Conscious Sedation Using a Patient-Controlled Sedation Technique / 대한마취과학회지

BACKGROUND: Patient-controlled sedation (PCS) involves the patient self administering the sedative agent to the point at which he or she is satisfied with the level of sedation with the advantage to overcome the pharmacodynamic differences between individual patients. We compared three different bolus dosages of propofol for providing effective and safe sedation during PCS. METHODS: Sixty patients underwent spinal anesthesia with 0.5% hyperbaric bupivacaine 12-18 mg or a brachial plexus block with 1% mepivacaine 40 ml. These patients were allowed to self-administer a propofol bolus dose of either 4 mg (P4 group), 10 mg (P10 group), or 20 mg (P20 group) at a time to the point of the patient's satisfaction with the level of sedation. Infusion rate, BIS (bispectral index), SpO2, duration of induction and recovery, recall of operative procedure and patient's satisfaction were checked. RESULTS: The mean (range) infusion rate (ug/kg/min) was not significantly different among the groups: P4 group, 24.2 (14.3 - 69.7); P10 group, 26.4 (19.4 - 72.1); and P20 group, 30.4 (21.4 - 89.1). Duration of induction was significantly extended in the P4 (14.1 min) and P10 group (12.9 min) as compared with the P20 group (6.0 min). The mean value of the OAA/S (observer's assessment of alertness/sedation) scale and BIS and the numbers of recall were significantly lower in the P20 group than the other groups (p < 0.05). Inadequate sedation and involuntary movement occurred more frequently in the P4 and P10 group than the P20 group, and the numbers of satisfaction were higher in the P20 group than the other groups. CONCLUSIONS: 20 mg of propofol as a PCS bolus dose provided more effective sedation than 4 mg or 10 mg. When we use 4 mg or 10 mg of propofol as a bolus dose, we may want to consider combining if with other sedatives or analgesics (midazolam, ketamine, fentanyl).

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.

Pain Management for the Cancer Pain by Continuous Intravenous Infusion of Ketamine: A case report / 대한마취과학회지

Although a major portion of terminal cancer patients have appealed pain, the management of their pains is not easy. We managed two terminal cancer patients. One subject was a 86-year-old female who, after pronounced lung cancer, suffered from shoulder pain. The other was a 28-year-old female who, after being subject to pronounced acute lymphocytic leukemia, suffered from hip joint and thigh pain. In our practice, their pain, which had not been controlled by various other sophisticated management strategies, was effectively alleviated by a continuous intravenous infusion of ketamine, a N-methyl-D-aspartic acid receptor antagonist. The initial dose was administered intramuscularly by injecting 10 mg. of ketamine into the patients and then an intravenous infusion was administered at the rate of 0.06 mg/kg/hr. After the continuous infusion of ketamine was initiated, the VAS decreased, respectively, from 9 and 10 to 4 and 3, without considerable side effects. In conclusion, intravenous infusion at the level of sub-anesthetic dose of ketamine is a good management to control totally bed-conditioned and intactable cancer pain.

The Effects of Doxapram on the Pulmonary Function during Total Intravenous Anesthesia with Propofol According to Nalbuphine Pretreatment / 대한마취과학회지

BACKGROUND: Total intravenous anesthesia with propofol can cause respiratory depression and apnea especially during induction of anesthesia. To study the possibility of reversal of respiratory depression during anesthesia with propofol, pretreated with nabuphine or not, the respiratory effects of doxapram to spontaneously ventilating patients were investigated. METHODS: Patients were divided into 4 groups - saline-propofol-saline group (SPS), saline-propofol- doxapram group (SPD), nalbuphine-propofol-saline group (NPS), and nalbuphine-propofol-doxapram group (NPD). After saline or nalbuphine pretreatment, anesthesia was induced with propofol and then doxapram or saline was intravenously injected. Apneic time interval, blood pressure, heart rate, respiratory rate, minute ventilation, end tidal CO2 partial pressure and oxygen saturation were measured in every minutes during induction of anesthesia. Percent changes of each values were compared. RESULTS: There is no differences in apneic time intervals in each groups. The percent change of first minute ventilation in SPD group after doxapram injection unchanged significantly compared with those depressions of SPS, NPS and NPD group (p<0.05). Respiratory rates increased in SPD and SPS groups after laryngeal mask insertion. There is no differences in minute ventilation, respiratory rate and end-tidal CO2 concentration between nalbuphine pretreated groups regardless of doxapram injection. CONCLUSIONS: Doxapram has effect in increasing minute ventilation after propofol induction within first few minutes, but it cannot reverse respiratory depression during propofol induction pretreated with nalbuphine.

Continuous Intravenous Infusion of Propofol and Succinylcholine Supplemented with Nitrous Oxide in Short Duration of Microlaryngeal Surgery Comparison with Thiopental/Enflurane-N2O and Succinylcholine Infusion / 대한마취과학회지

BACKGROUND: Anesthetic technique for laryngeal microscopic surgery should be focused on rapid recovery of deep anesthesia and full muscle relaxation. This study was taken to evaluate the effect of continuous infusion of propofol and succinylcholine for this kind of anesthetic goal. METHODS: Forty patients scheduled for laryngeal microscopic surgery of short duration(15 min) were randomly allocated into two groups. Anesthesia was induced and maintained with either propofol(2.5 mg/kg followed by a continuous infusion of 0.1 mg/kg/min) in group P or with thiopental (5.0 mg/kg) and inhalation of 1~2 vol % enflurane for maintenance of anesthesia in group T/E. Succinylcholine(1 mg/kg followed by continuous infusion of 0.1 mg/kg/min) was administered to facilitate tracheal intubation and maintain neuromuscular blockade. RESULTS: No significant difference of duration of anesthesia appeared between two groups. Additional doses of succinylcholine were needed in 10% of group P and 30% of group T/E (p<0.05). In group P, time to response to suction catheter(136+/-54 vs 232+/-116 sec), time to eye open spontaneously or to verbal commands (368+/-142 vs 549+/-165 sec) and time to extubation (454+/-117 vs 647+/-181 sec) were significantly shorter comparing to group T/E. The quality of awakening was more favorable in group P(p<0.05). Laryngeal suspension induced bradycardia in 15% of group P and in 5% of group T/E. Both group P and group T/E (10% vs 30%) needed esmolol infusion to control the blood pressure during surgical procedure. CONCLUSIONS: Rapid recovery of anesthesia and muscle relaxation can be expected after continuous infusion of propofol(2.5 mg/kg followed by 0.1mg/kg/min) and succinylcholine(1 mg/kg followed by 0.1 mg/kg/min) supplemented with 50% N2O in 50% O2 for short duration of laryngeal microscopic surgery.