Enhancement of analgesic effect of intrathecal neostigmine and clonidine on bupivacaine spinal anesthesia

The impact of neuraxial clonidine on postoperative analgesia and perioperative adverse effects in women having elective Caesarean section-a systematic review and meta-analysis

Neuraxial clonidine improves postoperative analgesia in the general surgical population. The efficacy and safety of neuraxial clonidine as a postoperative analgesic adjunct in the Caesarean section population still remains unclear. This systematic review and meta-analysis aims to evaluate the effect of perioperative neuraxial clonidine on postoperative analgesia in women having Caesarean section under neuraxial anaesthesia. We included randomized controlled trials comparing the analgesic efficacy of the perioperative administration of neuraxial clonidine alone or in combination with a local anaesthetic and/or opioids in women having elective Caesarean section under neuraxial anaesthesia when compared with placebo. PubMed, the Cochrane Central Register of Controlled Trials, and EMBASE were searched until February 2017. Eighteen studies were included in the meta-analysis. Neuraxial clonidine reduced 24 h morphine consumption [mean difference (MD): -7.2 mg; 95% confidence interval (CI): -11.4, -3.0 mg; seven studies] and prolonged time to first analgesic request (MD: 135 min; 95% CI: 102, 168 min; 16 studies) when compared with the control group. Neuraxial clonidine increased intraoperative hypotension [odds ratio (OR): 2.849; 95% CI: 1.363, 5.957], intraoperative sedation (OR: 2.355; 95% CI: 1.016, 5.459), but reduced the need for intraoperative analgesic supplementation (OR: 0.224; 95% CI: 0.076, 0.663). The effect of clonidine on intraoperative bradycardia, intraoperative and postoperative nausea and vomiting, postoperative sedation, and pruritus were inconclusive. Neuraxial clonidine did not negatively impact neonatal umbilical artery pH or Apgar scores. This review demonstrates that neuraxial clonidine enhances postoperative analgesia in women having Caesarean section with neuraxial anaesthesia, but this has to be balanced against increased maternal adverse effects.

A Comparison of Intrathecal Dexmedetomidine and Neostigmine as Adjuvant to Ropivacaine for Lower Limb Surgeries: A Double-blind Randomized Controlled Study

Objective:

The primary objective of this study was to compare the analgesic effects of intrathecal ropivacaine with or without neostigmine or dexmedetomidine in lower limb surgeries. Secondary objectives were to study the characteristics of block, duration of analgesia, postoperative analgesic requirement, and associated side effects.

Materials and Methods:

Seventy-five patients posted for elective orthopedic lower limb surgeries under spinal anesthesia were randomly divided into three equal groups to receive intrathecal ropivacaine 0.5% alone (Group R), with adjuvant 5 μg dexmedetomidine (Group R + D) or 50 μg neostigmine (Group R + N). Time to achieve T10 sensory block, time to 2-segment regression, duration of regression to L4, maximum modified Bromage score and duration of analgesia were noted. The incidences of adverse events such as nausea, vomiting, hypotension, bradycardia, desaturation, shivering, and itching were also noted. Statistical analysis was performed using two sample t-test for normally distributed variables and Pearson's Chi-squared test for categorical data. The level of significance was set as P < 0.05.

Results:

Quality of motor and sensory blockage was significantly better in both Group R + D and Group R + N than Group R. Mean time to achieve T10 sensory block was lowest, time taken in regression of block by 2-segments and duration of regression to L4 was longest in Group R + D and was significant when compared to other groups. Adverse effects such as nausea and vomiting were highest in Group R + N and was statistically significant as compared to other groups.

Conclusions:

Dexmedetomidine is a better intrathecal adjuvant emerged as compared to neostigmine due to faster onset of anesthesia, better intra- and post-operative analgesia and prolonged duration of motor and sensory blockade without significant increase in adverse effects.

Comparison of Enhancement of Analgesic Effect of Intrathecal Neostigmine by Intrathecal Clonidine and Transdermal Nitroglycerin Patch on Bupivacaine Spinal Anesthesia

Background

Relief of pain is very important goal intraoperatively and postoperatively. Neostigmine has been used successfully intrathecally with other agents such as clonidine and opioids for pain relief.

Aims

This study aims to compare and evaluate the efficacy and safety of combining intrathecal (IT) neostigmine with IT clonidine and transdermal nitroglycerin (tNTG) patch for the relief of pain in patients after surgery.

Settings and Design

This was a randomized, prospective, and comparative study.

