Comparision of Total Intravenous Anesthesia and Sevoflurane-N2O-Alfentanil Anesthesia for Laryngeal Microscopic Surgery / 대한마취과학회지

BACKGROUND: The aim of this study was to compare the clinical properties of sevoflurane-N2O-alfentanil with propofol- remifentanil anesthesia for patients undergoing laryngeal microscopic surgery. METHODS: Sixty patients scheduled for elective ambulatory surgery received either total intravenous anesthesia (TIVA group) with remifentanil and propofol or balanced anesthesia with sevoflurane-N2O-alfentanil (sevoflurane-N2O-alfentanil group). The TIVA group patients were induced with an effective-site concentration of 4microgram/ml propofol and a bolus dose of 0.5microgram/ml remifentanil. The anesthesia was maintained with a continuous infusions with an effective-site concentration of 2-5microgram/kg propofol and 0.05-0.5microgram/kg/min remifentanil, according to the hemodynamic response. The sevoflurane-N2O-alfentanil group patients were induced with 5 mg/kg thiopental and 20microgram/kg IV alfentanil. Maintenance was obtained with 1.5-3.0 vol% sevoflurane and a bolus dose of 10microgram/kg IV alfentanil if needed. The anesthetic depth was controlled under bispectral index (BIS) monitoring: propofol and sevoflurane concentrations were adjusted to achieve target BIS values, and were between levels of 40-60 during surgery. RESULTS: Both anesthetic methods provided acceptable hemodynamic responses during surgery. The late recovery times (postanesthetic discharge scoring system), patient satisfaction and postoperative side effects were similar between patients in the two groups. Early recovery times (eye opening and the aldrete score) were shorter in the TIVA group patients, but this difference was not associated with a shorter hospital length of stay. CONCLUSIONS: Total intravenous anesthesia with remifentanil-propofol and balanced anesthesia with sevoflurane-N2O-alfentanil both provided satisfactory anesthesia for laryngeal microscopic surgeryd

Effect of N-acetyl-cysteine on Allodynia in a Chronic Post-ischemia Pain Model of Rat

BACKGROUND: Complex regional pain syndrome type I (CRPS-I) is a clinical syndrome that is poorly understood and difficult to treat. Reactive oxygen species (ROS) and inflammatory responses may contribute to the development of CRPS-I. This study evaluated the effect of N-acetyl-cysteine (NAC) on both mechanical and cold allodynia in a rat CRPS-I model. METHODS: Male adult SD rats were used for the CRPS-I model that was produced following prolonged hindpaw ischemia/reperfusion. The rats were divided into 3 groups, Group O (-) (n = 8): rats without a tourniquet; Group O (+) (n = 8): rats received ischemic injury with a tourniquet on the hindpaw and they were reperfused 3 hours after the tourniquet application; and Group ON (+) (n = 8): rats received ischemic injury with a tourniquet ring on the hindpaw and they were reperfused 3 hours after the tourniquet application and they received intraperitoneal N-cetyl-ysteine (500 mg/kg) injection just after the tourniquet application and at 1 day and 2 days after the reperfusion. RESULTS: In the Group O (+), mechanical (von Frey hair) and cold (acetone exposure) allodynia were evident in the affected hindpaw as early as 1 day after reperfusion; this was extended for 2 weeks and it spread to the uninjured contralateral hindpaw. In the Group ON (+), the mechanical and cold allodynia were attenuated compared to those rats of Group O (+). CONCLUSIONS: NAC, a free radical scavenger, was able to reduce mechanical and cold allodynia in this model, and the generation of ROS is partly responsible for CRPS-I.

