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

A Comparison of Subarachnoid Block Characteristics Following Co-administration of Fentanyl Premixed With Hyperbaric Bupivacaine Versus Antecedent or Succedent to Hyperbaric Bupivacaine: A Randomized Controlled Study

Background Adjuvants are often used during subarachnoid block to enhance and prolong the analgesia and decrease the adverse effects of high doses of local anesthetic agents. Intrathecal fentanyl premixed with hyperbaric bupivacaine has been used in spinal anesthesia and compared with the sequential use of these drugs in separate syringes. However, given the paucity of literature, we conducted this study where premixed antecedent and succedent administration of intrathecal fentanyl with hyperbaric bupivacaine were compared in terms of flow dynamics, block characteristics, and hemodynamic alterations. Methodology This prospective, randomized, triple-blinded comparative study was conducted among 160 patients who were randomly allocated into four groups. Group A (n = 40) (control) received 3.0 mL (15 mg) of 0.5% hyperbaric bupivacaine and 0.5 mL of normal saline via a 5.0 mL syringe. Group B (n = 40) received 3.0 mL (15 mg) of 0.5% hyperbaric bupivacaine and 0.5 mL (25 µg) of fentanyl premixed via a single 5.0 mL syringe. Group C (n = 40) received 0.5 mL (25 µg) of fentanyl via a 1.0 mL syringe followed by 3.0 mL (15 mg) of 0.5% hyperbaric bupivacaine via a 5.0 mL syringe. Group D (n = 40) received 3.0 mL (15 mg) of 0.5% hyperbaric bupivacaine via a 5.0 mL syringe followed by 0.5 mL (25 µg) of fentanyl via a 1.0 mL syringe. The onset and regression of sensory and motor blockade, hemodynamic parameters, time to first rescue analgesia, and adverse events were observed. Data analysis was done using SPSS version 17.0 (SPSS Statistics Inc., Chicago, IL, USA). Results The mean time taken for the onset of sensory and motor blockade was least in Group D followed by Group C. Duration of sensory and motor blockade was prolonged in Group D. Patients in Group A experienced more hypotension than Groups B, C, and D. Requirement of rescue analgesia was delayed in Groups C and D. Conclusions Administering 25 µg (0.5 mL) of Fentanyl separately after 15 mg (3.0 mL) of 0.5% hyperbaric bupivacaine results in early onset and prolonged duration of sensory and motor blockade, intraoperative hemodynamic stability, the delayed requirement of rescue analgesia postoperatively, and fewer side effects compared to its co-administration as a premixed solution or antecedent to hyperbaric bupivacaine.

Comparing spinal anesthesia approaches for transurethral lithotripsy in patients with proximal ureteral stones: A randomized clinical trial of bupivacaine alone versus bupivacaine with fentanyl

Despite the benefits of spinal anesthesia and the preference of anesthesiologists for this technique, it is less accepted by urologists due to the proximity of the stone place in the ureter and the possibility of pain, restlessness, and occasional movements of the patient during surgery. The current study investigated the success of bupivacaine plus intrathecal fentanyl in patients undergoing transurethral lithotripsy (TUL). In this randomized clinical trial, from April 2021 to September 2021, 54 patients with proximal urolithiasis candidates for TUL were enrolled. Patients were randomly categorized into two groups: group A received bupivacaine 10 mg and 0.5 ml of normal saline, while group B received bupivacaine 10 mg with 0.5 ml (25µg) of intrathecal fentanyl. According to our findings, about 74% of the patients were men, and the mean age of the patients was 66.14±22.46 years. The onset time of the sensory block, sensory block level, pain score, degree of relaxation, depth of the motor block, occurrence of anesthesia complications, oxygen saturation, and mean arterial blood pressure were not significantly different between the two groups. However, the duration of the motor block in group B was longer than in group A (p<0.001). Also, retropulsion was observed only in five patients (18.5%) in group A, significantly higher than in group B (p=0.019). Bupivacaine with fentanyl 25µg provided adequate spinal anesthesia with lower retropulsion in patients with urolithiasis who are candidates for TUL.

Efficacy of premixed versus succedent administration of fentanyl and bupivacaine in subarachnoid block for lower limb surgeries: A randomised control trial

Background and Aims

Subarachnoid block is the most commonly used anaesthesia technique for lower limb surgeries. Opioids are the most commonly used adjuvants with local anesthetics (LA). Adjuvants are given premixed with LA loaded in a single syringe. This study was conducted to evaluate differences in level of sensory and motor block and incidence of hypotension whilst administering hyperbaric bupivacaine and fentanyl either in a single syringe or different syringes. The effect of administering opioid prior to LA and vice versa on these parameters was also assessed.

