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BACKGROUND Unilateral pulmonary hemorrhage is typically reported in young and healthy men with upper respiratory tract obstruction during anesthesia in special situations. Negative pressure in the lungs is created, resulting in negative pressure pulmonary edema (NPPE). CASE SUMMARY A 78-year-old male patient diagnosed with spinal stenosis was admitted to receive a unilateral laminectomy with bilateral decompression. The patient had been diagnosed with hypertension four years earlier and asthma more than 70 years earlier. We experienced a unilateral alveolar hemorrhage associated with NPPE that occurred in a longstanding asthma patient who bit the intubated endotracheal tube for a short period during posture change at the end of surgery. Because diffuse alveolar hemorrhage accompanied by NPPE was caused in this case by airway obstruction in an older patient with asthma without known risk factors, anesthesiologists should be careful not to induce airway irritation during anesthesia awakening in asthma patients. CONCLUSION Because diffuse alveolar hemorrhage accompanied by NPPE can occur, anesthesiologists should take care not to induce airway irritation.

Purpose Currently, there is no clear evidence to support any specific treatment as a principal therapy for stage IV gastric cancer outlet obstruction (GCOO) patients. This study evaluated the outcomes of palliative gastrectomies and survival prognostic factors in patients with stage IV resectable GCOO. Materials and methods We retrospectively reviewed the medical records of 48 stage IV GCOO patients who underwent palliative gastrectomies between June 2010 and December 2019. Palliative gastrectomies were performed only in patients with resectable disease. Early surgical outcomes and prognostic factors were analyzed using univariate and multivariate analyses. Results There were no specific risk factors for postoperative complications, except for being underweight. Severe postoperative complications developed in five patients, and most of the patients underwent interventional procedures and received broad-spectrum antibiotics for intra-abdominal abscesses. The multivariate survival analysis showed that palliative chemotherapy is a positive prognostic factor, while the specific type of hematogenous and lymphatic metastasis is a negative prognostic factor. Conclusions We recommend that the treatment method for stage IV GCOO should be selected according to each patient's physical condition and tumor characteristics. In addition, we suggest that palliative gastrectomies can be performed in stage IV resectable GCOO patients without unfavorable prognostic factors (types of hematogenous and lymphatic metastases).

Background: The Flo-TracTM/Vigileo system (Edwards Lifesciences, Irvine, CA, USA) can be used to estimate cardiac output and stroke volume variation for giant abdominal aortic aneurysm (AAA). Case Presentation: A 60-year-old male patient presented with a thrombosed abdominal aortic aneurysm approximately 8.8 x 8.4 cm in size. The patient was scheduled to undergo open repair. The left radial artery was punctured to monitor direct arterial pressure, stroke volume, cardiac output, and SVV. A Flo-TracTM sensor (Edwards Lifesciences, Irvine, CA, USA) was connected to the arterial monitor system. The aneurysm was opened and longitudinally incised. A total of 600 ml of blood in the aneurysm was drained, and mural thrombi were removed. The graft was proximally anastomosed to the pararenal abdominal aorta. The distal potion of the graft was anastomosed to the iliac bifurcation. The clamping time was 62 min. The CO and SVV measured by the Flo-TracTM sensor were 4.2 L/min and 8%, respectively. Conclusions: We report a case of giant AAA where intravascular volume control was obtained by CO and SVV, which were monitored by a Flo-TracTM/Vigileo system.

Background: Complex regional pain syndrome is a disease characterized by chronic pain caused by tissue damage and worsens over time. The quality of randomized controlled trials on complex regional pain syndrome is low due to the rarity of the disease and difficulty in designing studies. Therefore, we evaluated the completeness of evidence by assessing the quality. Methods: We searched articles that were published between 1998 and 2017. The quality was assessed using the Jadad scale, van Tulder scale, and the Cochrane collaboration risk of bias tool.Results: A total of 72 articles on complex regional pain syndrome have been published. Only 31 articles were found to have a low risk of bias according to the Cochrane Collaboration. On the Jadad and van Tulder scale, 52 and 58 articles, respectively, were assessed as high quality. Only a few trials described the randomization method adequately and presented allocation concealment correctly. We also found that research trials with funding statements had higher Jadad scales than unfunded (P = 0.03). Furthermore, articles that described the sample size were of significantly higher quality (P < 0.01) than those that did not. Conclusions: There was no observed improvement in quality over time. In particular, the performance rate of the allocation concealment for the analyzed papers was low. In addition, we found that the number of high-quality articles increased when institutional review board approval was granted and funding provided. For the future, we recommend that researchers focus their efforts on conducting high-quality studies.

