Comparison of Cost-Effectiveness of Propofol Using Target-Controlled Infusion (TCI) with Standard Anesthesia Regimens in Major Operations / 대한마취과학회지

BACKGROUND: The purpose of this study was to compare the cost-effectiveness of propofol using a target-controlled infusion (TCI) with two currently used anesthetic regimens during major operations. METHODS: Forty-two patients undergoing major gynecological surgery were divided into three groups according to the period during which the surgeries were performed. Group propofol/TCI (n = 16) received 1% propofol using TCI-50% N2O, Group isoflurane (n = 14) received thiopental 5 mg/kg-isoflurane-50% N2O, and Group enflurane (n = 12) received thiopental 5 mg/kg-enflurane-50% N2O. All patients also received 2 microgram/kg of fentanyl before induction. Concentrations of propofol and volatile anesthetics were varied according to the patient's hemodynamic responses. Consumption of volatile anesthetics was measured by weighing the vaporizers by a precision weighing machine. RESULTS: Biometric data, duration of surgery and of anesthesia were similar in the three groups. Recovery from anesthesia was significantly shorter in the propofol/TCI group. Episodes of postoperative nausea and vomiting in the recovery room were less common in propofol/TCI group. Patient satisfaction was similar in all three groups. Total (intra- and postoperative) costs were significantly higher in the propofol/TCI group. CONCLUSIONS: When compared with the standard anesthetic regimens, the use of propofol using TCI anesthesia during major operations was associated with higher costs, but did not offer any clinically significant advantages in cost-effectiveness over the standard anesthesia regimens.

The Effect of Induction Mode on Various Parameters and Vital Signs during Anesthesia Induction with Propofol Using a Target Contolled Infusion / 대한마취과학회지

BACKGROUND: Anesthesia induction time is related to speed of injection, injected volume, and Keo. In the case of target controlled infusion, induction time can be controlled by adjusting the induction time mode. The aim of this study was to estimate the effect of induction time mode on variable parameters and vital signs during anesthesia induction with propofol using a target controlled infusion (TCI). METHODS: Sixty unpremedicated adult patients (ASA class I or II, 18 55 yrs) scheduled for elective surgery were randomly allocated to four groups according to induction mode. Group 1 was assigned a flash induction mode, and groups 2, 3 and 4 were assigned 2, 3 and 4min respectively. The end point of anesthesia induction was loss of eyelash reflex. Various parameters including induction time, infused volume, current/effect concentration at induction, and vital signs were compared. RESULTS: As the induction time mode was prolonged, induction time was delayed, but there was no difference in infused volume. Also, the current concentration decreased gradually, but the effect concentration did not show any difference. The vital signs were more stable in groups 3 and 4 compared with groups 1 and 2. CONCLUSIONS: For anesthesia induction, a rapid induction mode showed more rapid induction and low current concentration, but vital signs were relatively unstable and the effect concentration at induction showed no difference. For critically ill patients or patients with unstable hemodynamics, a more gradual induction mode for anesthesia induction in propofol TCI is recommended.

Anesthesia Induction with Propofol Using a Target Controlled Infusion (TCI) / 대한마취과학회지

BACKGROUND: Target Controlled Infusion (TCI) is designed to achieve a predicted target blood concentration based on population pharmacokinetics and it provides the closest approximation for any individual patients. This study determined which target is appropriate for propofol induction using a TCI in korean adullt patients premedicated with midazolam. METHODS: Sixty six patients (ASA I or II, 18~55 years) premedicated with midazolam were allocated randomly to receive an infusion to achieve and maintain a target blood concentration of 3, 4, 5 and 6 microgram/ml using a TCI. Induction time was measured as the interval from the start of the infusion to loss of verbal contact and induction within 3 min was considered as successful. Calculated concentration, induction dose, context sensitive decrement time, vital signs, pain score and side effects were checked and compared each other during induction period. RESULTS: The success rate when the target was 3 microgram/ml was 25%, 58.8%, 77.8% and 100% when targets were 4 microgram/ml, 5 microgram/ml and 6 microgram/ml respectively. EC50 for induction was 3.87 microgram/ml and EC95 was 5.71 microgram/ml. Calculated concentration, induction dose, context sensitive decrement time in 3, 4, 5 microgram/ml group showed no differences among groups, but 6 microgram/ml group showed statistically significant differences compared with other groups. Vital signs, pain score and side effects showed no differences among groups. CONCLUSIONS: Target concentration of 5~6 microgram/ml would successfully induce anesthesia in the majority of patients premedicated with midazolam without major hemodynamic changes.