Endotracheal intubation by inexperienced trainees using the Clarus Video System: learning curve and orodental trauma perspectives

BACKGROUND: The ideal alternative airway device should be intuitive to use, yielding proficiency after only a few trials. The Clarus Video System (CVS) is a novel optical stylet with a semi-rigid tip; however, the learning curve and associated orodental trauma are poorly understood. METHODS: Two novice practitioners with no CVS experience performed 30 intubations each. Each trial was divided into learning (first 10 intubations) and standard phases (remaining 20 intubations). Total time to achieve successful intubation, number of intubation attempts, ease of use, and orodental trauma were recorded. RESULTS: Intubation was successful in all patients. In 51 patients (85%), intubation was accomplished in the first attempt. Nine patients required two or three intubation attempts; six were with the first 10 patients. Learning and standard phases differed significantly in terms of success at first attempt, number of attempts, and intubation time (70% vs. 93%, 1.4 ± 0.7 vs. 1.1 ± 0.3, and 71.4 ± 92.3 s vs. 24.6 ± 21.9 s, respectively). The first five patients required longer intubation times than the subsequent five patients (106.8 ± 120.3 s vs. 36.0 ± 26.8 s); however, the number of attempts was similar. Sequential subgroups of five patients in the standard phase did not differ in the number of attempts or intubation time. Dental trauma, lip laceration, or mucosal bleeding were absent. CONCLUSIONS: Ten intubations are sufficient to learn CVS utilization properly without causing any orodental trauma. A relatively small number of experiences are required in the learning curve compared with other devices.

Dynamic optic nerve sheath diameter responses to short-term hyperventilation measured with sonography in patients under general anesthesia / 대한마취과학회지

BACKGROUND: Rapid evaluation and management of intracranial pressure (ICP) can help to early detection of increased ICP and improve postoperative outcomes in neurocritically-ill patients. Sonographic measurement of optic nerve sheath diameter (ONSD) is a non-invasive method of evaluating increased intracranial pressure at the bedside. In the present study, we hypothesized that sonographic ONSD, as a surrogate of ICP change, can be dynamically changed in response to carbon dioxide change using short-term hyperventilation. METHODS: Fourteen patients were enrolled. During general anesthesia, end-tidal carbon dioxide concentration (ETCO2) was decreased from 40 mmHg to 30 mmHg within 10 minutes. ONSD, which was monitored continuously in the single sonographic plane, was repeatedly measured at 1 and 5 minutes with ETCO2 40 mmHg (time-point 1 and 2) and measured again at 1 and 5 minutes with ETCO2 30 mmHg (time-point 3 and 4). RESULTS: The mean +/- standard deviation of ONSD sequentially measured at four time-points were 5.0 +/- 0.5, 5.0 +/- 0.4, 3.8 +/- 0.6, and 4.0 +/- 0.4 mm, respectively. ONSD was significantly decreased at time-point 3 and 4, compared with 1 and 2 (P < 0.001). CONCLUSIONS: The ONSD was rapidly changed in response to ETCO2. This finding may support that ONSD may be beneficial to close ICP monitoring in response to CO2 change.

Dynamic optic nerve sheath diameter responses to short-term hyperventilation measured with sonography in patients under general anesthesia / 대한마취과학회지

BACKGROUND: Rapid evaluation and management of intracranial pressure (ICP) can help to early detection of increased ICP and improve postoperative outcomes in neurocritically-ill patients. Sonographic measurement of optic nerve sheath diameter (ONSD) is a non-invasive method of evaluating increased intracranial pressure at the bedside. In the present study, we hypothesized that sonographic ONSD, as a surrogate of ICP change, can be dynamically changed in response to carbon dioxide change using short-term hyperventilation. METHODS: Fourteen patients were enrolled. During general anesthesia, end-tidal carbon dioxide concentration (ETCO2) was decreased from 40 mmHg to 30 mmHg within 10 minutes. ONSD, which was monitored continuously in the single sonographic plane, was repeatedly measured at 1 and 5 minutes with ETCO2 40 mmHg (time-point 1 and 2) and measured again at 1 and 5 minutes with ETCO2 30 mmHg (time-point 3 and 4). RESULTS: The mean +/- standard deviation of ONSD sequentially measured at four time-points were 5.0 +/- 0.5, 5.0 +/- 0.4, 3.8 +/- 0.6, and 4.0 +/- 0.4 mm, respectively. ONSD was significantly decreased at time-point 3 and 4, compared with 1 and 2 (P < 0.001). CONCLUSIONS: The ONSD was rapidly changed in response to ETCO2. This finding may support that ONSD may be beneficial to close ICP monitoring in response to CO2 change.

