Coma State after Giant Cerebral Artery Aneurysm Clipping Surgery under Circulatory Arrest, Hypothermia and Barbiturate: A case report / 대한마취과학회지

Giant aneurysms and some basilar aneurysms can cause some problems due to their size and clot formation within them. Recently, profound hypothermia and barbiturate cerebral protection were used for successful surgical treatment of these complex intracranial vascular lesions. We experienced a female patient with a giant anterior aneurysm. After femoral arterial and venous cannulation, cardiopulmonary bypass was performed and the aneurysm was clipped under a state of deep hypothermic circulatory arrest. However, she developed postoperative brain swelling and coma and died due to respiratory failure in ICU.

A case of asbestosis / 대한산업의학회지

Asbestosis is the disease of pulmonary fibrosis caused by the inhaled asbestos fibers, and could be diagnosed clinically, in the case of exposure history to asbestos is proved, by clinical symptoms of dyspnea or dry cough, physical examination findings, and the radiographic features. But many other inorganic dusts would show similar findings in the chest radiogram and sometimes the exposure history is obscure, so for the exact diagnosis of asbestosis lung biopsy is needed. In Korea, there have been some reports of survey in the workplace where asbestos is handled or of asbestos related diseases. This is a case report of asbestosis with accompanying pleural plaques, who had the occupational exposure to asbestos for 30 years and the consistent clinical, radiographic and pathological findings in the lung tissue obtained by the videoscope assisted thoracoscopic biopsy(VATS).

The Effect of Brimonidine Premedication on the Sympathetic Nervous System during Ketamine Anesthesia in the Ratv / 대한마취과학회지

BACKGROUND: The use of ketamine as the sole anesthetic induces marked central sympathetic stimulation, causing an increase of heart rate and blood pressure. alpha2-receptor agonist has been demonstrated to attenuate many of these undesirable effects when used as a premedicant. Brimonidine is a new and highly selective alpha2-receptor agonist, and rauwolscine is a selective alpha2-receptor antagonist with little affinity for imidazoline receptors. Using power spectral analysis of heart rate variability, this study examines the effect of brimonidine premedication during ketamine anesthesia on the changes in the autonomic nervous system. METHODS: From 57 Sprague-Dawley rats, 12 rats were anesthetized by urethane (U Group, 1.5 g/kg), 18 rats by ketamine (K Group, 100 mg/kg, 2 mg/kg/min continuous infusion) intraperitoneal injection after saline premedication. Brimonidine (BK Group, 30 microgram/kg, n=15), brimonidine with rauwolscine (BRK Group, 30 microgram/kg, 20 mg/kg, n=12) were adminstered as a premedicant before induction of ketamine anesthesia. ECG signals were recorded for 5 min after a period of 10 min of anesthetic stabilization. Power spectal analysis of the data was computed, using short-time Fourier transform. The spectral peaks within each measurement were calculated; a low frequency area (0.04~1.0 Hz), a high frequency area (1.0~5.0 Hz), and a total frequency area (0.04~5.0 Hz) were measured. RESULTS: The results documented that the K Group showed sympathetic activation as compared with the U Group (p<0.001). The BK Group showed sympathetic depression compared with the K and BRK Groups (p<0.001). There were no significant differences in sympatho-vagal balance between the K and BRK Groups. CONCLUSIONS: These results suggest that premedication with brimonidine is effective in attenuating the sympathetic stimulatory effect of ketamine.

Drug Interactions of Intrathecal Carbachol and Clonidine in Neuropathic Pain Model of the Rats / 대한마취과학회지

BACKGROUND: After peripheral nerve injury in human, a syndrome of events (spontaneous pain, allodynia and hyperalgesia) may be observed that includes no response of morphine and dependency of this pain state on intact sympathetic function. Spinally delivered 2-adrenoceptor agonist and cholinergic agonist or cholinesterase inhibitors have been shown to have actions attenuating the hyperalgesia in rat models of nerve injury-induced pain. Using a fixed-dose analysis and an isobolographic paradigm, the spinal interaction between the 2-adrenoreceptor agonist, clonidine and cholinergic agonist, carbachol is characterized in rat model of nerve injury-induced tactile hyperalgesia. METHODS: Male Sprague Dawely rats were anesthetized with halothane, and the left L5 and L6 spinal nerve were ligated (Chung model). After recovery, a polyethylene tubing catheter was implanted into lumbar intrathecal space. After recovery from catheter implantation, intrathecal dose-response curves were established for the antiallodynic effect of carbachol (0.1, 0.3, 1.0, 3.0 microgram) and clonidine (0.3, 1.0, 3.0, 10 microgram) alone to obtain the ED50 for each agent. ED50 fractions (1/2, 1/4, 1/8, 1/16) of drug combinations of carbachol-clonidine were administered and thresholds for left hind limb paw withdrawal to von Frey hair application were assessed. The ED50 of carbachol-clonidine combination was established and isobolographic analysis of the drug interactions was carried out.c RESULTS: Intrathecal carbachol and clonidine alone produced dose-dependent reductions of tactile allodynia: ED50 of 66 ng (12~367 ng) and 39 ng (1~1452 ng), respectively. With the fixed dose analysis, the log dose-response curves showed a left shift that considerably exceeds the theoretical curves made by a simple sum of the effects of carbachol alone and clonidine. With the isobolographic analysis, ED50 of mixture was found to be statistically less than the theoretical additive ED50 of mixture. CONCLUSION: The experiments suggest that intrathecal carbachol and clonidine alone produce a dose dependent antagonism on touch evoked allodynia and intrathecal carbachol is synergistic when combined with intrathecal clonidine.

