Low dose intrathecal clonidine and fentanyl added to hyperbaric bupivacaine prolongs analgesia in gynecological surgery

Biased, Bitopic, Opioid-Adrenergic Tethered Compounds May Improve Specificity, Lower Dosage and Enhance Agonist or Antagonist Function with Reduced Risk of Tolerance and Addiction

This paper proposes the design of combination opioid-adrenergic tethered compounds to enhance efficacy and specificity, lower dosage, increase duration of activity, decrease side effects, and reduce risk of developing tolerance and/or addiction. Combinations of adrenergic and opioid drugs are sometimes used to improve analgesia, decrease opioid doses required to achieve analgesia, and to prolong the duration of analgesia. Recent mechanistic research suggests that these enhanced functions result from an allosteric adrenergic binding site on opioid receptors and, conversely, an allosteric opioid binding site on adrenergic receptors. Dual occupancy of the receptors maintains the receptors in their high affinity, most active states; drops the concentration of ligand required for full activity; and prevents downregulation and internalization of the receptors, thus inhibiting tolerance to the drugs. Activation of both opioid and adrenergic receptors also enhances heterodimerization of the receptors, additionally improving each drug's efficacy. Tethering adrenergic drugs to opioids could produce new drug candidates with highly desirable features. Constraints-such as the locations of the opioid binding sites on adrenergic receptors and adrenergic binding sites on opioid receptors, length of tethers that must govern the design of such novel compounds, and types of tethers-are described and examples of possible structures provided.

Modelling of the optimal bupivacaine dose for spinal anaesthesia in ambulatory surgery based on data from systematic review

BACKGROUND

Spinal bupivacaine is used for day-case surgery but the appropriate dose that guarantees hospital discharge is unknown.

OBJECTIVE

We sought to determine the spinal bupivacaine dose that prevents delayed hospital discharge in ambulatory surgery.

DESIGN

Systematic review of clinical trials.

DATA SOURCES

Comprehensive search in electronic databases of studies published between 1996 and 2014 reporting the use of spinal bupivacaine in ambulatory patients. Additional articles were retrieved through hyperlinks and by manually searching reference lists in original articles, review articles and correspondence published in English and French.

MAIN OUTCOME MEASURES

Data were used to calculate, motor block duration and discharge time, an estimated maximal effect (Emax: maximum theoretical time of motor block) and the effective dose to obtain half of Emax (D50) with 95% confidence intervals (CIs). A simulation was performed to determine the dose corresponding to a time to recovery of 300 min for motor function, and 360 min for discharge, in 95% of the patients.

RESULTS

In total, 23 studies (1062 patients) were included for analysis of the time to recovery of motor function, and 12 studies (618 patients) for the time to hospital discharge. The Emax for recovery of motor function was 268 min [95% CI (189 to 433 min)] and the D50 was 3.9 mg [95% CI (2.3 to 6.2 mg)]. A 7.5-mg dose of bupivacaine enables resolution of motor block and ambulation within 300 min in 95% of the patients. A 5-mg dose or less was associated with an unacceptable failure rate.

CONCLUSION

Ambulatory surgery is possible under spinal anaesthesia with bupivacaine although the dose range that ensures reliable anaesthesia with duration short enough to guarantee ambulatory management is narrow.

Comparison of Intrathecal Nalbuphine Hydrochloride and Clonidine Hydrochloride as an Adjuvant to Hyperbaric Bupivacaine in Abdominal Hysterectomy

Background

Various adjuvants for prolongation of intraoperative and postoperative analgesia have been clinically studied in the literature.

Aim

This study was done to evaluate and compare the effects of nalbuphine and clonidine as an adjuvant to bupivacaine in spinal anesthesia.

