The Effect of Isoflurane and Thoracic Epidural Anesthesia on Arterial Oxygenation in One Lung Anesthesia / 대한마취과학회지

BACKGROUND: During one lung ventilation (OLV) for thoracic surgery, hypoxic pulmonary vasoconstriction (HPV) may reduce venous admixture and ameliorate the decrease in arterial oxygenation by diverting blood from the non-ventilated to the ventilated lung. Volatile anesthethics are the drugs of choice in thoracic surgery despite numerous experimental data showing their inhibiting effect on the HPV. The effect of thoracic epidural anesthesia (TEA) on HPV during OLV has not been determined. The object of the present study was to compare the effects of TEA with those of isoflurane on oxygenation and shunting during two lung ventilation (TLV) and OLV in human volunteers. METHODS: Thirty patients who needed OLV for elective thoracic surgery were randomly assigned to receive either group isoflurane (1 MAC isoflurane + saline 6 ml TEA + 0.5 - 1ng/dl propofol + fentanyl + vecuronium, n = 15) and group TEA (0.5% bupivacaine 6 ml TEA + 0.5 - 1ng/dl propofol + fentanyl + vecuronium, n = 15) with 100% oxygen in separate groups. Systemic hemodynamic parameters were recorded, and blood gas values were obtained 30 min after the start of TLV and 30, 45 and 60 min after the start of OLV in the lateral position. RESULTS: Reductions in PaO2 and increases in shunt fraction at all study times after the start of OLV were observed. However, there were no differences in percentage changes between the groups. The other blood gas data (SaO2, SO2, PaCO2, PCO2, pH, Hb, CaO2, CO2) and systemic hemodynamics (mean arterial blood pressure, central venous pressure) did not change at all the study times after the start of OLV in the two groups. CONCLUSIONS: In clinical practice, isoflurane and TEA for OLV was no different in terms of arterial blood oxygenation and pulmonary shunt.

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.

Thumb Necrosis Following Radial Artery Cannulation / 대한구급학회지

Radial artery is frequently chosen for cannulation. Although the method is safe and simple, it can infrequently lead to tissue necrosis. This is a report of one case of amputation due to thumb necrosis developed from the radial artery cannulation in a patient who had open heart surgery. This is a 65 years old female who received a graft interposition of ascending aorta due to dissecting aortic aneurysm. Left radial artery cannulation was carried out after modified Allen's test appeared to be positive. On the 11 th postoperative days, we found that the catheter of left hand was obstructed, and we removed the catheter. On the 9 hrs after removal of catheter, thumb of left hand became color change and edematous with blister. On the 14 th days after removal of catheter, thumb of left hand became worsened to dusky purple to dark color change and pulseless, coldness. On the 20 th days after removal of catheter, amputation of thumb of left hand was performed.

Effects of Dobutamine and Epinephrine on Myocardial Function and Oxygen Balance in Normal and Stunned Myocardium in Dogs / 대한마취과학회지