Programmed death ligand 1 (PD-L1) expression has been associated with clinical outcome of programmed death 1 (PD-1) pathway blockade in non-small cell lung cancer (NSCLC). PD-L1 is highly expressed in approximately 30% of patients without EGFR mutation or ALK rearrangement in previous trials. The objective of this study was to determine the frequency of PD-L1 expression and the clinical outcome according to PD-L1 expression in lung adenocarcinomas harboring EGFR mutation and treated with tyrosine kinase inhibitors (TKIs). We retrospectively evaluated PD-L1 expression using 22C3 pharmDx assay in lung adenocarcinoma patients with EGFR mutations at two referral hospitals between January 2017 and June 2018. Samples were obtained from surgically resected tumors, small biopsy, or cytologic cell blocks. Of all 71 patients analyzed, 44 (58.7%) had PD-L1 tumor proportion score (TPS) of

Awareness with recall after general anesthesia is a relatively infrequent occurrence and this awareness is often associated with significant adverse psychological sequelae, including posttraumatic stress disorder. The occurrence of awareness is often the consequence of the light anesthetic techniques with using minor anesthetic agents. Because the locking lever of the Penlon Sigma Delta Anesthetic vaporizer (sevoflurane) was at the unlock position, disconnection happened between the anesthetic machine and the vaporizer (the Selectatec(R) vaporizing system). In our two cases, the inhalation agents were not supplied and awareness with recall was identified after surgery. We recommend to check the concentration of the inhalation agents by monitoring the concentration of using endtidal inhalation agents and to measure the hypnotic level of anesthesia via the bispectral index (BIS) and the auditory evoked potential (AEP). (Korean J Anesthesiol 2009; 56: 693~7)

Background: We hypothesized that pressure control ventilation allows a more even distribution in the lung and better maintenance of the mean airway pressure than is achieved with volume control ventilation. We try to compare the effect of pressure control ventilation (PC) with that of volume control ventilation without an end-inspiratory pause (VC) during one-lung ventilation (OLV) in an anesthetized, paralyzed patient for performing thoracopic bullectomy of the lung. Methods: We ventilated 20 patients with VC and PC after the insertion of a thoracoscope in continual order for, at least for 15 minutes, for each, VC and PC procedure. At the end of VC and PC, the respiratory mechanics, gasometrics, and hemodynamic parameters were measured and collected. Results: We found no significant differences between VC and PC except for the peak inspiratory airway pressure (PIP), the mean airway pressure and the arterial oxygen partial pressure (PaO2). The PIP was significantly decreased from 27.0 ± 6.0 cmH2O (VC) to 21.8 ± 5.4 cmH2O (PC). The mean airway pressure was significantly increased from 8.6 ± 1.6 cmH2O (VC) to 9.4 ± 2.0 cmH2O (PC), and the PaO2 was significantly increased from 252.9 ± 97.3 mmHg (VC) to 285.2 ± 103.8 mmHg (PC). Conclusions: If PC allows mechanical ventilation with the same tidal volume and respiratory rate as VC during OLV, then PC significantly increases the PaO2 but this is not clinically significant, and the PC significantly decreases the PIP, which induces barotrauma or volutrauma when the PIP is excessively high. (Korean J Anesthesiol 2009; 56: 492～6)

Background: During induction of general anesthesia, the intravenous injection of rocuronium is often associated with withdrawal movement of the arm due to pain, and this abrupt withdrawal may result in dislodgement of the venous catheter, injury, or inadequate injection of rocuronium. We performed this study to evaluate the 50 and 95% effective endtidal concentrations of sevoflurane (ET sev) for preventing rocuronium-induced withdrawal of the arm. Methods: We conducted a prospective double-blind study in 31 pediatric patients. After free flow of lactated Ringer’s IV fluid was confirmed, anesthesia was induced in the patients by using 2.5% thiopental sodium (4 mg/kg) and sevoflurane (4 vol%) with 6 L/min of oxygen. When the target ETsev was reached, preservative-free 1% lidocaine (1.5 mg/kg) was intravenously injected during manual venous occlusion and rocuronium (0.6 mg/kg) was injected after lidocaine injection under free-flow intravenous fluid. A nurse who was an investigator and was blinded to the ETsev injected the rocuroni um. The nurse evaluated the response. Results: Non-withdrawal movement was observed in 5 out of 11 patients with ETsev 3.0 vol% and in 5 out of 6 patients with ETsev 3.5 vol%. By Dixon’s up-and-down method, the 50% effective concentration (EC 50) of sevoflurane for nonwithdrawal movement at rocuronium injection was 3.1 ± 0.4 vol%. A logistic regression curve of the probability of nonwithdrawal movements showed that the 50% effective ETsev for abolishing withdrawal movement at rocuronium injec tion was 2.9 vol% (95% confidence interval [CI] 2.4 -3.8 vol%) and the 95% effective ETsev was 4.3 vol% (95% CI 3.6 -9.8 vol%). Conclusions: This study showed that the 50 and 95% effective ETsev that prevent withdrawal movement at rocuronium injection are 2.9 and 4.3 vol%, respectively. (Korean J Anesthesiol 2014; 66: 274-277)

Background: The relatively recently developed I-gel (Intersurgical Ltd., Workingham, England) is a supraglottic airway device designed for single-use that, unlike conventional LMAs, does not require an inflatable cuff. In addition, the I-gel, much like the Proseal LMA (PLMA), has a gastric drainage tube associated with an upper tube for decompression of the stomach, thereby avoiding acid reflux and decreasing the risk of pulmonary absorption. The purpose of this study was to compare PLMA and I-gel devices in patients undergoing gynecological laparoscopy based on sealing pressure before and during pneumoperitoneum, insertion time, and gas exchange. Methods: Following Institutional Review Board approval and written informed consent, 30 adult patients were randomly allocated to one of two groups (the PLMA or I-gel group). In each case, insertion time and number of attempts were recorded. After successful insertion, airway leak pressure was measured. Results: Successful insertion and mechanical ventilation with both supraglottic airway devices was achieved on the first attempt in all 30 patients, and there were no significant differences with respect to insertion time. Likewise, leak pressure did not vary significantly either between or within groups after CO2 insufflation. In addition, differences between leak volume and leak fraction between groups were not significant. Conclusions: The results of our study indicate that the I-gel is a reasonable alternative to the PLMA for controlled ventilation during laparoscopic gynecologic surgery. (Korean J Anesthesiol 2012; 63: 510-514)