Methods

In this prospective, randomized, placebo control, double-blind, and comparative study, a total of ninety patients of American Society of Anesthesiologists physical status Classes I and II undergoing abdominal hysterectomy under subarachnoid block were randomly divided into three groups. In addition to 15 mg of 0.5% hyperbaric bupivacaine administered, patients of groups BS, BN, and BC received 0.9% normal saline, 1.6 mg nalbuphine, and 30 μg clonidine, respectively. The total volume of drugs administered intrathecally was made up to 3.5 ml by addition of sterile isotonic normal saline in all. The onset time and duration of sensory and motor block, duration of analgesia, and total dose of postoperative analgesic requirement in the first 24 h were compared among groups. Hemodynamic changes and side effects were also recorded.

Results

Addition of study adjuvants brought significantly faster onset of sensory and motor block. Patients in clonidine group showed significantly longer mean time two segment sensory block regression (P < 0.05) lowest seen in control group. The regression time of motor block to modified Bromage Grade I was significantly longer in clonidine group and comparable in the other groups. Adjuvants have significantly increased the mean duration of analgesia, highest in clonidine group (P < 0.05).

Conclusion

Intrathecal clonidine is associated with prolonged motor and sensory block, better hemodynamic stability, and less postoperative analgesic requirement as compared to nalbuphine.

Comparative Evaluation of Ropivacaine and Fentanyl Versus Ropivacaine and Fentanyl with Clonidine for Postoperative Epidural Analgesia in Total Knee Replacement Surgery

Introduction

Clonidine an alpha 2 adrenoceptor agonist possesses analgesic properties and has been used as an adjuvant in epidural analgesia. The addition of clonidine to other analgesics may result in enhanced analgesia through additive mechanisms or synergistic mechanisms. The enhanced analgesia may lead to a decrease in the dosage of analgesic drugs along with reduction of side effects.

Aim

The purpose of this study was to evaluate the effect of adding clonidine to epidural ropivacaine and fentanyl mixture in terms of quality of analgesia and side effects in patients of total knee replacement surgery.

Materials and Methods

A prospective randomised double blind study was conducted on 60 patients of ASA physical status I, II and III who underwent unilateral total knee replacement surgery under combined spinal epidural anaesthesia. Patients were divided into two Groups A and B randomly. Postoperatively Group A received continuous epidural infusion of ropivacaine 2 mg.ml ^-1 and fentanyl 2 μg.ml ^-1 along with clonidine 2 μg.ml^-1 in the range of 3-7 ml.hr^-1 while Group B received the ropivacaine and fentanyl epidural solution. The postoperative VAS scores, haemodynamic parameters, motor block, sedation, nausea, vomiting and any other significant side effects were noted. The two groups were compared with student's t-test, Pearson's Chi square test and t-test using SPSS statistical software.

Results

Visual analog scale scores were lower in Group A (3.38) than in Group B (3.72). The average infusion rate was lower in Group A (4.7 ± 0.7 ml.hr ^-1) than in Group B (5.5 ± 0.7 ml.hr^-1). Patients in Group A required less dosage of rescue pain medication Paracetamol (1g i.v.), diastolic pressure and heart rate were lower in Group A. The groups were comparable in terms of sedation, motor block and nausea vomiting.

Conclusion

Clonidine added to a ropivacaine and fentanyl mixture augmented the postoperative epidural analgesia without significant side effects.

Spinal analgesia improves surgical outcome after open nephrectomy for renal cell carcinoma: a randomized controlled study

OBJECTIVE

This study evaluated whether more effective perioperative analgesia can be part of a multimodal approach to minimizing morbidity and improving postoperative management after the open surgical approaches frequently used in the treatment of renal cell carcinoma (RCC). The aim of the study was to determine whether spinal anesthesia with clonidine can enhance postoperative analgesia, speed up mobilization and reduce the length of hospital stay (LOS).

MATERIALS AND METHODS

Between 2012 and 2015, 135 patients with RCC were randomized, in addition to general anesthesia, to receive either spinal analgesia with clonidine or epidural analgesia, stratified to surgical technique. Inclusion criteria were American Society of Anesthesiologists (ASA) score of III or less, age over 18 years and no chronic pain medication or cognitive disorders.

RESULTS

The median LOS was 4 days for patients in the spinal group and 6 days in the epidural group (p = 0.001). There were no differences regarding duration of surgery, blood loss, RENAL score, tumor size or complications between the given analgesia methods. A limitation was that different anesthesiologists were responsible for administering spinal or epidural anesthesia, as in a real-world clinical situation.