Methods

One hundred and twenty patients were randomly allocated into three groups of 40 each: Group A received premixed 0.5% heavy bupivacaine 2.5 ml (12.5 mg) and 0.5 ml (25 microgram) of fentanyl in a single 3.0 ml syringe, Group B received 0.5 ml (25 microgram) of fentanyl in a 3.0 ml syringe followed by 0.5% heavy bupivacaine 2.5 ml (12.5 mg) in a 3.0 ml syringe, Group C received 0.5% heavy bupivacaine 2.5 ml (12.5 mg) in a 3.0 ml syringe followed by 0.5 ml (25 microgram) fentanyl in a 3.0 ml syringe. All statistical calculations were done using SPSS 21 version statistical program for Microsoft Windows.

Results

The mean time for onset of sensory and motor block was least in group C followed by group B. The duration of sensory and motor block was prolonged in groups B and C. Patients in group A experienced more hypotension as compared to groups B and C.

Conclusion

Administering hyperbaric bupivacaine first followed by fentanyl leads to an early onset and prolonged duration of sensory and motor block.

Comparative Study of Clonidine with Ropivacaine versus Ropivacaine Alone in Epidural Anesthesia for Lower Limb Orthopedic Surgery

Background:

Epidural anesthesia has been well established as a safe and effective technique not only for perioperative anesthesia but also for postoperative analgesia. Various adjuvants have been added to local anesthetic agent in an effort to prolong this duration.

Aims:

The aim of this study was to compare and evaluate the anesthesia and analgesic property of ropivacaine to its combination with clonidine for lower limb orthopedic surgery under epidural.

Materials and Methods:

In a prospective, randomized, double-blind study, eighty adult patients undergoing lower limb surgeries received either 0.75% ropivacaine or 75 μg clonidine with 0.75% ropivacaine through epidural route. Patients were compared for hemodynamic variability, quality of motor and sensory block, intra- and post-operative analgesia, and the side effects associated.

Statistical Analysis:

Data analysis was done by Student's paired t-test, Chi-square test, and Mann–Whitney test. P < 0.05 was considered statistically significant.

Results:

The time taken for onset of the motor as well as the sensory block was significantly shorter in ropivacaine with clonidine group as compared to ropivacaine alone group. Mean duration of analgesia was significantly higher in patients who received clonidine as an adjunct (P < 0.001). There was no significant difference observed in the incidence of hemodynamic changes or side effects.

Conclusion:

The study demonstrated that use of clonidine as an adjuvant to ropivacaine through epidural route provides a hemodynamically stable, faster, and prolonged epidural block and a longer analgesic effect as compared to ropivacaine alone.

A Comparative Study for the Analgesic Efficacy and Safety Profile of Fentanyl versus Clonidine as an Adjuvant to Epidural Ropivacaine 0.75% in Lower Abdominal Surgeries

CONTEXT

Different adjuvants are coadministered with local anesthetics to improve the speed of onset and duration of analgesia, and to reduce the dose, the selection of which is often left to the choice of an anesthesiologist.

AIM

The aim of this study was to compare the analgesic efficacy and safety profile of fentanyl and clonidine as an adjuvant to epidural ropivacaine anesthesia.

SETTING AND DESIGN

With institutional ethical committee clearance, a prospective, randomized, placebo-controlled double-blind clinical study was conducted at Vivekananda Polyclinic and Institute of Medical Sciences, Lucknow.

MATERIAL AND METHODS

Two groups with thirty patients each were randomly allocated to receive 15-20 ml of 0.75% ropivacaine with 75 μg clonidine or 15-20 ml of 0.75% ropivacaine with 75 μg fentanyl, respectively. Block characteristics such as onset of analgesia, maximum level of sensory blockade, complete motor blockade, hemodynamic, time to two-segment regressions, time for rescue analgesia, time to complete motor recovery, and side effects were analyzed.

RESULTS

Results showed that the onset of blockade is faster when fentanyl is used as additives. Time for two-segment regression was earlier in fentanyl group but time for rescue analgesia was longer in clonidine group.

STATISTICAL ANALYSIS

Two groups were compared by Student's t-test and Chi-square test; ANOVA and significance of mean difference bet were done by Newman-Keuls test.

CONCLUSION

Addition of clonidine to epidural ropivacaine provides superior analgesia than the addition of fentanyl to epidural ropivacaine without much difference in side effect profile.