Study Objective To determine the most suitable effect-site concentration of remifentanil during lightwand intubation when administered with a target-controlled infusion (TCI) of propofol at 4.0 μ g/mL without neuromuscular blockade. Design Prospective study using a modified Dixon's up-and-down method. Setting Operating room of an academic hospital. Patients 28 ASA physical status 1 and 2 patients, aged 18-65 years, scheduled for minor elective surgery. Interventions Anesthesia was induced by TCI propofol effect-site concentration to 4.0 μ g/mL, and the dose of remifentanil given to each patient was determined by the response of the previously tested patient using 0.2 ng/mL as a step size. The first patient was tested at a target effect-site concentration of 4.0 ng/mL of remifentanil. If intubation was successful, the remifentanil dose was decreased by 0.2 ng/mL; if it failed, the remifentanil dose was increased by 0.2 ng/mL. Successful intubation was defined as excellent or good intubating conditions. Measurements and Main Results The remifentanil effect-site concentration was measured. The optimal effect-site concentration of remifentanil for lightwand tracheal intubation during propofol induction using 2% propofol target effect-site concentration to 4 μ g/mL was 2.16 ± 0.19 ng/mL. From probit analysis, the effect-site concentration of remifentanil required for successful lightwand intubation in 50% (EC50) and 95% (EC95) of adults was 2.11 ng/mL (95% CI 1.16-2.37 ng/mL) and 2.44 ng/mL (95% CI 2.20-3.79 ng/mL), respectively. Conclusion A remifentanil effect-site concentration of 2.16 ± 0.19 ng/mL given before a propofol effect-site concentration of 4 μ g/mL allowed lightwand intubation without muscle relaxant.

Ⓡvideolaryngoscope is a new device for tracheal intubation that provides an improved view of the larynx. This study was performed to compare the Glidescope with the McGrath videolaryngoscope in terms of time to intubation (TTI) and number of attempts. Methods: Patients were randomly allocated to one of two groups, Glidescope or McGrath group, by using computergenerated numbers. Tracheal intubation was attempted by an anesthesiologist with extensive experience using these two devices. The operator recorded ease of visualization of glottic structures based on the classification described by Cormack and Lehane. Number of failures, number of attempts and their duration, total intubation time, and events during the whole procedure were recorded. The duration of one attempt was defined as the time elapsed between picking up the endotracheal tube and verification of tracheal intubation with visualization of three expiratory carbon dioxide waveforms. TTI was defined as the sum of the duration of all intubation attempts (as many as three), excluding preoxygenation procedures. Results: TTI was significantly shorter for the Glidescope Ⓡ compared to the McGrath Ⓡ laryngoscope (40.5 vs. 53.3 s, respectively, P < 0.05). However, glottic views obtained at intubation were similar between the two groups. Number of intubation attempts was not significantly different between the two groups (1.03 ± 0.19 vs 1.10 ± 0.32, respectively) (mean ± SD). Conclusions: Study results demonstrated that the Glidescope reduced total intubation time in comparison with the McGrath, in terms of TTI in patients with normal airways. (Korean J Anesthesiol 2011; 61: 19-23)

BACKGROUND: Several publications have reported the successful, safe use of Laryngeal Mask Airway (LMA)-Classic devices in patients undergoing laparoscopic surgery. However, there have been no studies that have examined the application of volume-controlled ventilation (VCV) or pressure-controlled ventilation (PCV) using a LMA during gynecological laparoscopy. The aim of this study is to compare how the VCV and PCV modes and using a LMA affect the pulmonary mechanics, the gas exchange and the cardiovascular responses in patients who are undergoing gynecological laparoscopy. METHODS: Sixty female patients were randomly allocated to one of two groups, (the VCV or PCV groups). In the VCV group, baseline ventilation of the lung was performed with volume-controlled ventilation and a tidal volume of 10 ml/kg ideal body weight (IBW). In the PCV group, baseline ventilation of the lung using pressure-controlled ventilation was initiated with a peak airway pressure that provided a tidal volume of 10 ml/kg IBW and an upper limit of 35 cmH(2)O. The end-tidal CO(2), the peak airway pressures (P(peak)), the compliance, the airway resistance and the arterial oxygen saturation were recorded at T1: 5 minutes after insertion of the laryngeal airway, and at T2 and T3: 5 and 15 minutes, respectively, after CO(2) insufflation. RESULTS: The P(peak) at 5 minutes and 15 minutes after CO(2) insufflation were significantly increased compared to the baseline values in both groups. Also, at 5 minutes and 15 minutes after CO(2) insufflation, there were significant differences of the P(peak) between the two groups. The compliance decreased in both groups after creating the pneumopertoneim (P < 0.05). CONCLUSIONS: Our results demonstrate that PCV may be an effective method of ventilation during gynecological laparoscopy, and it ensures oxygenation while minimizing the increases of the peak airway pressure after CO(2) insufflation.