On-line Assessment of Left Atrial Area and Function by Automated Border Detection Echocardiography

BACKGROUND: Automated border detection (ABD) echocardiography is a convenient and objective tool in the estimation of left atrial (LA) area and function when compared to the off-line, two-dimensional echocardiographic method that requires manual tracing of the endocardial border. In addition, the applicability of the ABD system to instantaneously derive LA area and function may provide a noninvasive method to assess the diastolic interaction between the left ventricle and the left atrium. METHOD: 53 patients with a normal sinus rhythm and an apical four chamber view of LA area (in which at least 75% of the endocardium was clearly visible) were selected for this study. The on-line echocardiographic assessment of LA areas and function with automated boundary detection was performed and compared with the off-line estimation. From the instantaneous cavity area displayed by the ABD system, the extents of left atrial area decrease resulting from rapid ventricular filling (D) and atrial contraction (AC) were measured. The D/AC ratio was compared with the transmitral Doppler flow velocity E/A ratio. RESULTS: 1) The end-systolic area (ESA) and the end-diastolic area (EDA) of the left atrium, diastolic atrial emptying index (AEMI) and the systolic atrial expansion index (AEXI) with the ABD system were not different from those with the off-line, manually trace method. 2) ESA, EDA, AEMI and AEXI determined by the ABD system and the off-line method showed strong correlations (r=0.87, 0.79, 0.52 and 0.49 respectively). 3) D/AC ratio with the ABD system correlated significantly with the transmitral Doppler velocity E/A ratio (r=0.70). CONCLUSION: The ABD system may be used in the assessment of LA area and LA function and the diastolic interaction between the left atrium and the left ventricle.

Assessment of Left Atrial Appendage Flow Pattern Using Multiplane Transesophageal Echocardiography in Patients with Nonrheumatic Atrial Fibrillation and Ischemic Stroke

BACKGROUND: The efficacy of oral anticoagulant therapy in reducing the risk of stroke and systemic embolism has been demonstrated in patients with nonrheumatic atrial fibrillation, but anticoagulation may introduce the risk for serious complications or adversely affect the patient's usual activities. Because the left atrial appendage(LAA) is the most likely site of thrombus formation in patients with nonrheumatic atrial fibrillation, evaluation of the LAA function with transesophageal echocardiography(TEE) may be helpful to deterrnine the high risk group for ischemic stroke. METHODS: Twenty patients with nonrheumatic atrial fibrillation(group I ), eighteen patients with rheumatic atrial fibillation(group II ) and twenty subjects in normal sinus rhythm without valvular heart disease(group III ) were underwent multiplane TEE examination. We measured maximal and minimal areas, ejection-fraction, and peak contraction and relaxation velocities of LAA. We also observed the presence or absence of thrombus and spontaneous echo contrast (SEC) in the left atrium or LAA. RESULTS: Maximal area of LAA was larger in group I and II compared with group III but there was no difference between group I and group II. Ejection fraction of LAA was much decreased in group I and II compared with group III. Peak contraction and relaxation velocities of LAA were over 45cm/sec in all cases from group Ill, but there was nearly negligible flow measurable in cases from group II. Patients from group I showed two distinct LAA flow patterns, either well defined saw tooth flow pattem(9 cases) or very low flow pattern like that of group II (11 cases). Therefore, patients from group I could be divided into two subgroups according to LAA flow profile. High flow profile subgroup had clear saw tooth flow pattern and revealed over 20cm/sec of peak contraction and relaxation velocities. The other low flow profile subgroup showed under 20cm/sec of both velocities. LAA ejection fraction was more increased in high flow profile subgroup but not significantly. Ischemic stroke occurred in six patients from group I, and all were in the low flow profile subgroup(p<0.05). SEC was observed in eight cases(73%) of the low flow profile subgroup but in only one case(11%) of the high profile sbugroup(p<0.05). All three cases with LAA thrombus belonged to the low flow profile subgroup. CONCLUSIONS: The assessrnent of LAA function by TEE may be helpful to discriminate the high risk group for the potential ischemic stroke in patients with nonrheumatic atrial firillation.