Transient adenosine-induced asystole in the surgical treatment of intracranial aneurysms: A report of two cases

Advances in anesthetic and surgical management, such as deep hypothermic circulatory arrest and temporary clipping, have improved outcomes for intracranial aneurysm patients. However, these techniques are associated with significant risks. We report on two cases in which adenosine administration was used to induce transient periods of cardiac asystole during intracranial aneurysm surgery. This asystole resulted in profound hypotension and collapse of the aneurysm, which facilitated its safe clipping.

Protective effects of propofol against hydrogen peroxide-induced oxidative stress in human kidney proximal tubular cells / 대한마취과학회지

BACKGROUND: We investigated the protective effects of propofol in the HK-2 cell line of human kidney proximal tubular cells against hydrogen peroxide (H2O2)-induced oxidative stress. METHODS: After pretreatment with different concentrations of propofol (0 microM, 10 microM, 25 microM and 50 microM) for 30 minutes, HK-2 cells were exposed to 8 mM H2O2 for 4 hours. Cell death was assessed by measuring the percentage of lactate dehydrogenase (LDH) release and by counting viable cells. The nature of cell death was assessed by doubles-taining cells with fluorescein isothiocyanate-labeled Annexin V and propidium iodide, and then analyzing the cells using flow cytometry. RESULTS: After exposure to 8 mM H2O2 for 4 hours, the percentage of LDH release was 45.1 +/- 4.2% and the number of viable HK-2 cells was 5.2 +/- 6.0%. Pretreatment with propofol suppressed H2O2-induced LDH release in a concentration-dependent manner, reducing the percentage of LDH release to 38.1 +/- 5.6%, 33.5 +/- 6.3%, and 26.2 +/- 3.8% of the controls at 10 microM, 25 microM and 50 microM propofol, respectively. Numbers of viable cells increased following propofol pretreatment, with 11.4 +/- 10.9%, 19.5 +/- 16.1%, and 32.4 +/- 23.3% cell survival rates after pretreatment with 10 microM, 25 microM and 50 microM propofol, respectively. Analyses of flow cytometry showed that the propofol pretreatment decreased the percentage of necrotic and late apoptotic cells. CONCLUSIONS: Propofol protects HK-2 human kidney proximal tubular cells against H2O2-induced oxidative stress.

Total intravenous anesthesia in a 10-month-old patient with congenital myotonic dystrophy undergoing endoscopic third ventriculostomy: A case report / 대한마취과학회지

Myotonic dystrophy is a rare genetic disorder characterized by muscle atrophy and weakness. Surgical treatment of this condition poses various problems for the anesthesiologist. We describe the anesthetic management of a 10-month-old infant with congenital myotonic dystrophy, who was scheduled for endoscopic third ventriculostomy under general anesthesia. Anesthesia was induced with thiopental sodium, fentanyl, and vecuronium, and thereafter maintained via continuous infusion of propofol and remifentanil. The train-of-four ratio was monitored throughout the operation, and muscle relaxation was reversed with pyridostigmine and glycopyrrolate at the end of the procedure. We show that total intravenous anesthesia using propofol and remifentanil is a satisfactory anesthetic technique in very young patients with congenital myotonic dystrophy.

