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.

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.

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.

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.

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.

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.

The Relation of Maximal Sensory Block Level and the Duration of Sensory Block in Spinal Anesthesia Using a Fixed Dose of Bupivacaine / 대한마취과학회지

BACKGROUND: The duration of spinal anesthesia depends upon two factors; concentration of local anesthetics in the CSF and vascular absorption of the local anesthetics. However, there are some arguments on the relationship between the maximum block level and the duration of the block in spinal anesthesia. METHODS: Fifty seven patients scheduled for surgery on a lower limb or perineum underwent spinal anesthesia with 11 mg of 0.5% hyperbaric bupivacaine. After confirming final block heights (T12-T3, range), we took two study groups, group I (block height > OR = T6, n = 30) and group II (block height < OR = T9, n = 27). We checked the maximal sensory block level, the time to maximal sensory block level, a two-segment regression time, the duration of sensory block to T12, and L5 during the first 30 minutes at 2.5 minute intervals and then, at 30 minutes intervals. Blood pressure and pulse rate were measured in the same time interval. RESULTS: The maximal sensory block level and the time to maximal sensory block level of group I was T5.0, 14.6 minutes and that of group II were T9.7, 11.4 minutes. The mean cephalad spread of analgesia in group I was more rapidly increased at 20 minutes and there were statistically significant differences between the two groups from 5 min to 110 minutes. The duration of sensory block to T12, L5 was similar in group I and II. No significant differences in blood pressure and pulse rate were found between the two groups. CONCLUSIONS: We found that there was no relationship between the sensory block level and duration of the block in spinal anesthesia using a fixed does of local anesthetic.

Comparision of Intrathecal 0.5% Hyperbaric and Isobaric Bupivacaine for Cesarean Section / 대한마취과학회지

BACKGROUND: Baricity differences between spinal anesthetic solutions are thought to produce differences in distribution of anesthetics within the subarachnoid space. We evaluated the influence of baricity of bupivacaine on the quality of the block and the incidence of side effects obtained following intrathecal injection of bupivacaine 8 mg with fentanyl 20 microgram. METHODS: Thirty healthy term parturients scheduled for a cesarean section under combined spinalepidural procedures were randomly allocated into Group I, hyperbaric bupivacaine (n = 15); or Group II, isobaric bupivacaine (n = 15). The dose of both groups was bupivacaine 8 mg combined with fentanyl 20 microgram. The maximum level of sensory blockade, time to reach T4 level and maximum level, time to get complete motor recovery and perioperative complications were assessed. RESULTS: Time to sensory block T4, motor block Bromage scale 3, complete resolution of motor block and sensory regression time to T10 was significantly delayed in Group II compared to Group I. Maximal block height, and time to maximal block had no significant differences between the two groups. There were no significant clinical advantages of one preparation over the other. CONCLUSIONS: The data from this study suggests that intrathecal injection of either hyperic or isobaric bupivacaine produces satisfactory anesthesia with similar side effects.

The Effects of Propofol on Cardiac Toxicity of Intravenous Bupivacaine in Rabbits / 대한마취과학회지

BACKGROUND: Propofol is an intravenous anesthetic agent, which has a protective effect on cardiovascular and CNS toxicity of local anesthetics compared with an inhalational agent. Also lipids have a has protective effects on local anesthetic cardiovascular toxicity. So, we had questioned that the protective effect on local anesthetic toxicity comes from the lipid solvent of propofol or propofol itself. METHODS: Eighteen healthy rabbits, weighing 3.0 Kg, were divided into three groups during continuous intravenous infusion of bupivacaine: the control group received normal saline (n = 6), the propofol group received propofol (n = 6), and the intralipid group received intralipid (n = 6). The changes in mean arterial pressure, heart rate and the electrocardiogram were observed during the continuous intravenous infusion of bupivacaine. RESULTS: The onset time of QRS widening and dysrhythmia was significantly prolonged in the propofol group compared with the control and intralipids group. The time required for 25% and 50% decrease in mean arterial pressure and heart rate during bupivacaine infusion was significantly prolonged in experimental groups compared with the control group. In the propofol group compared with the intralipids group, the time required for a 25% and 50% decrease in mean arterial pressure and heart rate were prolonged. CONCLUSIONS: This study suggests that infusion of propofol protection on cardiac toxicity of intravenous infusion by an bupivacaine, the dosage for sedation without cardiovascular adverse effects, is more profound than intarlipids.

