Brachial plexus block: Comparison of two different doses of clonidine added to bupivacaine

A Comparison Between Dexamethasone and Clonidine as Adjuvants to Levobupivacaine in the Supraclavicular Approach to the Brachial Plexus Block: A Double-Blind Study

OBJECTIVE

 The objective of this clinical study is to compare the efficacy of adding dexamethasone or clonidine as an adjuvant drug to levobupivacaine in supraclavicular brachial plexus block (BPB) with regard to the onset and duration of sensory and motor blocks along with duration of postoperative analgesia.

BACKGROUND

 Brachial plexus block (BPB), with or without general anesthesia, has been used widely for multiple upper limb surgical procedures, by virtue of its efficacy in terms of cost-effectiveness, efficiency, safety margins, and good postoperative analgesia. Various adjuvant drugs have been described to potentiate the analgesic effect of local anesthetic agents such as epinephrine, clonidine, dexamethasone, dexmedetomidine, or midazolam.

MATERIALS AND METHODS

This is a prospective, randomized, double-blind study in which a total of 90 American Society of Anesthesiology (ASA) physical status I and II patients of either sex, aged between 18 and 60 years, were scheduled for elective upper limb surgical procedures under supraclavicular BPB. They were divided into three equivalent randomized groups with 30 patients in each group. The patients were administered either normal saline 2 mL (in group L) or clonidine 0.5 mcg/kg body weight (in group LC) or dexamethasone 8 mg (in group LD) with 30 mL of 0.5% levobupivacaine. The time of onset and duration of sensory and motor blockades along with the time duration of analgesia were compared.

RESULTS

All groups were equivalent as per demographic data. The time duration for onset of sensory and motor blocks was comparable among all three included groups (12.77±2.60 minutes and 20.80±3.25 minutes, 15.93±2.08 minutes and 22.43±3.07 minutes, and 12.57±2.62 minutes and 22.47±3.10 minutes for group L, LC, and LD, respectively). The time duration of analgesia and motor blockade was significantly prolonged in the dexamethasone group (1195.33±50.01 minutes and 1173.17±43.57 minutes) and moderately prolonged in the clonidine group (696.33±36.74 minutes and 674.67±34.33 minutes) when compared to levobupivacaine group (416.33±35.98 minutes and 397.00±35.12 minutes), and the difference was statistically significant (p<0.001).

CONCLUSION

 Dexamethasone appears to be a superior adjuvant drug to clonidine for brachial plexus block via supraclavicular approach as it provides prolonged duration of motor block with lesser requirement of postoperative analgesia and lack of adverse effects.

Efficacy of analgesia using ilioinguinal-iliohypogastric (IIIH) nerve block, transversus abdominis plane (TAP) block and diclofenac after caesarean delivery under spinal anaesthesia: A non-randomised clinical trial

Background and Aims

Our aim was to assess the efficacy of analgesia using ilioinguinal-iliohypogastric (IIIH) nerve block, transversus abdominis plane (TAP) block and diclofenac after caesarean delivery (CD) under spinal anaesthesia (SA).].

Methods

A total of 457 healthy parturients undergoing CD under SA were included in this prospective, observational study. Groups differed in the postoperative analgesic strategies received by the parturient at the end of surgery: group D (n = 148) received intramuscular diclofenac sodium, group I (n = 153) received bilateral IIIH block with bupivacaine plus clonidine and group T (n = 156) received bilateral TAP block with bupivacaine plus clonidine. Total duration of postoperative analgesia, numerical pain rating scale (NRS) scores, patient satisfaction score, rescue analgesics in the first 48 h postoperatively and adverse effects were observed. A value of P < 0.05 was taken as significant.

Results

Total duration of analgesia was longest (18.2 ± 1.3 h) in group T and shortest in group D (6.3 ± 0.8 h) compared to group I (13.1 ± 1.2 h) (P < 0.001). Total analgesic requirement in postoperative 48 h was lowest in group T (152.1 ± 34.9 mg), highest in group D (355.0 ± 25.6 mg) and intermediate in group I (221.0 ± 30.0 mg) (P < 0.001). Mean NRS scores were lower in group T compared to those in groups D and I. The patients in group T were extremely satisfied, in group I were satisfied and in group D were dissatisfied (P < 0.001).

Conclusion

Bilateral TAP block with bupivacaine and clonidine after CD under SA increases the duration of postoperative analgesia.

A Randomized, Double-Blind, Prospective Study to Evaluate the Effect of Oral Pregabalin in Upper Limb Surgeries Under Brachial Plexus Block

Context

The oral pregabalin administration preoperatively has been reported to reduce acute postoperative pain and prolong the duration of anesthesia produced by single-injection peripheral nerve blockade.

