Combination of Small Doses of Subarachnoid Bupivacaine/Fentanyl and Epidural Bupivacaine in Combined Spinal-Epidural Anesthesia for Cesarean Section / 대한마취과학회지

BACKGROUND: An intrathecal injection of a small-dose local anesthetic and an opioid using combined spinal-epidural anesthesia (CSEA) technique is a new trend in regional anesthesia for cesarean section. Prophylactic epidural injection may be useful to complete the new regimen. METHODS: Spinal anesthesia via the CSEA technique was performed with 6 mg 0.5% hyperbaric bupivacaine plus 20ng fentanyl in 75 parturients undergoing cesarean section. group S (study, n = 38) received an epidural injection of 10 ml of 0.25% bupivacaine 5 min after intrathecal injection, and was compared with group C (control, n = 37) in sensory levels and Bromage scores, incidences of side effects such as hypotentsion, pain and discomfort, nausea and vomiting, dizziness, pruritus and shivering. Recovery times from sensory and motor block and the duration of postoperative analgesia were assessed between the groups. RESULTS: Sensory block levels were higher (but remained

Comparison between Epidural Analgesia and Combined Spinal-Epidural Analgesia for Labor and Delivery / 대한마취과학회지

BACKGROUND: This study was designed to compare analgesic efficacy and side effects of intrathecal morphine and fentanyl with epidural bupivacaine. METHODS: Twenty nine healthy women, ASA physical status 1 or 2 with an uncomplicated pregnancy and single fetus in vertex position were given lumbar epidural or combined spinal-epidural analgesia. In the epidural analgesia group (n = 18), 0.25% bupivacaine 8 - 10 ml and fentanyl 50 - 75ng was injected into the epidural space. In the CSE group (n = 11), analgesia performed dural puncture with a 27 gauge spinal needle and fentanyl 15ng and morphine 0.2 mg in 2 ml normal saline solution was injected. In both groups, whenever the patient requests further analgesia, we injected 0.125% bupivacaine 10 ml and fentanyl 50 - 75ng into the epidural space. RESULTS: There was no significant difference between the two groups in duration of analgesia, the second stage of labor and pushing. The CSE group offers rapid onset time. The total dose of bupivacaine and fentanyl administered during analgesia was significantly more in the epidural group than the CSE group. After intrathecal fentanyl 15ng and morphine 0.2 mg, the duration of analgesia was 162 +/- 122 min. After the first 0.25% bupivacaine 10 ml and fentanyl 50 - 75ng, it was 92.5 +/- 5 min in the epidural group and 190 +/- 101 min in the CSE group (P < 0.05). CONCLUSIONS: Compared with epidural analgesia, Intrathecal fentanyl 15ng and morphine 0.2 mg as part of CSE analgesia provide rapid onset time and prolonged analgesia, and a lower total dose of local anesthetics for labor and delivery. However women who received CSE analgesia were more likely to itch (64%) than solely epidural analgesia.

Influence of Temperature and Injection Speed of a 0.5% Bupivacaine Solution on the Distribution in a Spinal Canal Model Filledwith Human Cerebrospinal Fluid / 대한마취과학회지

BACKGROUND: The density of 0.5% bupivacaine solution at 37degreesC is known to be slightly hypobaric. However, its clinical character in spinal anesthesia appears to be nearly isobaric. We tried to find evidence on how the hypobaric 0.5% bupivacaine solution could show the pattern of isobaric distribution in the subarachnoid space. METHODS: The distribution of 0.5% bupivacaine solution containing 0.029 mg methylene blue per milliliter of bupivacaine solution (BMB) was examined in a vertically mounted spinal canal model filled with human cerebrospinal fluid (CSF) at 37degreesC. The CSF was collected from natural drainage bags of 5 brain tumor patients. Three milliliters of the BMB solution at 22degreesC or 37degreesC was injected into the middle of the spinal canal four times with a high speed of injection (0.6 ml/sec) and four times with a slow speed (0.05 ml/sec). Nine 1-ml samples were drawn simultaneously from the 9 sampling sites in the longitudinal direction, each 5 cm apart, then those samples were analyzed for the spectrophotometric absorbance of methylene blue concentration. RESULTS: The concentrations of methylene blue were decreased toward the upper and lower parts of our spinal model with the highest concentrations at the central 5th sampling site, regardless of the temperature and injection speed of the BMB solution. However, the high temperature (37degreesC) and low injection speed respectively contributed to a little more distribution of the BMB solution toward the upper part of the spinal model, and the low temperature (22degreesC) contributed to a little more distribution of the BMB solution toward the lower part of the spinal model. CONCLUSIONS: Our study shows that the distribution of plain 0.5% bupivacaine solution in the subarachnoid space is similar to that of isobaric solutions.