Change of Post-anesthetic Recovery Time after Colorectal Surgery with N-acetyl-cysteine Infusion / 대한마취과학회지

BACKGROUND: The gut is an important area for inflammatory responses. Gut manipulation during open laparotomy compared with laparoscopic surgery, increases the inflammatory responses. Laparoscopic assisted colectomy (LC) with less bowel manipulation might minimize the inflammatory responses and oxidative stress, and offer a faster postanesthetic recovery than an open colectomy (OC). This study evaluated the effect of N-acetyl-cysteine (NAC), an antioxidant, on the recovery after colectomy. METHODS: 116 colorectal tumor patients were reviewed retrospectively. The patients were divided into 3 groups; LC by surgeon A (A - L), OC by surgeon A (A - O) and OC by surgeon B (B - O). The postanesthetic recovery scores (PARS) were compared. In the prospective randomized controlled trial, the colorectal tumor patients were assigned to one of four groups; laparoscopic assisted colectomy (L - N) with NAC infusion (L + N), open colectomy (O - N) with NAC infusion (O + N). In the NAC groups, NAC (5 mg/kg/h) was infused after intubation to extubation. The PARS were compared. RESULTS: In the retrospective study, the time to reach 10 points, which satisfies the discharge criteria in the PACU, was significantly lower in the A-L group than in the other groups. In the prospective study, the time to 10 points was shorter in the O + N group than in the O-N group. NAC offered no added benefits to the L + N and L-N groups. CONCLUSIONS: NAC offered faster recovery in the OC group but not in the LC group.

Cardiovascular Responses to Endotracheal Intubation in Patients Receiving Desflurane Anesthesia for Anesthetic Induction / 대한마취과학회지

BACKGROUND: Desflurane is known to augment central and systemic sympathetic nervous activity. The present study was aimed at examining the effects of desflurane on cardiovascular responses to intubation. METHODS: Seventy-five ASA physical status I patients (aged 35-60 yr) were assigned randomly to receive one of three treatment regimens (n = 25 each): 1 minimum alveolar concentration (MAC) of sevoflurane, 1 MAC of desflurane or 2 MAC of desflurane. Anesthesia was induced with IV thiopental (5 mg/kg), while patients were ventilated with 100% oxygen. Tracheal intubation was facilitated with IV vecuronium (0.12 mg/kg). After intubation, patients received each anesthetic gas in oxygen via a semiclosed anesthesia circuit. Systolic arterial blood pressure (SAP), heart rate (HR) and rhythm, and plasma catecholamine concentrations were measured. RESULTS: The intubation resulted in immediate increases of SAP and HR in all groups; peak effects occurred within 1 min of the intubation. In addition, 2 MAC desflurane elicited a secondary hemodynamic effect at 3 to 5 min after the intubation. The plasma concentrations of norepinephrine increased significantly when measured at 1 min after intubation in all groups, and returned to preintubation values at 5 min in the 1 MAC desflurane groups, but showed further increases at 5 min in the 2 MAC group. CONCLUSIONS: These results show that 2 MAC desflurane elicits a biphasic hemodynamic response along with an augmented norepinephrine release, where the first appears within 1 min and the second at 3 to 5 min after intubation.

Difficult Extubation of Endotracheal Tube: Two case reports / 대한마취과학회지

The problem of difficult intubation is well known to anesthesiologists. However, difficulties associated with the extubation of endotracheal tubes are not common, and few reports exist. However, untoward incidents of diverse etiology can occur and the complications of difficult extubation may be fatal. We experienced 2 cases of difficult extubations. One was due to adhesion of the tube to the tracheal wall and the other was due to a fold in the deflated cuff of an excessively large-sized tube. We managed these difficult extubations by rotating the tube with a MaGill forcep under direct laryngoscopy. We report upon these clinical experiences and include a brief review of the literature.

The Effect of Calcium Chloride on Hemodynamic Responses to Protamine Sulfate in the Dog / 대한마취과학회지