CONCLUSIONS

In this randomized controlled study, spinal analgesia with clonidine was superior to continuous epidural analgesia in patients operated on with open nephrectomy, based on shorter LOS. A shorter LOS in the study group indicates faster mobilization and improved analgesia. Spinal analgesia did not carry more complications than epidural analgesia.

Comparison of Intrathecal Dexmedetomidine with Morphine as Adjuvants in Cesarean Sections

To compare the effects of intrathecal dexmedetomidine and intrathecal morphine as supplements to bupivacaine in cesarean sections under spinal anesthesia. Full-term parturients (n=120) undergoing elective cesarean sections under spinal anesthesia were randomly allocated into three groups: Group B received 10 mg bupivacaine, Group BD received 10 mg bupivacaine plus 5 µg dexmedetomidine, and Group BM received 10 mg bupivacaine plus 100 µg morphine. The onset and regression time of sensory and motor blockade, postoperative analgesia, and side effects were recorded. Group BD showed quicker onset time and a longer sensory and motor blockade than other groups (BD vs. B and BD vs. BM, p<0.05). The mean time of sensory regression to the S1 segment was 253.21±42.79 min in group BD, 192.50±40.62 min in group BM and 188.33±37.62 min in group B (p<0.001). Group BD showed an analgesia duration (time to requirement of first rescue analgesic) (17.59±6.23 h) similar to that of group BM (16.78±5.90 h) but longer than that of group B (3.53±1.68 h) (p<0.001). The incidence of pruritus was significantly higher in group BM compared with groups BD and B (p<0.001). Less shivering was observed in group BD than in groups BM and B (p=0.009). So intrathecal dexmedetomidine (5 µg) prolonged the motor and sensory blockade, provided a similar analgesic effect and reduced pruritus and shivering compared with morphine (100 µg) in cesarean sections.

Effect of intrathecal clonidine versus fentanyl on bupivacaine spinal block in transurethral resection of prostate surgeries

Aims:

Our study aimed at comparing the onset, degree and recovery time of sensory and motor block, the hemodynamic effects and postoperative pain relief using intrathecal bupivacaine alone, bupivacaine along with fentanyl and clonidine.

Materials and Methods:

A total of 90 patients, undergoing transurethral resection of prostate (TURP) surgeries under spinal anesthesia were studied. Patients were randomly divided in a double-blind manner into three groups of 30 patients each. Group A (control) patients given subarachnoid block with 0.5% hyperbaric bupivacaine with 0.5 ml of normal saline. Group B patients were given subarachnoid block with 0.5% hyperbaric bupivacaine along with fentanyl 25 μg. Group C patients were given subarachnoid block with 0.5% hyperbaric bupivacaine 10 mg along with clonidine 30 μg and 0.3 ml of normal saline. After administering the subarachnoid block, vitals were recorded before and after surgery. Level of sensory block, the duration of motor block (DOMB), duration of sensory blockade (DOSB), the quality of postoperative analgesia using linear visual analog scale (VAS), and side effects were evaluated.

Results:

The time required to attain a maximum height of the block was significantly more in Group B as compared to Groups A and C, which was statistically significant. However, there was no statistically significant difference between Groups A and C. The mean DOSB in Groups A, B, and C were 90.83 ± 9.48 min, 135.33 ± 12.59 min, and 155.17 ± 17.49 min, respectively. The mean DOMB in Groups A, B, and C were 83.83 ± 6.52 min, 115.50 ± 14.70 min and 120.67 ± 11.50, respectively. Time of the first request of analgesia in Groups A, B and C in postoperative period were 132.50 ± 21.53 min, 296.00 ± 50.07 min, and 311.83 ± 65.34 min. patients had. VAS was significantly of higher value in Group A than Groups B and C.

Conclusions:

Intrathecal clonidine in a combination of bupivacaine for TURP provides more satisfactory anesthesia and analgesia and has less side effects.