Beck Depression Inventory Score and Associated Factors in Korean Patients with Lumbar Spinal Stenosis / 대한통증학회지

BACKGROUND: Depression is a frequent comorbid disease of chronic pain patients. This study was conducted to evaluate the prevalence of depression and to correlate associated factors and depression in patients with lumbar spinal stenosis. METHODS: The data of this survey was collected from 97 patients that visited our pain clinic for the management of lumbar spinal stenosis. Depression was examined by a self-reported survey using the Korean version of the Beck Depression Inventory (BDI). The Oswestry Disability Index (ODI) and the life satisfaction scale score were also obtained. Demographic and clinical characteristics (including spouse status, employment status, smoking status, the number of patients with multiple painful areas, the number of patients with combined disease, pain duration, visual analogue scale, Roland 5-point scale and walking distance) were obtained from an interview with the patient. The patients were divided into group N (BDI 14, n = 54) according to the BDI scale. Of the 97 patients, 55.7% had a high BDI score. RESULTS: The patients in group N had a higher rate of employment (48.0%, P < 0.05) and had higher life satisfaction scale scores (9.4 +/- 2.5, P < 0.01) as compared to group D patients. The BDI score showed a close correlation with employment status and the life satisfaction scale. CONCLUSIONS: Many lumbar spinal stenosis patients had high BDI scores. Employment status and the life satisfaction scale were closely correlated with the BDI score.

The Effects of Lidocaine, Fentanyl, Nicardipine, and Esmolol on Hemodynamic and Bispectral Index Responses during Induction with Thiopental Sodium / 대한마취과학회지

BACKGROUND: The laryngoscopy and tracheal intubation may accompany with undesirable side effects such as hypertension, tachycardia, arrhythmia, and awareness. The aim of this study was to investigate whether the correlation between the hemodynamics and bispectral index (BIS) changes after tracheal intubation following the administration of various adjuvants to attenuate tracheal response exists or not. METHODS: The patients were randomly assigned to one of five groups (control, lidocaine, fentanyl, nicardipine, or esmolol) and the drugs were administered at preselected time before tracheal intubation. The heart rate (HR), blood pressure, rate-pressure product (RPP), BIS and the episode of BIS more than 65 (BIS > or = 65) were measured. RESULTS: There were significant differences in the mean arterial pressure and RPP between control group and other groups. The HR was the most attenuated in esmolol group. The HR and RPP was the most increased in nicardipine group except control group. There was no significant difference in the maximal BIS among the five groups. The BIS > or = 65 were 50% in control group and 0.3% in nicardipine group. CONCLUSIONS: All the adjuvant drugs in the study attenuated with a various degree of the tracheal responses. However, there was no correlation between the changes of hemodynamics and BIS after the administration of various adjuvants following tracheal intubation.

The Effect of Fenoldopam Administration Followed by Unclamping of Supraceliac Aortic Cross-Clamping on Renal Ischemic Injury / 대한마취과학회지

BACKGROUND: The overall rate of renal complication after surgery on the suprarenal aorta remains high. In this study, the changes in renal blood flow (RBF), urinary oxygen tension (PuO2), renal vascular resistance (RVR), and urinary volume following fenoldopam administration were investigated in supraceliac aortic cross-clamping and unclamping animal model. METHODS: Twelve dogs were divided into two groups; control group (n = 6), fenodopam group (n = 6). After brachial, femoral, and pulmonary arterial catheterization, midline abdominal incision was made. For the aortic cross-clamping the supraceliac aorta was exposed. A doppler flowmeter probe was placed around right renal artery. A ureteral catheter was positioned at the right renal pelvis to measure urine volume and urinary oxygen tension (PuO2). In fenoldopam group, 0.5microgram/kg/min of fenoldopam was administered immediately before suprarenal aortic reperfusion. Systemic hemodynamics, renal blood flow, renal vascular resistance, PuO2, and urine volume were compared between two groups. RESULTS: The systemic hemodynamics were not significantly different between the two groups throughout the experiment. After aortic reperfusion, the RVR significantly increased in control group, but the RVR in fenoldopam group remained to baseline level. The urine output, RBF, and PuO2 significantly increased in fenoldopam group compared to control group. BUN and serum creatinine were not different between the two groups. CONCLUSIONS: High dose of fenoldopam administration reverse ischemic renal insufficiency after supraceliac aortic cross clamping.

