A Successful Tracheostomy under General Anesthesia with Blind Intubation via ILMA in a Sitting Position / 대한마취과학회지

The intubating laryngeal masK airway is a newly available device designed to allow for blind endotracheal intubation and treatment of patients with difficult airways. Emergency tracheostomies are required for oropharyngeal, hypopharyngeal, and laryngeal tumors acutely obstructing the airway. Patients with an airway obstructive tumor maintain their airway by a very active inspiratory effort in a sitting position. In these patients, it may be impossible to position them for a tracheostomy with shoulder extension. We report a case where a patient was tracheostomized successfully under general anesthesia with blind intubation via ILMA insertion in a sitting position.

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).

The Effects of 10% Lidocaine Spray on the Pharyngolarynx during the Endotracheal Intubation without Muscle Relaxants? / 대한마취과학회지

BACKGROUND: Tracheal intubation is usually carried out under a combination of general anesthesia and muscle relaxation. Recent sutdies have found satisfactory conditions for intubation of the trachea without using muscle relaxants. However, these studies have used large amounts of propofol or expensive opioids like alfentanil and remifentanil. In this study, we evaluated intubation conditions and success rate with midazolam, fentanyl, propofol and either 10% lidocaine applied topically into the larynx and trachea or not. METHODS: Forty patients of ASA class I or II were randomly allocated to one of two groups. All patients received glycopyrrolate 0.2 mg, midazolam 0.03 mg/kg and fentanyl 2 mcg/kg IV before induction of anesthesia and propofol 2 mg/kg IV for induction of anesthesia. Group I patients (n = 20) received 10% lidocaine into the larynx and trachea topically, and group II patients (n = 20) did not. After loss of the eyelid reflex, laryngoscopy and endotracheal intubation were attempted and airway conditions were graded. The success rate of intubation was evaluated. RESULTS: Intubation without a muscle relaxant was possible in 19 of 20 (95%) patients in group I and 8 of 20 (40%) patients in group II. There were no significant differences in scoring criteria for various airway conditions such as jaw tone, vocal cord exposure and cord position. CONCLUSIONS: Induction of anesthesia with midazolam 0.03 mg/kg, fentanyl 2 mcg/kg and propofol 2 mg/kg combined with 2 ml of 10% lidocaine spray into the larynx and trachea offered a satisfactory success rate of intubation without muscle relaxants.

Persistent Myoclonus after Propofol Anesthesia / 대한마취과학회지

There are a few case reports describing prolonged myoclonus following propofol. A previously fit 26 year old woman presented for a left knee lateral impingement under general anesthesia as a day case. She had no personal or family history of epilepsy. Induction was smooth and anesthesia was maintained with propofol TCI, nitrous oxide 65% and oxygen 35%. 30 minutes after stopping of the propofol infusion, the patient developed involuntary movement and shivering that recurred intermittently. After drug therapy and psychotic therapy the patient was progressively stabilized. However 4 hours later the patient developed involuntary movement and myoclonus. She was admitted to the department of neurology under the diagnosis of propriospinal myoclonus. Forty days later she was discharged without long term sequelae.

Patient-controlled Sedation and Analgesia in Patients Undergoing Cataract Surgery / 대한마취과학회지

BACKGROUND: Patient-controlled sedation with propofol has been shown to provide safe and effective sedation for patients undergoing surgery under local anesthesia. The purpose of this study was to evaluate the efficacy of patient-controlled sedation and analgesia with propofol and fentanyl in 17 patients undergoing cataract surgery. METHODS: An admixture of 400 mg of propofol with 100microgram of fentanyl (42 ml) was loaded into a patient-controlled analgesia pump and administered at a rate of 10 ml/hr. The lock-out time was 1 minute and the bolus dose was 1 ml. At the end of surgery, pain relief, anxiety relief and the satisfaction score were recorded on a patient questionnaire with a 1 to 10 scale. RESULTS: The sedation level varied from patient to patient and there was no incidence of oversedation. Most patients were satisfied with this anxiety and pain relieving technique (more than a score of 8). Blood pressure and arterial oxygen saturation showed minimal changes and remained within normal ranges. There were no complications except complaints of pain at infusion sites from 3 patients. CONCLUSIONS: Patient-controlled sedation and analgesia is a safe and satisfactory method for most patients undergoing cataract surgery for relieving pain and anxiety.

