The Effect of Rilmenidine Pretreatment on the Cardiovascular Toxicity Caused by Intravenous Bupivacaine by Autonomic Nervous System Analysis in Anesthetized Cats / 대한마취과학회지

BACKGROUND: This study was designed to assess the effects of rilmenidine on the autonomic nervous system, and to evaluate whether it prevents bupivacaine-induced cardiovascular toxicity during intravenous bupivacaine infusion in anesthetized cats. METHODS: Thirty male cats were randomly divided into a control group (n = 15) and a rilmenidine group (n = 15). Following the injection of rilmenidine (10microgram/kg), systolic blood pressures (SBP) and R-R intervals (RRI) were recorded for 5 minutes. Then power spectral analyses of the SBP and RRI, and transfer function analysis were conducted to evaluate the autonomic nervous system. During the infusion of bupivacaine (0.5 mg/kg/min), blood pressures, heart rates, times to reach each events, and bupivacaine doses were measured at the first QRS modification, the first dysrhythmia, at 25% (HR25) and 50% reductions in baseline heart rate, and at 25% and 50% reductions in baseline mean arterial pressure and at final systole. RESULTS: The high frequency (HF) power of heart rate variability (HRV) was significantly elevated in the rilmenidine group versus the control group. Magnitude HF was significantly higher in the rilmenidine group than in the control group. The onset of dysrhythmia correlated significantly with the HFs of HRV and baroreflex sensitivity (BRS). Except for HR25, the rilmenidine group showed significantly higher bupivacaine doses and delayed event onsets versus the control group. CONCLUSIONS: We suggest that pretreatment with rilmenidine delays the onset of dysrhythmia by increasing vagal tone and BRS and by reducing cardiovascular toxicity when bupivacaine is infused continuously to isoflurane anesthetized cats.

Anesthetic Experience in Ex Situ Resection of The Liver: A case report / 대한마취과학회지

Ex situ resection of the liver is an alternative surgical procedure for patients with conventionally unresectable hepatic tumors, and with contraindications to liver transplantation. We experienced a case of ex situ resection of the liver in a 40-year-old female patient suffering from sclerosing hepatocellular carcinoma. Preoperative liver function was normal. The duration of the anhepatic period was 2 hours and 55 minutes. No severe hemodynamic or pulmonary complications, and no significant metabolic or coagulatory disorders occurred. To obtain good results by ex situ resection of the liver, anesthesiologist should understand the physiology of the anhepatic period and guard against possible problems during the operation. (Korean J Anesthesiol 2004; 46: 127~130)

Anesthesia for Living Related Liver Transplantation in Classic Citrullinemia: A case report / 대한마취과학회지

Citrullinemia is an autosomal recessive disorder resulting in a deficiency of the urea cycle enzyme, argininosuccinate synthetase, which is mainly found in the liver. Despite the improvement in a dietary therapy during the past 20 years for the treatment of urea cycle disorders with the systematic adjunction of sodium benzoate, sodium phenylbutyrate and arginine, the overall outcome of severe forms of hyperammonemia often remains disappointing. As the liver is the only organ in which ammonia is transformed into urea, liver transplantation has been considered as an elegant and radical alternative therapy to classical dietetic and medical therapy. A child with classical citrullinemia was treated at age 34 months by a living related liver transplantation. The levels of plasma and urinary citrulline decreased slightly after transplantation, but serum ammonia levels and amino acid concentrations returned to the normal range without protein restriction. We describe this case and include a brief review of the literature.

Fatal Pulmonary Hemorrhage after Reperfusion of a Grafted Liver: A case report / 대한마취과학회지

We report a case of fatal pulmonary hemorrhage developed after reperfusion of grafted liver during a living-related liver transplantation. A 53 year-old man who had hepatic encephalopathy grade 4 with fulminant hepatic failure was scheduled for a living-related liver transplantation. Preoperative evaluation showed fever, hypoxia, hypotension, pneumonia, and pulmonary edema. Cardiopulmonary stability was maintained with oxygen therapy and inotropic agents. During the anhepatic period, the patient's vital signs remained stable with inotropic agents except one episode of sudden hypotension presumably due to right heart strain. However, hypoxia, acidosis, and electrolyte imbalance were becoming worsen in spite of variable treatments for correction. Immediately after reperfusion, a sudden increase of central venous pressure and pulmonary artery pressure was noticed. evere bradyarrhythmia, hypotension, hemoptysis, hypoxia, and acidosis were followed by cardiac arrest. Cardiopulmonary resuscitation was not successful and the patient expired