Optimal Dose of Remifentanil to Attenuate Cardiovascular Responses to Laryngoscopic Double-lumen Endobronchial Intubation / 대한마취과학회지

BACKGROUND: The purpose of the present study was to determine the optimal dose of bolus remifentanil to attenuate hemodynamic changes to laryngoscopic double-lumen endobronchial intubation. METHODS: A total of 80 ASA I or II patients requiring double-lumen endobronchial intubation were randomly assigned to receive normal saline (NS) or one of the three different doses (0.5microgram/kg (group R0.5), 1.0microgram/kg (group R1.0) or 2.0microgram/kg (group R2.0)) of remifentanil. Study drugs for each group were administered over 30 seconds after induction of anesthesia with thiopental sodium and rocuronium. Laryngoscopic endobronchial intubation was carried out 90 seconds after the administration of study drug. Arterial blood pressure and heart rate were recorded at preanesthetic baseline, preintubation, postintubation, and every one minute during the initial 5 minute period after intubation. RESULTS: Mean arterial pressure at postintubation period increased significantly compared to baseline value in group NS, R0.5, and R1.0, but there were no significant changes in group R2.0. Heart rate showed significant increase in comparison to baseline value at every postintubation period in group NS, R0.5, R1.0, with no significant changes in group R2.0. CONCLUSIONS: We suggest that 2.0microgram/kg of remifentanil attenuate the hemodynamic changes to double-lumen endobronchial intubation without adverse effect.

Supraventricular Tachycardia Developed by the Concealed Bypass Tract in a Parturient: A case report / 대한마취과학회지

Specific mechanisms of supraventricular tachycardia include sinoatrial, intraatrial, atrioventricular nodal as well as manifest and concealed bypass tract. The concealed bypass tract is an anoamalous atriventricular conduction via an accessory pathway and the conduction pathway is always retrograde direction. A 29-year-old woman with a history of palpitation arrived at the operating room for her emergency cesarean section at 39 weeks' gestation. The heart rate was about 200 beats/min, and the blood pressure was 90/40 mmHg. After injection of beta blocker, the heart rate transiently decreased and we tried the epidural anesthesia for her delivery but the tachycardia sustained throughout the operation. The patient's tachycardia was recovered at the postanesthetic care unit spontaneously.

The Systemic Hemodynamic and Renal Effects of Nicardipine Administration Followed by Supraceliac Aortic Cross Clamping and Unclamping in Experimental Dogs / 대한마취과학회지

BACKGROUND: The incidence of renal insufficiency is reported about 18-27% during the thoracoabdominal aneurysm surgery. The possible mechanisms are reduction and maldistribution of renal blood flow, activation of renin angiotensin system, release of various mediators. In this study, we observed the effect of nicardipine, one of the calcium channel blockers that commonly used, on the systemic hemodynamics and the renal fuctions. METHODS: A total of 13 mongrel dogs were divided into two groups: control group (C, n = 7), nicardipine administration group (N, n = 6). After brachial arterial and Swan-Ganz catheterization, midline abdominal incision was made. For the aortic cross clamping the supraceilac aorta was exposed and the doppler flowmeter probe was placed on the left renal artery. The thermal diffusion microprobe was inserted in the renal parenchyme to measure local renal perfusion. At sixty minutes after aortic cross clamping, systemic hemodynamic data, renal blood flow and local renal perfusion were measured and at 1, 2, 3, 4, 5 and 6 hours after unclamping the same parameters were measured. RESULTS: There were no differences on renal blood flow, renal perfusion and oxygen extraction ratio between two groups. The renal blood flow and renal perfusion did not recover to the baseline level after unclamping in both groups. The plasma renin activity, serum creatinine concentration and cystatin-c did not show any difference between groups respectively. CONCLUSIONS: We concluded that the administration of nicardipine after supraceliac aortic unclamping to improve the renal function was not effective in experimental dogs.