BACKGROUND: Protamine sulfate (PS), used to neutralize the effect of heparin, is often associated with systemic hypotension. The present study was aimed to investigate the protective effects of CaCl2 on adverse hemodynamic reaction to PS. METHODS: Forty-six dogs of three groups were studied. Animals were randomly allocated to receive either; saline 10 ml (controls, n = 26), CaCl2 5 mg/kg (n = 10) or 10 mg/kg (n = 10), added to PS 3 mg/kg given intravenously 5 min after heparin (300 IU/kg, iv). Mean aortic pressure (MAP), mean pulmonary arterial pressure (MPAP), left ventricular end-diastolic pressure (LVEDP), LVdP/dtmax, and -LVdP/dtmin, and pulmonary artery (cardiac output) and left circumflex blood flow (LCX flow) were recorded up to 15 min after PS. RESULTS: PS caused significant reductions in MAP (-49%), cardiac index (CI, -66%), systemic vascular resistance index (SVRI, -22%), LVEDP (-67%), LVdP/dtmax (-36%), and LVdP/dtmin (-55%), but increased MPAP (39%) and PVRI (3.8 fold), which all increases and reductions peaked 1-3 min after PS injection in the control group. The addition of CaCl2 to PS significantly attenuated reductions of MAP (-35 and -26% in CaCl2 5 and 10 mg/kg treated dogs, respectively), CI (-34 and -37%), LVdP/dtmax (-14, -11% ), and -LVdP/dtmin (-34, -21%), and increases in PVRI (1.8 and 2.4 fold). However, both doses of CaCl2 increased MPAP (48, 82%), but not SVRI (-28, -21%) or LVEDP (-73, -75%). LCX flow increased similarly in all groups (75-137%). CaCl2 5 and 10 mg/kg iv increased plasma Ca2+ by 0.23 and 0.36 mM, respectively. CONCLUSIONS: These results suggest that the simultaneous administration of CaCl2 attenuates the adverse hemodynamic effects of PS, used to reverse heparin anticoagulation in the dog.

Effects of Amrinone on Regional Myocardial Function and Oxygen Balance in Stunned Myocardium in Dogs / 대한마취과학회지

BACKGROUND: Brief myocardial ischaemia has been demonstrated to result in mechanical and coronary endothelial dysfunction. We examined whether the mechanical and vascular responses to amrinone are altered in the postischaemic, reperfused myocardium. The effects of amrinone were compared with those of dobutamine. METHODS: In an open-chest canine model, coronary blood flow (CBF), myocardial oxygen consumption (MVO2), and regional mechanical function in response to either amrinone (2, 5, 7.5, and 10 ng/mL of CBF) or dobutamine (0.05, 0.125, 0.25, 0.375, and 10ng/mL of CBF) directly infused into the left anterior descending (LAD) artery were determined before (normal) and 30 min after 15-min- period of LAD occlusion (stunned). Percent segment shortening (%SS), peak segment lengthening rate (dL/dt(max)), and percent post-systolic shortening (%PSS) in the LAD territory was determined using ultrasonic crystals and CBF using Doppler transducer. Myocardial extractions of oxygen (EO2) and lactate (Elac) were calculated. RESULTS: Both amrinone and dobutamine in the normal myocardium caused a dose-dependent increase in mechanical functions (%SS and dL/dt(max)) and MVO2 that were comparable (range, 20 40%), but they had no effects on %PSS. Amrinone caused an increase of CBF in excess of MVO2, resulting in a modest decrease in EO2, whereas dobutamine increased CBF in proportion to MVO2, resulting in no changes in EO2. The ischemia and reperfusion insult reduced %SS, dL/dt(max), and Elac, while it did not affect mechanical (%SS and dL/dt(max)) and CBF responses to either agent, except for progressive reductions of %PSS. CONCLUSIONS: These results indicate that amrinone, similar to dobutamine, exert positive inotropic and lusitropic effects in normal and stunned canine myocardium. It is also indicated that amrinone causes direct coronary vasodilation, which is not affected by an ischemia and reperfusion insult.

Effect of Calcium Chloride on Protamine Sulfate-Induced Systemic Hypotension in Adult Open-Heart Patients / 대한마취과학회지