Causes of a Sudden Hypotension on Preanhepatic Stage during Liver Transplantation / 대한마취과학회지

BACKGROUND: Various hemodynamic disturbances and a rapidly changing circulatory blood volume necessitate the proper management of fluid administration. The causes of sudden hypotension can be anticipated with the usual monitoring devices. However, more accurate diagnosis of such event can only be made by actual measurement of cardiac output. And such an event may be related to cardiac depression due to autonomic disturbances. To elucidate the cause of sudden unexplainable hypotension during the preanhepatic stage, we analysed the hemodynamic data of patients undergoing liver transplantation prospectively. METHODS: Patients were divided into a normal and a hypotensive group, according to the presence of an episode of hypotension. The hypotensive group was further divided into an explainable and an unexplainable group, if causes were known or not. Preoperative echocardiograms and Child-Pugh scors were also analysed. The normal and unexplainable hypotensive groups were compared using Mann-Whitney non-parametric, Chi-square and Wilcoxon-signed rank tests. P<0.05 was considered statistically significant. RESULTS: The incidence of hypotension was 25.2%. A severe unexplainable hypotensive episode occurred 9.3% of the the liver transplantations. Causes of hypotension were preload deficiency, vena caval compression, bleeding, and vagal reflex. Unexplainable hypotensive patients showed decreased ejection fraction (cardiac depression) and systemic vasodilatation. CONCLUSIONS: These results suggest hepato-dyscirculatory syndrome is the main cause of unexplainable hypotension during the preanhepatic stage.

Anesthesia for Liver Transplantation in Patients with Fulminant Hepatic Failure under Intracranial Pressure and Jugular Venous Oxygen Saturation Monitoring / 대한마취과학회지

BACKGROUND: Fulminant hepatic failure is characterized by rapid progressive liver failure with the onset of encephalopathy within a few weeks of the appearance of jaundice. This illness is frequently complicated by hemodynamic instability, multiple organ dysfunction and intracranial hypertension associated with cerebral edema, which is the most common cause of death in this condition. We reviewed 8 cases of liver transplantation with fulminant hepatic failure with respect to anesthetic management and neurologic monitoring. METHODS: We analyzed anesthetic management, intracranial pressure (ICP), cerebral perfusion pressure (CPP), jugular venous oxygen saturation (SjvO2) and hemodynamics retrospectively during liver transplantation in 8 patients with fulminant hepatic failure. Intracranial hypertension was defined as an ICP >or= 20 mmHg for at least 5 minutes. The goal of management is to keep the CPP above 40 - 50 mmHg and ICP below 30 - 40 mmHg. There were 3 cases of hepatorenal syndrome and continous veno-venous hemodiafiltration (CVVHD) was used in 2 cases. RESULTS: All patients showed characteristic hyperdynamic circulation with severe vasodilation and vasopressive drugs were needed to maintain CPP. The episodes of intracranial hypertension occurred in all patients during transplantation. To decrease ICP, medical therapy with mannitol, furosemide and thiopental infusion were required. Intracranial hemorrhagic complications occurred in 3 cases. SjvO2 decreased transiently below 60% in 3 cases. However, it was improved with an increase of PaCO2 by hypoventilation and maintained above 60 - 80% in all cases. CONCLUSIONS: This data suggests that there is a risk of brain injury secondary to elevated ICP and low CPP during liver transplantation. ICP, CPP and SjvO2 monitoring in patients with fulminant hepatic failure can be useful for the prompt recognition of intracranial hypertension and for guiding therapy. However, correction of the coagulopathy before placement of the ICP tranducer must be performed to prevent hemorragic complications.

Hemodynamic Response to a Rapid Fluid Challenge in End-Stage Liver Disease / 대한마취과학회지