Aim

To study the effect of single dose pregabalin on duration of brachial plexus block

Settings and design

Prospective, randomised, double blind, comparative study

Material and methods

Patients were divided into two groups (groups A and B), with each group having 50 patients. In group A, the patient received a pregabalin capsule of 300 mg orally two hours before surgery with a sip of water. Group B received a placebo (vitamin B complex capsule) orally two hours before surgery. Brachial plexus block was performed, and data was collected.

Statistical analysis

Data analysis was done using SPSS version 21.0 statistical analysis software. Demographic data and clinical variables were compared using the student's t-test, chi-square test, and Mann-Whitney U test.

Results

The requirement of the first dose of analgesia was significantly earlier in group B as compared to group A (4:56±0:20 vs. 8:01±0:30 hours). Group B patients, as compared to group A patients, had significantly higher levels of pain after two hours of surgery (0.32±0.47 vs. 0.00±0.00) and at four hours of surgery (2.42±0.50 vs. 0.34±0.59).

Conclusions

Oral pregabalin prolongs analgesia from brachial plexus block without significant effect on the motor block. In addition, premedication with oral pregabalin increases the sensory block of brachial plexus block.

The Effects of Magnesium Sulfate with Lidocaine for Infraclavicular Brachial Plexus Block for Upper Extremity Surgeries

Background  An addition of analgesic to anesthetic agents is likely to increase the effects of anesthesia and reduce associated adverse outcomes. Several adjuvants are studied in this regard. The aim of this study is to investigate the effects of adding a magnesium adjunct to lidocaine for the induction of infraclavicular block. Methods  Patients referred to Shohada Ashayer Hospital, Khorramabad, for wrist and hand surgery were enrolled in this study. The intervention/case group included patients who received 18 mL lidocaine (2%) + 2 mL magnesium sulfate (50%), 10 mL normal saline; control group: 18 mL lidocaine (2%) + 12 mL of normal saline. After the induction of ultrasound-guided infraclavicular block, parameters such as duration of reach with respect to complete sensory and motor block, hemodynamic parameters (hypotension and bradycardia), and postoperative pain, using visual analogue scale criteria, were measured. The obtained data were analyzed using a Bayesian path analysis model. Results  A total of 30 patients were included in each group. In the case group, sensory and motor block was achieved for 12.136 ± 4.96 and 13 ± 3.589 minutes more than those in the control group. The duration of sedation and immobilization was 2.57 ± 0.764 minute and 4.66 ± 0.909 minutes lengthier in the case group. Regarding the hemodynamic parameters, blood pressure was 0.217 ± 5.031 and 1.59 ± 5.14 units lower in the case group, immediately following the block and the surgery. Similarly, heart rate was 0.776 ± 4.548 and 0.39 ± 3.987 units higher in the case group, after 30 minutes and 2 hours of the procedure. A decrease in the pain was seen at 8, 10, and 12 hours after the surgery, as compared with the control group. An addition of magnesium to lidocaine for infraclavicular block resulted in a significantly longer sedation and immobilization period and decreased postoperative pain at 12 hours. Conclusion  Heart rate and blood pressure did not decrease significantly in the case group. It can be concluded that addition of magnesium sulfate to lidocaine can produce better anesthetic and analgesic outcomes with low-to-no adverse effects.

Supraclavicular Brachial Plexus Block: Comparison of Varying Doses of Butorphanol Combined with Levobupivacaine - A Double-Blind Prospective Randomized Trial

Background:

The ideal dose of butorphanol for brachial plexus block is not well known.

Aims:

This study was carried out to evaluate 1 mg and 2 mg of butorphanol added to 0.375% levobupivacaine, with regard to the duration of analgesia. Our study also sought to assess the onset and duration of sensorimotor blockade, hemodynamic effects, sedation, and adverse effects.

Settings and Design:

This study was a prospective, randomized, double-blinded, and comparative study.

Methods:

Eighty adult patients of either sex undergoing upper limb surgeries under supraclavicular brachial plexus block were randomly allocated into two groups. Group LB1 received 29 ml of 0.375% levobupivacaine plus 1 mg of butorphanol diluted in 1 ml of normal saline. Group LB2 received 29 ml of 0.375% levobupivacaine plus 2 mg of butorphanol diluted in 1 ml of normal saline. The onset and duration of sensorimotor blockade, level of sedation, duration of analgesia, and adverse effects were assessed.

Statistical Analysis:

The data were analyzed with Student's t-test and Chi-square test.

Results:

The onset of sensory (P = 0.032) and motor block (P = 0.026) was earlier in Group LB2 than in Group LB1. The duration of analgesia was significantly prolonged in Group LB2 (643.55 ± 131.6 vs. 511.73 ± 128.6 min; P = 0.001). The incidence of sedation was observed in more number of patients in Group LB2 (P = 0.01). Furthermore, the incidence of nausea, vomiting, and pruritus were observed in more number of patients in Group LB2 (P < 0.05).