Optimal Dosage of Propofol for Prevention of Increase in IOP during Rapid Sequence Induction with Endotracheal Intubation / 대한마취과학회지

BACKGROUND: Operations for patients with eye injuries frequently require rapid sequence induction of general anesthesia with succinylcholine (Sch), but Sch as well as endotracheal intubation produce increases in intraocular pressure (IOP). The purpose of this study was to examine whether the increase in dosage of propofol from a usual dosage would prevent the increase in IOP due to endotracheal intubation with Sch during a rapid sequence induction of general anesthesia. METHODS: Changes in IOP were measured in three groups of 15 patients each. The patients randomly received thiopental 5 mg/kg (group 1, n = 15), propofol 2.5 mg/kg (group 2, n = 15) or propofol 3.0 mg/kg (group 3, n = 15), followed by Sch 1.0 mg/kg and endotracheal intubation. IOP, systolic arterial pressure (SAP) and heart rate (HR) were measured before induction (baseline), just after intubation, 3 minutes and 10 minutes after intubation. RESULTS: IOP and SAP just after intubaton in groups 1 and 2 increased significantly from baseline, but did not increase significantly from baseline in group 3. IOP and SAP at 3 minutes after intubation in group 1 did not decrease significantly from baseline, but decreased significantly from baseline in groups 2 and 3. IOP and SAP at 10 minutes after intubaton in all groups decreased significantly from baseline. HR just after intubaton in groups 1 and 2 increased significantly from baseline, but did not increase significantly from baseline in group 3. HR at 3 minutes and 10 minutes after intubation in all groups did not change significantly from baseline. CONCLUSIONS: The authors concluded that propofol 3.0 mg/kg could prevent the increase in IOP, systolic arterial pressure and heart rate just after intubation during a rapid sequence induction of general anesthesia.

Valuability of Propofol as Anesthetics and Effect of Hypercarbia on Awakening after Propofol TCI during Laparoscopic Cholecystectomy / 대한마취과학회지

BACKGROUND: It used to induce hypercarbia that carbon dioxide insufflated into the peritoneum in laparoscopic surgery. It might stimulate sympathetic nervous system, and decrease splanchnic circulation, hepatic function, and metabolism of anesthetics. The purpose of the present study was to examine the influence of hypercarbia on concentrations of propofol at the time of eye opening and recovery of orientation after propofol target controlled infusion (TCI) during a laparoscopic cholecystectomy. METHODS: Fifty patients were divided randomly into a laparoscopic group (group 1, n = 25) and an exploratory group (group 2, n = 25). A propofol infusion was started at a propofol target concentration of 6microgram/ml, and anesthesia was maintained at 4microgram/ml by using a Diprifusor (TM) turing the operation, intraabdominal pressure was maintained automatically at 12 14 mmHg by a CO2 insufflator and controlled ventilation settings were adjusted about 50 mmHg of PaCO2 after peritoneal insufflation. This ventilatory setting was not changed throughout the operation. We evaluated the estimated plasma concentrations of propofol at the time of eye opening and recovery of orientation in each group using user interface of a Diprifusor (TM). RESULTS: In the laparoscopic group, PaCO2, and PetCO2 increased significantly at 5, 15, 30 minutes after carbon dioxide insufflation, but there was no significant difference in concentrations of propofol at eye opening and orientation after propofol TCI between the two groups. CONCLUSIONS: Hypercarbia induced by insufflation of carbon dioxide into peritoneum didn't give rise to an influence on awakening concentrations after propofol TCI during a laparoscopic cholecystectomy.