Interaction between Bupivacaine, Ropivacaine and Diltiazem in the Isolated Rat Heart / 대한마취과학회지

BACKGROUND: Local anesthetics are often used for a regional block in patients who are being treated with calcium channel blockers (CCB). Bupivacaine is a local anesthetic with potential for serious cardiovascular toxicity. Ropivacaine is a relatively new local anesthetic. It is clinically equipotent and chemically similar to bupivacaine. Diltiazem (CCB) is a potent coronary and systemic vasodilator with antiarrhythmic properties. Local anesthetics such as bupivacaine and ropivacaine have been suggested to show drug interactions with diltiazem. Therefore, we tried to observe the drug interactions between bupivacaine, ropivacaine and diltiazem using an animal model. METHODS: This study was performed using an isolated rat heart (N = 40) by the Langendorff method. After a stabilization period, all hearts were subjected to the application of local anesthetics of a 1 microgram/ml or 3/ml concentration, respectively. Thereafter, they were subdivided into four groups; the bupivacaine (B) group, bupivacaine with diltiazem (BD) group, ropivacaine (R) group, and ropivacaine with diltiazem (RD) group. Parameters such as, LVP, dp/dt, heart rate (HR), coronary flow (CF), DO2, and MVO2 were measured. RESULTS: All parameters decreased in all groups, respectively (P < 0.05). The BD group and R group showed a lower LVP and dp/dt than those of the B group (P < 0.05). The BD group and B group showed lower HR than that of the R group (P < 0.05). The RD group showed a higher CF than other groups (P < 0.05). CONCLUSIONS: The negative inotropic potency of bupivacaine was enhanced in the presence of diltiazem. We suggest that diltiazem has a protective effect against reduction of CF by ropivacaine. Therefore, we should consider this when selecting local anesthetics for cardiovascular patients under the treatment of diltiazem.

The Evaluation of the Efficacy of the Egg PC/HA/water Drug Delivery System / 대한마취과학회지

BACKGROUND: Local anesthetics have been widely used to control postoperative pain and chronic pain. However, their usage in controlling long-lasting pain has been limited due to a relatively short duration of action. Many attempts have been made to develop a controlled release drug delivery system to provide long-lasting anesthesia. The goal of this study was to evaluate the histocompatibility and effectiveness of a new injectable lipid gel type drug delivery system (PHW, egg phosphatidylcholine/hyaluronic acid/water) using bupivacaine. METHODS: Eighty-four male Sprague-Dawley rats were divided into 3 groups; 44 in the bupivacaine group, 20 in the PHW-bupivacaine (PHW-B) group, and 20 in the PHW group; and each drug mixture was injected in a 0.1 ml solution near the sciatic notch. Motor block was assessed by direct observation of motor skills to splay toes. Sensory block was assessed by measuring withdrawal response latencies to radiant heat using an analgesiameter. Gross and microscopic examinations on the sciatic nerve and surrounding muscle were performed for 3weeks after the injection. RESULTS: Nerve block was significantly prolonged in the PHW-B group (190.0 +/- 42.8 min) compared to the plain bupivacaine group (99.0 +/- 30.5 min). There was no sign of nerve block in the PHW group. We observed moderate perimuscular inflammation in the PHW and PHW-B groups for the first 3 days. After 3 days, we did not observe inflammation of muscles and there was no sign of perineural inflammation. CONCLUSIONS: In conclusion, the histocompatibility of a bupivacaine incorporated PHW drug delivery system was satisfactory and the controlled releasing property of this drug delivery system was evaluated as effective.