BACKGROUND: Myocardial ischemia is known to depress systolic and diastolic functions for a prolonged period of time. Dobutamine and epinephrine are frequently administered to improve myocardial function during cardiac surgery. The vascular response to vasopressors might be altered by ischemia and reperfusion, since alterations in vascular control mechanisms have been demonstrated even after a short period of ischemia. The present study was aimed to investigate the effects of dobutamine and epinephrine on regional and global myocardial functions, coronary blood flow (CBF) and myocardial oxygen consumption (MVO2) in normal and stunned myocardium in an open-chest canine model. METHODS: Forty-eight dogs were acutely instrumented under enflurane anesthesia to measure aortic and left ventricular pressures, and pulmonary (cardiac output) and left anterior descending (LAD) blood flows via a Doppler flowmeter, and a subendocardial segment length in the region supplied by the LAD. In series 1, incremental doses of dobutamine (1, 2, 5, 10microgram/kg/min, n = 9) or epinephrine (0.02, 0.04, 0.1, 0.2microgram/kg/min, n = 10) were infused intravenously (IV) for 10 min before (normal) and after 15 min of LAD occlusion and subsequent 1 hr-reperfusion (stunned). In series 2, incremental doses of dobutamine (50, 125, 250, 375 ng/mL of LAD flow, n = 14) or epinephrine (4, 10, 20, 30 ng/mL of LAD flow, n = 15) were infused directly into the LAD (IC) for 3 5 min before (normal) and after myocardial ischemia (stunned). Segment shortening (%SS), as an index of regional myocardial contractility, and the peak segment lengthening rate (dL/dt max), as an index of regional diastolic function, were evaluated. Simultaneous arterial and coronary venous contents of oxygen and lactate were measured to calculate MVO2 and oxygen (EO2) and lactate extraction (Elac) ratios during IV or IC infusions of epinephrine or dobutamine. Effectiveness of metabolic vasodilation was determined from EO2. RESULTS: IV or IC infusions of dobutamine or epinephrine before ischemia resulted in dose-dependent increases in mechanical functions (%SS and dL/dt max) and MVO2. These changes were accompanied by parallel increases in CBF resulting in unaltered EO2 with an infusion of dobutamine, while CBF increased more than MVO2 with epinephrine, resulting in decreased EO2. After the ischemia and reperfusion, %SS and dL/dt max were depressed and Elac was reduced, but similar mechanical responses (%SS and dL/dt max) to both dobutamine & epinephrine were observed. Also, in the stunned myocardium, CBF increased in parallel with mechanical function and MVO2 with either IC or IV dobutamine, resulting in an unaltered EO2. However, IC but not IV epinephrine did not affect EO2, suggesting abolishment of its direct vasodilating effect in stunned myocardium. In addition, IC epinephrine infusion further decreased Elac, while IC dobutamine did not affect it in stunned myocardium. During IV infusions, dobutamine caused a dose-dependent increase in the heart rate but epinephrine did not affect it, despite the comparable increase in cardiac index and mean aortic pressure. CONCLUSIONS: The results indicate that dobutamine and epinephrine exert similar positive inotropic and lusitropic effects in normal and stunned myocardium in dogs. However, epinephrine causes direct coronary vasodilation in normal myocardium, but it does not directly affect coronary vascular tone in stunned myocardium. In addition, epinephrine infusion dose-dependently depresses Elac in stunned myocardium. In contrast, dobutamine affects neither direct coronary vascular tone nor Elac regardless of ischemia and reperfusion injury.

Effects of Opioids on the Contractility of Isolated Human Pregnant Uterine Muscle / 대한마취과학회지

BACKGROUND: Effects of fentanyl, sufentanil, meperidine, and morphine on the spontaneous contractility of isolated human pregnant uterine muscle strips were determined. METHODS: Uterine specimens were obtained from normal full-term parturients undergoing elective lower-segment cesarean section. Longitudinal muscle strips were made and mounted individually and vertically in tissue chambers to record their isometric tension. After establishment of rhythmic contractions in the buffer solution, opioid concentration-response curves were constructed. The responses to opioids were repeated in the presence of opioid receptor blocker, nitric oxide synthase inhibitor, beta-adrenoceptor blocker, or cyclo-oxygenase inhibitor. RESULTS: Fentanyl and meperidine caused concentration-dependent decreases of the uterine contractility, their IC50 (concentration which causes 50% inhibition of the amplitude of spontaneous contractions) being 6.8 x 10(-6) M and 2.2 x 10(-3) M, respectively. On the contrary, sufentanil and morphine were without significant effects on the contractility. Pretreatment with either naloxone, N(G)-nitro-L-arginine methyl ester, atenolol, or indomethacin did not affect the uterine responses to opioids. CONCLUSIONS: These results demonstrate that fentanyl and meperidine may have direct inhibitory effects on the contractility of the human uterus. However, the opioid concentrations needed to significantly reduce the uterine contractility were at a supraclinical range.

Effects of Desflurane and Isoflurane on Arterial Oxygenation and Intrapulmonary Shunt in One Lung Anesthesia / 대한마취과학회지

BACKGROUND: During one-lung ventilation (OLV) for thoracic surgery, hypoxic pulmonary vasoconstriction (HPV) may reduce the venous admixture and ameliorate the decrease in arterial oxygenation by diverting blood from the non-ventilated to the ventilated lung. Volatile anesthetics (halothane, enflurane, isoflurane, desflurane and sevoflurane) have been shown to depress the HPV with essentially the same potency in vitro. However, clinical studies suggest that isoflurane and sevoflurane provide superior arterial oxygenation during OLV over halothane or enflurane. However, these have not been compared with desflurane. This study compared the effects of desflurane with those of isoflurane on oxygenation & shunt during two lung ventilation (TLV) and OLV in human volunteers. METHODS: Twenty adults who needed OLV with minimal trauma to the nonventilated lung (esophageal surgery) were randomly assigned to receive either 1 MAC desflurane (n = 10) or 1 MAC isoflurane (n = 10) with 100% oxygen in separate groups. Systemic and pulmonary hemodynamic data were recorded, and blood gas values were obtained 30 min after TLV and OLV in lateral position. RESULTS: Reductions in PaO2 (445.2 +/- 72.3 to 125.9 +/- 52.5 and 483.2 +/- 86.2 to 110. 2 +/- 39.8 mmHg, in desflurane and isoflurane respectively) and increases in shunt fraction (Qs/Qt%; 17.2 +/- 3.8 to 33.1 +/- 5.7, 13.4 +/- 4.5 to 32.5 +/- 4.1, in desflurane and isoflurane respectively) at 30 min after the start of OLV were observed, but there were no differences between the groups. The other blood gas data (PaCO2, PCO2, pH, Hb, CaO2, CO2) and systemic and pulmonary hemodynamics (mean arterial blood pressure, heart rate, cardiac output, mean pulmonary arterial pressure, central venous pressure) did not change 30 min after the start of OLV in the two groups. CONCLUSIONS: In clinical practice, there was no difference between desflurane and isoflurane for OLV was no difference in the arterial blood oxygenation and the intrapulmonary shunt.