The Efficacy of Patient-Controlled Sedation and Analgesia in Patients Undergoing Endoscopic Sinus Surgery / 대한마취과학회지

BACKGROUND: Patients receiving surgery under local anesthesia might feel anxiety during surgery and suffer pain due to the insufficiency of local anesthesia. The purpose of this study was to evaluate the efficacy and side effects of patient-controlled sedation and analgesia in patients undergoing endoscopic sinus surgery (ESS). METHODS: We studied 63 adult patients. A mixture of 400 mg of propofol and 200microgram of fentanyl (total 44 ml) was infused to the patient at a rate of 10 ml/hr using a PCA device. The lock-out time was 1 minute and the bolus dose was 1 ml. During surgery, we monitored vital signs and sedation state. At the end of surgery, we assessed the degree of satisfaction about pain and anxiety relieving effects by using a questionnaire with a 1 to 10 scale. RESULTS: About 90% of patients were wide awake during surgery, others were drowsy or intermittently sleeping. About 95% of the patients were satisfied with anxiety relief (more than a score of 8) and 84% were satisfied with pain relief in painful episodes (more than a score of 8). Vital signs were within normal limits. The oxygen saturation was maintained above 94% during surgery, except three patients whose oxygen saturation was 92% for short while. Twenty-two percent of the patients complained of pain at their drug infusion sites. CONCLUSIONS: We concluded that patient-controlled sedation and analgesia using the mixture of fentanyl and propofol might be a good way to relieve patient's anxiety and pain without respiratory depression and excessive sedation for those undergoing ESS under local anesthesia.

Comparison of Poloxamer-407 to Soybean Oil as an Emulsifying Agent for Propofol: Histamine Release and Plasma Lipid Levels / 대한마취과학회지

BACKGROUND: To reduce side effects (hyperlipidemia, pain on injection, etc.) of the present formation of propofol, many attempts to change the emulsifying agent for propofol have been tried. This study was designed to examine the poloxamer-407 as an emulsifying agent for propofol compared to soybean oil regarding histamine release and plasma lipid levels. METHODS: Twelve Beagle dogs weighing 12 - 16 kg were randomly assigned to one of two groups according to the formulation of propofol. Group 1 received Diprivan propofol 1% (AstraZeneca Co. UK), and group 2 received poloxamer-407 formulated propofol by a continuous intravenous infusion at 30 mg/kg/h for 3 hours. Three, 6, 9 and 12 hours after discontinuing the propofol infusion, venous blood samples from the cranial tibial vein were analysed by an ELISA kit for the histamine level. Also, blood lipid levels were checked 3 hours after the infusion and blood propofol concentration were checked every hour during the infusion. RESULTS: Group 2 showed significantly less histamine release than group 1 at 3, 6 and 9 hours after the infusion (P < 0.05). In the plasma lipid study, there was no difference in high-density lipoprotein (HDL) between the two groups, but triglyceride and cholesterol were significantly higher in group 2 (P < 0.05). There was no difference in propofol concentrations between the two groups. CONCLUSIONS: Poloxamer-407 as an emulsifying agent for propofol showed no advantage compared to a present formulation regarding hyperlipidemia, and even decreased the histamine level.

Monitoring of Anesthetic Depth by BIS & Anemon Monitor / 대한마취과학회지

BACKGROUND: Monitoring of "Depth of anesthesia" is an ongoing problem in anaesthesia. In this study, the author has compared the bispectral index (BIS) and Anemon monitor for monitoring depth of anesthesia in propofol or isoflurane anesthesia. METHODS: Anemon-1 and BIS index were obtained from 24 patients (ASA I, II) during general anesthesia with propofol or isoflurane. For patients in the propofol group, anesthesia was induced with fentanyl 100ng followed by propofol 2 mg/Kg. For patients in the isoflurane group, anesthesia was induced with thiopental 5 mg/Kg. The author observed changes of these values at 5 major times: before induction, during induction, after induction, at sKin incision, before extubation, after extubation. RESULTS: The anemon index showed a significant increase during induction (propofol group: 86.9 +/- 26.4, isoflurane group: 106.0 +/- 18.6) and at sKin incision (propofol group: 89.9 +/- 22.7, isoflurane group: 92.0 +/- 23.1), but this did not correlate with the level of consciousness. The BIS index showed a significant decrease in the score after induction (propofol group: 55.0 +/- 9.6, isoflurane group: 61.0 +/- 17.2), but no response to surgical stimuli. CONCLUSIONS: BIS had a good correlation with level of consciousness. The Anemon-1 index was recognized to reflect invasive stimulus. As the BIS and Anemon-1 had no correlation, it was not possible to assume changes of each index from the other. Both the anemon-1 index and BIS are useful to monitor the anesthesia level during surgery.