Electrocardiographic and Hemodynamic Changes during Recovery from Bupivacaine Toxicity in Anesthetized Dogs / 대한마취과학회지

BACKGROUND: Severe cardiac arrhythmia after accidental intravascular injection of bupivacaine in the practice of regional anesthesia has been reported and is known to be difficult to treat. We evaluated the electrocardiographic and hemodynamic changes during recovery from bupivacaine-induced cardiac toxicity. METHODS: In eight male dogs receiving pentobarbital, after baseline recordings were obtained, 0.5% bupivacaine was infused at a rate of 0.5 mg/kg/min intravenously until cardiac output decreased to 50% or less(1/2 CO), which was defined as the point of cardiac depression in this study. The hemodynamic and electrocardiographic parameters were recorded at 1/2 CO, and 5, 10, 15, 20, 30 and 40 min after 1/2 CO. The following electrocardiographic parameters were measured: duration of QRS complex and T wave, PR interval and the corrected QT interval, all determined on the lead II. RESULTS: Mean arterial pressure was significantly decreased throughout the experimental period after 1/2 CO, and cardiac output and SO2 were significantly decreased until 20 min after 1/2 CO in comparison with those at baseline. All dogs had serious changes on the ECG. Heart rate and ECG changes returned to baseline within 20 min after 1/2 CO, but QRS duration remained increased until 30 min after 1/2 CO. Systemic vascular resistance, pulmonary vascular resistance and serum electrolytes were not changed with time. CONCLUSIONS: In the absence of hypoxia, acidosis, and hyperkalemia, QRS duration returned to control values more slowly than other variables on the EKG after bupivacaine cardiac toxicity. MAP and PCWP recovered the slowest of all hemodynamic variables.

Comparison of 0.075% Bupivacaine/Fentanyl and 0.125% Ropivacaine/Fentanyl Infusion for Postoperative Epidural Analgesia / 대한마취과학회지

BACKGROUND: The new, long-acting local anesthetic ropivacaine is structurally very similar to bupivacaine, but the motor block is less profound and of shorter duration. The aim of this study was to compare analgesic effectiveness and side effects during postoperative pain control after a Caesarean section with either a bupivacaine/fentanyl or ropivacaine/fentanyl mixture. METHODS: Thirty-nine patients undergoing a Caesarean section were randomized in a double-blinded manner to receive bupivacaine or ropivacaine. Postoperative epidural analgesia was provided using a PCA pump with either bupivacaine/fentanyl 0.075%/3.4 microgram/ml after 10 ml of 0.125% bupivacaine with morphine (n = 18) or ropivacaine/fentanyl 0.125%/3.4 microgram/ml after 10 ml of 0.2% ropivacaine with morphine (n = 21). Verbal rating pain scores (rest and cough), side effects (nausea, vomiting, pruritus, sedation, motor block and hypotention) and time to ambulation were measured for 48 hr after surgery. RESULTS: There were no significant differences between the groups in verbal pain scores, sensory level, motor blockade and other side effects, but time to ambulation was earlier in the ropivacaine group. CONCLUSIONS: 0.125% ropivacaine with 3.4 microgram/ml fentanyl provided similar successful pain relief as 0.075% bupivacaine/fentanyl. However, earlier recovery of ambulation in patients receiving ropivacaine/ fentanyl will improve outcome after surgery.