BACKGROUND: Protamine sulfate (PS), used to neutralize the anticoagulant effect of heparin, is often associated with systemic hypotension. The present study was aimed to investigate the protective effects of calcium chloride (CaCl2) on adverse hemodynamic reactions to PS in patients undergoing open heart surgery. METHODS: After IRB approval, sixty-one patients undergoing open heart surgery were allocated randomly to receive either saline 10 ml (control group, n = 26), CaCl2 5 mg/kg (CaCl2 5 group, n = 18) or 10 mg/kg (CaCl2 10 group, n = 18), added to PS 3 mg/kg given over 3 min through the right atrium to reverse heparinization. Hemodynamic measurements, including systolic (SAP), diastolic (DAP), and mean arterial pressure (MAP), heart rate, and central venous pressure (CVP) were continuously recorded in a baseline condition and up to 10 minutes after PS infusion. Plasma Ca2+ level and arterial blood gas tension were also measured. RESULTS: PS caused immediate and significant decreases in SAP, DAP, and MAP in all three groups. However, the degree of hypotension was significantly less in the CaCl2 10 group than in the CaCl2 5 and control groups. Heart rate and CVP remained unchanged throughout the study in all groups. Intravenous CaCl2 5 and 10 mg/kg IV caused an increase in plasma Ca2 by 0.13 +/- 0.08 mM and 0.45 0.08 mM at 2 min after its injection, respectively. Arterial oxygen tension did not change significantly throughout the study in any group. CONCLUSIONS: These results suggest that simultaneous administration of 10 mg/kg CaCl2 attenuates the hypotensive effect of PS used to reverse heparin anticoagulation in patients undergoing open heart surgery. However, hypotensive reactions may still occur.

Effects of Sildenafil Citrate on Sodium Nitroprusside and Nitroglycerin-Induced Hypotension in Dogs / 대한마취과학회지

BACKGROUND: Nitrovasodilators are known to induce hypotension through activating nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) pathway. By inhibiting the breakdown of cGMP, sildenafil citrate may augment the nitrovasodilator-induced hypotension. The present study was aimed to investigate whether sildenafil would reduce the dose of nitrovasodilators needed to induce the hypotension. METHODS: Ten mongrel dogs were acutely instrumented with a femoral artery catheter and a pulmonary artery catheter. They were intravenously given sodium nitroprusside (SNP; 1-16ng/kg/min) or nitroglycerin (NTG; 2 - 32ng/kg/min) to induce hypotension. The study was composed of two occasions in each animal: one with sildenafil pretreatment (1 mg/kg IV followed by 0.3 mg/kg/h) and the other without to serve as control, one week apart. Hemodynamic parameters were continuously monitored. Plasma cGMP concentrations were measured by radioimmunoassay. RESULTS: Both SNP and NTG produced dose-dependent reductions in mean arterial pressure (MAP) without affecting the heart rate in both the control and sildenafil groups. Systemic vascular resistance index (SVRI) and mean pulmonary arterial pressure were also decreased. However, SNP caused a greater reduction of MAP and SVRI in the sildenafil group than in the control group; whereas, NTP caused similar reductions in both groups. Neither SNP nor NTG altered the plasma cGMP concentrations. Sildenafil increased the plasma cGMP concentration, which was further increased by SNP, but not by NTG. CONCLUSIONS: These results indicate that sildenafil may reduce the dose of SNP, but not that of NTG needed to produce hypotension in the dog. The potentiation of SNP-induced hypotension by sildenafil may be related to an augmented cGMP effect.

Effects of Fentanyl and Morphine on Epinephrine - induced Arrhythmia in Halothane Anesthetized Dogs / 대한마취과학회지

The purpose of this study was to elucidate the effects of fentanyl and morphine on the ability of epinephrine to induce arrhythmias in halothane-anesthetized dogs. Epinephrine was infused in progressively increasing doses from 0.5 ug/kg/min. Arrhythmogenic dose of epinephrine(ADE), defined as that induces 4 or more premature ventricular contractions within 15 s during 3 min iafusions of epinephrine, was determined before(control) and after pretreatment of either fentanyl(6 ug/kg i.v. plus 6 pg/kg/hr) or morphine(0.2mg/kg i.v. plus 0.2 mg/kg/hr). Blood pressure and heart rate were also measured immediately before(baseline), immediately after infusion of epinephrine. The results were as follows. l) Fentanyl and morphine increased ADE by 37%(2.19+/-0.49 to 3.00+/-0.44 ug/kg/min, p<0.01) and by 43%(2.50+/-0.60 to 3.58+/-0.93 ug/kg/min, p<0.05), respectively. 2) Percent increases in systolic blood pressure at control were similar to those after pretreatment with fentanyl or morphine in both groups, but systolic blood pressures at the time of arrhythmia after pretreatment were lower than those at control in fentanyl(p<0.05) and morphine group(NS). 3) Fentanyl and morphine decreased heart rate by 27%(127+/-8 to 93+/-6 beats/min, p<0.001) and by 13%(118+/-5 to 103+/-5 beats/min, p<0.05), respectively. These results suggest that fentanyl or morphine inhibits epinephrine induced arrhythmias during halothane-oxygen anesthesia. Thus, pretreatment of surgical patients, who were supposed to receive epinephrine during halothane anesthesia, with either fentanyl or morphine might be safe.