Effect of Isoflurane on the Hearing in Mice

BACKGROUND AND OBJECTIVES: The aim of this study was to investigate the relationship between inhalation anesthetics and hearing in mice. MATERIALS AND METHODS: As inhalation anesthetics, isoflurane was used. Auditory brainstem response and distortion product otoacoustic emission were used as measurement of hearing. Mice were divided into 2 groups. 'Isoflurane group' consisted of mice that were anesthetized with an inspired concentration of 2.0 vol% isoflurane with 2 L/min of oxygen (n=10). 'Control group' consisted of mice that were anesthetized with ketamine and xylazine (n=10). RESULTS: Auditory brainstem response thresholds in mice anesthetized with ketamine and xylazine was not different from those in mice anesthetized with isoflurane. Threshold of DPOAE was higher in mice with isolurane than with ketamine and xylazine. Changes of efferent control may be induced by isoflurane and consequently change the threshold of DPOAE in mice. CONCLUSIONS: These results infer that, there was a change of central nervous system induced by inhalation anesthetics, this change also can be applied to the strategies for prevention of hearing loss.

Bilateral tension pneumothorax caused by an abrupt increase in airway pressure during cervical spine surgery in the prone position: A case report / 대한마취과학회지

Elevated peak inspiratory airway pressure (PIP) can occur during general anesthesia and is usually easily rectified. In rare circumstances it can lead to potentially fatal conditions such as tension pneumothorax. We report on a 77-year-old male patient admitted for a cervical laminoplasty. The preoperative chest radiograph showed normal findings and there was no medical history of allergy or underlying airway inflammation. Anesthesia induction and maintenance progressed uneventfully. However, 5 minutes after prophylactic antibiotic administration, PIP suddenly increased and blood pressure dropped. The operation was abandoned and the patient was moved to a supine position to perform chest radiography. Cardiac arrest occurred, and cardiopulmonary resuscitation was performed. The radiograph showed bilateral tension pneumothorax. Needle aspiration was immediately performed, and chest tubes were inserted. Ventilation rapidly improved and the vital signs normalized. The patient was discharged without sequelae on postoperative day 36.

Spinal epidural hematoma related to an epidural catheter in a cardiac surgery patient: A case report / 대한마취과학회지

The addition of thoracic epidural anesthesia to general anesthesia during cardiac surgery may have a beneficial effect on clinical outcome. However, epidural catheter insertion in a patient anticoagulated with heparin may increase the risk of epidural hematoma. We report a case of epidural hematoma in a 55-year-old male patient who had a thoracic epidural placed under general anesthesia preceding uneventful mitral valve replacement and tricuspid valve annular plasty. During the immediate postoperative period and first postoperative day, prothrombin time (PT) and activate partial thromboplastin time (aPTT) were mildly prolonged. On the first postoperative day, he complained of motor weakness of the lower limbs and back pain. An immediate MRI of the spine was performed and it revealed an epidural hematoma at the T5-6 level. Rapid surgical decompression resulted in a recovery of his neurological abnormalities to near normal levels. Management and preventing strategies of epidural hematoma are discussed.

Comparison of the effects of propofol and pentobarbital on hydrogen peroxide-stimulated hepatic SNU761 cells / 대한마취과학회지

BACKGROUND: Propofol and barbiturates are both known to protect cells of several organs against ischemia/reperfusion injury, but there are few reports on any possible protective effects on human hepatocytes. We investigated the activities of both agents on human hepatic SNU761 cells under hydrogen peroxide (H2O2)-induced oxidative stress. METHODS: To determine whether propofol and pentobarbital protect hepatocytes from H2O2-induced toxicity, we used SNU761 cells, a human hepatocellular carcinoma (HCC) cell line. Cells were pretreated with different dosages (1, 10, 50 micrometer) of propofol or pentobarbital (1, 10, 50, 100, 400 micrometer) 30 min before H2O2 application. Lactate dehydrogenase (LDH) was measured to assess and quantify cell death. To determine the nature of cell death, treated hepatocytes were doubly stained with fluorescein isothiocyanate (FITC)-labeled Annexin V and propidium iodide (PI), and analyzed by flow cytometry. RESULTS: Pretreatment with propofol, but not pentobarbital, suppressed H2O2-induced LDH release. In Annexin V-FITC/PI binding analysis, propofol decreased the number of necrotic and late apoptotic cells, but no significant decreases in such cell numbers were seen when pentobarbital was used. CONCLUSIONS: Unlike pentobarbital, propofol, at clinical concentrations, protected SNU-761 HCC cells against oxidative stress.