Comparing the Effects between a Continuous Epidural Infusion of an Opioid or an Opioid-Local Anesthetic Mixture and a Continuous IV Infusion of an Opioid after a Spinal Laminectomy / 대한마취과학회지

BACKGROUND: Postoperative pain after a spinal laminectomy has very harmful effects on human physiology, and many people are trying to control it more easily and safely. There are controversies in methods used for controlling postoperative pain after a spinal laminectomy. The purpose of this study was to examine an effective way to control postoperative pain after a spinal laminectomy. METHODS: Ninety patients (ASA I-II, aged 40 to 70) scheduled for a spinal laminectomy were divided into three groups. In group A, we administered fentanyl 1,000 microgram and morphine 5 mg (mixed in 0.9% normal saline) using the continuous epidural infuser; in group B, we administered fentanyl 500 microgram and morphine 5 mg and 0.25% bupivacaine (mixed in 0.9% normal saline) using the continuous epidural infuser; in group C, we administered fentanyl 1,500 microgram and morphine 10 mg (mixed in 0.9% normal saline) using the continuous IV infuser. We compared effects between the continuous epidural infusion and the continuous intravenous infusion by using the visual analogue scale and side effects. RESULTS: There was no significant difference between continuous epidural infusion groups. When the continuous epidural infusion groups and the continuous IV infusion group were compared, there were significant differences in 3 hr, 6 hr, and 12 hr VAS scores (P < 0.01). The incidence of side effects was very low, and there was no significant difference in side effects between the continuous epidural infusion and the continuous IV infusion groups. CONCLUSIONS: It was found that continuous epidural infusion methods were more effective than the continuous IV infusion method, but none of them showed satisfactory postoperative pain control in the early periods.

Differential Analgesic and Adverse Effects of 0.125% Bupivacaine vs. Ropivacaine Coadministered Epidurally with Morphine / 대한마취과학회지

BACKGROUND: This study aimed to compare analgesic efficacy and occurance of motor block and other side effects of a 48 hr postoperative continuous epidural infusion of 0.125% bupivacaine or ropivacaine with morphine. METHODS: Forty patients undergoing a Cesarean section were allocated randomly into two groups. Both groups received an epidural injection of 2.0% lidocaine 18 20 ml and 0.5% bupivacaine 2 5 ml with fentanyl 50microgram 20 minutes before surgical incision and received 2 mg of epidural morphine by bolus 40 minutes after surgical incision. For post-operative pain control, a continuous epidural infusion was started using a two day infusor containing 6 mg of morphine in 100 ml of 0.125% bupivacaine (Group 1, n = 20) or 100 ml of 0.125% ropivacaine (Group 2, n = 20). Visual analog scale (VAS) for pain during rest and movement, sensory change and motor blockade were assessed for 48 hrs. after surgery. RESULTS: There were no significant differences in VAS for pain during rest and movement. The incidences of side effect were similar in both groups. CONCLUSIONS: Using 0.125% bupivacaine with morphine via the epidural route provided similar pain relief and side effects as 0.125% ropivacaine with morphine.

Effects of Intravenous and Epidural Patient-Controlled Analgesia on Postoperative Pain and Knee Rehabilitation after a Unilateral Total Knee Replacement / 대한마취과학회지

BACKGROUND: Postoperative pain is a major concern after a total knee replacement (TKR). It hinders early intense physical therapy, the most influential factor for good postoperative knee rehabilitation. The purpose of this study was to compare intravenous patient-controlled analgesia (IV-PCA) using morphine and continuous ketorolac IV infusion with patient-controlled epidural analgesia (PCEA) using morphine and continuous bupivacaine infusion in terms of analgesic efficacy and postoperative knee rehabilitation after a unilateral TKR. METHODS: Eighteen patients undergoing a unilateral total knee replacement were randomly allocated to one of the two groups. In group IV-PCA (n = 9), 30 min before the end of surgery, patients received ketorolac 30 mg IV bolus followed by continuous infusion with ketorolac (5 mg/h) and IV-PCA with morphine (20microgram/kg, lockout 10 min). In group PCEA (n = 9), 30 min before the end of surgery, patients received 2 mg morphine bolus followed by continuous infusion with 0.1% bupivacaine (2 ml/h) and PCEA with morphine (1 mg, lockout 15 min). RESULTS: There were significant differences in visual analogue scale scores at the first 2-hours after the unilateral TKR, cumulative morphine consumption and number of postoperative days required to obtain 90o knee flexion. CONCLUSIONS: PCEA using a morphine-bupivacaine combination provided better pain relief and faci litated the continuous passive motion more than IV-PCA using a morphine-ketorolac combination. This results in possible faster postoperative knee rehabilitation.