Effects of Halothane and Fentanyl Anesthesia on Coronary Endothelial Endothelin-1 Production During Myocardial Ischemia-Reperfusion in Dogs / 대한마취과학회지

Endothelin(ET), is the most potent endogenous vasoconstrictor. Myocardial ischemia and chemical stimuli including calcium ionophores are known to release ET-1. Recently, halothane has been shown to block calcium channel. Thus, halothane might attenuate coronary endothelial ET-1 production during myocardial ischemia-reperfusion. To test this hypothesis, we measured plasma ET-1 level continuously in open chest dogs subjected to 15 min of left anterior coronary arterial occlusion and 1 hour of reperfusion during fentanly(n=8) or halothane(n=7) anesthesia. The results were as follows. I) Baseline ET-1 levels of both femoral artery and great cardiac vein in the halothane group were lower than in the fentanly group(NS). 2) ET-1 level of femoral artery and great coronary vein in both halothane and fentanyl group remained unchanged 10 min into ischemia. 3) Coronary blood flow increased by 325, 250% in the halothane group and by 315, 258% in the fentanly group 2, 5 min into reperfusion, respectively. 4) ET-1 production increased from baseline of -2.9+/-1.7 pg/min to 66.0+/-21.5(p<0.05), 20.8+/-5.1 (p<0.01), 13.2+/-6.2(p<0.05) pg/min 5, 15, 30 min into reperfusion, respectively in the fentanyl group, but it remained unchanged from baseline of 0.8+/-3.1 pg/min in the halothane group. These findings suggest that ET-1 production or release is diminished by halothane during myocardial ischemia-reperfusion. Thus, halothane provides an advantage over fentanyl in patients with myocarial ischemic episodes.

Cardiovascular Effect of Lidocaine in Patients under Halothane , Enflurane and Diazepam Anesthesia / 대한마취과학회지

To evaluate the cardiovascular effect of lidocaine and serum electrolytes during inhalational or intravenous anesthesia, thirty-two healthy patients were randomly divided into three groups and measured systolic pressure, diastolic pressure, mean pressure, heart rate and serum K+ and Na+ level were measured at 30 sec, l, 3, 6, 12 minutes after intravenous injection of lidocaine(1.5 mg/kg) during halothane-N2O-O2 or enflurane-N2O-O2 or diazepam-N2O-O2 anesthesia. In all 3 groups, the values of hemodynamic and serum electrolytes were not changed by 2% lidocaine. These results indicate that intravenous injection of lidocaine(1.5 mg/kg) to prevent undesirable reflexes and to prevent intracranial hypertension is a safe method without depression of hemodynamics.

Comparison of Propofol and Thiopental Anesthesia for Ambulatory Surgery / 대한마취과학회지

The purpose of the present study was to compare prapofol, newly introduced anesthetic agnet, & thiopental as to the characteristics of induction & recovery as well as the safety of both anents. Fifty patients who presented for termination of pregnancy were allocated at random to recieve either propofol 2 mg/kg IV or thiopental 4 mg/kg IV. In addition all patients recevied fentanyl, 1 ug/kg IV, one minute befor the induction. Repeated bolus doses of either propofol 20 mg or thiopental 50 mg were given, if the patient respond to surgical stimulation by moving. The result were as follows. 1) Both propofol and thiopental produced smooth and rapid induction, but caused significant respiratory depression. 2) There was more cardiovascular depression with propofol than with thiopental. 3) Postoperative recovery(time to ambulation) was faster with propofol than with thiopental (36.5+/-1.4 vs 72.9+/-5.1 min, p<0.001). 4) Propofol was associated with less side effects(Nausea, vomithing, and dizziness) than thiopental. These results suggest 1) that propofol has significant advantage over thiopental in outpatient surgery, where early ambulation and discharge is desirable, and 2) that both propofol and thiopental should be administered by expert anesthesiologist only when ventiatory assistant device with oxygen is immediately available.