Effects of propofol and etomidate on hydrogen peroxide-induced oxidative damage in hepatocyte / 대한마취과학회지

BACKGROUND: The present investigation was undertaken to evaluate the protective effect of propofol and etomidate against hydrogen peroxide (H2O2) induced oxidative damage in human hepatic SNU761 cells by measuring lactate dehydrogenase (LDH). METHODS: The cell line of human hepatocellular carcinoma was grown for 24 hours in dissociated cell culture. They were divided into eight groups: negative control (NC) group with no drug administration, positive control (PC) group with H2O2 250 micrometer and other groups pretreated with propofol (P; 1, 10, 50 micrometer) or etomidate (ET; 1, 10, 50 micrometer) followed H2O2 administration. After 7 hours, cell death was assessed by morphology under the light microscope and quantified by measuring the LDH in the culture media. RESULTS: In the light microscopic findings, the intact cells were increased in all three propofol groups compared to group PC. H2O2-induced LDH production was also significantly suppressed in all three propofol groups compared to group PC (P < 0.001). There were no significant differences in the microscopic findings and LDH production between the etomidate groups and group PC. CONCLUSIONS: These results suggest that the propofol has protective effect on the hepatocyte against H2O2-induced oxidative stress.

Effect of propofol and etomidate in respiratory epithelial cell infected with rhinovirus / 대한마취과학회지

BACKGROUND: There have been no previous studies on the effect of anesthetic agents on rhinovirus (RV) infection, which is the most common pathogen of the common cold in human airway epithelial cells. We investigated the effects of propofol and etomidate on the airway epithelial cells infected with RV. METHODS: RV-infected A549 cells were treated with propofol and etomidate for 24 hours. On the third day of infection, cells and supernatant were collected to measure the intercellular adhesion molecule-1 (ICAM-1) expression, viral titer and the amount of cytokine. The extents of the viral replication were expressed as viral titers by 50% tissue culture infection dose (TCID50). RESULTS: The ICAM-1 expression of the groups treated with propofol 1, 10, 100micrometer vs etomidate 1, 5, 25micrometer were 15.6 +/- 4.2, 16.4 +/- 3.7, 14.1 +/- 4.7% vs 16.8 +/- 5.7, 16.4 +/- 5.3, 17.2 +/- 4.5%, but there were not significantly different among subgroups. Productions of cytokines were increased after RV-infection, but there were not significantly different among the propofol and etomidate treated subgroups. The viral titers of the groups treated with propofol and etomidate were not significantly different among subgroups either. CONCLUSIONS: Propofol and etomidate had no effect on the replication of RV and the cytokine release after RV infection in human airway epithelial cells.

Effect of the Preoperative Intercostal Nerve Block in a Rat Model of Postthoracotomy Pain / 대한통증학회지

BACKGROUND: Chronic pain after thoracotomy has been recently reproduced in a rat model that allows investigating the effect of potentially beneficial drugs that might reduce the incidence of allodynia or alleviate pain. Local anesthetics produce antinociception in normal animals and alleviate mechanical allodynia in animals with nerve injury although their mechanisms of action may differ in these situations. Our purpose of this study was to test whether the preoperative intercostal nerve block of bupivacaine could prevent the development of allodynia in a rat model of chronic postthoracotomy pain. METHODS: All male Sprague-Dawley rats were anesthetized and the right 4th and 5th ribs were exposed surgically. The pleura were opened between the ribs to which a retractor was placed and was opened 10 mm in width. Retraction was maintained for one hour. Total 1 mg of 0.5% bupivacaine was injected at the intercostal nerves before (n = 17) or after (n = 16) surgery. A control group (n = 25) that underwent rib retraction did not receive any drug. Rats were tested for mechanical allodynia using calibrated von Frey filaments applied around the incision site during the three weeks following surgery. RESULTS: The incidence of development of mechanical allodynia in the group that received intercostal injection with bupivacaine before surgery was significantly lower than that in the control group (P < 0.05). CONCLUSIONS: Preoperative intercostal nerves block around the surgical incision before thoracotomy may decrease the incidence of postthoracotomy pain syndrome.