BACKGROUND: Patients with end-stage liver disease have a hyperdynamic circulatory state complicated by a high right ventricular end-diastolic volume index (RVEDVI) and a low ventricular performance. These changes often make if difficult to evaluate volume status and preload. In this study, we analyzed hemodynamic profiles after a rapid fluid challenge in the recipients of a liver transplant. METHODS: Hemodynamic responses were evaluated before and after 200 ml of a 5% albumin challenge in forty patients, recipients of a liver transplant with a Swan-Ganz right-heart ejection fraction oximetry thermodilution cathether. Patients were divided into two groups, group A (responders, n=12, >or= 10% increase in stroke volume index (SVI) after fluid challenge) and group B (non-responders, n = 28, decrease or < 10% increase in SVI after fluid challenge). We analyzed hemodynamic data obtained from the two groups before and after the fluid challenge. RESULTS: Group B had a lower baseline right ventricular ejection fraction (REF) (49.9+/-5.9% vs 42.8+/-5.7%), a higher RVEDVI (120.8+/-19.4 ml/m2 vs 143.6+/-26.3 ml/m2), and a higher right ventricular end-systolic volume index (RVESVI) (60.8+/-14.0 ml/m2 vs 82.8+/-20.5 ml/m2) than group A. In group B, the cardic index (CI) and right ventricular stroke work index (RVSWI) were not increased after the fluid challenge. There was a mild decrease in the mean arterial pressure (MAP) in group B after the fluid challenge. There was a moderate negative correlation between the fluid-induced change in SVI and the baseline RVEDVI in all patients (r =-0.40, P<0.05). CONCLUSIONS: Our study suggests that there is no improvement of hemodynamic profiles after a rapid fluid challenge in many patients with end-stage liver disease, especially those with a high RVEDVI.

Effect of Rilmenidine and Clonidine Premedication on the Cardiovascular Action of Phenylephrine and Nitroprusside in Rats / 대한마취과학회지

BACKGROUND: Patients premedicated with clonidine often present with hypotension and bradycardia. The hypotensive patient premedicated with clonidine should be given a vasopressor to treat hypotension. In these patients, an augmented vasopressor response would be shown. Rilmenidine as an allied drug of clonidine is an antihypertensive agent with selectivity for the imidazoline receptor that acts centrally by reducing sympathetic overactivity. This study was designed to evaluate the effect of clonidine and rilmenidine on changes in mean blood pressure and baroreflex sensitivity following phenylephrine and nitroprusside administration. METHODS: Sixty Sprague-Dawley rats were assigned randomly into one of three groups, control group (n = 20), clonidine group (n = 20) or rilmenidine group (n = 20). Saline (control group), clonidine 30ng/kg (clonidine group) or rilmenidine 300ng/kg (rilmenidine group) were intraperitoneally injected respectively. Following the injection, a phenylephrine and nitroprusside test were performed. RESULTS: The percent change in mean blood perssure from the baseline values in the control group, clonidine group and rilmenidine group were 35 +/- 18%, 54 +/- 17% and 62 +/- 38%, respectively. There was no difference between the baroreflex sensitivity in the pressure (phenylephrine) test (0.94 +/- 0.43, vs 1.05 +/- 0.62, vs 1.13 +/- 0.59 msec/mmHg). In contrast, the slopes of the depressor (nitroprusside) test were decreased in rats receiving clonidine and rilmenidine (0.51 +/- 0.34, vs 0.12 +/- 0.08, vs 0.18 +/- 0.09 msec/mmHg, P < 0.05). CONCLUSIONS: It is concluded that the rilmenidine and clonidine groups showed a more augmented pressure response to vasopressors than the control group. Therefore, the decreased dosage of vasopressors is recommended to treat hypotension in rilmenidine premedicated patients.

Anesthesia for Synchronous Liver-Kidney Transplantation / 대한마취과학회지

Until recently liver transplantation has been considered a contraindication in patients with multi-organ failure. However, developements in surgery and anesthetic technique involving intraoperative extrarenal purification provide adequate conditions for performing synchronous liver-kidney transplantation (SLKT), and it is clear that double transplantation is the best therapeutic option in end stage liver and kidney disease. Liver transplantation involves a large blood loss and fluid replacement, as well as administration of large amounts of blood products. Patients with end stage liver and kidney disease have a reduced capacity to excrete free water, predisposing them to an accumulation of extravascular water. Precise monitoring and the intraoperative use of an extrarenal purification technique to maintain these patients within acceptable hydroelctrolyte and hemodynamic parameters is needed. We experienced two cases of SLKT and report on anesthetic management and problems.

Anesthesia for Living Related Liver Transplantation in Homozygous Protein C Deficiency / 대한마취과학회지

Protein C exerts anticoagulant effects by inactivating factor Va and VIIIa and stimulating fibrinolysis. The homozygous protein C deficiency is extremely rare and often results in life threatening thrombosis and purpura fulminans with necrotic cutaneous lesions. A child with homozygous protein C deficiency was treated at 6 months by a living-related liver transplantaion. After induction of anesthesia, we started an FFP infusion for protein C replacement and a low molecular weight heparin continuous infusion to prevent thrombosis. A complete reconstitution of protein C activity and resolution of the thrombotic condition occured postoperatively. So we report this case with a brief review of the literature.