Preventive Effect of Lidocaine Pretreatment and Tourniquet Use on Propofol Injection Pain / 대한마취과학회지

BACKGROUND: Pain on injection of propofol is a common problem, the cause of which remains unKnown. We evaluated the optimum time of a tourniquet with intravenous lidocaine, to decrease the intensity of pain during intravenous propofol injection. METHODS: In 72 patients undergoing general anesthesia, we subdivided all patients into 4 groups. Patients in group 1 (n = 18) received propofol only (1 mg/Kg IV) without a tourniquet, patients in group 2 (n = 18) received 1% lidocaine 20 mg IV with an upper arm tourniquet inflated to 50 mmHg applied for 1 minute followed by propofol (1 mg/Kg IV). We applied a tourniquet to patients in group 3 (n = 18) and 4 (n = 18) for 3 minutes and 5 minutes respectively. The intensity of pain along the forearm was classified in 4 degrees (none, mild, moderate, severe) by the patients and the observer simultaneously. The mean arterial pressure and heart rate were recorded before injection and at the time when the patient complained of pain. RESULTS: All groups were similar in age, sex, weight and height. The group with the tourniquet applied for 5 minutes followed by a lidocaine injection showed the lowest intensity of pain. However, between the group with 3 minutes and 5 minutes, the difference of the pain score was not statistically significant. CONCLUSIONS: We conclude that intravenous lidocaine administered after a tourniquet has been inflated to 50 mmHg for 3 minutes before propofol injection attenuates profoundly the pain associated with intravenous propofol injection.

Effects of Propofol on Hypoxic Pulmonary Vasoconstriction after Pretreatment with L-NAME and Glibenclamide in Isolated Rat Lungs / 대한마취과학회지

BACKGROUND: It is generally accepted that propofol does not inhibit hypoxic pulmonary vasoconstriction (HPV). However, because the previous studies for the effects of propofol on HPV were established in vivo, the effects of physiologic variables could not be ruled out. Therefore, we investigated the effects of various concentrations of propofol on HPV at isolated rat lungs and the relationship of these effects of propofol on HPV and endothelium-derived relaxing factor (EDRF) and an ATP-dependent K+ channel which were candidates as the mechanism of HPV. METHODS: In 30 isolated rat lungs, after three hypoxic challenges for 5 minutes, we administered saline in the control group, N(G)-nitro-L-arginine methyl ester (L-NAME) in the L group and glibenclamide in the G group followed by three hypoxic challenges for 5 minutes. In addition, we studied the effects of various concentrations of propofol on HPV in the three groups. RESULTS: L-NAME and glibenclamide did not alter baseline pulmonary arterial pressure but L-NAME significantly enhanced HPV. Clinical concentrations of propofol did not affect HPV and high concentrations of propofol inhibited HPV. The pretreatment of L-NAME and glibenclamide did not alter the inhibition of HPV even at high concentrations of propofol. CONCLUSIONS: The EDRF and ATP-dependent K+ channel did not largely contribute to baseline pulmonary arterial tone but EDRF might be released and downregulate HPV. Clinical concentrations of propofol did not inhibit HPV but high concentrations of propofol inhibited HPV. In addition, the mechanism of inhibition of HPV at high concentrations of propofol did not relate to the EDRF pathway and ATP-dependent K+ channel.

Effects of Flow Rate and Dilution during Anesthesia Induction with Propofol / 대한마취과학회지

BACKGROUND: The Pharmacokinetic parameter and the degree of dilution can have an effect on induction time and vital signs during general anesthesia with propofol. Induction time, induction dose and vital signs according to various flow rates and the degrees of dilution during anesthesia induction with propofol were studied. METHODS: After institutional review board approval, and informed consent, One hundred and eighty ASA I or II adult patients undergoing elective surgery were assigned to one of four groups according to their degree of dilution. One group was undiluted and another 3 groups were diluted with 5% D/W (1:1, 1:2, 1:3). Each group was divided into 3 subgroups according to their flow rates of 25, 50, 100 mg/kg/hr. No premedication was given. With routine monitoring including radial arterial cannulation, propofol was infused using a syringe or infusion pump (Becton Dickinson pump, Franklin Lakes New Jersey, USA) in the previously designed manner. Induction time defined as loss of eyelash reflex, induction dose, and vital signs were checked. RESULTS: The faster the flow rate and the more diluted a drug, the shorter the induction time. The faster the flow rate and the less diluted a drug, the greater the induction dose. The more diluted a drug, the less the decrease in systolic blood pressure. Flow rate has little influenced decreasing systolic blood pressure. CONCLUSIONS: We concluded that it is reasonable to reduce flow rate and dilute propofol when the hemodynamic changes of the patient should be minimal during propofol based sedation/anesthesia.