The Effect of Esmolol on Changes of Heart Rate during Induced Hypotension with Sodium Nitroprusside / 대한마취과학회지

BACKGROUND: The goal of this study was to demonstrate the effect of esmolol to prevent reflex tachycardia occurred during sodium nitroprusside(SNP) induced hypotension. METHODS: Thirty patients were randomly assigned to the SNP group(n=15) received continuous infusion of SNP at 2.72+/-0.56 mcg/kg/min or combined SNP and esmolol(SNP-ESM) group(n=l5) received combined continuous infusion of SNP at 1.54+/-0.34 mcg/kg/min and esmolol at 200 mcg/kg/min for 1 hour to maintain a 20~25% reduction of mean arterial pressure(MAP) from baseline. Heart rate(HR) and MAP were measured at baseline, during hypotensive period(5, 10, 20, 30, 60 min) and after hypotensive period(70, 80, 90,1 20 min). RESULTS: SNP-induced hypotension resulted in significant(P<0.001) increases in heart rate during hypotensive period and MAP after the end of SNP infusion. However, infusion of SNP-ESM resulted in significant(p<0.05) reduction in heart rate and SNP requirement during hypotensive period, and rebound hypertension was not observed after the end of induced hypotension. CONCLUSIONS: SNP-ESM infusion is a safe and effective pharmacologic means and provides several advantages over single SNP that include reduction in SNP requirement, no reflex tachycardia during induced hypotension and no rebound hypertension following hypotensive period.

The Effect of Esmolol on Changes of Heart Rate during Induced Hypotension with Sodium Nitroprusside / 대한마취과학회지

BACKGROUND: The goal of this study was to demonstrate the effect of esmolol to prevent reflex tachycardia occurred during sodium nitroprusside(SNP) induced hypotension. METHODS: Thirty patients were randomly assigned to the SNP group(n=15) received continuous infusion of SNP at 2.72+/-0.56 mcg/kg/min or combined SNP and esmolol(SNP-ESM) group(n=l5) received combined continuous infusion of SNP at 1.54+/-0.34 mcg/kg/min and esmolol at 200 mcg/kg/min for 1 hour to maintain a 20~25% reduction of mean arterial pressure(MAP) from baseline. Heart rate(HR) and MAP were measured at baseline, during hypotensive period(5, 10, 20, 30, 60 min) and after hypotensive period(70, 80, 90,1 20 min). RESULTS: SNP-induced hypotension resulted in significant(P<0.001) increases in heart rate during hypotensive period and MAP after the end of SNP infusion. However, infusion of SNP-ESM resulted in significant(p<0.05) reduction in heart rate and SNP requirement during hypotensive period, and rebound hypertension was not observed after the end of induced hypotension. CONCLUSIONS: SNP-ESM infusion is a safe and effective pharmacologic means and provides several advantages over single SNP that include reduction in SNP requirement, no reflex tachycardia during induced hypotension and no rebound hypertension following hypotensive period.

Oral Clonidine Blunts the Heart Rate Response to Intravenous Atropine in Adults / 대한마취과학회지

BACKGROUND: Clonidine, which is known to have analgesic and sedative properties, has recently been shown to be an effective preanesthetic medication in humans. The drug may cause side effects, including bradycardia and hypotension. This study was conducted to evaluate the ability of intravenous atropine to increase the heart rate (HR) in awake adults receiving clonidine preanesthetic medication. METHODS: We studied HR responses to intravenous atropine in 45 patients assigned randomly to either a control group, who received no medication (group 1, n=15), or clonidine groups, who received oral clonidine of 2~2.5 mcg/kg (group 2, n=15), or 4.5~5 mcg/kg (group 3, n=15) 90 min before scheduled induction of anesthesia. When HR and blood pressure had been confirmed to be stable in operating room, all patients received incremental doses of atropine, 2.5, 2.5 and 5 mcg/kg at 2-min intervals. The HR and mean arterial pressure were recorded at 1-min intervals. RESULTS: Before atropine injection, the HR decreased significantly (P<0.05) in group 3. The increases in HR in response to a cumulative dose of atropine 10 mcg/kg were 21+/-8, 17+/-7 and 7+/-5 beats/min (mean+/-SD) in group 1, 2 and 3, respectively (P<0.05). The positive chronotropic response to intravenous atropine was attenuated significantly only in group 3 (P<0.01). CONCLUSIONS: It was concluded that oral clonidine of 4.5~5 mcg/kg decreased HR significantly, and blunted the increase in HR after intravenous atropine in awake adults although oral clonidine of 2~2.5 mcg/kg did not.