Low-dose intrathecal clonidine combined with sufentanil as analgesic drugs in abdominal gynecological surgery

The Effect of Dexmedetomidine on Lumbar Epidural Injection for Failed Back Surgery Syndrome

Purpose. Failed back surgery syndrome is a chronic pain condition requiring rapid, effective, and efficient management. This study evaluates the effect of adding dexmedetomidine to lumbar epidural steroids in patients with failed back surgery syndrome. Methods. Fifty patients suffering from failed back surgery syndrome were randomly assigned to one of two groups, receiving an epidural injection of 20 mL of either a mixture of betamethasone (14 mg) and bupivacaine 0.5 mg (group C) or a mixture of betamethasone (14 mg), bupivacaine 0.5 mg, and dexmedetomidine (0.5 μg/kg) (group D) adjusted to the volume with normal saline. The effect was evaluated using visual analogue scale (VAS), analgesic requirement, and Oswestry disability index 2 weeks, 4 weeks, 8 weeks, and 12 weeks after injection. Results. VAS and ibuprofen consumption showed a significant reduction in group D. The Oswestry disability index was significantly improved in group D. There were no records of hypotension, bradycardia, sedation, or hypoxemia in both groups. Conclusion. The present study demonstrated potential safe and effective usage of adding dexmedetomidine to epidural steroid to control pain in patients with failed back surgery syndrome.

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

Background:

We undertook this study to ascertain if a small dose of clonidine (30 μg) when added to a bupivacaine-fentanyl mixture improves spinal analgesia, without producing side effects, as compared to a bupivacaine-fentanyl or a bupivacaine-clonidine mixture.

Materials and Methods:

In this prospective, randomized, double-blind study, 75 (American Society of Anesthesiologists) ASA grade I-II patients, aged between 45 and 65 years, who were scheduled for vaginal hysterectomy with pelvic floor repair or non-descent vaginal hysterectomy under spinal anesthesia were recruited. The patients received hyperbaric bupivacaine (2.3 ml) with fentanyl 15 μg (Group BF) or clonidine 30 μg (Group BC) or both fentanyl (15 μg) and clonidine (30 μg) (Group BCF). The total amount of intrathecal mixture was constant (2.8 ml) in all the groups. Duration of sensory, motor block and effective analgesia, hemodynamic profile, postoperative pain score and analgesic requirements were recorded.

Results:

The duration of effective analgesia, mean time till two-segment regression, and duration of sensory and motor block were significantly longer in group BCF as compared to group BC (P ~ 0.002), and in group BC as compared to group BF (P ~ 0.01). The incidence of intraoperative pain and requirement of postoperative analgesics in the first 24 hours was significantly more in group BF as compared to the other groups (P ~ 0.01). There was no difference in the hemodynamic profile between the groups.

Conclusion:

Low-dose clonidine (30 μg) when added to a bupivacaine-fentanyl mixture increased the duration of effective analgesia and the duration of sensory and motor block in gynecological surgery. The incidence of intraoperative pain and requirement of postoperative analgesics was significantly less when clonidine was added to intrathecal bupivacaine with or without fentanyl.

Addition of intrathecal fentanyl to bupivacaine clonidine mixture effect on quality of subarachnoid block and postoperative analgesia

CONTEXT

This study was undertaken in 100 patients scheduled for lower limb orthopaedic surgeries.

AIM

The objective of this study was to study the effect of addition of intrathecal fentanyl to bupivacaine clonidine mixture on the quality of subarachnoid block and compare it with intrathecal bupivacaine clonidine mixture without fentanyl.

SETTINGS AND DESIGN

In this prospective and double blind randomized controlled study, one hundred patients, between 20-40 years of age, of either sex, weighing between 40-65 Kg, measuring more than 150 cm in height, of ASA Grade I and II who were undergoing orthopaedic lower limb surgeries were selected in order to study the quality of subarachnoid block and post-operative analgesia produced by a combination of bupivacaine clonidine and fentanyl in comparison with bupivacaine clonidine.

MATERIALS AND METHODS

The patients were randomly divided in two groups of 50 each: Group BC: 2.4 ml of 0.5% hyperbaric bupivacaine (12 mg) + 0.2 ml (30 μg) clonidine + 0.4 ml of 0.9% NaCl. Group BCF: 2.4 ml of 0.5% hyperbaric bupivacaine (12 mg) + 0.2 ml (30 μg) clonidine + 0.4 ml (20 μg) of fentanyl. The total volume of solution in both the groups was 3.0 ml. The quality of subarachnoid block and post-operative analgesia were studied.

STATISTICAL ANALYSIS USED

The data thus obtained was statistically analysed using the following tests: Unpaired student's t-test. Average % change in data over baseline values to detect trends. A 'P' value of <0.05 was considered to be statistically significant.