Anesthesia for Liver Transplantation in Patients with Hepatopulmonary Syndrome / 대한마취과학회지

Hepatopulmonary syndrome is essentially the triad of liver disease, pulmonary vascular dilations and abnormal arterial oxygenation, which can result in severe hypoxia. We managed two cases of 9 and 49-year-old males for liver transplantation with hepatopulmonary syndrome. Preoperative evaluation showed decreased diffusion capacity of carbon monooxide and severe hypoxemia, while breathing room air (PaO2 < 60 mmHg) but they responded to oxygen therapy. The pulmonary vascular resistance was low, consistent with an intrapulmonary vascular shunt but the pulmonary artery pressure was normal, reflecting a high cardiac output. Intraoperative oxygenation was satisfactory (PaO2 of 100 - 200 mmHg) in spite of a high shunt fraction (Qs/Qt 18.5 +/- 9.2%). This means that the impairment in gas exchange is not the result of a true shunt, suggesting the presence of a functional shunt, which is characterized by diffusion-perfusion impairment. The intraoperative course was uneventful in the two patients and they are in a successful postoperative course. In case 1, the hypoxemia was resolved promptly, but in case 2, it was persistent for sixteen months after transplantation. The hypoxemia itself in hepatopulmonary syndrome is not regarded as a contraindication to liver transplantation. (Korean J Anesthesiol 2001; 40: 677 ~ 683)

Cardiac Tamponade Recognized after Reperfusion during an Orthotopic Liver Transplantation / 대한마취과학회지

Cardiac tamponade is a life-threatening predicament which demands early recognition and immediate treatment. We report a case of iatrogenic intraoperative cardiac tamponade during an orthotopic liver transplantation. A 55 year-old man was scheduled for an orthotopic liver transplantation due to hepatocellular carcinoma. During the anhepatic period, the patient's vital signs remained stable, but the central venous pressure and pulmonary artery diastolic pressure were increased. However, immediately after reperfusion, sudden hypotension and tachycardia developed. Fluid volume resuscitation and epinephrine injection led only to a transient improvement of the blood pressure. It took approximately 30 minutes to realize the possibility of the cause of hypotension might be due to cardiac tamponade rather than post-reperfusion syndrome. After an emergent transdiaphragmatic pericardiocentesis, we found that the cause of the cardiac tamponade was tearing of an epicardial coronary vein. Evacuation of a massive hematoma resulted in a rapid improvement in the patient's cardiovascular status. The patient has made an uneventful recovery.

Changes of Pulmonary Artery Pressure during Liver Transplantation / 대한마취과학회지

BACKGROUND: Pulmonary hypertension (PH) associated with end stage liver disease is rare but the risk of hemodynamic deterioration during liver transplantation may be high. This study was done to characterize the pulmonary hemodynamics during liver transplantation and to seek the relationship between pulmonary artery pressure (PAP) and other hemodynamic variables. METHODS: One hundred patients undergoing liver transplantation were chosen and we divided patients into normal and PH groups (mean pulmonary artery pressure [MPAP] > 25 mmHg). Hemodynamic data was collected throughout the surgery. Studied variables between groups were analyzed with an unpaired t-test. The relationship between MPAP and other hemodynamic variables was analyzed with a linear regression test. Survival analysis was performed by cumulative survival analysis (Logrank test). RESULTS: Incidence of PH during liver transplantation was 34%, and true PH (pulmonary vascular resistance index [PVRI] > 150 dyne.sec/cm5/m2, MPAP > 25 mmHg) was 7%. MPAP, systemic vascular resistance index, cardiac index, right ventricular ejection fraction, maximum elastance, central venous pressure (CVP), pulmonary artery occlusion pressure (PAOP), and right ventricular end-diastolic volume index were significantly higher in the PH group. In the PH group, right ventricular function curve was abnormal. MPAP correlated significantly with PAOP, and CVP (P < 0.01). One year survival rate showed no significant difference between groups (Logrank test P = 0.49). CONCLUSIONS: Episodes of increased pulmonary artery pressure during liver transplantation was not infrequent. PAP was more dependent on preloads. In patients with high PAP, RV diastolic dysfunction was usually observed. Early mortality rate after liver transplantation was not associated with PH.