Conclusion:

Higher dose of butorphanol in brachial plexus block hastens the onset and prolongs the duration of sensorimotor blockade and analgesia but is associated with a higher incidence of sedation which requires intense monitoring.

Transversus Abdominis Plane Block: Comparison of Efficacy of Varying Doses of Clonidine Combined with Levobupivacaine - A Double-Blind Randomized Trail

Background:

Transversus abdominis plane block (TAP) has an evolving role in postoperative analgesia following laparoscopic-assisted vaginal hysterectomy (LAVH).

Aims:

This study was carried out to evaluate 75 μg and 150 μg of clonidine added to 0.25% levobupivacaine, with regard to the duration of analgesia. Our study also sought to assess the hemodynamic effects, sedation, and adverse effects.

Settings and Design:

This was a prospective, randomized, double-blinded, comparative study.

Methods:

A total number of 80 patients undergoing elective LAVH surgery under general anesthesia were randomly assigned to one of the two equal groups to receive either of the following: Group LC75 – 29 ml of 0.25% levobupivacaine plus 75 μg of clonidine diluted in 1 ml of normal saline (total 30 ml) and Group LC150 – 29 ml of 0.25% levobupivacaine plus 150 μg of clonidine diluted in 1 ml of normal saline (total 30 ml). Duration of analgesia was the primary outcome. Hemodynamic variables, sedation score, and adverse effects were secondary outcomes.

Statistical Analysis:

The data were analyzed with Student's t-test and Chi-square test.

Results:

The duration of analgesia was significantly prolonged in Group LC150 (609.18 ± 6.59 vs. 410.52 ± 7.18 min; P = 0.001). The visual analog scale score in patients who received clonidine 150 μg Group LC150 as an adjunct was significantly lower than who received 75 μg Group LC75. Significantly higher sedation score was observed in Group LC150. The incidence of bradycardia was also significant between two groups. Significantly fewer patients in Group LC150 required rescue analgesia.

Conclusion:

The 150 μg dose of clonidine in TAP block prolongs the duration of analgesia but with higher incidence of sedation.

The effect and safety of dexmedetomidine added to ropivacaine in brachial plexus block: A meta-analysis of randomized controlled trials

BACKGROUND

Dexmedetomidine has been used as an adjuvanty added to local anesthetics to prolong analgesia following peripheral nerve blockade. The aim of this meta-analysis was to investigate the effect and safety of dexmedetomidine added to ropivacaine in brachial plexus block (BPB).

METHODS

A search strategy was created to identify eligible randomized clinical trial (RCT) in PubMed, Embase, and The Cochrane Library (updated May, 2018). The methodologic quality for each included study was evaluated using the Cochrane Tool for Risk of Bias by 2 independent researchers.

RESULTS

Twelve RCTs were included in the meta-analysis (n = 671). As an adjuvant to ropivacaine, dexmedetomidine significantly reduced the onset time of sensory (mean difference [MD], -3.86 minutes, 95% CI -5.45 to -2.27 minutes; I = 85%) and motor (MD, -5.21 minutes; 95% CI -7.48 to -2.94 minutes; I = 94%). In addition, it increased the blockade duration of sensory (MD, 228.70 minutes; 95% CI 187.87-269.52 minutes; I = 93%) and motor (MD, 191.70 minutes; 95% CI 152.48-230.91 minutes; I = 92%). Moreover, the combination prolonged the duration of analgesia (MD, 303.04 minutes; 95% CI 228.84-377.24 minutes; I = 86%). There was no difference of the incidence of bradycardia (risk difference [RD], 0.01, 95% CI -0.02 to 0.05, I = 45%; P = .45) and hypotension (RD, 0.01, 95% CI -0.01 to 0.03, I = 0%; P = .57) between 2 groups.

CONCLUSION

Dexmedetomidine added to ropivacaine in BPB has a better analgesia effect (shorter onset time and longer duration) compared to ropivacaine alone. At the same time, there was no difference in the incidence of bradycardia and hypotension.

Comparison of Magnesium Sulfate and Dexmedetomidine as an Adjuvant to 0.5% Ropivacaine in Infraclavicular Brachial Plexus Block

Background:

Magnesium sulfate and dexmedetomidine were used as adjuvants to local anesthesia to improve the quality of regional anesthesia.

Aims:

The aim of this study is to evaluate and compare the effects of magnesium sulfate and dexmedetomidine when added to ropivacaine on the quality of infraclavicular brachial plexus block (BPB).