Comparison of intrathecal clonidine and magnesium sulphate used as an adjuvant with hyperbaric bupivacaine in lower abdominal surgery

Background and Aims:

Use of various adjuvants to spinal anaesthesia is a well-known modality to provide intra- and post-operative analgesia. This study was designed to evaluate and compare the analgesic efficacy of clonidine and magnesium when used as an additive to intrathecal 0.5% hyperbaric bupivacaine.

Methods:

Ninety patients of the American Society of Anesthesiologists’ physical status grade I or II, scheduled for lower abdominal surgery under spinal anaesthesia, were randomly allocated into three groups. Group B received 3 mL of 0.5% hyperbaric bupivacaine with 1 mL of normal saline, Group C received 3 mL of 0.5% hyperbaric bupivacaine with 1 mL (30 μg) of clonidine and Group M received 3 mL of 0.5% hyperbaric bupivacaine with 1 mL (50 mg) magnesium sulphate. The primary outcome variable was duration of analgesia and secondary outcome variables included onset and duration of sensory and motor block, sedation level and adverse effects. Data were analysed with ANOVA, Kruskal–Wallis and Chi-square tests.

Results:

The time to first rescue analgesia was significantly (P < 0.01) longer in the Group C (330.7 ± 47.7 min) than both Groups. Group M (246.3 ± 55.9 min) showed significantly prolonged analgesia than Group B (134.4 ± 17.9 min). Group C and Group M showed significantly prolonged duration of both sensory and motor block compared to Group B.

Conclusion:

Intrathecal clonidine added to bupivacaine prolongs the duration of post-operative analgesia, and hastens the onset and prolongs the duration of sensory and motor block compared to magnesium or controls.

Effect of adding clonidine to intrathecal bupivacaine on the quality of subarachnoid block: A prospective randomized double-blind study

Context:

The purpose of adding an adjuvant to local anesthetic in a central neuraxial blockade is to augment the desirable pharmacological actions of the agent and/or to minimize its undesirable pharmacological effects. Clonidine is an alfa-2 receptor agonist which has gained popularity in recent times as an adjuvant in spinal anesthesia.

Aims:

To evaluate the influence of clonidine on the hemodynamic stability and the duration of anesthesia when added to intrathecal hyperbaric bupivacaine.

Settings and Design:

Prospective randomized double blind study.

Subjects and Methods:

Fifty patients scheduled for spinal anesthesia were randomized into two Groups A and B with 25 in each. Group A patients received 3 ml 0.5% heavy bupivacaine + 30 μg (0.2 ml) clonidine and Group B patients received 3 ml 0.5% heavy bupivacaine + 0.2 ml normal saline in the subarachnoid space. The blood pressure and heart rate were closely monitored. The time for attaining peak sensory block, time for two segment regression, decrease in the heart rate, total requirement of mephentermine to counter the hypotension, and the number of patients requiring mephentermine in each group was tabulated and analyzed.

Statistical Analysis Used:

Descriptive and inferential statistical methods were used to analyse the data. The power of the study was calculated using online power calculator for two independent sample study.

Results:

The time for attaining peak sensory block was similar in both the groups. The time for two segment regression in Group A was 62.6 min and in Group B was 38.08 min. Twelve percent of patients in Group A and 52% of patients in Group B required mephentermine with the mean consumption being 0.72 mg in Group A and 5.65 mg in Group B.

Conclusions:

Addition of low-dose clonidine to intrathecal bupivacaine not only prolonged the duration of spinal anesthesia but also provided a stable intraoperative hemodynamic profile.

Effect of clonidine and/or fentanyl in combination with intrathecal bupivacaine for lower limb surgery

Background and Aims:

Various adjuncts to local anesthetics have been used with the purpose of improving the quality of subarachnoid block. This randomized double-blind study was conducted to evaluate the efficacy of adding clonidine to bupivacaine and bupivacaine-fentanyl combination.

Material and Methods:

A total of 100 patients scheduled for surgery under spinal anesthesia were randomly allocated into four groups (n = 25 each) to receive intrathecal bupivacaine 7.5 mg plus normal saline 0.5 ml (group BS), intrathecal bupivacaine 7.5 mg, and fentanyl 25 μg (group BF), intrathecal bupivacaine 7.5 mg and clonidine 75 μg (group BC), intrathecal bupivacaine 7.5 mg, clonidine 37.5 μg, and fentanyl 12.5 μg (group BCF). The time of onset and duration of sensory block, highest dermatome level of sensory block, time of onset of motor block, time to complete motor block recovery and duration of spinal anesthesia, intraoperative and postoperative hemodynamics and side effects if any were recorded. VAS, total number of patients who were administered supplemental analgesic in each group and the total amount of supplemental analgesic administered in the next 24 h was quantified and documented in all the groups.