Recovery Profile after Inhalation Anesthesia Using Desflurane-N2O-O2 Versus Isoflurane-N2O-O2 / 대한마취과학회지

BACKGROUND: Desflurane is a new inhalation anesthetic with a low blood/gas solubility which should allow fast induction and emergence from anesthesia. This study was designed to compare the induction and recovery characteristics of gynecologic surgical patients receiving either desflurane or isoflurane with nitrous oxide for the maintenance of general anesthesia. METHODS: After standardized induction of anesthesia with fentanyl, propofol, succinylcholine and tracheal intubation, patients undergoing elective gynecologic surgery randomly divided into desflurane group (n=21) or isoflurane group (n=20). Induction and recovery time and the incidence of postoperative nausea and vomiting and recall were compared between the two groups. RESULTS: Although anesthetic conditions were similar during operation in the two groups, significant differences were noted in induction and recovery profiles from anesthesia. Induction time was 124+/-66 sec for desflurane vs. 422+/-257 sec for isoflurane (mean SD). The time required for the end-tidal concentration of anesthetics to decrease by 50% was 168.0+/-160.1sec for desflurane vs. 222.9+/-127.5sec for isoflurane. The time to response (eye opening follow simple command), orientation (recall of name and date of birth), reach 10 point of PAR (postanesthetic recovery) score and discharge from recovery room were significantly shorter after desflurane than after isoflurane (417.0+/-158.7 vs. 577.1+/-207.4sec, 591.0+/-193.0 vs. 800.0+/-326.0sec, 31.3+/-18.0 vs 41.8+/-15.0min, 66.9+/-27.2 vs. 80.1+/-11.8min, respectively). CONCLUSIONS: From the above study it can be concluded that a balanced anesthetic technique using desflurane as the main anesthetic has certain advantages compared with isoflurane in terms of faster emergence, however the frequency of side effects such as nausea, vomiting and recall during postoperative period were similar after both anesthetic drugs.

Relapsing Polychondritis Diagnosed after Stellate Ganglion Block: A case report / 대한마취과학회지

Relapsing polychondritis (RP) is an uncommon disorder of unknown etiology characterized by inflammation and destruction of the cartilaginous structures of many organs, including the tracheobronchial tree. We experienced a rare case of RP diagnosed after stellate ganglion block. A 56-year-old female has been treated under impression of rheumatoid arthritis and bronchial asthma for several years, but her symptoms were not markedly relieved. We performed right stellate ganglion block with 8 mL of 1% mepivacaine for the relief of the right shoulder pain. About 5 minutes later, she complained severe dyspnea and became cyanotic. Bronchoscopic finding was diffuse bronchoconstriction during expiration. We confirmed the diagnosis of relapsing polychondritis by bronchoscopic biopsy finding. Unfortunately, she died 3 months later due to recurrent pneumonia and acute respiratory distress syndrome.

A Comparison of Intravenous Morphine and Ketorolac Using Patient-Controlled Analgesia after Total Abdominal Hysterectomy / 대한마취과학회지