RESULTS

There was no significant difference in duration of sensory and motor blockade in group BCF compared to BC. The duration of analgesia as assessed by, either VAS score of >5 or demand of additional analgesia was > 524.6 ± 32.21 mins in group BC and > 774.4 ± 59.59 mins in group BCF. This prolongation of duration of analgesia in group BCF compared to group BC has statistical significance. Blood pressure and heart rate changes were not significantly different among groups, whereas sedation and pruritus were significantly more frequent in Group BCF.

CONCLUSIONS

In conclusion, this study has demonstrated that addition of 20 μg fentanyl to intrathecal 30 μg clonidine and 12 mg bupivacaine enhanced the duration of post-operative analgesia with moderately increased sedation and was not associated with hemodynamic instability or other complications.

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.

Effects of a continuous low-dose clonidine epidural regimen on pain, satisfaction and adverse events during labour: a randomized, double-blind, placebo-controlled trial

BACKGROUND AND OBJECTIVE

Epidural clonidine has been proposed as an adjunct for anaesthetic mixtures during labour. Administered as a bolus, clonidine may have side effects such as sedation and hypotension; its continuous infusion could be attractive in this respect. We, therefore, conducted a randomized, double-blind trial using patient-controlled epidural analgesia with a background infusion using a low dose of clonidine during labour.

METHODS

A total of 128 healthy parturients in active labour received a patient-controlled epidural analgesia solution of 0.0625% levobupivacaine and sufentanil 0.25 microg ml(-1) with or without clonidine 2 microg ml(-1). Ninety-five parturients were analysed. The pain score over time was evaluated as well as drug volume utilization; supplementation bolus and side effects were recorded. The primary endpoint was maternal satisfaction [ClinicalTrials.gov Identifier (NCT00437996)].

RESULTS

Three patients in the control group failed to achieve satisfactory epidural analgesia owing to a technical issue. Although the primary endpoint was not statistically significant, analgesia was more pronounced and obtained earlier in the clonidine group. The area under the curve for the visual analogue pain score was significantly lower in the clonidine group. In this group, hourly doses of levobupivacaine and sufentanil were reduced (13.9 +/- 4.3 vs. 16.3 ml +/- 4.0; P = 0.005) as well as rescue supplementation and pruritus incidence (18 vs. 46%; P = 0.004). Maternal blood pressure was significantly lower, over time, in the clonidine group but remained within the normal range. Sedation was similar in both groups (4.3 vs. 2.0%; not significant).

CONCLUSION

The addition of clonidine to epidural levobupivacaine and sufentanil for patient-controlled epidural analgesia in labour improved analgesia, reduced the supplementation rate and reduced pruritus without improvement in maternal satisfaction. Blood pressure was significantly lower in the clonidine group over time but without clinical consequence.

Drug-enhanced spinal stimulation for pain: a new strategy

Neuropathic pain is notoriously difficult to manage and only a few classes of drugs may provide adequate benefits. Thus, in many cases spinal cord stimulation (SCS) is considered; however, in this group of patients, between 30-50% of the cases offered a percutaneous SCS trial may fail to obtain a satisfactory effect. Additionally, a certain number of patients with a good initial effect, report that after a period the benefits are reduced necessitating additional peroral drug therapy. Based on animal studies of transmitters and receptors involved in the effects of SCS in neuropathic pain, the GABA-B receptor seems to play a pivotal role for the effect and, moreover, the agonist baclofen injected intrathecally in rats potentiated the SCS effect in animals not responsive to SCS per se. Based on these and further studies, 48 patients with neuropathic pain and inadequate response to SCS were given intrathecal (i.t.) baclofen (ITB) in bolus doses as an adjuvant. In this group 7 patients enjoyed such a good effect that they were implanted with both SCS and drug delivery systems for ITB. Four additional cases received baclofen pumps alone. Some other patients were given intrathecal (i.t.) adenosine in combination with SCS and initially preferred this to baclofen. The chronic use of this drug in a pump however proved to be technically problematic and all the adenosine cases were eventually terminated. At follow-ups, in average 32 and 67 months after start of SCS + baclofen therapy, more than 50% still enjoy a very good effect. The daily dose of baclofen needed to maintain the effects was approximately doubled during the observation period. There were few and mild side-effects. However, in a group of three patients with peroral baclofen therapy and SCS, complaints of side-effects were common and this therapy was terminated. Informal reports from collegues support the negative experience with additional peroral baclofen. In conclusion, in patients with neuropathic pain demonstrating inadequate response to SCS (small VAS reduction; short duration) a trial of intrathecal baclofen in combination with SCS may be warranted.

The combination of epidural clonidine and S(+)-ketamine did not enhance analgesic efficacy beyond that for each individual drug in adult orthopedic surgery

STUDY OBJECTIVES

To evaluate the benefit of epidural clonidine and S(+)-ketamine combination through the epidural route in adult orthopedic surgery.

DESIGN

Randomized double-blinded study.

SETTING

Teaching hospital.

PATIENTS

Scheduled to undergo knee surgery, 56 American Society of Anesthesiologists physical status 1 and 2 adult patients.