Evaluation of Marsh's Pharmacokinetic Parameter Set for Target Controlled Infusion of Propofol in Korean / 대한마취과학회지

BACKGROUND: Marsh's pharmacokinetic parameter set is the most widely used parameter for target controlled infusion for propofol. However, Marsh's model was derived from a European population, and it is uncertain whether this model is accurate for Koreans. METHODS: Thirty ASA 1 or 2 adult patients undergoing orthopedic surgery participated in this study. Atropine 0.5 mg was injected for premedication. Anesthesia was induced by a TCI of propofol with a target concentration of 6 microgram/ml and maintained around 3 - 5 microgram/ml according to the bispectral index (35 - 45). In the middle of surgery, target concentrations were increased to 6 microgram/ml and maintained until effect site concentration was the same concentration. Three minutes after equilibration, 3 ml of blood was drawn from the radial artery and contralateral antecubital cephalic vein for measuring blood concentration using HPLC. Target concentrations were gradually decreased at the interval of 1 microgram/ml until the end of surgery and a blood sample was drawn as described in the method. A sample for every 1 microgram/ml was collected in the recovery room. Performance error of the predicted concentration of blood was calculated. RESULTS: The performance error was -12.86 - 16.55% for 1 - 6 microgram/ml of predicted concentration. Measured concentrations were higher than predicted at higher concentrations, but lower at lower concentrations. Measured cardiac output and arteriovenous concentration differences at 1 - 6 microgram/ml showed no difference. CONCLUSIONS: Marsh's pharmacokinetic model was accurate for propofol TCI in Koreans in terms of relatively low performance error (< 20%) in the concentration range of 1 - 6 microgram/ml.

Comparison of Thiopental Sodium and Propofol as an Induction Agent in Propofol-N2O Anesthesia for Cesarean Sections / 대한마취과학회지

BACKGROUND: We compared thiopental sodium with propofol as induction agents under propofol-N2O anesthesia for cesarean sections. METHODS: We selected 68 pregnant women with a single fetus undergoing an elective cesarean section under general anesthesia and randomly allocated them to the thiopental sodium group (group N) or the propofol group (group P). Without premedication, thiopental sodium 5 mg/kg and succinylcholine 1 mg/kg were injected for induction in group N, and propofol 2 mg/kg and succinylcholine 1 mg/kg in group P. Propofol 10 mg/kg/hr was infused continuously with 50% N2O in both groups. We checked the blood pressure and the heart rate before and after injection. We analysed blood gas of maternal artery, umbilical artery, and umbilical vein at delivery and checked Apgar scores at 1 minute and 5 minutes after delivery. RESULTS: There was no significant difference in blood pressure, heart rate and Apgar scores between groups. Oxygen partial pressure (35.6 +/- 5.8 mmHg) and oxygen saturation (66.2 +/- 12.0%) of the umbilical vein in group P was higher than in group N (32.7 +/- 4.9 mmHg, 58.7 +/- 11.5%). Carbon dioxide partial pressure and pH did not differ between groups. CONCLUSIONS: There was no beneficial effect of thiopental sodium compared with propofol as an induction agent under propofol anesthesia. Propofol is a useful drug for cesarean sections.