The Effects of Insulin in Treating Bupivacaine-Induced Cardiac Depression / 대한마취과학회지

Backgroud: Bupivacaine blocks the sodium channels enhanced by hypokalemia. Bupivacaine also inhibits the transient outward K+ current (Ito). Insulin, in contrast, enhances Ito and induces hypokalemia. The current study was performed to confirm the efficacy of insulin for the treatment of bupivacaine- induced cardiac depression in dogs. METHODS: After dogs were anesthetized with pentobarbital, 0.5% bupivacaine was administered at a rate of 0.5 mg/kg/min until S O2 decreased to 60% or less, which was defined as the point of cardiac depression in this study. The insulin group (n = 9, 16.9 +/- 3.1 kg) received 2 ml/kg of a mixed solution of regular insulin 30 units and 5% D/W 50 ml, followed by a glucose infusion (50 ml 5% dextrose in water) over 15 min. The control group (n = 9, 15.8 +/- 3.4 kg) received 2 ml/kg of 5% D/W 50 ml, followed by a normal saline infusion over 15 min. Mean arterial pressure (MAP), heart rate (HR), pulmonary artery pressure (PAP), central venous pressure (CVP), pulmonary capillary wedge pressure (PCWP), cardiac output (CO), SO2, blood gas analysis, serum electrolytes, ECG and the local anesthetic concentraton of the blood were taken. RESULTS: Changes in hemodynamic variables and ECG of the insulin group normalized more rapidly than in the control group. There were no statistical differences in serum Na and Ca2 concentratons between the two groups. The serum K concentration of the insulin group was lower than that of the control group after 5 min of resuscitation. The changes in plasma bupivacaine concentration over time were not significantly different between groups. CONCLUSIONS: Insulin is effective in reversing bupivacaine-induced cardiac depression. This study suggests insulin can be considered an immediate treatment for cardiac depression by bupivacaine.

Treatment of Refractory Angina Pectoris with High Thoracic Epidural Analgesia / 대한마취과학회지

A 64-year-old woman presented with severe chest pain and indigestion for ten days. She had been repeatedly admitted for the same symptoms, and had been treated with oral medication with no improvement. Coronary angiography revealed total occlusion of the left anterior descending and circumflex arteries. The patient was referred to our department because the other medical treatments had been unsuccessful and neither angioplasty nor coronary artery bypass surgery was safe. An epidural catheter was placed at the T2-3 level and a 5 mL bolus of 0.25% bupivacaine completely relieved the patient's angina. The arterial blood pressure and heart rate remained unchanged and the IV nitrates were discontinued. An infusion of 100 mL 0.0625% bupivacaine with 10 mg morphine was started at 4 mL/h. During the following 13 days, the patient remained pain free with 5 mL of 0.25% bupivacaine. Her symptoms continued to diminish and she remained free of pain even after discontinuing the high thoracic epidural anesthesia (HTEA), but she still took an occasional oral dose of nitrates.

The Preemptive Analgesic Effect of Bupivacaine Infiltration on Postoperative Pain after Inguinal Herniorrhaphy / 대한마취과학회지

BACKGROUND: Preemptive analgesia is an antinociceptive treatment that prevents the establishment of central sensitization, which amplifies the postoperative pain. In this study, we investigated the preemptive effect of local infiltration of bupivacaine on postoperative pain after inguinal herniorrhaphy. METHODS: Thirty adult patients scheduled for inguinal herniorrhaphy were randomly assigned to one of two groups. 0.25% bupivacaine 20 ml was infiltrated in the surgical wound site either 15 min before skin incision or immediately after skin closure. Postoperatively, visual analogue scale (VAS) at rest and movement were assessed. Also the time to the first request for postoperative analgesic and the total dose of postoperative analgesics were assessed. In addition, the number of patients who didn't require any analgesics during the postoperative period were assessed. RESULTS: The VAS at rest and movement was not significantly different between the two groups. The time to the first request for postoperative analgesic, the total dose of supplemental analgesics and the number of patients who didn't require any analgesics were not significantly different. CONCLUSIONS: In pain after inguinal herniorrhaphy, we could not demonstrate the pre-emptive analgesic effect of preincisional bupivacaine infiltration. Traction pain after inguinal herniorrhaphy was sustained during the study period and this kind of pain was not inhibited (or prevented) by local infiltration of bupivacaine.