Venovenous bypass using central venous catheter during liver transplantation / 대한마취과학회지

No abstract available.

The Effect of Halothane on Hearing Loss and Apoptosis in Noise Exposing Mouse / 대한마취과학회지

BACKGROUND: In large clinical series, noise induced hearing loss (NIHL) following middle ear surgery has been demonstrated in 1.2% to 4.5% of patients and it is associated with a lower incidence than expected. The aim of the present work was to analyze the effect of halothane anesthesia on NIHL and hair cell morphological change. METHODS: We used 40 BALB/c mice with normal Preyer's reflex to investigate the effect of halothane on the NIHL. Control (n = 20) and halothane group (n = 20, respectively) were exposed to 120 dB SPL (sound pressure level), broad band white noise 3 hours daily for 3 consecutive days. The halothane group was anesthetized with halothane while exposed to noise. Hearing thresholds were determined with the auditory brainstem response (ABR). On day 7 post-noise, mice were sacrificed and the cochlea were collected for the histological study. RESULTS: ABR thresholds in the halothane group were less elevated after noise exposure than in the control group and then gradually recovered. In control group, the damage to the outer hair cell and supporting cell was noticeable, but not in halothane group. The expression of Bcl-2 protein was detected in halothane group, the expression of Bax protein was seen in control group. As a result in TUNEL stain, the result is positive in the control group but negative in the halothane group. CONCLUSIONS: The occurrence of NIHL decreased and the tissue damage was suppressed while anesthetized by halothane. And the noise-induced cell death of hair cell was also suppressed during anesthesia.

Changes in Jugular Venous Oxygen Saturation during Liver Transplantation / 대한마취과학회지

BACKGROUND: Marked changes in systemic hemodynamics during liver transplantation may lead to changes in cerebral hemodynamics and metabolism. Therefore, continuous monitoring of the jugular venous oxygen saturation (SjvO2) may help the anesthetic management of liver transplantation. METHODS: We observed changes in SjvO2 using a double lumen oximetry catheter for continuous monitoring and analyzed the correlation between SjvO2 and hemodynamic measurements in thirty patients undergoing liver transplantation. RESULTS: There were no significant changes in SjvO2 compared to initial SjvO2 during liver transplantation. SjvO2, however, increased from 72.5 to 79.6 % (P < 0.05), before and after reperfusion. There was a weak correlation between changes in SjvO2 and cardiac output (r = 0.38, P < 0.05), whereas no correlation was found among changes in SjvO2 and arterial carbon dioxide tension, mean arterial pressure, central venous pressure, or mixed venous oxygen saturation before and after reperfusion. CONCLUSIONS: SjvO2 that reflects changes in cerebral oxygen demand-supply balance was well maintained during liver transplantation except the reperfusion period. Continuous monitoring of changes in SjvO2 at this period may provide further insight to understand physiology of cerebral oxygenation during liver transplantation and merits further studies.

Effect of Etomidate on N-methyl-D-aspartate Induced Neurotoxicity in Rat Cortical Neurons / 대한마취과학회지

BACKGROUND: The present investigation was undertaken to evaluate the neuroprotective effect of etomidate against N-methyl-D- aspartate (NMDA) induced neurotoxicity in rat cortical neurons by measuring lactate dehydrogenase (LDH). METHODS: The cerebral cortical neurons of fetal rat were grown for 12 days in dissociated cell culture. They were divided into four groups: first group acted as control with no drug administration and other groups treated with either NMDA 100microM or Etomidate (ET) 10microM + NMDA 100microM or ET 100microM + NMDA 100microM After 24 hrs, cell death was assessed by morphology under the light microscope and quantified by measuring the LDH in the culture media. RESULTS: In the light microscopic findings, the intact cortical neurons were increased in the ET groups. NMDA-induced LDH production also significantly suppressed in ET group (P<0.05). There were no significant difference between the ET 10microM and 100microM groups. CONCLUSIONS: These results suggest that the etomidate has protective effect on the cultured rat cortical neurons against NMDA-induced neurotoxicity.