Spinal Anesthesia Using 0.5% Hyperbaric Bupivacaine/Meperidine Mixture for Cesarean Section / 대한마취과학회지

BACKGROUND: Spinal anesthesia for cesarean section is regaining popularity because it can prevent pulmonary aspiration, failure of endotracheal intubation, depression of neonate by anesthetic agent in general anesthesia. Meperidine is unique in having significant local anesthetic properties that differentiate with morphine and fentanyl. Therefore, we compared the effects of adding meperidine 25 mg to intrathecal bupivacaine with fentanyl mixture. METHODS: Sixty parturients were allocated (n = 30 per group) to group 1; 0.5% hyperbaric bupivacaine 7.5 mg plus meperidine 25 mg and group 2; 0.5% hyperbaric bupivacaine 10 mg plus fentanyl 25 microgram in random order. Time to reach T4 sensory level, starting time of surgery, maximal spread of sensory block, incidence of complications, duration of motor block, perioperative analgesic effects, duration of postoperative analgesia were evaluated. We observed Apgar score and umbilical cord blood gas analysis for evaluation of the status of neonate. RESULTS: There were no significant differences in Time to reach T4 sensory level, starting time of surgery, maximal spread of sensory block, incidence of hypotension, perioperative analgesic effects, duration of motor block and neonatal status between two groups. The incidence of intraoperative nausea was greater in group 1 (60%) compared to the group 2 (20%) but the incidence of postoperative nausea and vomiting were not significantly different between two groups. Duration of postoperative analgesia was longer in group 1 (576.4 +/- 197.8 min) compared to the group 2 (192.6 +/- 75.5 min). CONCLUSIONS: Addition of meperidine 25 mg to intrathecal bupivacaine for Cesarean section improves intraoperative analgesia and also provides postoperative analgesia without significant adverse effects on the mother and neonate.

The Renal Effects of Furosemide Administration Followed by Unclamping of Supraceliac Aortic Cross Clamping in Experimental Dogs / 대한마취과학회지

BACKGROUND: The overall rate of renal complications after surgery on the suprarenal aorta remains high. Possible mechanisms are, a reduction and maldistribution of renal blood flow, activation of the renin-angiotensin system, and the release of various mediators. In this study, changes in renal blood flow, local renal perfusion, the oxygen extraction ratio, and in renal function by furosemide following supraceliac aortic cross clamping and unclamping were observed. METHODS: A total of 13 mongrel dogs were divided into two groups; a control group (n = 7), and a furosemide group (n = 6). For aortic cross clamping the supraceliac aorta was exposed and a doppler flowmeter probe was placed on the left renal artery. A thermal diffusion microprobe was also inserted in the renal parenchyme to measure local renal perfusion. Sixty minutes after aortic cross clamping, systemic hemodynamic data, renal blood flow, and local renal perfusion were measured. These parameters were also repeatedly measured at 1, 2, 3, 4, 5, and 6 hours after unclamping. Biomarkers of renal dysfunction and injury (renin activity, creatinine, and Cystatin-C) were measured. RESULTS: No differences were observed between the two groups in terms of renal blood flow, local renal perfusion, and oxygen extraction ratio. Renal blood flow and perfusion did not recover to the baseline level after unclamping in either group. Plasma renin activity significantly reduced in the furosemide group 3 hours after clamping, but serum creatinine, and Cystatin-C concentrations were similar in the tow groups. CONCLUSIONS: We conclude that the administration of furosemide after supraceliac aortic unclamping to improve renal function is not effective in experimental dogs.