Measurement of Auto-PEEP in Anesthetized Patients Using a Laser-Flex Endotracheal Tube with Changes in Respiratory Rates and Tidal Volume / 대한마취과학회지

BACKGROUND: The aim of the present study was to detect and quantify auto-positive end-expiratory pressure (auto-PEEP) in anesthetized patients using a Laser-Flex endotracheal tube (Mallincrodt, ID, 6.0 mm), by comparing the effects of changes in tidal volume and respiratory rate. METHODS: All patients (n = 30) undergoing elective surgery were anesthetized, paralyzed and intubated with a ID 8.0 mm endotracheal tube (n = 10, control), ID 6.0 mm endotracheal tube (n = 10, group S), or ID 6.0 mm Laser-Flex endotracheal tube (n = 10, group L), respectively. After anesthetic induction, ventilator settings using a Siemens Servo 900C were changed for a tidal volume of 8, 10 ml/kg, respiratory rates of 10, 12 or 14 breaths/min. Peak airway pressure was measured and auto-PEEP was quantified using an end-expiratory occlusion method. Data recorded on the Bicore CP-100 pulmonary monitor was transfered to a PC and analyzed by processing software (ANADAT). RESULTS: In group S and L, peak airway pressure and auto-PEEP were higher than control group and increased during an increase in tidal volume (P < 0.05). But they were increased significantly during an increase of respiratory rate, only when the tidal volume was 10 ml/kg (P < 0.05). CONCLUSIONS: There was an increase of auto-PEEP in anesthetized patients using a Laser-Flex endotracheal tube during incremental changes of tidal volume and respiratory rates.

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.

Anesthetic Management for Pediatric Living Related Liver Transplantation: Experience of 30 Cases / 대한마취과학회지

BACKGROUND: Living related liver transplantation (LRLT) was developed to alleviate the mortality resulting from the scarcity of suitable cadevaric grafts. The purpose of this study is to review 30 cases of pediatric living-related liver transplantation, and to find the proper anesthetic management for this operation. METHODS: We retrospectively analyzed the medical records of 23 cases (body weight < 15 kg) of liver transplantation from living related donors between August 1995 and May 1998. RESULTS: Mean age and body weight were 14 (range; 6-29) months, 8.7 (range: 5.4-12.2) kg, respectively. The most common cause of end stage liver disease was biliary atresia. After reperfusion there were significant decreases of mean arterial pressure and body temperature, and increases of central venous pressure (P< 0.05), whereas the change of heart rate was not significant. The incidence of postreperfusion syndrome was 26%. Serum Na levels increased significantly (P< 0.05) from 133 3 to 144+/-3 mEq/L, and K level decreased from 4.1+/-0.7 to 3.2+/-0.5 mEq/L during surgery. Hematocrit was 26+/-3.5%, platelet 10.3+/-7.2 x 104/mm3 at the time of peritoneal closure. Wide inter-individual RBC and FFP requirements were observed, 43+/-40 (range: 5-133) mL/kg, 108+/-82 (range: 22-300) mL/kg, respectively. CONCLUSIONS: We conclude that anesthetic management for pediatric LRLT and LRLT in recipients less than 15 kg in body weight can be carrid out, through with some precautions.

The Effect of Oral Clonidine Premedication on Changes in Respiratory System Mechanics by Tracheal Intubation / 대한마취과학회지

BACKGROUND: The aim of this study was to evaluate the influence of oral clonidine premedication on respiratory mechanics by tracheal intubation in smokers. METHODS: Thirty male smoker patients were randomly divided into 3 groups. For group 1 (n = 10), l microgram/kg of clonidine was premedicated. For group 2 (n = 10), 2 microgram/kg of clonidine was premedicated. Group 3 (n = 10, control group) was the no premedication group. After anesthetic induction, CMV was applied with a Siemens Servo 900C ventilator, and anesthetic gases were supplied via the low pressure inlet of the ventilator. Tidal volume (10 ml/kg) was fixed during measurements for each patient. End-inspiratory occlusion was applied for at least 3 seconds and tracheal pressure was measured at the distal end of the endotracheal tube. Pressure, flow and volume were monitored and recorded with a Bicore CP-100 pulmonary monitor. Data were measured after 2 (100% O2) and 5 (1.5 vol% enflurane with 50% N2O) minutes of tracheal intubation. Data were transferred to PC and analyzed by processing software (ANADAT). Total respiratory (Rrs), airway (Raw) and tissue (Rve) resistances, along with static (Cstat), dynamic (Cdyn) compliances were calculated. RESULTS: There were no significant differences for Rrs, Raw, Rve, Cstat and Cdyn in the three groups. CONCLUSIONS: Oral clonidine premedication in dosages up to 2 microgram/kg do not affect the changes of respiratory mechanics caused by tracheal intubation in smokers.