BACKGROUND: Intravenous (IV) morphine is commonly used for postoperative pain management. Ketorolac has been proposed as a potent analgesic for treatment of moderate to severe pain. The purpose of this study was to determine the equianalgesic dose of morphine and ketorolac using intravenous patient-controlled analgesia (IV-PCA) system in human volunteers. METHODS: Fourty-five patients undergoing elective total abdominal hysterectomy were randomly assigned to receive either morphine (n=22) or ketorolac (n=23) when postoperative pain first increased to 40/100 mm (by visual analogue scale; VAS). Until postoperative pain decreased to 40/100 mm, morphine and ketorolac group received repeated IV boluses of 3 mg of morphine and 18 mg of ketorolac respectively and then followed by a IV-PCA with morphine (basal infusion 0 mg/hr, PCA dose 1 mg/1 ml, lock-out interval 5 min) and ketorolac (basal infusion 0 mg/hr, PCA dose 5 mg/1ml, lock-out interval 5 min). Analgesic efficacy with VAS (0~100 mm), PCA demand ratio and rate, analgesics consumptions, patient satisfaction and side effects were compared. RESULTS: There were no significant differences in VAS, PCA demand ratio and patient satisfaction. Mean 48-hour morphine and ketorolac consumptions were 35 (SEM=2.9) mg and 224 (SEM=16.5) mg, respectively (ratio=1:6.4). Morphine group experienced side effects such as pruritus (45%), nausea and vomiting (41%) and respiratory depression (5%). However, ketorolac group only showed side effects such as nausea and vomiting (26%). CONCLUSION: We concluded the ratio of equianalgesic dose of morphine versus ketorolac using intravenous patient-controlled analgesia (IV-PCA) after total abdominal hysterectomy was 1 versus 6.4.

A Comparison of Intravenous Morphine and Ketorolac Using Patient-Controlled Analgesia after Total Abdominal Hysterectomy / 대한마취과학회지

BACKGROUND: Intravenous (IV) morphine is commonly used for postoperative pain management. Ketorolac has been proposed as a potent analgesic for treatment of moderate to severe pain. The purpose of this study was to determine the equianalgesic dose of morphine and ketorolac using intravenous patient-controlled analgesia (IV-PCA) system in human volunteers. METHODS: Fourty-five patients undergoing elective total abdominal hysterectomy were randomly assigned to receive either morphine (n=22) or ketorolac (n=23) when postoperative pain first increased to 40/100 mm (by visual analogue scale; VAS). Until postoperative pain decreased to 40/100 mm, morphine and ketorolac group received repeated IV boluses of 3 mg of morphine and 18 mg of ketorolac respectively and then followed by a IV-PCA with morphine (basal infusion 0 mg/hr, PCA dose 1 mg/1 ml, lock-out interval 5 min) and ketorolac (basal infusion 0 mg/hr, PCA dose 5 mg/1ml, lock-out interval 5 min). Analgesic efficacy with VAS (0~100 mm), PCA demand ratio and rate, analgesics consumptions, patient satisfaction and side effects were compared. RESULTS: There were no significant differences in VAS, PCA demand ratio and patient satisfaction. Mean 48-hour morphine and ketorolac consumptions were 35 (SEM=2.9) mg and 224 (SEM=16.5) mg, respectively (ratio=1:6.4). Morphine group experienced side effects such as pruritus (45%), nausea and vomiting (41%) and respiratory depression (5%). However, ketorolac group only showed side effects such as nausea and vomiting (26%). CONCLUSION: We concluded the ratio of equianalgesic dose of morphine versus ketorolac using intravenous patient-controlled analgesia (IV-PCA) after total abdominal hysterectomy was 1 versus 6.4.

Clinical Survey of Patients in the Post-Anesthesia Care Unit / 대한구급학회지

BACKGOUND: The purpose of this study was to evaluate characteristics and mortality rates of patients admitted to the post-anesthesia care unit (PACU) for obtaining the better clinical guidances and more advanced therapeutic plan in the future. METHODS: The medical records of total 425 patients admitted to the PACU from January to December 1998 were reviewed and analyzed according to age, sex, department, duration of stay, mechanical ventilator care, and mortality rates. RESULTS: Patients admitted PACU were 6% of total anesthesia patients. The ratio of male to female was 1.5:1. Patients of manhood aged from 45 to 64 were 37%, pediatric patients under 15 year-old were 23%. and elderly patients over 64 year-old were 18% of total PACU patients. The ratio of patients with ventilatory support was 42%. Mortality rate of neonate under 1 month of age was about 47%. Total mortality rate was 12%. CONCLUSIONS: To improve the outcome of the patients in PACU, continuous nutritional and medical support, cardiovascular and pulmonary monitoring, appropriate nursing care, and availability of medical staff were needed.