Background Reactive oxygen species (ROS) induce lipid peroxidation and tissue damage in endothelium. We studied the influences of ketorolac and diclofenac on ROS effects using the endothelium of rabbit abdominal aorta. Methods Isolated rabbit aortic rings were suspended in an organ bath filled with Krebs-Henseleit (K-H) solution bubbled with 5% CO2 and 95% O2 at 37.5℃. After being stimulated to contract with phenylephrine (PE, 10-6 M), changes in arterial tension were recorded following the cumulative administration of acetylcholine (ACh, 3 × 10-8 to 10-6 M). The percentages of ACh-induced relaxation of aortic rings before and after exposure to ROS, generated by electrolysis of K-H solution, were used as the control and experimental values, respectively. The aortic rings were pretreated with ketorolac or diclofenac at the same concentrations (10-5 M to 3 × 10-4 M), and the effects of these agents were compared with the effects of ROS scavengers: catalase, mannitol, sodium salicylate and deferoxamine and the catalase inhibitor, 3-amino-1,2,4-triazole (3AT). Results Both ketorolac and diclofenac maintained endothlium-dependent relaxation induced by ACh in a dose-related manner inspite of ROS attack (P < 0.05 vs. control value). The 3AT pretreated ketorolac (3 × 10-3 M) group was decreased more significantly than un-pretreated ketorolac (P < 0.05). Conclusions These findings suggest that ketorlac and diclofenac preserve the endothelium-dependent vasorelaxation against the attack of ROS, in a concentration-related manner. One of the endothelial protection mechanisms of ketorolac may be hydrogen peroxide scavenging.

BACKGROUND: The use of remifentanil before propofol administration facilitates the insertion of the Laryngeal Mask Airway. We designed the present study to determine whether remifentanil would also create more suitable conditions for providing Cobra Perilaryngeal airway (CobraPLA) insertion when administered with propofol. METHODS: Both remifentanil and propofol were given as effect-site target-controlled infusions. There were four groups of 25 patients each. The propofol effect-site concentration was set at 6 microg/mL in all groups. Group R1 received a target effect-site remifentanil concentration of 1 ng/mL, Group R2 received remifentanil at 2 ng/mL, Group R3 received remifentanil at 3 ng/mL, and Group R4 received remifentanil at 4 ng/mL before the induction of anesthesia with propofol. The ease of insertion of CobraPLA was graded by the following 3-point scale: Grade 1, excellent, no response to CobraPLA insertion; Grade 2, acceptable, gagging or swallowing with insertion of CobraPLA; Grade 3, poor, unable to open mouth or biting upon insertion of CobraPLA. RESULTS: The most patients ranked as excellent for the first CobraPLA insertion (Grade 1) were found in Group R4, which was significantly higher than Groups R1 and R2 (P < 0.01), whereas no significant difference was found when compared with Group R3. The duration of apnea showed a significant dose-related increase (P < 0.01), especially between Group R2 (median 2.95 min) and R3 (median 7.9 min), but there was no significant difference between Groups R3 and R4. The incidence of hypotension in Group R4 within 1 min after insertion of CobraPLA was significantly more than for Groups R1 and R2 (P < 0.01). No significant differences could be found between the incidence of hypotension between Group R3 and the other groups. The incidence of hypertension at 1 min postinsertion was significantly more common in Groups R1 and R2 than Groups R3 and R4 (P < 0.01). CONCLUSION: An effect-site concentration of remifentanil of 2 ng/mL provides excellent conditions for insertion of the CobraPLA on the first attempt with minimal hemodynamic perturbations and a shorter duration of apnea.

The GlideScope videolaryngoscope is widely used in the management of the difficult airway. However, passing the tracheal tube through the vocal cords can be awkward, and the use of a stylet to guide insertion is recommended. This randomised controlled trial evaluated a forceps-guided tube exchanger as an alternative to the stylet to aid intubation with the GlideScope in patients undergoing anaesthesia, with a simulated difficult airway created by the application of a semi-rigid cervical collar. Data were analysed from 178 patients randomly assigned to undergo intubation using either the stylet (n = 88) or a forceps-guided tube exchanger (n = 90). All intubations were completed successfully, with first attempt rates of 93.2% using the stylet and 94.4% using the exchanger (p = 0.597). The mean (SD) intubation time was 67.8 (28.7) s in the stylet group and 66.1 (15.5) s in the forceps-guided tube exchanger group (p = 0.11). The frequency of sore throat 1 h after extubation was 34.1% in the stylet group and 2.2% in the tube exchanger group (p < 0.001); 24 h after extubation the corresponding figures were 40.0% and 11.1% (p < 0.001). Using a forceps-guided tube exchanger may offer an advantage over a stylet in guiding tracheal intubation when the GlideScope is used.

Patients with chronic aortic regurgitation have a hemodynamically fragile equilibrium; increased afterload during infrarenal aortic cross-clamping and acute decompensation. The tolerance of patients with severe coronary artery disease to the stress of infrarenal aortic cross-clamping differs from patients without overt coronary artery disease. Therefore, careful anesthetic management is needed during infrarenal aortic cross-clamping in patients with aortic regurgitation and coronary artery disease. We describe the anesthetic management of a man with an infrarenal aortic aneurysm that underwent cardiac arrest after aortic-cross clamping for aortoiliac bypass surgery.