Changes in Renal Blood Flow and Real-time Renal Cortical Perfusion According to Low-dose Nitroglycerin and Dopamine Administration Following the Occlusion and Reperfusion of Liver Blood Flow in Experimental Dogs / 대한마취과학회지

BACKGROUND: Pringle maneuver and nitroglycerin (NTG) administration to reduce hemorrhage during hepatectomy may affect renal blood flow (RBF) and renal cortical perfusion (RCP) by reducing blood pressure (BP), perload and others. However, so far there have been no studies on RBF and RCP changes during and after hepatic vascular maneuver in hepatectomy. The purpose of this study was to evaluate the changes in RBF and RCP along with low dose (2 microgram/kg/min) NTG with or without low dose (3 microgram/kg/min) dopamine after the occlusion and reperfusion of hepatic blood flow. METHODS: Eighteen mongrel dogs were divided into three groups according to drug administration after hepatic reperfusion; control group (group C, n = 6), NTG group (group N, n = 6), and NTG with dopamine group (group N-D, n = 6). After femoral arterial and central venous catheterization, a midline abdominal incision was made, and the hepatic artery (HA) and the portal vein (PV) were exposed for clamping and declamping. Thereafter, the right renal artery was exposed, and a doppler probe for measuring RBF was placed around the right renal artery, and a thermal diffusion microprobe was inserted in the renal outer cortex to measure RCP. Hemodynamics, RBF and RCP, were repeatedly measured before and after HA and PV reperfusion. RESULTS: No significant change in heart rate was observed in any group. The BP decreased in all the groups after HA and PV occlusion. In group C, the BP recovered to the baseline level after hepatic reperfusion but not in groups N and N-D. The RBF and RCP decreased in all groups after HA andPV occlusion. The RBF increased compared to baseline in N-D after hepatic reperfusion, and the RCP increased versus baseline in N-D, 10 minutes after hepatic reperfusion. CONCLUSIONS: In conclusion, it was observed that the RBF and RCP increased compared to baseline by administering dopamine during HA and PV reperfusion. Therefore, the prophylactic administration of low dose dopamine during hepatectomy offers an effective method of protecting renal function.

The Effect of Low Dose Nitroglycerin on Hepatic Blood Flow, Real-time Local Liver Perfusion and Oxygen Extraction Ratio Following the Occlusion and Reperfusion of Hepatic Blood Flow in Experimental Dogs / 대한마취과학회지

BACKGROUND: The Pringle maneuver is traditionally used during the hepatectomy to reduce the blood loss. However, there have been no studies about local liver perfusion (LLP) and oxygen extraction ratio (ERO2) following hepatic ischemia and reperfusion. In this study, the changes in hepatic blood flow (HBF), LLP, ERO2 following hepatic ischemia and reperfusion were observed. And the effects of low dose nitroglycerin (NTG) were observed too. METHODS: A total of 14 mongrel dogs were divided into two groups; control group (C, n = 7), NTG administration group (N, n = 7), NTG administration was started 5 minutes before HBF occlusion. After femoral arterial and central venous catheterization, midline abdominal incision was made. Hepatic artery (HA) and portal vein (PV) were exposed to clamp and declamp. And then doppler flowmeter probes were applied on HA and PV to measure their blood flow and a thermal diffusion microprobe was inserted in the liver parenchyme to measure LLP. RESULTS: The HA and PV blood flow, LLP, and ERO2 were not different between two groups. However, HBF more increased compared to the baseline level in N group after reperfusion. In C group, LLP did not recover after reperfusion. The LLP in N group recovered to the baseline level after reperfusion. CONCLUSIONS: In conclusion, it was observed that the HBF increased and LLP recovered to the baseline level after reperfusion by administration of low dose NTG. The use of low dose NTG is safe and effective for hepatectomy.