The Studies on the Epinephrine - Induced Arrhythmias During Halothane Anesthesia in Dogs / 대한마취과학회지

It is known that the concurrent administration of epinephrine, whether applied subcutaneously or parenterally during halothane anesthesia, can result in the initiation of ventrieular arrhythmias, which may be life threatening. However the mechanism by which halothane sensitizes the heart to catecholamines are not known yet. The purpose of this study was to investigate the mechanism of epinephrine induced cardiac arrhythmias during 1.2 MAC halothane anesthesia in dogs. Thirty-eight dogs were randomly assigned to five groups, halothane anesthesia were measured the arrythmogenic doses of epinephrine(ADE) before and after each treatment with sodium nitroprusside (SNP) (n=9), lidocaine(n=7), propranolol(n=7), prazosin(n=7) and verapamil(n=8), and compared each other. The results were follows. 1) The control ADE to induce ventricular arrhythmias was 2.160.15 ug/kg/min. 2) Treatment with SNP resulted in a decrease(28%) in mean blood pressure, but did not increase the ADE compared to the control. 3) Lidocaine and propranolol significantly increased the control ADE by 1.5 times, respectively, but there was no different between the ADE of lidocaine and that of propranolol. 4) Prazosin and verapamil also significantly increased the control ADE by 3.3 times and 2.6 times respectively, and the increased amplitudes were significant greater than the effect noted after lidocaine or propranolol treatment. There results suggest that the mechanism of epinephrine-induced cardiac arrhythmias during halothane anesthesia is mainly mediated via alpha-1 receptor and calcium channel, and alpha-1 blocker and calcium channel blocker may be useful to prevent the epinephrine-induced cardiac arrhythmias during halothane anesthesia.

Utility of the Preoperative Electrocardiographic Screening / 대한마취과학회지

In order to evaluate the utility af routine preoperative 12 lead eleetrocardiogram, 4,089 patients aged above 16 years who were scheduled for elective surgical operations under general or regional anesthesia at Chonnam University Hospital from September 1988 to August 1990 were analysed retrospectively in terms of age, sex and specific abnormal ECG findings that may alter anesthetic management. The results were as follows. 1) Among the total 4,089 patients, abnormal ECG findings were noted in 2,094 patients (51.2%) and more frequently noted in male (57.3%, 1,231/2,149) than female (44.5%, 863/1,940), and there was significant inrease in its frequency above the age of middle 6 decades. 2) Ventrieular hypertrophy was noted in 19.3% of the total subjects and more frequently noted in male (24.2%) than female (13.7%), and there was significant increase in its frequency above the age of middle 6 decades. 3) Atrioventricular block was noted in 1.8% of the total subjects with 2.1% of male and 1.5% of female, and there was no significant difference in its frequency between each sex and age. 4) Bundle branch block was noted in 5.3% of the total subjects and more frequently noted in male (6.8%) than female (3.7%), and there was significant increase in its frequency above the age of middle 6 decades. 5) ST-T wave abnormality was noted in 3% of the total subjects and more frequently noted in female (4.2%) than male (2.0%) and there was no significant difference in its frequecy between each age groups in male, but the female in respect to male, showed significant increased frequency from the age of middle 5 decades to middle 7 decades. 6) Myocardial infarction was noted in 1.5% of the total subjects with 1.7% of male and 1.2% of female, and there was no significant difference in its frequency between each sex groups but there was significant increase in its frequency above the age of sixty five. 7) Cardiac arrhythmia was noted in 2.8% of the total subjects with 3.0% of male and 2.5% of female, and there was no significant difference in its frenquecy between each sex groups but there was significant increase above the age of sixty five. From the above results, it is essential to check the preoperative 12 lead ECG before emergency operation, and to keep a more careful cautions in mind during anesthetic management for patients above the age of middle 6 decaeds.

