Effect of Additional Epinephrine on Spinal Anesthesia with Bupivacaine / 대한마취과학회지

Background: Bupivacaine was introduced to be a long-acting spinal anesthetic agent. It has been argued about whether the addition of epinephrine prolongs the bupivacaine action or not. The aim of this present investigation was to find out the effect of additional epinephrine on spinal anesthesia with bupivacaine. Methods: 47 patients undergoing an operation on lower extremity were randomly allocated to 2 groups. All patients were anesthetized by subarachnoid block with 0.5% bupivacaine in 8% glucose, which was mixed with 0.2 ml of normal saline in group non-E (n=24) and 0.2 ml of 1:1,000 epinephrine in group E (n=23). We evaluated blood pressure and heart rate, the sensory and motor blockade and voiding time after spinal anesthesia. Results: The systolic blood pressure (SBP) at 8 and 10 min after anesthesia were lower in group non-E than in group E (p<0.05). The trend of decreasing diastolic blood pressure was similar in both groups. The heart rate(HR) at 2 min after anesthesia was lower in group non-E than in group E (p<0.05). The sensory block in T10 was produced faster in group non-E (7 min) than in group E (11 min)(p<0.05). And the maximal sensory block level and its reaching time was T7 and 14 min in group non-E, and T8 and 17 min in group E (p=0.12, p=0.11). Two segment regression time was 124 min in group non-E, and 184 min in group E (p=011). The onset time of motor block to Bromage scale 3 was 12 min in group non-E and 16 min in group E (p=0.06). The recovery time from complete motor block to Bromage scale 1 after maximal motor block was 263 min in group non-E, and 278 min in group E. The time at which patients voided after anesthesia was 469 min in group non-E, and 466 min in group E. Three patients urinated by using a urinary catheter in each group. Conclusions: The addition of epinephrine to bupivacaine for spinal anesthesia can slow the decrease in SBP and increase the HR at early stage of anesthesia, and slow the sensory block.

The Effects of Thoracic Epidural Anesthesia and Vagotomy on the Enflurane-Epinephrine Induced Arrhythmias in Rabbits / 대한마취과학회지

BACKGROUND: To evaluate the effects of thoracic epidural anesthesia, with or without bilateral vagotomy, epinephrine-induced arrhythmias were studied in 31 rabbits anesthetized with 1 MAC enflurane. METHODS: Logdose protocol was used for the infusion of epinephrine; its arrhythmic dose being defined as the smallest infusion rate produced four or more continuous or intermittent arrhythmias within 15 seconds. RESULTS: The values (geometric mean) of arrhythmic doses and the plasma concentration of epinephrine during arrhythmia were as follows: 10.21 g.kg 1.min 1 and 83.16 ng/ml in epidural control group; 118.90 g.kg 1.min 1 and 677.76 ng/ml in epidural lidocaine group (p<0.05); 6.34 g.kg-1.min 1 and 96.42 ng/ml in intravenous lidocaine group; 8.65 g.kg 1.min-1 and 44.64 ng/ml in vagotomized-epidural control group; and 12.03 g.kg 1.min 1 and 95.35 ng/ml in vagotomized- epidural lidocaine group. CONCLUSIONS: The data suggest that thoracic epidural anesthesia raises the threshold for enflurane- epinephrine arrhythmias in rabbits and that this effect is eliminated by bilateral vagotomy.

Clinical Anaylsis of Anesthetic Dosage and Use of Ephedrine in Epidural Anesthesia for Cesarean Section / 대한마취과학회지

BACKGROUND: Hypotension occurs frequently after epidural anesthesia. Intravenous fluid or vasopressors are among treatment methods to many suggested causes. This study was undertaken retrospectively to determine if the age, weight and height of parturients are related to the local anesthetic dosage in epidural anesthesia for the cesarean section, and if the dosage of local anesthetic influence the change of blood pressure and the requirement of fluid or epherine. METHODS: Sixty-nine parturients were studied by reviewing patients' anesthetic records. During lumbar epidural anesthesia to T4 sensory level, all patients were monitored with mean arterial blood pressure, and prevented from hypotension by administration of Ringer's lactated solution. But if hypotension has been sustained in spite of rapid fluid loading, intermittent ephedrine was injected. We studied the correlation of local anesthetic dosage, decrement of mean blood pressure and total required intravenous fluid volume, and difference of these variables between cases using ephedrine and not using. RESULTS: The volume of local anesthetic to achieve a T4 sensory level was 21.20 3.81ml, which did not correlate with age, weight and height, and did not influence the decrease of mean blood pressure and the volume of administered fluid. But the patients (n=30) who needed ephedrine were adminstered significantly larger dose of the local anesthetic and showed more decrease in the mean blood pressure than those (n=39) who did not. CONCLUSIONS: The dose requirement of local anesthetic during epidural anesthesia for the cesarean section is not determined by the age, weight and height of parturients. But when larger dose of local anesthetic is administered, the patients seem to be more hypotensive and need ephedrine as well as intravenous fluid administration.