Objective To investigate whether the peri pheral administration of amitri ptyl ine and bupivacaine produces anti-hyperalgesic effect and to screen the neurotoxicological effect on sciatic nerve blockade in a rat model of neuropathic pain. Methods Twenty-four adult male SD rats [weighing (200 ± 20) g] were made the models of chronic constriction injury (CCI) and randomly divided into 3 groups (n=8) 5 days after operation: group A (amitriptyl ine), group B (bupivacaine) and group C (normal sal ine). 0.5 mL 0.5% amitriptyl ine, 0.5% bupivacaine or normal sal ine were given in group A, group B, and group C, respectively through implanted cannulas after 5, 7 and 9 days of CCI once a day for successive 3 days. The motor function was measured before administration and 1, 2, 4, 8, 12 and 24 hours after every administration. Mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were measured before administration and 1, 3, 5 and 7 days after the third administration. The operated sciatic nerve samples were obtained for neuropathological examination under l ight microscope. Results Twenty-four CCI rats were all survival without infection, palsy and catheter fall ing off. Compared with group C, the rats of group A and group B both produced significant ambulation deficits after every administration (P lt; 0.05). The ambulation deficits lasted 2 hours (group B) and 8 hours (group A) respectively. But the ambulation deficits of CCI rats were all reversible. The MWT and TWL of group A 1 and 3 days after the third administration increased when compared with those before administration and 5 and 7 days after the third administration, and when compared with group B and group C (P lt; 0.05). There was no significant difference (P gt; 0.05) in l ight microscopic neuropathological examination among three groups. Epineurial tissue and endoneurium tissue integrity, tidy arrangement of fibers, less inflammatory cell and no marked degeneration of myel inated fibers were observed. Conclusion Repeated sciatic nerve blockade with 0.5% amitriptyl ine has peripheral anti-hyperalgesic effects on neuropathic pain of rats. No morphological evidence of neurotoxicity in the sciatic nerve of rats is observed in 0.5% amitriptyl ine.
Objective To evaluate the effectiveness and safety of ropivacaine in spinal anesthesia. Methods We searched PubMed (1999 to 2008), OVID (1999 to 2008), EBSCO (1999 to 2008), The Cochrane Library (2000 to 2008), and CNKI (1999 to 2008) databases to identify randomized controlled trials (RCTs) that compared ropivacaine and bupivacaine for spinal anesthesia. The quality of the included RCTs was evaluated by two reviewers independently, and meta-analysis was performed by RevMan 5.0 software. Results Six RCTs were included. The methodological quality of them were all poor. Among the six RCTs, 215 patients received ropivacaine and 215 received bupivacaine. The results of meta-analyses showed that the motor-block time to complete block of ropivacaine was significantly shorter than that of bupivacaine (WMD=2.18 min, 95%CI 0.32 to 4.03, P=0.02). The motor-block time to complete recovery of ropivacaine was significantly shorter than that of bupivacaine for cesarean delivery in spinal anesthesia (SMD= – 1.82, 95%CI – 3.05 to – 0.59, P=0.004). The incidence rate of hypotension and bradycardia in spinal anestheisa with ropivacaine was lower than that with bupivacaine (OR=0.49, 95%CI 0.31 to 0.80, P=0.004; OR=0.40, 95%CI 0.03 to 4.99, P=0.47). Conclusion Equivalent doses of ropivacaine and bupivacaine provide similar analgesia in spinal anesthesia for cesarean delivery. However, haemodynamics in spinal anesthesia with ropivacaine fluctuate lightlier than with bupivacaine. Ropivacaine is suitable for spinal anesthesia in low-abdominal operations.
Objective To assess the analgesic effect of caudal bupivacaine with neostigmine for hypospadias surgery in children. Methods We searched The Cochrane Library (Issue 2, 2008), MEDLINE (1966-2008), EMbase (1980-2008), CBMdisc (1978-2008), CNKI (1989-2008) and Wanfang Database using the keywords “bupivacaine”, “neostigmine” and “hypospadias” to identify randomized control trials (RCTs) of caudal bupivacaine with neostigmine versus bupivacaine alone for hypospadias surgery in children. The methodological quality of included RCTs was evaluated by two reviewers independently, and Meta-analysis was conducted using RevMan 5.0.13 software. Results We identified 3 RCTs including 160 patients which had an uncertain risk of bias. The results of meta-analysis showed no significant difference found between bupivacine alone and bupivacine plus 1 µg/kg neostigmine (WMD= 0.05, 95%CI – 6.76 to 6.86, P= 0.99), but a difference was found between bupivacine alone and bupivacine plus 1 µg/ kg, 2 µg/kg, or 3 µg/ kg neostigmine (WMD= 12.79, 95%CI 10.96 to 14.62, Plt; 0.000 01; WMD= 12.10, 95%CI – 6.76 to 6.86, Plt; 0.000 01; WMD= 11.90, 95%CI 9.17 to 14.63, Plt;0.000 01). The duration of postoperative analgesia of the bupivacaine with neostigmine group was longer than that of bupivacine alone. Conclusions Because of the small sample size and the unclear risk of bias in the included RCTs, the effectiveness of caudal bupivacaine with neostigmine for postoperative pain management after hypospadias surgery in children is not completely confirmed. So more large sample size, double-blind RCTs are needed.