Comparison of Intrathecal Isobaric and Hyperbaric Bupivacaine during Combined Spinal Epidural Anesthesia for Cesarean Section / 대한마취과학회지

BACKGROUND: We aimed to compare the clinical effects of 7 mg of intrathecal isobaric and hyperbaric 0.5% bupivacaine during combined spinal epidural (CSE) anesthesia for a cesarean section. METHODS: Thirty patients scheduled for an elective cesarean section under the CSE technique were randomly divided into two groups. 0.5% hyperbaric bupivacaine (Hyperbaric group, n = 15) or 0.5% isobaric bupivacaine (Isobaric group, n = 15) was separately injected into the subarachnoid space through a 26 G Quincke needle. Immediately after fixing the epidural catheter, 2% lidocaine 4 ml and fentanyl 50 microgram were injected through the epidural catheter. We measured the level and time of maximal sensory block, hemodynamic variables and many other clinical effects according to times. RESULTS: The level of maximal sensory block and duration of sensory block were not significantly different between the two groups. The time to maximal sensory block was significantly shorter in group I. Five of group H and two of group I needed an additional injection of epidural lidocaine and two of group H and four of group I needed IV fentanyl. However, all patients had the operation in comfort. CONCLUSIONS: An intrathecal injection of 7 mg of isobaric or hyperbaric 0.5% bupivacaine both with an epidural dose of 2% lidocaine 4 ml and fentanyl 50 microgram during CSE anesthesia is suitable for an elective cesarean section.

Effects of Local Anesthetics and Opioids on Human Isolated Umbilical Arteries / 대한마취과학회지

BACKGROUND: An adequate uteroplacental and fetal blood flow during labor and cesarean delivery is of prime importance for fetal well-being and neonatal outcome. METHODS: Using the vascular smooth muscle of the human isolated umbilical arteries, this study was performed to see whether commonly used local anesthetics (bupivacaine, lidocaine and 2-chloroprocaine) and opioids (morphine,fentanyl and meperidine) could induce contracion or relaxation of these resting and precontracted vessels. Rings from human umbilical arteries were prepared by microdissection. The vessel rings were mounted in tissue baths for an isometric recording of the contractile activity. For resting muscles, the reactivity to drugs is expressed as a percentage of a maximal KCl-induced contraction, and for precontracted muscle, it is expressed as a percentage of a submaximal KCl-induced contraction. RESULTS: Bupivacaine, lidocaine and 2-chloroprocaine all induced contractions. Bupivacaine showed a maximal contraction (46.7 +/- 10.5%) at concentrations of 43 micrometer, lidocaine 19.7 +/- 4.8% at 0.11 mM. and 2-chloroprocaine showed 14.6 +/- 2.9% at 0.65 mM. Morphine, fentanyl and meperidine all induced contractions. Morphine showed a maximal contraction (19.6 +/- 7.1%) at a concentration of 10 4 M, meperidine at 17.2 +/- 8.4% at 3 x 10 5 M, and fentanyl at 1.7 +/- 2.0% at 3 x 10(-6)M. When umbilical arteries were induced to contract with a submaximal concentration of KCl, bupivacaine and lidocaine showed an ability to increase the magnitude of the sustained contraction, but 2-chloroprocaine showed a relaxation of the sustained contraction. Morphine, fentanyl and meperidine showed no change in the sustained contraction. CONCLUSIONS: This study demonstrates these local anesthetics and opioids as vasoactive on human umbilical arteries. If applicable in vivo, these drugs might have some influence on umbilical vessel tone and thus might reduce umbilical blood flow.

