2005 Fiscal Year Final Research Report Summary
Local anesthetic toxicity : differential neurotoxic effects among nerve fibers
| Project/Area Number |
15591630
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Anesthesiology/Resuscitation studies
|
|---|
| Research Institution | Shimane University (2004-2005)
Shimane Medical University (2003) |
|---|
Principal Investigator |
SAKURA Shinichi Shimane University, Faculty of Medicine, Associate Professor, 医学部, 助教授 (80170637)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KIRIHARA Yumiko Shimane University, Faculty of Medicine, Teaching Assistant, 医学部, 教務職員 (90234400)
|
|---|
| Project Period (FY) |
2003 – 2005
|
| Keywords | spinal anesthesia / neurotoxicity / local anesthetic / epidural anesthesia / lidocaine / bupivacaine / myelinated fiber / unmylelinated fiber |
|---|
| Research Abstract |
The main results of studies performed during the term concering this project were as follows :
The first study sought to determine whether the difference in nerve injury can be observed between intrathecal lidocaine and bupivacaine when the two are administered as equipotent solutions in doses larger than used clinically in our rat model. The results of the study demonstrate that bupivacaine is less neurotoxic than lidocaine and that the neurotoxic effects are similar for myelinated and unmyelinated fibers.
The second study sought to determine whether racemic bupivacaine, levobupivacaine, and R(+) enantiomer, dextrobupivacaine differ with respect to sensory impairment and histologic damage when administered intrathecally in rats. The results suggest that the three drugs are similar for neurotoxicity and that the neurotoxic effects are similar for myelinated and unmyelinated fibers.
The third study sought to determine whether epidural lidocaine is neurotoxic when a large dose was continuously administered in rats. The results suggest that epidural lidocaine has dose-dependent neurotoxicity following continuous infusion in rats and that the neurotoxic effects are similar for myelinated and unmyelinated fibers.
In the next preliminary study, we used two neural tracers, wheat germ agglutinin and choleragenoid toxin B, to observe a differential nerve injury by intrathecal lidocaine. The results suggest that intrathecal lidocaine causes nerve injury preferentially in unmyelinated C fibers in rats.
|