Background: Myoclonus is a common problem during induction of general anesthesia with etomidate. We investigated the optimal dosage of alfentanil pretreatment for prevention of myoclonus after injection of etomidate. Methods: In a double blinded fashion, 76 patients scheduled for outpatient elective surgery were randomized into 4 groups according to pretreatment drug: alfentanil 2.5μg/kg, alfentanil 5μg/kg, alfentanil 10μg/kg, or normal saline. The pretreatment was followed by etomidate 0.3 mg/kg IV. Laryngeal mask airway (LMA) was inserted at 5 minutes after the induction. The patients were observed for any myoclonic movement. Onset time, duration and intensity of myoclonus, side effects of alfentanil, mean arterial pressure and heart rate were measured during the study period. Results: There were significant differences in the incidence and intensity of myoclonus. An injection of 5, and 10μg/kg alfentanil before etomidate prevented increase of mean arterial pressure and heart rate after LMA insertion. But injection of 10 μg/kg alfentanil before etomidate appeared generalized muscle rigidity, bradycardia and hypotension. Conclusions: An injection of 2.5, 5, and 10μg/kg alfentanil before etomidate decreases the incidence and intensity of myoclonus. But injection of 10μg/kg alfentanil before etomidate appeared side effects. Therefore the optimal dosage of alfentanil pretreatment for prevention of myoclonus after injection of etomidate is 5μg/kg.

Background: The sniffing position is recommended for optimal glottic visualization under direct laryngoscopy. However, there is no study assessing whether sniffing position is superior to a neutral position during lightwand-guided intubation. This prospective, randomized study was performed to compare facilitation of lightwand-guided intubation between the sniffing and neutral positions. Methods: The study included 180 patients with normal cervical spines requiring tracheal intubation for elective surgery. Patients were randomly allocated into two groups: neutral or sniffing position. Mallampati class, mouth opening distance, thyromental distance, and laryngeal view grade were measured. A lightwand railroaded with an endotracheal tube was bent 90 o at 5 cm from the distal end for both groups. Time to intubation, success rate and intubation time for the first attempt, hydrodynamic changes, and BIS values were recorded. Results: There were no significant differences in time to intubation, success rate and intubation time of the first trial, hydrodynamic changes, or BIS values between the two positions. Conclusions: Routine use of the sniffing position does not provide any advantage over the neutral position during lightwand-guided intubation. (Korean J Anesthesiol 2008; 54: 25∼9)

Background: The Rhodes index of nausea, vomiting and retching (RINVR) is a reliable and valid instrument to assess PONV. The purpose of this study was to investigate the incidence of PONV in high risk group with using RINVR. Methods: Patients scheduled for elective surgery under general anesthesi a were classified in three groups (group I: two risk factors, group II: three risk factors, group III: four risk factors) by using a simplified risk score. We investigated the incidences of PONV in each group. Results: The incidence of PONV was 12.8% in group I, 25% in group II, and 33.1% in group III, which showed a significant difference between group I and group II, between group I and group III. The incidence of PONV, which was over moderate was significantly increased in group III. Conclusions: For patients with three or four risk factors a multimodal antiemetic strategy should be considered. (Korean J Anesthesiol 2008; 54: 278∼82)

Background: In the previous studies, remifentanil reduces the hemodynamic change induced by endotracheal intubation. We studied the optimal effect site concentration of remifentanil for endotracheal intubation using light wand. Methods: Sixty ASA 1 or 2 patients scheduled for elective surgery under general anesthesia were classified in three groups according to the TCI (target controlled infusion) dose of remifentanil. Each group was administered 4μg/ml of propofol TCI, rocuronium, with 2 ng/ml (group 1), 4 ng/ml (group 2), 6 ng/ml (group 3) of remifentanil TCI. Blood pressure, heart rate and bispectral index score were measured before induction, 3 minutes after remifentanil and propofol TCI, after endotracheal intubation using light wand, and 3 minutes after endotracheal intubation. Statistical analysis was done for comparison of time and dose dependant change among the groups. Results: After endotrachal intubation, blood pressure and heart rate were significantly increased in group 1, and decreased in group 2 and 3. 3 minute after endotracheal intubation, heart rate significantly decreased in group 3, but there were no changes in group 2. Conclusions: The spontaneous BRS was decreased during ketamine induction of general anesthesia. These results suggest that anesthesia induction with ketamine impairs baroreflex control of heart rate, which may provoke hemodynamic instability. (Korean J Anesthesiol 2007; 52: 278~83)

Background: Midazolam has a direct relaxing effect on vascular smooth muscle, but the mechanisms that this agent produces muscle relaxation are not fully understood. The current study was performed to identify the effects of the midazolam on K+ channels current in rabbit cerebral arterial smooth muscle cells. Methods: Whole cell patch-clamp recording technique was used to evaluate the effects of midazolam (0.1 to 100μM) on outward K+ channel currents in dispersed rabbit cerebral arterial smooth muscle cells. Results: Outward K+ currents of rabbit cerebral artery smooth muscle cells were voltage-dependent. Midazolam (10, 100μM) tested significantly inhibited outward K+ currents in a dose-dependent manner and half-blocking concentration (IC50) was 15.94μM at 60 mV. Conclusions: Midazolam inhibit outward K+ currents of rabbit cerebral arterial smooth muscle cells. Further study will be needed to determine the effect of midazolam on calcium channel current because it is unclear if the inhibitory effect of midazolam on outward K+current induces vasoconstriction. (Korean J Anesthesiol 2007; 52: 67～71)

