1.25~1.31 mg/kg) of propofol and induction time(range: 46~76 sec) showed no difference among groups. Use of fentanyl was effective for blood pressure stability immediately after intubation, but not effective before and 3 min following intubation. The higher the dosage of fentanyl, the more stable the heart rate. CONCLUSION: It suggest that use of fentanyl for the prevention of abrupt hemodynamic change during propofol induction using target controlled infusion mode is not necessary.
Adult ; Blood Pressure ; Fentanyl* ; Heart Rate ; Hemodynamics* ; Humans ; Intubation ; Orthopedics ; Plasma ; Propofol* ; Syringes

BACKGROUND: We wanted to determine an adequate combination of target effect-site concentrations of remifentanil and propofol during anesthetic induction with target controlled infusion (TCI).We also determined whether increasing remifentanil concentrations might reduce propofol consumption at loss of consciousness (LOC). METHODS: Sixty ASA 1 or 2 patients were randomly allocated according to the target effect-site concentration of remifentanil and propofol (R7P3: remifentanil 7 ng/ml + propofol 3microgram/ml, R5P4: remifentanil 5 ng/ml + propofol 4microgram/ml, R3P5: remifentanil 3 ng/ml + propofol 5microgram/ml). After the target effect-site concentration of remifentanil had been reached, the TCI of propofol was started. The effect-site concentration of propofol at LOC was recorded. When the target effect-site concentration of propofol was reached, 0.6 mg/kg of rocuronium was administered. Tracheal intubation was performed after 2 minutes. The noninvasive blood pressure, heart rate (HR), bispectral index (BIS), and infused dose of remifentanil and propofol were recorded. RESULTS: R3P5 groupd showed a significant increase in mean blood pressure after intubation (104 +/- 31.9 mmHg, P < 0.05) compared to R7P3 and R5P4. BIS at the time when propofol reached its target effect-site concentration was significantly higher in the R7P3 group (71.6 +/- 9.9, P < 0.05 compared to R5P4 and R3P5). There was a significant relationship between the effect-site concentration of remifentanil and propofol at LOC (Y = 2.032 - 0.351X, R(2) = 0.551, P < 0.0001). CONCLUSIONS: The R5P4 target effect-site concentrations are adequate dosing combinations during TCI induction based on hemodynamic responses and BIS values.
Androstanols ; Blood Pressure ; Heart Rate ; Hemodynamics ; Humans ; Intubation ; Piperidines ; Propofol ; Unconsciousness