The Effect of Clonidine Added to Bupivacaine on Intercostal Nerve Block for Postoperative Pain Control / 대한마취과학회지

BACKGROUND: The addition of clonidine to local anesthetics for regional block has been shown to increase the duration of anesthesia and analgesia. This study was designed to determine whether the addition of clonidine to bupivacaine would produce an extension of the analgesic effect after intercostal nerve block (ICNB). METHODS: After informed consent, 30 ASA 1 or 2 patients undergoing appendectomy under general anesthesia were randomly divided into two groups. Before induction of anesthesia, ICNB using a posterior approach was performed with 15 ml of 0.25% bupivacaine plus epinephrine 1:200,000 with (Group BEC; n = 15) or without (Group BE; n = 15) clonidine 75 microgram. Analgesia was assessed by cold testing at 1/min intervals until cold sensation decreased. The duration of analgesia (time between injection and onset of pain) was recorded. We also recorded the visual analogue scale (VAS) of pain, the number of supplemental analgesics, heart rate and blood pressure, and side effects over 24 hours postoperatively. RESULTS: The onset time, duration of analgesia, number of analgesics, and heart rate and blood pressure were comparable in both groups. VAS scores were significantly lower in Group BEC than in Group BE at 12, 16, and 20 hours postoperatively. CONCLUSIONS: The addition of clonidine to bupivacaine with epinephrine may be a useful adjunct and can prolong the duration of analgesia after ICNB without significant side effects.

Intraarticular Neostigmine and Bupivacaine for Pain Relief after Knee Arthroscopy / 대한마취과학회지

BACKGROUND: Evidence has accumulated that neostigmine can produce potent antinociceptive effects by interacting with muscarinic receptors in peripheral tissues. This study assesses the analgesia and side effects of intraarticular neostigmine alone and the combination of neostigmine and bupivacaine. METHODS: In a double-blind, randomized manner, sixty ASA class 1 or 2 patients were selected for arthroscopic knee surgery under general anesthesia. In the control group (Group 1, n = 15), the patients received 30 ml of intraarticular normal saline. In Group 2 (n = 15), the patients received a combination of intraarticular 500 microgram neostigmine and 30 ml normal saline. In Group 3 (n = 15), 500 microgram neostigmine diluted in 0.125% bupivacaine 30 ml was injected into the knee joint. In Group 4 (n = 15), 750 microgram neostigmine diluted in 30 ml of normal saline was injected into the knee joint. Postoperative pain was assessed using the visual analogue scale (VAS) score at 1, 2, 4, 6, 12, and 24 hours after the intraarticular injection, and the side effects of the four groups were evaluated. RESULTS: Groups 2, 3 and 4 resulted in significantly low VAS scores up to 6 hr after injection compared with Group 1 (P < 0.05). The difference was not significant between Groups 2 and 3, nor between Groups 2 and 4. Side effects such as nausea, vomiting, and urinary retention were observed. However, the intensity of side effect was mild. CONCLUSIONS: The results suggest that intraarticular injection of the acetylcholinesterase inhibitor neostigmine produces a significant analgesic effect following knee arthroscopy. (Korean J Anesthesiol 2000; 39: 212-217)

The Effect of Morphine on Pain and Bowel Function after Colonic Surgery:Epidural Bupivacaine-morphine Versus Intravenous Patient-controlled Analgesia with Morphine / 대한마취과학회지

BACKGROUND:Gastrointestinal paralysis after abdominal surgery has long troubled both patients and surgeons. Gastrointestinal side effects still constitute a major drawback in the acute use of opioids. Choice of postoperative analgesia may affect the rate of recovery of gastrointestinal function. The purpose of the present study was to investigate the influence of intravenous and epidural morphine on recovery of bowel function and pain by measuring intestinal motility and the visual analogue scale after colon surgery. METHODS: Twenty patients undergoing colon surgery used postoperative pain contol. Patients were allocated to receive either IV PCA (patient-controlled analgesia) with morphine or CEA (continuous epidural analgesia) with 0.1% bupivacaine-0.04% morphine. Patients were assessed for pain with a visual analogue scale, and for side effects at 1, 6, 12, 24, 48 hours postoperatively. Arterial blood samples for the measurement of blood gas and plasma concentration of morphine were taken. The time to first postoperative passage of flatus and feces, length of nasogastric therapy, time to liquid, soft and solid food intake, daily and total morphine requirement and length of hospital stay were recorded. RESULTS: There were no significant differences in bowel movement outcome except in length of nasogastric therapy, but the CEA group had significantly lower pain scores and required fewer days of nasogastric therapy when compared with the IV PCA group. CONCLUSIONS: These observations indicate that IV PCA with morphine and CEA can be used to relieve postoperative pain without prolonging the recovery of bowel movements, but CEA with bupivacaine and morphine constitutes an effective means of analgesia.