Effect of propofol, an intravenous anesthetic agent, on KATP channels of pancreatic beta-cells in rats

ATP-sensitive potassium channels (KATP channels) play an important role in insulin secretion from pancreatic beta cells. We have investigated the effect of propofol on KATP channels in cultured single pancreatic beta cells of rats. Channel activity was recorded from membrane patches using the patch-clamp technique. In the inside-out configuration bath-applied propofol inhibited the KATP channel activities in a dose-dependent manner. The half-maximal inhibition dose (ED50) was 48.6+/-8.4 micrometer and the Hill coefficient was 0.73 0.11. Single channel conductance calculated from the slope of the relationship between single channel current and pipette potential (+20~+100 mV) was not significantly altered by propofol (control: 60.0+/-2.7 pS, 0.1 mM propofol: 58.7+/-3.5 pS). However, mean closed time was surely increased. Above results indicate that propofol blocks the KATP channels in the pancreatic beta cells in the range of its blood concentrations during anesthesia, suggesting a possible effect on insulin secretion and blood glucose level.

Anesthetic Management of Carotid Endarterectomy: A case report / 대한마취과학회지

Carotid endarterectomy is the preferred treatment for a patient with transient ischemic attacks (TIAs) in whom carotid artery stenosis is present. This patient was a 58-year-old male associated with 60 kg in body weight and 172 cm in height. He was scheduled for elective carotid endarterectomy in ASA physical status III. For premedication, he was administered triflupromazine (Veprin ) 10 mg and glycopyrrolate 0.2 mg IM 1 hour prior to induction. Induction was established with thiopental sodium, succinylcholine after preoxygenation. N2O/O2 (2:1), isoflurane and pancuronium were administered for maintenance. For monitoring, ECG, EEG, direct arterial pressure, ETCO2, CVP and rectal temperature were performed. A primary goal of the intraoperative management is the prevention of the cerebral ischemia. He was challenged to maintain adequate cerebral perfusion without causing myocardial ischemia. The EEG is the reliable indication of cortical function during general anesthesia. No signs of the cerebral ischemia were occurred at the time of the carotid occlusion. Minute ventilation was kept mild hypo-or normocapnia. He had no new neurologic deficits and myocardial ischemia, and discharged on 14 day postoperation.

Anesthetic Management of Carotid Endarterectomy: A case report / 대한마취과학회지

Carotid endarterectomy is the preferred treatment for a patient with transient ischemic attacks (TIAs) in whom carotid artery stenosis is present. This patient was a 58-year-old male associated with 60 kg in body weight and 172 cm in height. He was scheduled for elective carotid endarterectomy in ASA physical status III. For premedication, he was administered triflupromazine (Veprin ) 10 mg and glycopyrrolate 0.2 mg IM 1 hour prior to induction. Induction was established with thiopental sodium, succinylcholine after preoxygenation. N2O/O2 (2:1), isoflurane and pancuronium were administered for maintenance. For monitoring, ECG, EEG, direct arterial pressure, ETCO2, CVP and rectal temperature were performed. A primary goal of the intraoperative management is the prevention of the cerebral ischemia. He was challenged to maintain adequate cerebral perfusion without causing myocardial ischemia. The EEG is the reliable indication of cortical function during general anesthesia. No signs of the cerebral ischemia were occurred at the time of the carotid occlusion. Minute ventilation was kept mild hypo-or normocapnia. He had no new neurologic deficits and myocardial ischemia, and discharged on 14 day postoperation.