Results:

The time of onset of sensory block (min) in groups BS, BC, BCF, and BF was 10.80 ± 2.26, 10.20 ± 1.00, 10.00 ± 0.00, and 13.80 ± 2.61 respectively, thus onset of sensory block was significantly earlier in groups BC and BCF. Similarly, onset of motor block was also quicker in groups BC and BCF. Time of requirement of supplemental analgesia was 135.20 ± 12.70 min, 199.2 ± 21.92 min, 209.80 ± 26.32 min, and 208.00 ± 26.58 min in groups BS, BF, BC, and BCF respectively. Intraoperative and postoperative changes in heart rate, mean arterial blood pressure, oxygen saturation, and respiratory rate were comparable. Sedation scores were significantly higher in group BC. Pruritus was only observed in groups BF and BCF. Mean nausea vomiting scores were comparable in all groups.

Conclusion:

We conclude that the addition of clonidine in doses of 75 μg and 37.5 μg to low-dose bupivacaine and bupivacaine-fentanyl prolongs the sensory and motor block while increasing the duration of postoperative analgesia without significant side-effects.

Analgesic Effect of Clonidine Added to Bupivacaine in Spinal Anesthesia for Cruciate Ligament Repair

Background:

Several researchers have suggested that addition of local anesthetics to spinal anesthesia increases the duration of post-operative analgesia.

Objectives:

This study sought to assess the effect of addition of clonidine to bupivacaine in spinal anesthesia on analgesia after cruciate ligament repair.

Patients and Methods:

This double-blind clinical trial was conducted on 50 American Society of Anesthesiologists (ASA) class I or II patients who were candidates for cruciate ligament repair. Patients were randomly assigned to two groups; one group received 15 mg of bupivacaine (group B) and the other 15 mg of bupivacaine plus clonidine (75 µg, group BC). The two groups were compared in terms of post-operative analgesia and related factors using the SPSS software version 20.

Results:

All patients were males with a mean age of 24.9 years in group B, and 25.2 years in group BC (P > 0.05). In group BC, time lapse to request analgesics was 160 minutes longer and the Visual Analog Scale (VAS) at this time was 0.3 units less than group B. The time to regression of sensory block by two dermatomes was seven minutes longer, VAS in the recovery room was 1 unit less and Bromage scale in the recovery room and ward was 0.6 and 0.9 units more, respectively in the BC group. Hypotension and ephedrine usage was 36% more in the BC group (P < 0.05).

Conclusions:

Clonidine plus bupivacaine can increase the duration of motor and sensory block in arthroscopic cruciate ligament repair under spinal anesthesia. However, due to significant hemodynamic changes, further studies are required to determine a safer dose.

Efficacy of premixed versus sequential administration of clonidine as an adjuvant to hyperbaric bupivacaine intrathecally in cesarean section

Background:

Density of the drugs injected intrathecally is an important factor that influences spread in the cerebrospinal fluid. Mixing adjuvants with local anesthetics (LA) alters their density and hence their spread compared to when given sequentially in seperate syringes.

Aims:

To evaluate the efficacy of intrathecal administration of hyperbaric bupivacaine (HB) and clonidine as a mixture and sequentially in terms of block characteristics, hemodynamics, neonatal outcome, and postoperative pain.

Setting and Design:

Prospective randomized single blind study at a tertiary center from 2010 to 2012.

Materials and Methods:

Ninety full-term parturient scheduled for elective cesarean sections were divided into three groups on the basis of technique of intrathecal drug administration. Group M received mixture of 75 μg clonidine and 10 mg HB 0.5%. Group A received 75 μg clonidine after administration of 10 mg HB 0.5% through separate syringe. Group B received 75 μg clonidine before HB 0.5% (10 mg) through separate syringe.

Statistical analysis used:

Observational descriptive statistics, analysis of variance with Bonferroni multiple comparison post hoc test, and Chi-square test.

Results:

Time to achieve complete sensory and motor block was less in group A and B in which drugs were given sequentially. Duration of analgesia lasted longer in group B (474.3 ± 20.79 min) and group A (472.50 ± 22.11 min) than in group M (337 ± 18.22 min) with clinically insignificant influence on hemodynamic parameters and sedation.

Conclusion:

Sequential technique reduces time to achieve complete sensory and motor block, delays block regression, and significantly prolongs the duration of analgesia. However, it did not matter much whether clonidine was administered before or after HB.