Effects of Adenosine Triphosphate Triphosphate on Hemodynamics and Intrapulmonary Shunting in Ethrane - N2O Anesthetized Man / 대한마취과학회지

In order to evaluate the efficacy of adenosine triphosphate (ATP) in the reduction of left ventricular afterload, we studied the hemodynamic and intrapulmonary shunt effects of intravenous ATP during ethrane-N2O anesthesia. Hemodynamic measurements and arterial and mixed venous blood gas analyses were made in ten patients before (baseline) and 10 min after. ATP infusion at 80,60,120 and 250 mcg/kg/min, respective. The results were as follows: 1) ATP produced a rapid and stable reduction in mean arterial pressure resulting from a marked decrease in systemic vascular resistance. 2) Cardiac index increased significantly by 14, 47 and 72% from baseline value after intravenous infusion of ATP at rates of 60, 120 and 250 mcg/kg/min, respectively. 3) Stroke volume index, heart rate, mean pulmonary arterial pressure, pulmonary capillary wedge pressure and central venous pressure increased significantly, whereas systemic vasular resistance and pulmonary vascular resistance decreased significantly in a dose related fashion during ATP infusion. 4) Intrapulmonary ehunt fraction increased from 5.67% to 6.73, 8.28, 9.85 and 13.38% after intra- venous infusion of ATP at rates of 30, 60, 120 and 250 mcg/kg/min, respectively. 5) Arterial oxygen tension decreased significantly after ATP infusion. These results suggest that ATP might be of value in augmentation of cardiac performance in patients with low cardiac output with high peripheral vascular resistance.

Effects of Verapamil and Propranolol on Hemodynamic Responses to Laryngoscopy and Tracheal Intubation in Hypertensive Patients / 대한마취과학회지

Laryngoscopy and endotracheal intubation in patients undergoing general anesthesia causes hypertension and tachycardia with concomitant increases in plasma catecholamine concentration. These transient stress responses are greatly exaggerated in patients with hypertension and cardiovascular disease and can lead to cardiac arrhythmia, pulmonary edema, cardiac failure and cerebral hemorrhage. Therefore, several attempts have been made to attenuate the hypertensive and tachycardiac responses, but none have been satisfactory. This study was designed to evaluate verapamil or propranolol as a valuable adjuvant in attenuating hemodynamic responses to tracheal intubation in 53 patients with hypertension. They were randomly divided into three groups according to premedication used. Group 1 (n=19) was without pretreatment, and group 2 (n=18) and group 3 (n=16) were pretreated with verapamil (0.1 mg/kg) iv and verapamil (0. 1 mg/kg)-propranolol (0.01 mg/kg) mixture iv, respectively, just prior to the intubation. Mean arterial pressure (MAP) and heart rate (HR) were measured, just prior to intubation (baseline), after induction, and at 1, 2, 3, 4, 5 and 7 minutes following intubation. The results were as follows. 1) In the control group. tracheal intubation produced increases in MAP (27% average increase from baseline) and heart rate (31% increase) at one minute after the procedure. 2) In group 2, verapamil abolished pressor response to tracheal intubation, but did not affect tachycardiac responses. 3) In group 3, the verapamil-propranolol mixture attenuated both pressor and tachycardiac responses to tracheal intubation. 4) The rate-pressure product increased after tracheal intubation by 61% and 31% in group 1 and group 2, respectively, but it remained unchanged in group 3. These findings suggest that intravenous verapamil-propranolol mixture is a valuable adjuvant in attenuating hypertensive and tachyeardiac responses to tracheal intubation.

The Effects of Succinylcholine on Serum Potassium in Patients with Spinal Cord Lesion / 대한마취과학회지

Succinylcholine (Sch) has long been used to facilitate laryngoscopy and endotracheal intubation for general anesthesia, because of a rapid onset of intense but brief paralysis. However, exaggerated potassium (K+) release following Sch, sufficient to cause ventricular dysrhythmias and cardiac arrest, has sporadically been reported in susceptible conditions, including spinal cord injury, severe burn, massive trauma and neuromuscular disorder. And diazepam has been shown to attenuate the increase in serum K+ following Sch administration. The purpose of this study was to assess the effect of Sch on serum K+ in patients with spinal cord lesions, and to assess the effect of pretreatment with diazepam (0.05 mg/kg IV) on potassium flux. The results were as follows: 1) Baseline K+ values were not significantly different among the groups. 2) The time to peak increases in K+ was 3 minutes following Sch in all groups. 3) The magnitude of maximum increases in K' following Sch were 0.32 Eq/l, 0.63 mEq/l, 0.06 mEq/I and 1,10 mEq/I in group 1, group 2A, group 2B, and group 3, respectively. 4) Diazepam pretreatment attenuated the increases in K+ following Sch. From the above results, it can be concluded that Sch may safely be used to facilitate intubation in paraplegic patients, provided that they are normokalemic and pretreated with diazepam.