Effects of Inhibition of Endogenous Nitric Oxide System on Regional Myocardial Function and Systemic Hemodynamics in Anesthetized Dogs / 대한마취과학회지

BACKGROUND: The present study was aimed (1) to assess the effects of nitric oxide (NO) synthesis inhibitor on regional myocardial function and systemic and pulmonary hemodynamics; (2) to determine whether the blockade of the cyclo-oxygenase (COX) pathway modifies these effects on the variables, and (3) to investigate the mechanism of cardiac depression following NO synthesis inhibition in an open-chest canine model. METHODS: Twenty-five dogs of either sex were acutely instrumented under 1.6% ethrane anesthesia to measure aortic, pulmonary arterial and left ventricular pressure, pulmonary (cardiac output) and left circumflex coronary flow, and subendocardial segment length. NG-nitro-L-arginine methyl ester (L- NAME) at doses of 0.3, 1.0, 3.0, or 10.0 mg/kg i.v. was administered alone (control dogs, n = 10) or in the presence of COX inhibitor, indomethacin (10 mg/kg i.v., n = 10). Seven dogs (n = 7) received phenylephrine at doses of 0.1, 0.3, 1.0, or 3.0 microgram/kg/min i.v. to compare its hemodynamic effects with those of L-NAME. The preload recruitable stroke work slope (Mw) and percent systolic shortening (%SS) as an index of regional myocardial contractility, and the maximum segment lengthening rate (dL/dt max) and percent post-systolic shortening (%PSS) as an index of regional diastolic function, were evaluated. RESULTS: L-NAME dose-dependantly attenuated both regional systolic (Mw and %SS) and diastolic functions (dL/dt max and %PSS), whereas it caused an increase of coronary flow. L-NAME dose- dependently increased systemic blood pressure and vascular resistance as well as pulmonary arterial pressure and vascular resistance. L-NAME also reduced cardiac and stroke volume indices. Pretreatment with indomethacin did not affect the regional myocardial and systemic hemodynamic responses to L-NAME, but did blunt the coronary flow and pulmonary pressure responses. The magnitude of decreases in cardiac and stroke volume indices and Mw was greater with L-NAME than with phenylephrine (P <0.05), despite the comparable blood pressure increases. CONCLUSIONS:These results suggest (1) that NO plays a significant role in cardiac function as well as in systemic and pulmonary but not coronary, vasomotor activities, and (2) that COX products are involved in pulmonary hemodynamic responses to NO synthesis inhibition. It is also suggested that the decline in cardiac output following the NO synthesis inhibition results from a direct myocardial depressant effect of the drug.

Effects of Epidural Ketamine for Postoperative Pain Management / 대한마취과학회지

BACKGROUND: Ketamine hydrochloride, NMDA receptor antagonist is a potent analgesic and anesthetic. Other analgesics, like opioid, have been shown to effectively relieve postoperative pain when infused into epidural space, but effects of ketamine hydrochloride infused into epidrual space for postoperative pain control is still controversial, and therefore the present study was undertaken. METHODS: Ninety adult patients (ASA I or II) scheduled for upper abdominal and chest surgery were randomized into ketamine and fentanyl groups. For all patients, informed consent was obtained preoperatively. Anesthesia was induced with thiopental sodium/succinylcholine and maintained with nitrous oxide/oxygen/enflurane. Skeletal muscle relaxation was maintained with vecuronium. Epidural catheterization was done after operation. Ketamine group received epidural bolus of 0.1% bupivacaine 10 ml followed by continuous epidural infusion of 0.1% bupivacaine 100 ml containing ketamine 200 mg. Fentanyl group received epidural bolus of 0.1% bupivacaine 10 ml containing fentanyl 100 microgram followed by continuous epidural infusion of 0.1% bupivacaine 100 ml containing fentanyl 600 microgram. Continuous infusion rate was 2 ml/hr in both groups. Analgesic effects were assessed using VAS (visual analogue score), PHS (Prince Henry score) and PRS (pain relief score). Side effects and number of patients using additional analgesics were evaluated. RESULTS: Analgesic effects were significant in both group after drug administration. But fentanyl group had greater analgesic effects than ketamine group. Fentanyl group experienced side effects such as pruritus (27 cases), nausea and vomiting (9 cases). Ketamine group had side effects such as nausea and vomiting (13 cases). Number of patients using additional analgesics were seven and twenty-four in the fentanyl and ketamine groups, respectively. CONCLUSIONS: We conclued continuous epidural infusion of ketamine had fewer analgesics effect at early state of postoperative pain than fentanyl.

