Neostigmine intrathecal and transdermal nitroglycerine augment intrathecal bupivacaine-fentanyl postoperative analgesia following lower limb surgery

Sixty patients were scheduled for lower limb operations. Their age ranged from 24 to 49 years [mean 41.7 +/- 6.4]. Patients were divided into four groups each group included 15 patients. All patients were given intrathecal bupivacaine - fentanyl, plus group [I] was given [non transdermal nitroglycerine patch] as placebo, group [II] transdermal nitroglycerine patch 5mg /24 hours, group [III] intrathecal neostigmine 10 ug and [non transdermal nitroglycerine patch] as placebo and group [IV] transdermal nitroglycerine patch 5mg /24 hours plus intrathecal neostigmine 10 ug. All groups were assessed for intraoperative and a period of postoperative 24 hours for vital parameters, postoperative analgesia and duration of effective analgesia as time from intrathecal drug administration to the patients first requested for analgesic medication, adverse side effects and total dose to control pain in 24 hours postoperative. Results of this study revealed multiple drug combination may be useful in extending postoperative analgesia of spinal bupivacaine - fentanyl associated with transdermal nitroglycerine patch and neostigmine intrathecal .Suggesting that transdermal nitroglycerine patch and neostigmine may enhance each other's antinociceptive effects at the dose studied

Intrathecal neostigmine diminishes, but does not abolish, hypotension from spinal bupivacaine in dogs

Hypotension is the most common side effect from spinal anesthesia, and studies in rats suggest that this side effect could be abolished by the coadministration of neostigmine with spinal local anesthetics. Therefore, the aim of the present work was to study the hemodynamic effects of spinal neostigmine and to test whether neostigmine would prevent spinal bupivacaine-induced hypotension in dogs. Fifteen dogs were included in this study. They were anesthetized with i.v. pentobarbital. Polyvinyl cannulas were inserted into a femoral artery and vein. The femoral artery cannula was connected to the Super Speed Kymograph via heparinized tubing for arterial blood pressure [BP] monitoring. ECG electrodes were connected to the dog via special needles for decubitus, a polyvinyl [epidural] catheter was inserted intrathecally [IT] via a Tuohy needle inserted in L 4-5 space. After a period of 30 mm, baseline values for HR and BP were recorded. The dogs were divided into three groups of five each. In the first group, 1 ml 0.5% bupivacaine in 8.33% dextrose was injected via the IT catheter. In the second group, 1mg [lml] neostigmine was injected via the IT catheter and followed by 1 ml 0.5% bupivacaine in 8.33% dextrose after 30 min. HR and BP were recorded at 10-min intervals. The third group was the control one in which l ml normal saline was injected via the IT catheter. Transverse sections were taken from the spinal cord at the lumbar region from neostigmine-treated dogs and from the control ones for histopathological examination by light and electron heart rate [HR] recording. In the lateral microscopes. Spinal neostigmine alone increased [non significantly] arterial BP by 5% with a latency of 15 min, but it had no effect on HR. Compared with spinal bupivacaine alone, pretreatment with neostigmine resulted in hypotension of slower onset [15 vs 5 min] shorter duration [60 vs 90 min] and smaller magnitude [-11% vs - 19%]. Light and electron microscope examination did not reveal any change between control and neostigmine treated dogs. In conclusion, spinal bupivacaine-induced hypotension was partially counteracted by spinal neostigmine in dogs