Materials and Methods

In this study, recruited patients were randomly allocated into three groups. Groups I, II, and III received intrathecally 25 μg of neostigmine + 15 mg hyperbaric 0.5% bupivacaine, 25 μg of neostigmine + 25 μg clonidine + 15 mg hyperbaric 0.5% bupivacaine, and 25 μg of neostigmine + tNTG patch (3 cm × 5 cm, 5 mg/24 h) +15 mg hyperbaric 0.5% bupivacaine, respectively. Heart rate, mean arterial pressure, analgesic properties, and complications were assessed and compared among groups.

Statistical Analysis

Mean and standard deviation were calculated. Test of analysis between two groups was done by t-test and among three groups by ANOVA, then P value was calculated.

Results

Duration of analgesia was significantly longer in Group III in comparison to Group II (7.142 ± 1.81 vs. 4.408 ± 0.813 h) and was significantly longer in Group II in comparison to Group I (4.408 ± 0.813 vs. 2.583 ± 0.493 h). Analgesic requirement was significantly less in Group III in comparison to Group II (1.9 ± 0.76 vs. 2.5 ± 0.51) and was significantly less in Group II in comparison to Group I (2.5 ± 0.51 vs. 3.1 ± 0.48). Sedation score was found significantly high in Group II than other groups.

Conclusion

Both IT clonidine and tNTG patch with bupivacaine + neostigmine spinal anesthesia were found effective in pain control. Results were found better with tNTG patch.

A comparison between intrathecal clonidine and neostigmine as an adjuvant to bupivacaine in the subarachnoid block for elective abdominal hysterectomy operations: A prospective, double-blind and randomized controlled study

BACKGROUND AND AIMS

Adjuvant to the local anesthetic agent has proven benefits when used intrathecally. With regards to intrathecal bupivacaine as control, we have compared in this study the effects of clonidine and neostigmine when co-administered intrathecally with hyperbaric (0.5%) bupivacaine for abdominal hysterectomy.

MATERIALS AND METHODS

This prospective, randomized, double-blind study was conducted from May 2009 to June 2011. A total of 150 patients of American Society of Anaesthesiology grades I and II scheduled for abdominal hysterectomy under spinal anesthesia were randomly allocated into three groups. A volume of 3 ml of 0.5% hyperbaric bupivacaine was respectively added 1 ml solution containing 5% dextrose and 75 mcg of neostigmine in Group N, 1 ml containing 5% dextrose and 30 mcg of clonidine in Group C and 1 ml of 5% dextrose in Group D (control). We compared the sensory and motor block, the surgical condition, the duration of spinal analgesia and the side-effect profile.

RESULTS AND OBSERVATIONS

Sensory and motor blocks and duration of spinal analgesia were significantly increased in both Group C and Group N compared to Group D. More incidences of Nausea and vomiting were observed in Group N compared to other groups. The surgical condition was poorer in Group N compared to Group C.

CONCLUSION

Both intrathecal clonidine and neostigmine increase the bupivacaine-induced spinal block. However, clonidine provides better surgical condition and fewer incidences of nausea and vomiting.

The evolution of spinal/epidural neostigmine in clinical application: Thoughts after two decades

Since the first clinical application of analgesia following spinal anticholinesterase by 1940's, several clinical double-blind studies have been conducted to date, where intrathecal doses of neostigmine in humans ranged from 750 to 1 μg, due to side-effects. Conversely, epidural neostigmine has been evaluated in proportionally higher doses and represents an alternative, but still deserves more investigation concerning both acute and chronic pain, as it seems devoid of important side-effects.

Intrathecal clonidine added to small-dose bupivacaine prolongs postoperative analgesia in patients undergoing transurethral surgery

INTRODUCTION

The aim of this prospective, double-blinded study was to investigate the effects of clonidine in co-administration with bupivacaine during spinal anesthesia, regarding the onset and regression of motor and sensory block, postoperative analgesia and possible side effects.

METHODS

We randomly selected 66 male patients (age 35 to 70), from the American Society of Anesthesiologists (ASA) class I-II; these patients were scheduled for transurethral surgical procedures. These patients were randomly allocated into two groups of 33 patients each: group B (bupivacaine) only received 0.5% isobaric bupivacaine 7.5 mg intrathecally and group BC (bupivacaine + clonidine) received bupivacaine 7.5 mg and clonidine 25 μg intrathecally. We performed the spinal anesthesia at a level of L3-L4 with a 25-gauge needle. We assessed the sensory block with a pin-prick, the motor block using the Bromage scale, analgesia with the visual analog scale and sedation with the modified Wilson scale. We also recorded the hemodynamic and respiratory parameters.