Influence of Acute Pulmonary Hypertension on the Protamine-induced Systemic Hypotension in the Heparinized Dog / 대한마취과학회지

INTRODUCTION: The present study was aimed to investigate the hemodynamic effects of protamine and to determine whether the increases of pulmonary arterial pressure (deltaPAP) after protamine is related to development of systemic hypotension in heparinized dogs. METHODS: Nineteen mongrel dogs were acutely instrumented during 1.5% halothane anesthesia. All dogs then received protamine 3 mg.kg (-1) over a period of 30 s given through right atrium 5 minutes after heparin (300 IU.kg (-1), iv). Animals were retrospectively assigned into two groups, control (deltaPAP<6 mmHg, n=9) and pulmonary hypertensive (PHT, deltaPAP<6 mmHg, n=10) groups. Mean arterial pressure (MAP), mean pulmonary arterial pressure (MPAP), left ventricular pressure, heart rate (HR), and cardiac output and left circumflex coronary flow (LCX flow) via Doppler flowmeter were continuously recorded throughout the experiments. Changes in MPAP were related to changes in MAP using standard regression analysis. RESULTS: MPAP (66% in PHT vs 7% in control group) and pulmonary vascular resistance index (5.1- vs 3.0-fold) increased more markedly immediately after protamine administration in PHT group than in control group. However, protamine caused similar reductions of MAP (-40 vs -46%), cardiac index (-60 vs -59%), and left ventricular end- diastolic pressure (-47 vs -53%) in both groups. No correlation was found between deltaPAP and deltaMAP in either group. LCX flow increased significantly but similarly immediately after protamine in both groups (183 vs 238%), indicating rapid release of potent vasodilator. CONCLUSIONS: These results suggest that, in heparinized dogs, protamine produces transient severe hypotension but does not consistently elevate pulmonary arterial pressure and, that acute pulmonary vasoconstriction does not play a major role in protamine-induced hypotension.

Mechanism of the Hypotension Produced Protamine Sulfate in Dogs / 대한마취과학회지

INTRODUCTION: Protamine reversal of heparin anticoagulation often produces profound hypotension. However, the precise mechanisms of its hypotensive effect have not been fully elucidated. Using a canine model, we explored the effects of cyclo-oxygenase inhibitor, indomethacin (INDO), and nitric oxide synthetase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME) either alone or both on the cardiopulmonary responses to protamine. METHODS: Fifty-four mongrel dogs in five groups were studied during 1.5% halothane anesthesia. GroupI (n=17) received heparin (300 IU/kg iv) followed by protamine (3 mg/kg iv over 30 s) 5 min after the heparin. The same protocol were used in groups II (n=11), III (n=12), and IV (n=7), except that L-NAME (20 mg/kg), INDO (10 mg/kg), and INDO (10 mg/kg) plus L-NAME (10 mg/kg) were infused over 10 min beginning 30 min before the protamine injection, respectively. Animals in group V (n=7) were given protamine (3 mg/kg) alone. Mean arterial pressure (MAP), mean pulmonary arterial pressure (MPAP), left ventricular end-diastolic pressure (LVEDP), LVdP/dt and cardiac output and left circumflex coronary flow (LCX flow) via Doppler flowmeter and heart rate were continuously recorded in baseline conditions and up to 15 min. Plasma NOx (NO2-, NO3-) levels were also measured before (baseline) and 3, 5, 10, and 15 min after protamine injection. RESULTS: In group I, protamine caused immediate but transient decreases of MAP (41%), cardiac index (CI, 58%), dP/dt (28%), and LVEDP (62%) and increases of MPAP (38%) and systemic and pulmonary vascular resistance indices (SVRI, 30%; PVRI, 316%). INDO significantly attenuated the hemodynamic responses to protamine, whereas L-NAME did not affect them at all. INDO plus L-NAME prevented protamine-induced hypotension, but CI (-24%) and LVEDP (-30%) showed similar changes as those in group II. Protamine increased MPAP but inconsistently, meanwhile no correlation was found between the magnitude of increase of MPAP and decrease of MAP at peak responses in groups I-IV. LCX flow increased significantly (124~188%) immediately after protamine infusion without any changes in plasma NOx levels in groups I-IV. Neither significant hemodynamic effects nor NOx release was found in animals given protamine alone. CONCLUSION: Protamine in the presence of heparin induces profound hypotension which may be mediated by a prostanoid and other potent vasodilators. In addition, increase of PAP and NO release may not play a significant role in the protamine-induced hypotension.