Influence of Verapamil Pretreatment on Hemodynamic Responses & Pulmonary Gas Exchange during Sodium Nitroprusside Induced Hypotension in Isoflurane-N2O Anesthetized Man / 대한마취과학회지

Controlled hypotension induced with sodium nitroprusside (SNP) has been most widely used to facilitate the surgical procedure and to reduce blood loss. However, major problem with its clinical use is cyanide toxicity, which is dose related. And resitance and tachyphylaxis, probably being mediated by sympathoadrenal response to lowered blood pressure, is known to increase dose requirements. Accordingly, several attempts have been made to attenuate sympathetic activity and therefore to reduce dose requirement of SNP. Verapamil, a representative calcium channel blocker, exerts inotropic and chronotropic effect, as well as vasodilation. And it is, also, known to impair pulmonary gas exchange. The purpose of these experiments was to evaluate hemodynamic and gas exchange effects of verapamil, and also its efficacy for reducing the amount of SNP during induced hypotension in patients anesthetized with isoflurane and N2O. Twenty five patients, scheduled to undergo general anesthesia with hypotension, were randomly assigned to two groups. Twelve patients were pretreated with verapamil (160mg, SOD: verapamil group) and the other thirteen were not (control group). The results were as follows: 1) Cardiac index remained unchanged in both groups and did not differ significantly between groups at all times. 2) Heart rate was significatly lower in verapamil group than in control group in the hypotensive period. (113+/- 3.3 vs 103+/- 2.7, p < 0.05) 3) Hypotension induced by SNP resulted from a marked decrease in systemic vascular resistance in both groups. 4) MPAP, PCWP, CVP, SVR and PVR significantly decreased after SNP infusion in both groups, but they did not differ significantly between the groups at all times. 5) SNP dose requirements to attain the same MAP reduction did not differ significantly between groups. (5.5+/-0.8vs 4.1+/-0.8mcg/kg/min, NS) 6) Verapamil pretreatment produced no significant change in intrapulmonary shunt fraction at all times. 7) SNP caused a signficant decrease in arterial oxygen tension in both group, but there were no significant difference between groups at all times. From the above results, it might be concluded 1) that verapamil, in clinical doses, does not blunt a reflex increase in sympathetic activity in response to SNP induced vasodilation, since it produced only a minor influence on SNP induced hemodynamics and the SNP dose requirements, and that verapamil does not inhibit hypoxic pulmonary vasoconstriction during isoflurane-N2O anesthesia. Thus, verapamil could not be a valuable adjunct of SNP in enhancing the hypotensive effect in spite of preserved arterial oxygenation.

Effects of Intravenous Verapamil on Hemodynamics and Pulmonary Gas Exchanges in Isoflurane-N2O-O2 Anesthetized Man / 대한마취과학회지

The purpose of this study was to evaluate the effects of verapamil on hemodynamics and pulmonary gas exchanges during isoflurane-N2O-O2(FIO2, 50%) anesthesia. Hemodynamic measurements and arterial and mixed venous blood gas analyses were made in thirteen healthy patients immediately before (control) and at 1, 5,10min after 5mg of intravenous verapamil administration as single bolus. 1) Verapamil produced a rapid and transient reduction of 15% in mean arterial pressure resulting from a decrease in systemic vascular resistance. 2) Heart rate and cardiac index increased by 14%, 9% respectively only immediately after i.v. verapamil injection and restored thereafter toward control values. 3) SVI, MPAP, PCWP, PVR and CVP revealed only minor changes. 4) Verapamil did not cause any significant changes in intrapulmonary shunt. These findings suggest that during isoflurane-N2O-O2(50%) anesthesia verapamil might safely be used, even in the presence of ventilation/perfusion inequalities, (i.e. lung disease, one lung anesthesia) provided patient has good cardiovascular reserve.