Background: Currently, combined spinal-epidural anesthesia (CSE) is frequently administered, especially in obstetrics and orthopedic surgery. The aim of this study is to determine the appropriate concentration of bupivacaine to use with epidural volume extension that is suitable for total knee replacement during CSE. Methods: Eighty patients (ASA physical status I and II) scheduled for totalknee replacement were randomly allocated to four groups of 20 patients each: All patients intrathecally received 2 ml of 0.5% hyperbaric bupivacaine. After fixation of spinal anesthesia, the groups received the following treatments. Group S patients received a 10 ml administration of normal saline for 15 min followed by a continuous 10 ml/hr epidural infusion. Group B1 patients received a 10 ml administration of 0.125% bupivacaine for 15 min followed by a continuous 10 ml/hr epidural infusion. Group B2 patients received a 10 ml administration of 0.25% bupivacaine for 15 min followed by a continuous 10 ml/hr epidural infusion. Group B3 patients received a 10 ml administration of 0.5% bupivacaine for 15 min followed by a continuous 10 ml/hr epidural infusion. Results: The incidence of intraoperative movement in group S and group B1 patients were significantly greater than the incidence for group B2 and B3 patients. The incidence of intraoperative pain in group S patients was significantly greater than for patients in any of the other groups. Conclusions: We conclude that it is necessary to administer more than a 0.25% concentration of epidural bupivacaine load and provide continuous administration after a spinal block during total knee replacement. (Korean J Anesthesiol 2007; 53: 593～7)

Background: High monitors are patients who require information on anesthesia and surgery and generally carry out active searches. These patients will benefit from more information related to surgery preoperatively whereas low monitors will benefit from less detailed information. This study examined whether or not patients' desire for information related to anesthesia and surgery differ according to their coping style classified by the Amsterdam Preoperative Anxiety and Information Scale (APAIS). Methods: 465 patients were asked to fill out the questionnaires in APAIS, State-Trait anxiety inventory (STAI) and also to mark their perception on a 10 cm line in a visual analog scale (VAS). The APAIS with the other subjective measurements of anxiety were evaluated according to their gender, ASA class, past history of surgery and degree of education. Thirteen questionnaires were evaluated according to their coping styles. Results: High monitors wanted to know all 13 questions compared with low monitors, whereas low monitors preferred not to know (P ＜ 0.05). The APAIS has a significant relationship with the VAS and STAI (P ＜ 0.05). Women, patients with no prior history of surgery, and patients with ASA 2 were significantly more anxious than men, patients with a prior experience of surgery and ASA 1 patients, respectively (P ＜ 0.05). The VAS and APAIS were in good agreement in defining patients as anxious and there were significant correlations between the two instruments (P ＜ 0.05). Conclusions: The APAIS can be used as an efficient tool for identifying patients who are particularly anxious or require information.

Background: Pneumoperitoneum for a gynecologic laparoscopic surgery induces hemodynamic changes. We evaluated the effects of nicardipine on induction, maintenance, and recovery. Methods: Thirty patients scheduled for gynecologic laparoscopic surgery were randomly allocated to two groups: control group (placebo group, n = 15), group N (nicardipine group, 10g/kg followed by 0.5-2.0g/kg/min). The systolic arterial pressure, mean arterial pressure, and heart rate were measured at preinduction, induction, intubation and 5, 10, 15, 20 min after insufflation. Loss of consciousness, induction dose, effective site concentration, propofol maintenance dose (the maintenance dose of propofol from intubation to end of anesthesia, PMD) were also measured. Propofol was titrated to maintain a bispectal index value of 40-60. Results: There was a significant difference in PMD between two groups. The PMD of group N was significantaly less than group C. Nicardipine adminstration attenuated increase in the blood pressure, but did not affect on heart rates during insufflation. Conclusions: Co-administration of nicardipine was effective in attenuating the hemodynamic changes after pneumoperitoneum during gynecologic laparoscopic surgery, without changes of induction and recovery.

Background: Nitrous oxide is generally avoided in order to prevent either hypoxia or graft dislodgment during tympanoplasty. The aim of this study was to investigate the effect of nitrous oxide on the bispectral index during sevoflurane anesthesia at the anesthetic dose. Methods: The bispectral index was continually measured during nitrous oxide-oxygen-sevoflurane anesthesia, discontinuation of nitrous oxide and the reintroduction of nitrous oxide. Results: The bispectral index of nitrous oxide-oxygen-sevoflurane anesthesia increased after discontinuing the nitrous oxide and decreased after its reintroduction. Conclusions: Nitrous oxide decreased the bispectral index of nitrous oxide-oxygen-sevoflurane anesthesia compared with oxygen-sevoflurane anesthesia at the anesthetic dose.