Effect of Propofol on Regional Myocardial Function and Metabolism in the Canine Stunned Myocardium / 대한마취과학회지

BACKGROUND: A brief period of coronary artery occlusion followed by reperfusion is known to produce prolonged period of ventricular dysfunction without necrosis (myocardial stunning). The present study was aimed to investigate the effects of propofol on regional myocardial functions and metabolism in postischemic stunned myocardium in an open-chest canine model. METHODS: Twenty-two dogs were acutely instrumented under halothane anesthesia to measure aortic and left ventricular pressure, pulmonary, left anterior descending (LAD) and circumflex (LCX) coronary artery flow, and subendocardial segment length in both the regions supplied by LAD and LCX. All animals were then subjected to a 15 min of LAD occlusion and subsequent reperfusion. In the expermental group (n=12), after 30 min of reperfusion halothane was replaced by a bolus of 5 mg.kg 1 of propofol followed by a continuous infusion for 30 min at 0.2 (baseline), 0.3, 0.4, and 0.5 mg.kg 1.min 1, whereas halothane was maintained without propofol infusion throughout the reperfusion period in the control group (n=10). Percent segment shortening (%SS) and the preload recruitable stroke work slope (Mw), as an index of regional myocardial contractility, and peak lengthening rate (dL/dtmax) and percent post-systolic shortening (%PSS), as an index of regional diastolic function, were evaluated. Metabolic data were determined from simultaneous arterial and coronary venous measurements of oxygen and lactate. RESULTS: Significant and dose-dependent decreases in both %SS (8.8 +/- 1.7 at 0.2 to 6.5 +/-1.6% at the 0.5 mg.kg 1.min 1 infusion) and Mw (1.45 +/- 0.15 at 0.2 to 0.87 +/- 0.07 erg.cm 3.104 at the 0.5 mg.kg 1.min 1) in the LAD region were observed. Concomitant decrease in dL/dtmax (52.4 +/- 3.9 at 0.2 to 40.2 +/- 3.6 mm.sec 1 at the 0.5 mg.kg 1.min 1 infusion) in the LAD region was also observed. In contrast, %SS, Mw, and dL/dtmax in the LCX region as well as %PSS in both regions remained unchanged throughout the infusion period. Propofol infusion was accompanied by progressive Although propofol produced progressive decreases in coronary blood flow and myocardial oxygen consumption in both regions, its administration was not associated with any changes in oxygen and lactate extraction ratios. CONCLUSION: The results indicate that propofol produces a greater depression on both regional systolic and diastolic functions in stunned myocardium than those in normal myocardium. However, propofol does not impair myocardial aerobic metabolism in both stunned and normal myocardium.

Intrathecal Endothelin-1 Reduced the MAC of Isoflurane in the Rat / 대한마취과학회지

BACKGROUND: Recent evidences suggest that anesthetic action within the spinal cord is important in suppressing somatic responses to painful stimuli. Intrathecal endothelin-1 (ET-1) is known to have antinociceptive effect. The purpose of this experiment was to determine whether intrathecal ET-1 may influence the minimum alveolar concentration (MAC) of isoflurane in rats and access the role of the spinal cord as the sites of anesthetic action in blocking somatic responsiveness. METHODS: In Sprague-Dawley rats fitted with an indwelling intrathecal catheter, we determined the MAC of isoflurane using a tail-clamp technique as a painful stimulus, combined with end-tidal anesthetic sampling. In experiment 1, the control MAC was determined and changes of control MAC were observed after intrathecal ET-1 (4x10-2 nmol, 4x10-3 nmol) administration. In experiment 2, we observed the effects of L or N type Ca++ channel blocker such as verapamil (50 g) or W-conotoxin (0.5 g) on the MAC after measurement of the control MAC. In experiment 3, after measurement of the control MAC, ET-1 (10-2 nmol) was administered intrathecally and the MAC was determined again. Next, intrathecal verapamil (50 g) or W-conotoxin (0.5 g) was injected. After that, the MAC was determined again. RESULTS: In experiment 1, ET-1 decreased the MAC of isoflurane and its effect was sustained over 2 hours. In experiment 2, the MAC, determined following administration of verapamil or W-conotoxin, was not different from that of the control. In experiment 3, the MAC was decreased after ET-1 administration and then increased following injection of verapamil or W-conotoxin. CONCLUSIONS: These results suggested that ET-1, in relation to calcium, might play an important role in determining the MAC of isoflurane in the spinal cord.

Effects of Nicardipine and Sodium Nitroprusside on Functional Recovery of Stunned Myocardium in Dogs / 대한마취과학회지