Etiology of the Cancellation in the Elective and Emergency Surgery / 대한마취과학회지

BACKGROUND: All population had been taken the medical insurance period. Because the most patients like the third medical institute, the many problems of the side effects in the admission, bed lacks, etc were occurred. The aim of the study was analysed several factors to decrease the etiology of the cancellation in the elective and emergency surgery occurred in the admitted patients for operation. METHODS: We examined the etiology and cancellation in the elective and emergency surgical patients from July 1st to December 31th, 1997. Total number, department, anesthetic type, etiology and cancellation of the elective and emergency surgical patients were recorded daily. Total number, the important etiologies and department of the cancelled cases were also recorded daily. RESULTS: The total and cancel number of the operative patients were 5,415 and 578 cases. The cancel rate of the total operative, elective and emergency surgical patients was 10.7%, 10.7% and 10.6%. In general anesthesia, the cancel rate of the total operative, elective and emergency surgical patients was 10.6%, 10.4% and 11.1%. In regional anesthesia, the cancel rate of the total operative, elective and emergency surgical patients was 11.9%, 14.9% and 4.9%. By monthly, the peak and the lowest cancel rate of the total operative patients was August as 18.5% and October as 4.8%. The single most frequent etiology was affairs of operator or operating department. The second was no admission. The peak cancal rate of department was pediatric surgery. CONCLUSIONS: We found that there were several factors to decrease the etiology of the cancellation in the elective and emergency surgery performed in the operation room. These were a careful preopertive evaluation of patient's physical status and results of the laboratory examination before hospitalization, removal of affairs of the operator and operating department, removal of no admission, appropriate schedule of elective surgery, consultation with anesthesiologist, prevention of the inappropriate operative schedule, etc.

Anesthesia for Multiple Cerebral Aneurysms in a 7 Year Old Child with Ventricular Septal Defect: A case report / 대한마취과학회지

Multiple cerebral aneurysms in children are rare lesions, occurring at a frequency of approximately 0.5% to 4.6%. In children, infective endocarditis from congenital or rheumatic heart disease are the important causes of cerebral mycotic aneurysms. Subarachnoid hemorrhage, most commonly caused by the rupture of an intracranial anurysm is associated with mortality and morbidity. We reported a case of multiple cerebral aneurysms in a 7 year old child with ventricular septal defect (VSD) in operation of the two times performed under general anesthesia. He was scheduled for elective surgery for clipping of cerebral aneurysm in ASA physical status II. For premedication, he was administered triflupromazine 10 mg (Veprin ) and glycopyrrolate 0.1 mg IM 1 hour prior to induction. Induction was established with thiopental, vecuronium after preoxygenation. N2O/O2 (2 L/min:2 L/min), isoflurane and vecuronium were administered for maintenance. For monitoring, ECG, direct arterial pressure, CVP, ETCO2 were performed. In second operation, we were performed the general anesthesia the same as the first operation. He had discharged in coma state on 4 day after the second operation hopelessly.

Intravenous Propofol Anesthesia in Epilepsy Surgery: A Comparative Clinical Study on the Usefulness of Pofol(R) and Diprivan(R) / 대한마취과학회지

BACKGROUND: Propofol is a new, short-acting intravenous sedative-hypnotic anesthetics for induction and maintenance. Awakening craniotomy for resection of seizure focus is performed when the area to be excited is too close to an eloquent area to be mapping accurately. This study was performed to evaluate the efficacy and the hemodynamic effects of Pofol(R) in comparison with Diprivan(R) for the maintenance of total intravenous anesthesia (TIVA) in epilepsy surgery. METHODS: This procedure is carried out under what has been euphemistically called local anesthesia or monitored anesthesia care (MAC). For induction, 2 mg/kg in bolus was administered in both groups, and the usual maintaining dose was 100 mcg/kg/min. Surgical procedures are divided in 6 stage (I: Craniotomy, II: Electrocorticography (ECoG), III: Functional mapping, IV: Cortical resection, V: Post-resection EEG, VI: Craniotomy closure). RESULTS: Arterial blood gases and vital signs of Pofol(R) group and Diprivan(R) group were analysed. But, awakening time was slightly rapid in Pofol(R) group (8.9+/-2.64 min.) compared with Diprivan(R) group (10.6+/-3.22 min.). And there were no statistically significant differences between the two groups. CONCLUSIONS: We concluded that both Pofol(R) and Diprivan(R) are the ideal total intravenous anesthetics for long time epilepsy surgery. However, Pofol(R) group is more helpful in intraoperative ECoG and functional brain mapping because of its slightly rapid awakening time.