Protective Effect of Isoflurane on Noise-induced Hearing Loss in Mice / 대한마취과학회지

BACKGROUND: It is well known that the loud noise exposure can lead to noise-induced hearing loss (NIHL). Drilling during mastoid surgery may result in NIHL. The noise level produced by drilling of the mastoid bone can exceed 125 dB HL (hearing level); therefore, mastoid surgery itself is associated with a lower incidence of NIHL than expected. The aim of this study was to analyze the effects of isoflurane on NIHL and hair cell morphological changes. METHODS: BALB/c mice were divided into 2 groups; a control group (n = 20) and an isoflurane group (n = 20). The mice of both groups were exposed to 120 dB SPL (sound pressure level) broadband white noise for 3 hours per day, for 3 consecutive days. The mice in the isoflurane group were anesthetized with isoflurane while exposed to the noise. The auditory brainstem response (ABR) thresholds were determined 1 day before and after the noise-exposure and then again after 7 days. Both cochlea were removed and stained using fluorescent isothiocyanate (FITC) phalloidin. RESULTS: 1 day prior to noise-exposure, the ABR thresholds were those of a normal hearing level in both the control and isoflurane groups. In the control group, the mean hearing threshold was 78.0+/-2.6 dB HL after 1 day of noise-exposure and 81.5+/-3.4 dB HL after 1 week; in the isoflurane group, the mean hearing threshold was 49+/-11.7 dB HL after 1 day and 30.5+/-9.3 dB HL after 1 week. The hearing thresholds after noise exposure in the control were significantly higher than those in the isoflurane group (P<0.05). CONCLUSIONS: The occurrence of NIHL decreased and the hair cell damage suppressed in the mice exposed to intense noise while anesthetized by isoflurane.

Effect of Etomidate on the Expressions of c-JUN and Heat Shock Protein 70 Induced by Kainic Acid in Rats / 대한마취과학회지

BACKGROUND: The present investigation was undertaken to evaluate the neuroprotective effect of etomidate against kainic acid (KA) induced neurotoxicity in rats by Western immunoblotting for heat shock protein 70 (HSP-70), c-JUN, and by acid-fuchsin histochemistry. METHODS: Etomidate (20 mg/kg, i.p.) was administered in sequence, first being just one hour after KA (10 mg/kg, i.p.) injection, then three times one hour intervals. Neuronal damage in hippocampus was evaluated by using acid-fuchsin stain to detect cell death and HSP-70 and c-JUN induction as an index of cell injury at 3, 6, 24 and 48 h after the administration of KA. RESULTS: Acid fuchsin positive neurons were increased in the CA1 and CA3 regions of the hippocampus after KA injection, but were significantly decreased by etomidate injection (P <0.01). Etomidate administration also significantly suppressed the KA-induced induction of c-JUN and HSP-70 in both regions of the rat hippocampus. CONCLUSIONS: These results suggest that etomidate has a protective effect on hippocampal neurons against KA-induced neurotoxicity.

Protective Effect of Etomidate on Kainic Acid-induced Neurotoxicity in Rat Hippocampus / 대한마취과학회지

BACKGROUND: The present investigation was undertaken to evaluate the neuroprotective effect of etomidate against kainic acid (KA) induced neurotoxicity in rats by using the immunoreactivity of heat shock protein-70 (HSP-70) and the acid-fuchsin stain. METHODS: Administration of etomidate (20 mg/kg, I.P.) was performed in sequence; first being just one hour after a KA (10 mg/kg, I.P.) injection, then three more times at one hour intervals. Neuronal damages in the hippocampus were evaluated by using the acid-fuchsin stain to detect cell death and HSP-70 induction as an index of cell injury at 24 h after the administration of KA. RESULTS: HSP-70 induction and acid fuchsin positive neurons were increased in the CA1 and CA3 regions of the hippocampus after a KA injection but significantly decreased by an injection of etomidate (P < 0.01). CONCLUSIONS: These results suggest that the etomidate has a potential effect on the protection of neurons against KA-induced neurotoxicity.