INTERVENTIONS

Patients were randomized to 1 of 4 groups to receive the combined epidural-intrathecal technique. A 10-mL epidural injection of either study drug or normal saline was first administered to all patients. Intrathecal anesthesia was performed with 15 mg of bupivacaine. The control group (CG) received epidural saline. The 0.1-mg/kg S(+)-ketamine epidural group received 0.1 mg/kg epidural S(+)-ketamine. The 0.5-microg/kg clonidine epidural group received 0.5 microg/kg epidural clonidine. The S(+)-ketamine/clonidine group received 0.1 mg/kg epidural S(+)-ketamine plus 0.5 microg/kg epidural clonidine.

MEASUREMENTS AND MAIN RESULTS

Pain and adverse effects were evaluated by visual analog scale. Rescue analgesics were available to patients. The groups were demographically similar. Sensory level to pinprick, surgical and anesthetic time, and visual analog scale scores for pain at first rescue medication were similar among the groups. The time to first rescue analgesic (minute) was lowest in CG (P < .005). The CG required more rescue analgesics in 24 hours than any of the other groups (P < .0005). Patients who received either epidural clonidine, S(+)-ketamine, or both displayed similar analgesia. The frequency of adverse effects was similar among groups (P > .05).

CONCLUSIONS

The association of epidural clonidine or S(+)-ketamine did not result in a greater analgesic effect in the model of acute postoperative pain studied, although the interaction of epidural clonidine and S(+)-ketamine is not attributable to sharing of a common second messenger system.

Small-Dose Intrathecal Clonidine and Isobaric Bupivacaine for Orthopedic Surgery: A Dose-Response Study

We examined the dose-response relationship of intrathecal clonidine at small doses (<or=150 microg) with respect to prolonging bupivacaine spinal anesthesia. We aimed for establishing doses of intrathecal clonidine that would produce clinically relevant prolongation of spinal anesthesia and pain relief without significant side effects. Eighty orthopedic patients were randomly assigned to intrathecally receive isobaric 0.5% bupivacaine, 18 mg, plus saline (Group 1), clonidine 37.5 microg (Group 2), clonidine 75 microg (Group 3), and clonidine 150 microg (Group 4). Duration of the sensory block (regression below level L1) was increased in patients receiving intrathecal clonidine: 288 +/- 62 min (Group 1, control), 311 +/- 101 min in Group 2 (+8%), 325 +/- 69 min in Group 3 (+13%), and 337 +/- 78 min in Group 4 (+17%) (estimated parameter for dose 0.23 [95% confidence interval -0.05-0.50]). Duration of pain relief from intrathecal clonidine administration until the first request for supplemental analgesia was significantly prolonged: 295 +/- 80 min (Group 1, control), 343 +/- 75 min in Group 2 (+16%), 381 +/- 117 min in Group 3 (+29%), and 445 +/- 136 min in Group 4 (+51%) (estimated parameter for dose 1.02 [95% confidence interval 0.59-1.45]). Relative hemodynamic stability was maintained and there were no between-group differences in the sedation score. We conclude that small doses of intrathecal clonidine (<or=150 microg) significantly prolong the anesthetic and analgesic effects of bupivacaine in a dose-dependent manner and that 150 microg of clonidine seems to be the preferred dose, in terms of effect versus unwarranted side effects, when prolongation of spinal anesthesia is desired.

Postoperative pain relief following intrathecal bupivacaine combined with intrathecal or oral clonidine

BACKGROUND

The purpose of the present study was to evaluate the postoperative analgesic and adverse effects of equal doses of oral or intrathecal clonidine in spinal anaesthesia with bupivacaine plain.

METHODS

Forty-five ASA I-III orthopaedic patients scheduled for osteosynthesis of a traumatic femur fracture were randomised in a double-blind fashion to one of 3 groups. Patients received 15 mg of plain bupivacaine intrathecally (group B) or an intrathecal mixture of bupivacaine 15 mg and clonidine 150 mg (group CIT). In group CPO oral clonidine 150 mg was administered 60 min before intrathecal injection of bupivacaine 15 mg.

RESULTS

Oral and intrathecal clonidine prolonged the time until the first request for analgesics, 313 +/- 29 and 337 +/- 29 min, respectively, vs. 236 +/- 27 min in group B (P < 0.01). The total 24- h PCA morphine dose was significantly lower in group CIT(19.3 +/- 1.3 mg) compared to groups B and CPO(33.4 +/- 2.0 and 31.2 +/- 3.1 mg). MAP was decreased significantly during the first hour after intrathecal clonidine(14%) and during the first 5 h after oral clonidine(14-19%). HR decreased in CIT during the 5th and 6th postoperative hours(7-9%) and during the first 2 h(9%) in CPO (P < 0.01). The degree of sedation was more pronounced in group CPO during the first 3 h. Four patients had pruritus in group B.

CONCLUSIONS

Addition of intrathecal clonidine prolonged analgesia and decreased morphine consumption postoperatively more than oral clonidine. Hypotension was more pronounced after oral than after intrathecal clonidine. Intrathecal clonidine is therefore recommended.