Electrocardiographic Abnormalities after Subarachnoid Hemorrhage / 대한마취과학회지

BACKGROUND: Electrocardiogram was one of the routine monitorings not only using for preanesthetic assessment but also in the operation room and ICU. Electrocardiographic changes are reported frequently after subarachnoid hemorrhage. Preanesthetic assessment of ECG abnormalities in the patients with subarachnoid hemorrhage is important. The aim of this study was to investigate the functional significance of ECG changes for perioperative assessment of cardiac function. METHODS: For premedication, patients were administered glycopyrrolate 0.2 mg 1 hour prior to induction. Induction was established with pentothal sodium, succinylcholine after precurarization and preoxygenation. N2O/O2 (2:1), isoflurane and pancuronium were administered for maintenance. The monitorings for patients were performed ECG (5 leads), direct atrial pressure, ETCO2, CVP and rectal temperature. RESULTS: ECG abnormalities consisted of T wave abnormalities, ST segment changes, abnormal Q wave, QT interval prolongation, LVH and arrhythmia etc. We analyzed 41 of 108 SAH patients who had ECG abnormalities of neurogenic origin preoperatively. Of these, 46% in T wave, 17% in LVH, 15% in Q wave, 15% in ST segment changes and 7% in the others (CRBBB, PAC, AF) were found. CONCLUSIONS: It is concluded that we found a poor relationship between electrocardiographic changes after subarachnoid hemorrhage and evidences of myocardial dysfunction on the echocardiogram. General anesthesia in the patients of the subarachnoid hemorrhage must not be delayed in the patients with ECG abnormalities of neurogenic origin. A preanesthetic cardiac assessment in the patients with ECG abnormalities of cardiogenic origin must be always performed.

Changes of Blood Gases, Plasma Catecholamine Concentrations and Hemodynamic Data in Anesthetized Dogs during Graded Hypoxia Induced by Nitrous Oxide / 영남의대학술지

The sympathoadrenal system plays an important role in homeostasis in widely varing external environments. Conflicting findings, however, have been reported on its response to hypoxia. We investigated the effect of hypoxia an the sympathoadrenal system in dogs under halothane anesthesia by measuring levels of circulating catecholamines in response to graded hypoxia. Ten healthy mongreal dogs were mechanically ventilated with different hypoxic gas mixtures. Graded hypoxia and reoxygenation were induced by progressively decreasing the oxygen fraction in the inhalation gas mixture from 21%(control) to 15%, 10% and 5% at every 5 minutes, and then reoxygenated with 60% oxygen. Mean arterial pressure, central venous pressure and mean pulmonary arterial pressure were measured directly using pressure transducers. Cardiac output was measured by the thermodilutional method. For analysis of blood gas, saturation and content, arterial and mixed venous blood were sampled via the femoral and pulmonary artery at the end of each hypoxic condition. The concentration of plasma catecholamines was determined by radioenzymatic assay. According to the exposure of graded hypoxia, not only did arterial and mixed venous oxygen tension decreased markedly at 10% and 5% oxygen, but also arterial and mixed venous oxygen saturation decreased significantly. An increased trend of the oxygen extraction ratio was seen during graded hypoxia. Cardiac output, mean arterial pressure and systemic vascular resistance were unchanged or increased slightly. Pulmonary arterial pressure(PAP) and pulmonary vascular resistance(PVR) were increased by 55%, 76% in 10% oxygen and by 82%, 95% in 5% oxygen, respectively(p<0.01). The concentrations of plasma norepinephrine, epinephrine and dopamine increased by 75%, 29%, 24% in 15% oxygen and by 382%, 350%, 49% in 5% oxygen. These data suggest that the sympathetic nervous system was activated to maintain homeostasis by modifying blood flow distribution to improve oxygen delivery to tissues by hypoxia, but hemodynamic changes might be blunted by high concentration of nitrous oxide except PAP and PVR. It would be suggested that hemodynamic changes might not be sensitive index during hypoxia induced by high concentration of nitrous oxide exposure.