The Effect of Intrathecal Midazolam on Bupivacaine Induced Spinal Anesthesia after Hemorrhoidectomy / 대한마취과학회지

BACKGROUND: Benzodiazepines acting on the GABA receptor complex in the spinal cord are known to induce antinociception. In the present study we aimed to evaluate the effect of intrathecal midazolam with bupivacaine following hemorroidectomy. METHODS: Forty five patients were involved in this study. Patients were randomly allocated to one of 3 groups: the control group received 0.5% heavy bupivacaine 5 mg and 0.9% NaCl 0.2 ml intrathecally, group BM1 0.5% bupivacaine and midazolam 1 mg (0.2 ml), group BM2 0.5% bupivacaine 5 mg and midazolam 2 mg (0.4 ml), respectively. The analgesic effects and side effects were compared among the 3 groups. RESULTS: There was a significant difference among the 3 groups in time-to-first-pain medication and total consumption of analgesics during the 24 h after surgery. Furthermore, the analgesic effect of midazolam was dose-dependent: 2 mg of midazolam showed better results than 1 mg. All the patients showed no considerable side effects. CONCLUSIONS: We conclude that intrathecal midazolam caused a significant delay in time-to-first-pain medication and reduced utilization of analgesics within 24 h. Therefore, intrathecal midazolam can be used as an effective adjunct for spinal anesthesia for postoperative pain control.

Patient Controlled Analgesia Using Surgical Wound Infusion / 대한마취과학회지

BACKGROUND: This study was undertaken to evaluate the analgesic effect of a self administered surgical wound infusion of local anesthetic alone compared to combination of local anesthetic and morphine or ketorolac. METHOD: Forty eight patients undergoing minor surgery were randomly classified into four groups: Group 1 (saline, n = 10), Group 2 (bupivacaine only, n = 11), Group 3 (bupivacaine with morphine, n = 14), and Group 4 (bupivacaine with ketorolac, n = 13). A two-hole 19 G epidural catheter was tunneled subcutaneously into the surgical wound and was connected to 100 ml elastometric balloon pump filled with either 0.5% bupivacaine only, 0.5% bupivacaine and morphine 40 mg, or 0.5% bupivacaine and ketorolac 80 mg. We assessed the postoperative visual analogue scale (VAS) pain scores at postoperative 0.5, 1, 2, 6, 12, 24, 36, and 48 hours, and the side effects, sedation score and total amount of infused bupivacaine were recorded. RESULTS: VAS pain score were significantly decreased until 36 hours in groups 2, 3, and 4 compared to group 1, and significantly lower at 1, 2, 12, and 24 hrs in groups 3, 4 than in group 2 (P < 0.05). The total requirement of infused bupivacaine in groups 3, 4 is significantly decreased compared to that of group 2. Side effects like nausea, vomiting, urinary retension, pruiritis, respiratory difficulty, sedation, and dizziness did not occur in the four groups but seroma did in one case. CONCLUSION: Patient-controlled surgical wound infusion of bupivacaine reduced postoperative pain after minor surgery without any side effects. The combination of bupivacaine with morphine or ketorolac gave rise to a significant additive effect to local analgesia.

The Effects of Midazolam and Droperidol Pretreatment on the Cardiac Toxicity of Bupivacaine in Rabbits / 대한마취과학회지

BACKGROUND: Unintended intravenous injection of bupivacaine causes severe cardiovascular complication, which is known for its difficulty in resuscitation. This study was performed to evaluate the effects of pretreatment with midazolam and droperidol in the cardiac toxicity caused by intravenous infusion of bupivacaine. METHODS: Thirty rabbits were divided into three groups; saline- as a control, midazolam, and droperidol pretreated group. We observed the time intervals for the arrhythmia, 25% and 50% reduction in baseline mean arterial blood pressure, and arrest. We also checked the dose of infused bupivacaine to be required for arrest during continuous intravenous infusion of bupivacaine at the rate of 1 mg/kg/min. RESULTS: The onset of dysrhythmia and the time to 50% reduction in baseline mean arterial blood pressure and arrest were significantly more delayed in the midazolam group than the control group (P < 0.05). With respect to the time to 25%, 50% reduction in baseline mean arterial blood pressure and arrest, the data of the droperidol group was significantly shorter than that of the control group (P < 0.05). CONCLUSIONS: Droperidol pretreatment hastened bupivacaine induced cardiac arrest in rabbits. Midazolam pretreatment exerted protective effects on arrhythmia and cardiac arrest. Thus midazolam would be a preferable agent as a supplement for regional anesthesia using bupivacaine.