RESULTS

The groups were demographically similar. The mean time of achievement of motor block (Bromage 3) and sensory block at level T9 was significantly shorter in the BC group compared with B group (p = 0.002, p = 0.000, respeectively). The motor block regression time was not significantly different between the two groups (p = 0.237). The postoperative analgesia requirement was significantly longer in group BC compared with group B (p = 0.000). No neurological deficit, sedation or other significant adverse effects were recorded.

CONCLUSION

The intrathecal application of clonidine in combination with bupivacaine improves the duration and quality of spinal anesthesia; it also provides longer duration of postoperative analgesia, without significant side effects.

Use of neostigmine in the management of acute postoperative pain and labour pain: a review

Neostigmine is a parasympathomimetic agent that has been recently investigated for use as an adjunct analgesic agent in the perioperative and peripartum period. A number of studies have investigated the intrathecal, epidural, caudal and intra-articular routes of administration of this agent, as well as the addition of neostigmine to local anaesthetics used for brachial plexus block and intravenous regional anaesthesia. While the intrathecal administration of neostigmine produced useful analgesic effects in the postoperative period in some studies, the high incidence of adverse events, mainly nausea and vomiting, limit the clinical usefulness of this route of administration. Several studies investigated the postoperative analgesic effects of epidural neostigmine using a number of different regimens. Overall, this route of administration appeared to improve postoperative analgesia in most studies without increasing the incidence of adverse events, and merits further research. Neuraxial administration of neostigmine appears to be safe in the obstetric population, with no reported adverse effects in the mother or fetus. While intrathecal administration is limited by a high incidence of nausea and vomiting in this patient population, the epidural route appears more promising and requires further investigation. The addition of neostigmine to caudal local anaesthetics was associated with improved postoperative analgesia in a number of studies. A dose of 2 microg/kg proved to be effective in several studies but was associated with an increased incidence of vomiting in some studies. Intra-articular administration of neostigmine 500microg produced a useful analgesic effect in the postoperative period in several studies and was not associated with an increase in the incidence of adverse effects. Studies investigating the efficacy of adding neostigmine to the local anaesthetics used for brachial plexus block and intravenous regional anaesthesia reported conflicting results. Further studies are required to determine the place of the administration of neostigmine by these routes.

Adrenergic and cholinergic compounds

Adrenergic and cholinergic signalling contributes significantly to the endogenous antinociceptive system. Exogenous alpha 2 adrenergic agonists have a well-established analgesic profile; however, recent investigations suggest that this class of agents is underused, and herein we highlight the potential for both current application and future development of these agents. Nicotinic and muscarinic cholinergic ligands represent a novel class of agents with much promise for the management of problematic pain. In this chapter we review advances in both preclinical and clinical arenas and highlight potential avenues for further research.

Intrathecal clonidine in the treatment of intractable pain: a phase I/II study

OBJECTIVE

Epidural clonidine has been proven effective in relieving intractable cancer pain, especially neuropathic. This phase I/II study was performed to investigate if intrathecal clonidine is well tolerated and effective for long-term treatment of intractable chronic pain.

DESIGN

Thirty-one patients, previously implanted with programmable pumps and unable to obtain adequate pain relief with opioids and adjuvant oral medications, were enrolled. Clonidine monotherapy was initiated at 1 mcg/hr and escalated to a maximum of 40 mcg/hr (960 mcg/day). Efficacy measurements included Verbal Digital Pain Ratings, and side effects were determined by physical exam and patient reports.

RESULTS

Patients achieving 50% or greater reduction in pain intensity scores in the dose-titration phase continued for long-term follow-up. Twenty-two patients (71%) entered long-term follow-up with intrathecal clonidine; nine patients (29%) did not obtain adequate pain control in the dose-titration phase. Thirteen patients were considered long-term successes with a mean follow-up of 16.7 months (range = 6.3 to 44 months). Nine patients failed to achieve adequate pain relief due to side effects or lack of efficacy. Fifty-nine percent of the patients successful in the dose-titration stage (42% of all patients considered) were considered long-term successes. Patients in the long-term phase maintained adequate pain control with minimal dose escalation.

CONCLUSIONS

This study demonstrates the tolerability and effectiveness of intrathecal clonidine in the treatment of chronic pain. The physician using clonidine for long-term intrathecal infusion should be cognizant of the risk that severe rebound systemic hypertension can occur with abrupt cessation of the intrathecal infusion of clonidine.