Comparison of Hemodynamic and Oxygen Availability after Apnea between a Case with Anesthesia and a Case without Anesthesia / 대한마취과학회지

BACKGROUND: Acutely induced hypoxia causes an increase in the mean arterial pressure, cardiac output and oxygen consumption. However, comparisons of hemodynamic changes and oxygen consumption between subjects with and without anesthesia are rare. The purpose of this study was to examine and compare the hemodynamic changes and oxygen availability after acute apnea between the dogs with and without anesthesia. METHODS: Apnea was induced to 19 healthy mongrel dogs. Group 1 (N=10) constituted dogs with anesthesia and group 2 (N=9) constituted dogs without anesthesia. Hemodynamic data and oxygen levels were rapidly measured with 1 minute intervals. RESULTS: The survival time of group 1 was longer than that of group 2. The mean arterial pressure increased in group 1. Although the cardiac outputs in both groups increased at the same time course in early phase of apnea, the preload values increased more rapidly in group 1. Systemic vascular resistance decreased at 2 and 3 minutes of apnea in group 1 but not in group 2. The oxygen extraction ratio increased significantly at 4 and 5 minutes of apnea in group 2. CONCLUSION: In this study the dogs with anesthesia had a prolonged survival time compared to the dogs without anesthesia. Most hemodynamic values did not differ significantly between the two groups, except for an increased mean arterial pressure and decreased systemic vascular resistance in the dogs with anesthesia. It was suggested that the cause of early death in the dogs without anesthesia was decreased oxygen delivery.

Surgery of Intractable Epilepsy with Calcified Mass Lesions in the Temporal Lobe

We present 10 patients who underwent temporal lobe surgery for seizure control on our institution between December, 1992 and October, 1994. Preoperative neuroimaging studies of all 10 patients showed calcified mass lesions within the temporal lobe. Among them, 5 cases had mesial temporal calcified mass close to the hippocampus, 3 diffuse mass in the temporal lobe or multilobes and 2 in the temporal tip. All patients presented with complex partial seizure and seven had secondary generalization from their seizures. The duration of epileptic seizure varied between 4 and 23 years(mean 13 year). The patients were refractory to therapeutic levels of anticonvulsant medication. Presurgical evaluations of epilepsy included a detailed clinical history, multiple scalp/shenoidal EEG, prolonged Video-EEG monitoring, neuroimaging, neuropsychological test, WADA test and invasive study with subdural strip electrodes. Anterior temporal lobectomy with lesionectomy were performed in six cases and anterior temporal lobectomy in four cases using intraoperative electrocorticography(EcoG) and/or functional mapping under local or general anesthesia. The extent of resection of amygdala and hippocampus were determined according to electrocorticographic findings. The verified histopathology of the calcified lesions revealed 1 oligodendroglioma, 1 mixed glioma, 1 arterioveous malformation, 1 paragonimiasis, 2 neurocysticercosis, 1 other parasitic granuloma and 3 calcified fibrous nodule. In four patients, severe hippocampal sclerosis with neuronal cell loss and gliosis were observed. After a mean postoperative follow-up of 9 months, 9 patients showed a seizure-free outcome and one patient a significant reduction in seizure activity. We conclude from our studies that temporal lobe surgery for patients refractory to therapeutic levels of long-term anticonvulsant medication can result in excellent postoperative seizure-free outcome in the majority of the patients, and that brain tumors, vascular malformations, and parasitic infections may be considered as etiologic factors of calcified mass lesions in the temporal lobe of such patients.