BACKGROUND: Cytosolic Ca2+ overload and oxygen derived free radicals may contribute to stunned myocardium. The pnt study was aimed to investigate the effects of nicardipine and sodium nitroprusside (SNP) on the functional recovery of postischemic reperfused myocardium. METHODS: Fifty-seven halothane-anesthetized dogs were subjected to 15 minutes of 1eft anterior descending coronary artery (LAD) occlusion and 3 hours of reperfusion. They were randomly assigned to receive either intracoronary nicardipine (n=11) or SNP (n=10) alone or both (nicardipine plus SNP, n=10). Eleven dogs that received saline i.c. served as the controL Regional myocardial contractility was evaluated by systolic shortening (%SS), the preload recruitable stroke work slope (Mw), and intramyocardial pressure (IMPs). Diastolic function was assessed by time constant of myocardial relaxation (IMP-tau) and postsystolic shortening (%PSS), LAD blood flow was measured by a Doppler flowmeter as well. RESULTS: LAD occlusion produced a significant reduction in systolic as well as diasto1ic functions to similar degrees in all groups. However, %SS was significantly higher in the nicardipine, SNP and nicardipine-SNP groups (67%, 56%, and 68% of baseline values, respectively) than in the controls (20%) at 3 hours of reperfusion. Furthermore, Mw recovered to the baseline with the onset of reperfusian in the three experimental groups. IMP-tau was restored to the baseline during early nperfusion in the SNP-treated groups but was significantly prolonged in the control and nicardipine poups throughout the seperfusion. LAD blood flow during reperfusion was higher in the SNP-treated groups in comparison to the control group. CONCLUSIONS: Treatment with either nicardipine or SNP enhances the recovery of mgional contractile function in the canine model of myocardial stunning. SNP not nicardipine is also beneficial in attenuation of early diastolic dysfunction. Nicardipine combined with SNP improved systolic as well as early diastolic functions more significantly when compared to either nicardipine or SNP alane.

The Effect of Succinylcholine on the Action of Pipecuronium / 대한마취과학회지

For the assessment the effect of succinylcholine (SCh) on pipecuronium, 52 adult patients undergoing elective surgery under general anesthesia were subjected to this study in which the EMG response (twitch height of the hand to TOF stimulation with 2Hz) of ulnar nerve was monitored and recorded with Datex Relaxograph. According to the amount and mode of the drugs administered, the patients were divided into four experimental groups: 1) Group I: a bolus injection of pipecuronium in dose of 0.05 mg/kg. 2) Group II: pipecuronium 0.1 mg/kg, a double dose of group l. 3) Group IU: pipecuronium 0.05 mg/kg given when the depressed twitch height by SCh (1 mg/kg) recovered to 25%6 of initial twitch height. 4) Group IV: mixed injection of SCh (1 mg/kg) and pipecumnium (0.05 mg/kg). The results were as follows ; 1) Mean onset time of pipecuronium was 6.5+/-0.5 minutes in group I and 4.1+/-0.5 minutes in group II, the latter being significantly shorter than group I (p<0.01). In group Ill, it was 2.1+/-0.23 minutes being significantly shorter than group I, II (p<0.001). In group IV it was 1.1+/-0.1 minutes which was more significantly shorter than group I, II, and IU. 2) Mean action duration of pipecuronium was 50.9+/-6.7 minutes in group I and 141.9+/-15.4 minutes in group II, the latter being longer significantly (p<0.001). In group IIl, it was 53.9+/-5.2 minutes which was similar to group I, but it was 69.8+/-6.5 minutes in group IV, being significantly longer than those of group I and III (p<0.05). 3) Mean potency of pipecuronium expressed by the percentage change of initial twitch height was 7.6+/-1.9% in group I, but it was significantly decreased to 4.2+/-0.9% in group II (p<0.05). In group III, it was 0.2+/-0.1% being sinificantly decreased than group I, II (p<0.001). In group IV, it was 0.0+0.0% being more significantly decreased than other groups (p<0.001). 4) Presence of pipecuronium in group IV did not affect on the intensity of fasciculation induced by SCh. These results indicate that succinylcholine may potentiate the pipecuronium based on the findings that succinylcholine increased the potency and lengthened the duration of action of pipecuronium.

The Evaluation of the Incidence of Intraoperative Awareness, the Degree of Difficulty with Intubation and Postanesthetic Complication in Surgical Patients / 대한마취과학회지

Randomly selected 193 patients who received elective operation under general anesthesia and were able to communicate with anesthesiologists and follow up for 5 days between May and September 1994 at Chonnam University Hospital, were interviewed and evaluated on the night before, 2 and 5 days after their operation. Distribution of physieal status by ASA was that more than half the total patients belongs to class I and 36.8% of patients were under class II. Sedation scores did not chang between on the night before and the day of operation. A significant correlation existed among the visibility of pharyngeal structures, the exposure of glottis by laryngoscopy, and the degree of difficulty with intubation. About 83% of patients was readily intubated, and none of patient was impossible to intubate. All of the patients lost consciousness during induction of anesthesia, and did not recall during operation. Postanesthetic complications were sore throat(30%), nausea and vomiting(28%), lumbago(15%), urticaria(3%), and dizziness(3%).