Franks and Lieb found a K current that is activated by volatile general anesthetics in certain identified neurons of the pond snail Lymnea stagnalis in 1988. Perfusion of these neurons with halothane and isoflurane opened K channels, causing hyperpolarization and decreases in membrane resistances which in turn tended to inhibit neuronal electrical activity. But the targets to which volatile agents bind to open these channels were not determined. About a decade ago, a new family of resting K channels was discovered. These channels, known formally as the KCNK subfamily, contain four presumed transmembrane segments with two presumptive pore forming regions in tandem within their primary amino acid sequences. Currently, fourteen mammalian members of this family have been cloned and heterologously expressed. These background K channels have been implicated in various important physiological functions including mechano-, lipid-, acidand possibly oxygensensing in specialized cells. Recently, Patel et al reported that inhalational volatile anesthetics including chloroform, ether, halothane, and isoflurane modulate KCNK activity (KCNK2, KCNK3 and KCNK5) in transfected COS-7 and HEK-293 cells. These include TOK1, KCNK2 and KCNK3 and KCNK5. They suggested that KCNK2 and KCNK3 are critical mediators of the central actions of volatile general anesthetics, based on their hyperpolarizing actions. KCNK2 is an outward rectifier mechanosensitive K channel opened by membrane stretch, cell swelling and shear stress. Mechanical activation of KCNK2 is mimicked by polyunsaturated fatty acids such as arachidonic acid and by the anionic amphiThe Effect of Halothane and Isoflurane on KCNK2 Transfected HEK-293 Cells

Severe hypoxemia is considered by many to contraindicate major surgery. Several studies have shown that dependency on oxygen, PaO2 60 mmHg, 45 mmHg, FEV1 50%, and FVC 75% are indicative of a high risk of morbidity and mortality following major surgical procedures. Here, we report our experience of the use of regional anesthesia in such patients. One patient was a 82-year-old female patient who was scheduled for partial hip replacement due to a fracture of the right femur. Her pulmonary function test and preoperative arterial blood gas analysis results were as follows: FVC 1.23 L (49.1%), FEV1 1.11 L (61.3%), FEV1/FVC 90.2%, a room air pH 7.423, 43.0 mmHg, 46.4 mmHg, 84.5% and base excess 2.7 mM/L. Another patient was a 79-year-old COPD male patient scheduled for appendectomy. His immediate preoperative arterial blood gas analysis results were; room air pH 7.368, 62.1 mmHg, 43.8 mmHg, 77.4% and base excess 7.3 mM/L. Both patients underwent and tolerated surgery safely with regional anesthesia. No permanent sequela occured postoperatively in these cases. No severe changes in room air arterial blood gas levels were observed before and after surgery. We present a review of two cases of severe hypoxemia in which a regional block was used.

Background: We performed a prospective, randomized, controlled trial to compare the quality, hemodynamic response, and recovery index of laryngeal mask airway (LMA) insertion after either propofol alone or co-administration of alfentanil-propofol anesthesia. Methods: Sixty patients (ASA 1 or 2, 17-63 years) were randomly allocated to control and experimental group. Control group(Group I) was received placebo (saline), experimental groups were received alfentanil 10/kg (Group II), 20/kg (Group III), 30/kg (Group IV). Results: Loss of consciousness and LMA insertion were more rapid in patients with alfentanil 30 /kg group than control group (P＜ 0.05). In alfentanil 20/kg group, loss of consciousness was more rapid than control group. Also, there were significant differences in propofol induction dose, effect site concentration on induction, and propofol maintenance dose between control and experimental group (P＜ 0.05). Conclusions: We conclude that co-adminstration of alfentanil-propofol, especially 30/kg group, compares favorably with propofol alone, although LMA removal time is prolonged.

Background: Pulmonary vasoconstriction greatly contibutes to the elevated pulmonary vascular resistance in patients with pulmonary hypertension. A rise in cytosolic concentration in pulmonary arterial smooth muscle cells (PASMCs) is a major trigger for pulmonary vasoconstriction. Presently, little is known about the nature of the store-operated channels (SOCs) in PASMCs, even though store depletion-mediated capacitative entry (CCE) is a critical mechanism for refilling the empty sarcoplasmic reticulum (SR) with , and for maintaining a sustained increase in cyt. The goal of this in vitro study was to investigate the effects of nickel and manganese on store-operated channels in canine PASMCs. Methods: Isolated PASMCs were obtained from an enzymatically treated canine pulmonary artery. Currents were recorded at room temperature using the dialyzed whole cell recording technique. The protocol used to deplete the intracellular stores and to monitor the development of the store-operated currents, involved voltage-clamping cells at 0 mV to inactivate any voltage-dependent calcium currents. Crrents were recorded in response to a 200 ms voltage step from 120 to 40 mV in 20 mV increments every 15 seconds. Results: Simultaneous depletion of intracellular leads to a voltage-independent and linear store-operated current () reversal near 0 mV. Nickel and manganese inhibit . Conclusions: In canine PASMCs, the depletion of intracellular stores leads to the activation of Isoc, which is inhibited by nickel and manganese. These metals are non-specific inhibitors of non-selective cation channels. Our results indicate that - and -sensitive pathways may mediate entry, or that a class of non-selective cation channels may contribute to CCE in canine PASMCs.