The Effects of Propofol Anesthesia or Prophylactic Droperidol on Postoperative Nausea and Vomiting in Patients Undergoing a Gynecologic Laparoscopy / 대한마취과학회지

BACKGROUND: Postoperative nausea and vomiting (PONV) is a common complication of a gynecologic laparoscopy. This study was designed to assess the effect of prophylactic droperidol 1 mg or propofol as the induction and maintenance anesthetic agent for prophylaxis of PONV in women undergoing a gynecologic laparoscopy. METHODS: Eighty ASA physical status 1, 2 patients undergoing an elective gynecologic laparoscopy were randomly allocated into four groups. Group 1 (n = 20) recieved an intravenous placebo of noraml saline 1 ml prior to induction of anesthesia and N2O-enflurane general anesthesia. Group 2 (n = 20) recieved an intravenous placebo of noraml saline 1 ml prior to induction of anesthesia and N2O-propofol general anesthesia. Group 3 (n = 20) recieved intravenous prophylactic droperidol 1 mg prior to induction of anesthesia and N2O-enflurane general anesthesia. Group 4 (n = 20) recieved intravenous prophylactic droperidol 1 mg prior to induction of anesthesia and N2O-propofol general anesthesia. RESULTS: The incidence and severity of PONV and sedation scores were assessed at 0, 30 min, 1, 3, 6, 24 and 48 hours postoperatively. The incidence of PONV was 75% in group 1, 10% in group 2, 30% in group 3 and 20% in group 4. The incidence of PONV during the first 6 hours postoperatively was 70% in group 1, 0% in group 2, 10% in group 3 and 5% in group 4 and there were no statistical differences among the four groups in the 6 to 24 hour postoperative period. Sedation scores were significantly higher in group 3 and 4 than in 1 and 2 in the 3 to 6 hour postoperative period. CONCLUSIONS: Propofol anesthesia, prophylactic droperidol 1 mg and a combination to prevent PONV were highly effective during the first 6 hours postoperatively.

Does Perioperative Monitoring of the Train-of-Four Response Influence the Frequency of Postoperative Residual Curarization in Propofol Anesthesia? / 대한마취과학회지

BACKGROUND: Sometimes hypoxemia occurs in the postoperative recovery room because of postoperative residual curarization (PORC). Some reports show that postoperative residual curarization is common. PORC occurs after the use of the long-acting muscle relaxants. It has been recommended to use intermediate-acting muscle relaxants and a TOF monitor to decrease PORC. The purpose of this study was to examine whether the use of the TOF monitor during propofol anesthesia affects the incidence of postoperative residual curarization. METHODS: 38 ASA I or II patients were divided randomly into two groups of 19 each. They received propofol-fentanyl-nitrous oxide for anesthesia. Pancuronium (80 100 microgram/kg) was used to facilitate tracheal intubation and additional doses were used to maintain surgical relaxation. The requirement for incremental doses of pancuronium and adequacy of recovery following reversal were assessed, either with (control group:n = 19) or without (experimental group:n = 19) TOF monitoring. Fifteen minutes after the arrival at the recovery room, neuromuscular function was assessed clinically and by using TOF. RESULTS: There were no statistical differences in body weight, age, or duration of operation between the two groups. There was no statistical difference in the total dose of pancuronium and total dose of pancuronium relative to body weight and duration of operation. There were statistical differences in TOF ratio in the recovery room (0.73 vs. 0.86). The incidence of PORC was 47% in the control group and 5% in the experimental group. CONCLUSIONS: Though the monitoring of TOF did not effect the dose of muscle relaxant, it may have reduced the incidence of PORC. However, the PORC had no clinical significance because the mean TOF ratio in the two groups was over 0.7 and there were no clinical signs of residual muscle weakness.

The Cerebral Oxygen Extraction Ratio during Propofol and Isoflurane Anesthesia / 대한마취과학회지

