Conscious Sedation Using Target-Controlled Infusion with Propofol in Regional Anesthesia Patients / 대한마취과학회지

BACKGROUND: The technique using target-controlled infusion (TCI) with propofol produces safe intraoperative sedation during regional anesthesia with rapid recovery and high patient satisfaction. The objective of this study was to define the blood propofol concentration necessary for conscious sedation in regional anesthesia patients according to age. METHODS: Sixty patients scheduled to undergo regional anesthesia were allocated into one of three groups according to age, such as group 1 (n = 20): 16 24 yr, group 2 (n = 20): 30 39 yr, group 3 (n = 20): 40 55 yr. Thirty minutes after performing regional anesthesia, TCI of propofol started at a target plasma level of 1 microgram/ml adjusted in steps of 0.2 microgram/ml to maintain a sedation level 3 on a 5-point sedation scale. RESULTS: The mean target concentration was 0.9 microgram/ml (group 1), 0.8 microgram/ml (group 2), 0.7 microgram/ml (group 3). The mean propofol consumption was 38.5 microgram/kg/min (group 1), 34.3 microgram/kg/min (group 2), and 30.8 microgram/kg/min (group 3). The recovery time was significantly delayed in group 3 (2.8 min) compared to group 1 (1.5 min) and group 2 (1.8 min). CONCLUSIONS: TCI of propofol within at 0.7 0.9 microgram/ml blood concentration range produces safe intraoperative sedation during regional anesthesia with rapid induction, rapid recovery and high patient satisfaction without severe complications in 16 55 yr old patients.

Comparison of Anesthesiologist-Controlled Sedation and Patient-Controlled Sedation with Propofol in Regional Anesthesia Patients / 대한마취과학회지

BACKGROUND: Propofol is a drug which has both sedative and anxiolytic properties which when given in IV form can provide a rapid onset of effects. However inter-individual dose requirement can vary widely, making titiration to effect essential. Patient-controlled sedation (PCA), which administers bolus doses of the sedative agent to the point at which the patient is satisfied have been found to be both effective and popular for patients undergoing surgery under loco-regional anethesia. The aim of this study was to compare the effectiveness and quality of target-controlled infusion (TCI) of propofol by the anesthesiologist (anesthesiologist-controlled sedation: ACS) versus PCS to achieve conscious sedation. METHODS: Sixty patients scheduled to undergo spinal anesthesia with 0.5% hyperbaric bupivacaine 12-18 mg or brachial plexus block with 1% lidocaine 40 ml were divided into 2 groups. In the ACS group (n = 30), the initial target concentration of propofol was 1.0 microgram/ml and the target concentration was adjusted in steps of 0.2 microgram/ml to maintain an Observer's Assesment of Alertness/Sedation (OAA/S) score of 3 with a TCI pump. In the PCS group (n = 30), a 20 mg bolus of propofol was delivered at each button without a lockout interval to the point at which a patient was satisfied with the level of sedation. Infusion rate, total dosage, duration of induction and recovery and recall of operative procedure were checked. BIS, EKG, heart rate, noninvasive anterial blood pressure, respiratory rate and SpO2 were recorded during the operation. RESULTS: The mean (range) infusion rate and total infusion dose were not significantly different with each group: ACS 38.5 (13.1-101.0) microgram/ml, 132 (80-241) mg/h and PCS 25.4 (21.3-80.1) microgram/ml, 118 (69-220) mg/h. Duration of induction was significantly extended in the PCS group (5.8 min) as compared with the ACS group (2.9 min)(P < 0.05). The intensity of amnesia related to blood propofol concentration was more improved in the ACS group and inadequate sedation and involuntary movement were occurred more frequently in the PCS group. CONCLUSIONS: PCS with propofol provided more effective sedation, but had more frequent delayedinduction time, inadequate sedation and incomplete amnesia than ACS.

Comparison of Midazolam-Ketamine with Midazolam for Sedation during Retrobulbar Block in Cataract Surgery / 대한마취과학회지

BACKGROUND: Many ophthalmic procedures can be performed using a retrobulbar regional anesthetic technique. However, retrobulbar block is painful and most of patients express anxiety about the procedure. In addition, several life-threatening complications may occur. We compared the effects of midazolam and midazolam-ketamine as a sedative during retrobulbar block in cataract surgery. METHODS: Thirty patients undergoing cataract surgery were randomly allocated into two groups, group I (n=15) was received midazolam and group II (n=15), midazolam-ketamine. Mean arterial pressure (MAP), heart rate (HR), and peripheral oxygen saturation (SpO2) were compared before administration of drugs and 1, 2, 3, 4, 5, 10, 20, and 30 min after administration of drugs. Patients' movement requiring restraint were also checked. In the recovery room, postoperative nausea and vomiting, recall, delirium and/or hallucinations, and ocular complications were recorded. RESULTS: There were no significant differences in MAP and SpO2 between groups but heart rates were significantly increased at 1, 2, 3, 4, and 5 min than baseline in group II. Movement score was significantly lower in Group II than in Group I during the block (p<0.05). Recall during performance of the nerve block occured more often in Group I than in Group II (p<0.05). CONCLUSION: Low-dose midazolam-ketamine sedation sequence was superior to a midazolam technique regarding patients' movement and recall.

Comparison of Intraoperative Patient-Controlled Sedation and Anesthesiologist-Controlled Sedation using Midazolam / 대한마취과학회지

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.