Background: Laryngoscopy and tracheal intubation are associated with hemodynamic pressor responses, which can have adverse effects. During anesthesia induction with propofol target-controlled infusion (TCI), we aimed to determine the most appropriate dosage of alfentanil required for intubation, using a steady effect-site concentration of propofol and with the use of vecuronium. Methods: Eighty ASA class 1 or 2 patients presenting for elective surgery were allocated at random to one of four groups. Anesthesia was induced in all patients with TCI of propofol target concentration 8/ml, followed by vecuronium (0.12 mg/kg). This was reduced to 5/ml when the effect-site concentration had been 4/ml. After the effect-site concentrations had reached to 5/ml, control group received normal saline, group 1 received alfentanil 10/kg, group 2 received alfentanil 20/kg, and group 3 received alfentanil 30/kg. Laryngoscopy and intubation were performed 90 s later. Heart rate was monitored continuously. Systolic blood pressure, diastolic blood pressure and mean arterial pressure were measured at pre-induction, post-induction (pre-intubation) and post-intubation, respectively. Complications such as hypotention and bradycardia were recorded until 5 minutes had elapsed after tracheal intubation. Results: Control group showed significant increases associated with tracheal intubation in all hemodynamic variables (P /kg constitutes the optimal dosage to obtund the hemodynamic responses to tracheal intubation, using propofol TCI (5/ml) and vecuronium for induction of anesthesia.

Background: The bispectral index (BIS) has been used as an indicator of a sedative state. In this study, we investigated the influence of intravenous clonidine 2 or 3/kg on the bispectral index and cardiovascular response to anesthetic induction. Methods: The study design is prospective, randomized and double-blind. Ninety patients scheduled to undergo elective surgery under general anesthesia were divided into 3 groups. Each group received no premedication (group 1, n = 30), clonidine 2/kg (group 2, n = 30) and clonidine 3/kg (group 3, n = 30). The sedation and responsiveness scores of the Modified Observer's Assessment of Alertness/Sedation Scale (MOAAS/S) were measured before induction and the BIS, blood pressure, and heart rate were measured at before induction, after propofol injection, and after intubation. Results: The BIS was significantly lower in groups 2 and 3 than in group 1 before anesthetic induction and intubation. Mean blood pressure was significantly lower in groups 2 and 3 than in group 1 before anesthetic induction, after propofol infusion and after intubation. Heart rate was also significantly lower in groups 2 and 3 than in group 1 after intubation. The sedation score and MOAAS/S were significantly lower in groups 2 and 3 than in group 1. Conclusions: Clonidine-premedicated patients appear to maintain stable hemodynamics during anesthetic induction and intubation. The bispectral index can be objectively used in clonidine-premedicated patients when evaluating the degree of sedation.

Background: Clonidine, an -adrenergic receptor agonist, has been shown to have a sedative effect and to suppress hemodynamics when used as a premedicant. We evaluated the change of AEP index and hemodynamics after clonidine premedication and induction with propofol. Methods: The study design was a prospective, randomized, double-blind study. 90 patients who were scheduled for elective surgery were randomly assigned in 3 groups (Group 1, 2 and 3). In groups 2 and 3, the patients were administered 2/kg or 4/kg of i.v. clonidine 30 minutes before the induction of propofol anesthesia, respectively. We measured A ARX index (AAI), systolic blood pressure, mean arterial pressure, diastolic blood pressure and heart rate at the ward; before the administration of clonidine premedication, before induction, just before intubation and 1 minute after endotracheal intubation, and compared these parameters among the 3 groups. Results: Each dose of clonidine had a suppressive effect before the induction of anesthesia and suppressed hemodynamics successfully during intubation. In groups 2 and 3, the AAI was lower than in group 1 (P ＜ 0.05), but 7 patients had bradycardia and 3 patients had been hypotensive in group 3. Conclusions: Intravenous injection of 2/kg clonidine as a premedicant reduced AAI significantly (P ＜ 0.05) compared to the control group, with good hemodynamic stability. Therefore, we believe that AAI can be used to predict hypnotic state during propofol anesthesia.

Background: Capacitive calcium entry involves the influx of across the sarcolemma in response to the depletion of intracellular stores. Presently, little is known about the nature of the intracellular store (s) in pulmonary arterial smooth muscle cells (PASMCs), even though the unique contractile response of this tissue to hypoxia may at least partially involve the intracellular release of . The authors aimed to investigate the effects of nicardipine on capacitative calcium entry. Methods: Isolated pulmonary smooth muscle cells were obtained from enzymatically treated canine pulmonary artery. Currents were recorded at room temperature using the dialyzed whole cell recording technique. The protocol used to deplete intracellular stores and to monitor the development of the store-operated currents, involved cells being were voltage-clamped at 0 mv to inactivate any voltage-dependent calcium currents, which were recorded in response to a 200 ms voltage step from 120 to 40 mV in 20 mV increments. Results: Simultaneous depletion of intracellular leads to linear store-operated current (ISOC) reversal near 0 mV. Nicardipine does not affect ISOC. Conclusions: In canine PASMCs, the depletion of intracellular stores leads to the activation of ISOC, which is not inhibited by nicardipine, a voltage-dependent channel (VDCC) blocker, indicating that VDCC blocked by nicardipine does not contribute to CCE in canine PASMCs.