Comparative Study of 0.5% Hyperbaric Bupivacaine and 0.5% Hyperbaric Tetracaine in Spinal Anesthesia / 대한마취과학회지

BACKGROUND: Marcaine is a recently introduced hyperbaric bupivacaine. The aim of this study was to compare the difference in hemodynamic change and sensory or motor block between 0.5% hyperbaric bupivacaine and 0.5% hyperbaric tetracaine in spinal anesthesia. METHODS: Thirty patients belonging to ASA classes I and II were divided into either a tetracaine (Group I) or bupivacaine (Group II). All patients received an infusion of lactated Ringer's solution (1,000 ml). We standardized techniques and injected equal doses (12 mg) in equal volume (2.4 ml) intrathecally for spinal anesthesia. After intrathecal injection of the agents, we measured the blood pressure, heart rate, change of sensory block level according to pinprick test and motor block by the modified Bromage score until fixation was achived. RESULTS: The onset time of sensory block was more rapid in Group I than in Group II. There was no difference in the level of sensory block between Group I and Group II. The time for maximum motor block was significantly shorter in Group I than in Group II (p < 0.05). The change in systolic and mean blood pressure in Group II was less than the change in Group I. CONCLUSIONS: Bupivacaine has a longer sensory block duration, a weaker intensity and shorter duration of motor block and yields less change in blood pressure than tetracaine in spinal anesthesia. Therefore, we concluded that spinal anesthesia with hyperbaric bupivacaine may be used more safely in comparision with hyperbaric tetracaine in hemodynamically troublesome cases.

The Effect of Spinal Anesthesia for Cesarean Section on Hemodynamics in Patients with Severe Preeclampsia / 대한마취과학회지

BACKGROUND: Epidural anesthesia is thought to be relatively indicated for cesarean section in patients with severe preeclampsia. In contrast, avoidance of spinal anesthesia is recommended, postulating excessive hypotensive risks. In addition, general anesthesia is often avoided in this population because malignant hypertension following tracheal intubation is common and risks for difficult airway management are excessive. METHODS: In this study, we compared hemodynamic changes in patients with severe preeclampsia and normal pregnant women during spinal anesthesia for elective cesarean section. Spinal anesthesia was performed with 10 mg of 0.5% heavy bupivacaine mixed with 25 microgram fentanyl in 18 patients with severe preeclampsia and 17 normal pregnant women. We compared MAP, CI, and SVRI changes before and after spinal anesthesia. RESULTS: MAP responses following induction of spinal anesthesia for elective cesarean section in patients with severe preeclampsia and normal pregnant women showed a statistically significant decrease from 2 min after spinal anesthesia. CI responses following induction of spinal anesthesia in patients with severe preeclampsia showed a statistically significant increase from 8 min after and normal pregnant women also showed a statistically significant increase from 4 min after spinal anesthesia. SVRI responses from induction of spinal anesthesia in patients with severe preeclampsia and normal pregnant women showed a statistically significant decrease from 2 min after spinal anesthesia. Incidence of hypotension before delivery and used total dose of ephedrine during operation were statically insignificant between severe preeclamptic and normal pregnant women. CONCLUSIONS: We conclude that changes of MAP, CI and SVRI following spinal anesthesia for elective cesarean section in the severely preeclamptic and normal pregnant women are clinically similar. We suggest that spinal anesthesia for cesarean section is not contraindicated in the severely preeclamptic patient.