The Effects of Intralipos Pretreatment on the Cardiovascular Toxicity of Bupivacaine in Rabbits / 대한마취과학회지

BACKGROUND: This study was performed to evaluate the effects of pretreatment with intralipos on the cardiovascular toxicity caused by continuous intravenous infusion with bupivacaine. METHODS: Fourteen healthy white rabbits were selected for this study and divided into the control group (n = 7) (normal saline administered for 30 minutes) and the intralipos pretreated group (n = 7) (intralipos administered for 30 minutes). The cardiovascular toxic effect during the continuous intravenous infusion of bupivacaine was observed between the control and the intralipos group by meaning the changes in mean arterial pressure, heart rate and electrocardiogram. RESULTS: In intralipos group, mean arterial pressure significantly increased after intralipos infusion for 30 minutes as compared with the control values (P < 0.05). The time intervals for 25, 50, 75 and 100% decrease in mean arterial pressure and heart rate and the onset time of the first QRS modification and dysrhythmia during continuous intravenous infusion of bupivacaine were significantly prolonged in the intralipos group compared with the control group (P < 0.05). The time intervals for 100% decrease in heart rate after the stop of bupivacaine administration was significantly prolonged in the intralipos group compared with the control group (P < 0.05). CONCLUSIONS: The present study suggests that prophylactic intravenous infusion with intralipos prevents the cardiovascular toxicity caused by bupivacaine in rabbits.

Patterns of Nerve Conduction Blockade by Different Combinations of Lidocaine-bupivacaine Mixture / 대한마취과학회지

BACKGROUND: A mixture of local anesthetics such as lidocaine and bupivacaine has frequently been used in clinical practice. The rationale behind this is to take advantage of lidocaine's rapid onset and bupivacaine's perpetuation in anesthesia. The purpose of this study was to examine the changes in the onset and recovery of nerve blocking action exerted by the different combinations of these two in the mixture. METHODS: Isolated sciatic nerve preparations obtained from adult male Sprague-Dawley rats were used in this study. Recordings of A-fiber compound action potentials (A-CAPs) were made at the end of the isolated nerve while single pulse stimuli (0.5 msec, supramaximal intensity, 2 Hz) were applied to the opposite end of the nerve. Seven different composition of lidocaine-bupivacaine mixtures were prepared (0 : 6, 1 : 5, 2 : 4, 3 : 3, 4 : 2, 5 : 1, 6 : 0 vol./vol.), where basal concentrations of lidocaine and bupivacaine were 0.2% and 0.05%, respectively. Amplitudes of A-CAPs were measured before, during and after perfusion of mixture solution. The time needed for A-CAPs amplitude to decrease to 10% of the basal value after starting perfusion (onset time) and that needed to reach to 50% of the basal value after ceasing the perfusion (recovery time) were measured. RESULTS: With increasing concentration ratios of lidocaine to bupivacaine in the mixture as mentioned above, the following onset and recovery times were obtained (6.0 +/- 0.3, 5.6 +/- 0.3, 6.0 +/- 0.5, 8.3 +/- 0.5, 7.3 +/- 0.6, 7.8 +/- 0.3, and 10.8 +/- 0.8, minutes; 38 +/- 4, 63 +/- 12, 87 +/- 19, 100 +/- 13, 104 +/- 18, 137 +/- 27, and 157 +/- 18 minutes, respectively). CONCLUSION: Onset times were, in general, exponentially decreased with the increase in the lidocaine concentration. However, recovery times were lineary increased with the increase in the bupivacaine concentration. So, it should be kept in mind that rapid onset can only be obtained with the expense of substantial reduction in the duration of local anesthetic effect of the mixture, and vice versa.