BACKGROUND: The cerebral vascular response to CO2 has been reported to be preserved during isoflurane and propofol anesthesia. This study compared the cerebral oxygen extraction ratio during normoventilation versus hyperventilation in propofol anesthesia and isoflurane anesthesia. METHODS: 28 patients undergoing cerebral aneurysmal surgery were studied following informed consent. In the isoflurane group (n = 14), anesthesia was induced with thiopental 5 mg/kg, and maintained with isoflurane and nitrous oxide (N2O) in oxygen (FiO2 0.33). In the propofol group (n = 14), anesthesia was induced with propofol 2 mg/kg, and maintained by infusion of propofol and N2O-O2 (FiO2 0.33). Monitoring included measurement of mean arterial blood pressure, heart rate, body temperature, end-tidal CO2 (PetCO2), jugular bulb O2 saturation (SjO2) and arterial O2 saturation (SaO2). Mechanical ventilation was adjusted to achieve PetCO2 levels of 40 and 25 mmHg. Ten minutes of equilibration were allowed at each PetCO2 level. Blood was sampled from the jugular bulb and radial artery at each PetCO2 level (40 and 25 mmHg). The cerebral oxygen extraction ratio was calculated as (CaO2 CjO2) / CaO2 (CaO2; arterial oxygen content, CjO2; jugular bulb oxygen content). RESULTS: The cerebral oxygen extraction ratio was higher in hyperventilation (PetCO2 25 mmHg) compared to normoventilation (PetCO2 40 mmHg) in each group (P < 0.05) and higher in the propofol group compared to the isoflurane group (P < 0.05). CONCLUSIONS: The increased cerebral oxygen extraction ratio in hyperventilation during both isoflurane and propofol anesthesia showed that cerebral vascular CO2 reactivity was maintained during both isoflurane anesthesia and propofol anesthesia. The cerebral oxygen extraction ratio was higher during propofol anesthesia compared to isoflurane anesthesia in both normoventilation and hyperventilation, therefore this data showed that cerebral blood flow was lower during propofol anesthesia compared to isoflurane anesthesia.

The Effect of Propofol Pretreatment on the Focal Ischemic Injury of Brain in the Rat / 대한마취과학회지

BACKGROUND: Propofol is widely used in neurosurgical anesthesia as an intravenous anesthetic agent. There have been some reports on the protective effects of propofol in cerebral ischemia. However conflicting results also exist. This study was designed to test the hypothesis that propofol pretreatment would provide protective effect on the focal cerebral ischemia-reperfusion injury. METHODS: Thirty Sprague-Dawley rats were divided into two groups; 15 for a halothane group, 15 for a propofol group. After induction of anesthesia with halothane in 100% oxygen, the tracheas were intubated and mechanical ventilation was maintained. For the entire experimental period normocapnia was maintained and scalp temperature was maintained in the range of 37 - 37.5oC. In the propofol group, propofol was infused at the rate of 2 mg/kg/min for 30 min without halothane administration prior to the ischemic period. In the halothane group, propofol was not infused. The left middle cerebral artery was occluded for 90 minutes with an intraluminal monofilament. After ischemia, perfusion was restored and rats were awakened. After 24 hours, the brain was removed and sectioned coronally and immersed in the 2% 2,3,5-triphenyltetrazolium choride solution. Percent mean infarcted area was calculated and compared between groups by Wilcoxon rank sum test. RESULTS: The percent infarcted area of halothane and propofol groups was 18.8 +/- 19.2% and 15.7 +/- 16.4%, respectively. There was no difference between groups in the aspect of percent infarcted area and physiologic variables such as mean arterial pressure, scalp temperature and serum glucose concentration. CONCLUSIONS: The pretreatment of propofol does not produce protective effect on focal cerebral ischemia compared with treatment with halothane.

The Comparison of Propofol, Isoflurane and Enflurane Anesthesia on Recovery in Day Surgery / 대한마취과학회지

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) is expected to provide fast and comfortable recovery, plus an early return to normal daily activities. This study was carried out to compare the characteristics of recovery after VATS in patients anesthetized with isoflurane, enflurane or propofol. METHODS: Sixty patients undergoing VATS were allocated randomly to receive propofol-N2O, isoflurane-N2O or enflurane-N2O anesthesia. The time between the end of anesthesia and extubation were compared. The orientation, cooperation and degree of sedation in Numeric Rating Scale (NRS) were recorded 5, 10, 30 and 60 min after anesthesia. Recovery was also evaluated by the P-deletion test (PDT) and Digit Symbol Substitution test (DSST) 30, 60 and 120 min after anesthesia for the comparison of the recovery of cognitive and psychomotor function. RESULTS: Early recovery was significantly (P < 0.05) faster in the propofol group (orientation, cooperation and degree of sedation in 10 min) when compared to the isoflurane and enflurane groups, but there was no significant difference in the other parameters of recovery. CONCLUSIONS: The authors concluded that although propofol was associated with faster emergence from anesthesia than enflurane and isoflurane after VATS, recovery of cognitive and psychomotor function were similar in the three anesthetic groups.