The Effect of Oral Clonidine Premedication on Changes in Respiratory System Mechanics by Tracheal Intubation / 대한마취과학회지

BACKGROUND: The aim of this study was to evaluate the influence of oral clonidine premedication on respiratory mechanics by tracheal intubation in smokers. METHODS: Thirty male smoker patients were randomly divided into 3 groups. For group 1 (n = 10), l microgram/kg of clonidine was premedicated. For group 2 (n = 10), 2 microgram/kg of clonidine was premedicated. Group 3 (n = 10, control group) was the no premedication group. After anesthetic induction, CMV was applied with a Siemens Servo 900C ventilator, and anesthetic gases were supplied via the low pressure inlet of the ventilator. Tidal volume (10 ml/kg) was fixed during measurements for each patient. End-inspiratory occlusion was applied for at least 3 seconds and tracheal pressure was measured at the distal end of the endotracheal tube. Pressure, flow and volume were monitored and recorded with a Bicore CP-100 pulmonary monitor. Data were measured after 2 (100% O2) and 5 (1.5 vol% enflurane with 50% N2O) minutes of tracheal intubation. Data were transferred to PC and analyzed by processing software (ANADAT). Total respiratory (Rrs), airway (Raw) and tissue (Rve) resistances, along with static (Cstat), dynamic (Cdyn) compliances were calculated. RESULTS: There were no significant differences for Rrs, Raw, Rve, Cstat and Cdyn in the three groups. CONCLUSIONS: Oral clonidine premedication in dosages up to 2 microgram/kg do not affect the changes of respiratory mechanics caused by tracheal intubation in smokers.

Hemodynamic Changes during the Pringle Maneuver in Patients with Abnormal Liver Function / 대한마취과학회지

BACKGROUND: During the Pringle maneuver (PM), the increase of systemic vascular resistance (SVR) and the active constriction of the intrahepatic capacitance vessels could minimize arterial blood pressure change. Pressor reactivity to sympathetic agonists is impaired and blood volume buffering capability is less efficient in a cirrhotic liver. Accordingly, we evaluated the relations between hemodynamics during PM and preoperative liver function test (LFT) by serum aminotransferase and Indocyanine Green (ICG) clearance. METHODS: Twenty-seven patients undergoing hepatectomy with PM were classified into two groups according to the liver function state assigned by serum aminotransferases and ICG clearance test. Sequential changes of hemodynamics were measured with Doppler flowmeter during PM. Hemodynamic data were analyzed by using ANOVA for repeated measurement. Correlation between LFTs were sought using Pearson correlation and logistic regression. RESULTS: During the PM, cardiac output decreased significantly compared to the preclamping period in the abnormal LFT group. There were no significant changes in any other hemodynamic variables in the normal LFT group. When comparing the two groups during PM, mean arterial blood pressures and cardiac output were significantly lower in the abnormal LFT groups compared to the normal LFT groups (P< 0.05). CONCLUSIONS: These differences may suggest that cardiovascular responsiveness to reflex autonomic stimulation during the PM is significantly impaired in patients with abnormal LFT compared with normal LFT subjects.

The Effects of Pressor Response upon Intravenous Ephedrine Following Oral Clonidine Premedication in Anesthetized Patients / 대한마취과학회지

BACKGROUND: In some studies, 5 microgram/kg clonidine premedication was claimed to enhance the pressor effects of ephedrine in anesthetized patients. We studied hemodynamic responses to intravenous responses, themselves responses to intravenous ephedrine in patients who received clonidine 3 microgram/kg. METHODS: 40 ASA pysical status I or II patients were randomly assigned to either the clonidine group (n = 20), receiving oral clonidine 3 microgram/kg 90 min before general anesthesia, or the control group (n = 20), receiving no clonidine. Hemodynamic measurements were made at one-minute intervals for ten minutes after ephedrine 0.1 mg/kg was injected as a bolus. RESULTS: The magnitude of maximal systolic blood pressure increases in the clonidine group (13.2+/-9.3%) was no different in the control group (12.4+/-12.3%). There were no difference in the pressor effect and duration of response of ephedrine in both groups. CONCLUSIONS: The pressor effect of ephedrine is not enhanced in patients given 3 microgram/kg clonidine premedication during general anesthesia.