Settings and Design:

This was a prospective randomized double-blinded controlled study.

Patients and Methods:

A total of 105 adult patients undergoing surgery in hands, wrist, and forearm using infraclavicular BPB were randomly assigned into three groups. Ultrasound-guided infraclavicular BPB was performed using 35 ml ropivacaine 0.5% diluted with 4 ml normal saline 0.9%. Magnesium sulfate 150 mg and dexmedetomidine 100 μg were added in the magnesium sulfate group and dexmedetomidine group, respectively. Duration of analgesia, onset times and durations of sensory block (SB) and motor block (MB), patient's satisfaction, and complications were recorded.

Statistical Analysis:

Statistical software SPSS 16 was used for statistical analysis.

Results:

Dexmedetomidine and magnesium sulfate provided longer duration of analgesia and lesser consumption of postoperative rescue analgesia than the control group (P = 0. 000); dexmedetomidine provided the longest duration of analgesia versus control and magnesium sulfate groups (P = 0.000). Dexmedetomidine provided the quickest onset times and the longest durations of both SB and MB than control and magnesium sulfate groups (P = 0.000). Dexmedetomidine group had higher incidences of bradycardia and hypotension.

Conclusions:

Magnesium sulfate or dexmedetomidine is a useful adjuvant to ropivacaine for infraclavicular BPB in lengthening the duration of analgesia. Dexmedetomidine provided quicker onset and longer duration of both SB and MB and longer duration of analgesia with lesser consumption of postoperative rescue analgesia; however, it showed a higher incidence of intraoperative hypotension and bradycardia than magnesium sulfate.

Perineural Nalbuphine in Ambulatory Upper Limb Surgery: A Comparison of Effects of Levobupivacaine with and without Nalbuphine as Adjuvant in Supraclavicular Brachial Plexus Block - A Prospective, Double-blinded, Randomized Controlled Study

Background and Aims:

Various opioid additives have been trialed to prolong brachial plexus block. We evaluated the effect of adding nalbuphine hydrochloride to levobupivacaine for supraclavicular brachial plexus blockade. The primary end-points were the onset and duration of sensory and motor blocks and duration of analgesia.

Materials and Methods:

Seventy-eight patients (aged 25–45 years) posted for ambulatory forearm and hand surgery under supraclavicular brachial plexus block were divided into two equal groups (Groups LN and LC) in a randomized, double-blind fashion. In Group LN (n = 39), 30 ml 0.5% levobupivacaine + 10 mg (diluted in 2 ml 0.9% saline) nalbuphine hydrochloride, and in Group LC (n = 39), 30 ml 0.5% levobupivacaine + 2 ml normal saline (0.9%) were administered in supraclavicular block. Sensory and motor block onset times and block durations, time to first analgesic use, total analgesic need, postoperative visual analog scale (VAS), hemodynamics, and side effects were recorded for each patient.

Results:

Although with similar demographic profile and block (sensory and motor) onset time, sensory and motor block duration and time to first analgesic use were significantly longer and the total need for rescue analgesics was lower in Group LN (P < 0.05) than Group LC. Postoperative VAS value at 24 h was significantly lower in Group LN (P < 0.05). Intraoperative hemodynamics was comparable between two groups, and no any appreciable side effect was noted throughout the study period.

Conclusion:

It can be concluded that adding nalbuphine hydrochloride to supraclavicular brachial plexus block increases the sensory and motor block duration and time to first analgesic use, and decreases total analgesic use with no side effects.

Preemptive Oral Clonidine Provides Better Sedation Than Intravenous Midazolam in Brachial Plexus Nerve Blocks

Background

Preemptive analgesia is the blocking of pain perception afferent pathways before noxious painful stimuli. Clonidine is an alpha agonist drug that is partially selective for α-2 adrenoreceptors. Clonidine is used as anti-anxiety medication and an, analgesic, and it prolongs the duration of the block in the brachial plexus block.

Objectives

To compare the effect of preemptive clonidine with midazolam on intraoperative sedation, duration of block, and postoperative pain scores.

Patients and Methods

In a randomized clinical trial, 80 patients with orthopedic fractures of an upper extremity who underwent supraclavicular nerve block were randomly assigned to receive 0.2 mg oral clonidine or 2 mg oral midazolam. Intraoperative sedation was measured at one hour after the start of urgery and again in the PACU (Post-Anesthesia Care Unit) using the Ramsay scale. The duration of sensory blockade was measured. Postoperative pain scores were measured using the VAS (Visual Analogue Scale) after entrance to recovery up to 2 hours.

Results

The percentages of patients in the calm and sedated scale were significantly higher in clonidine group (35 and 42.5%, respectively), compared to the midazolam group (17.5 and 17.5%, respectively) (P = 0.042, 0.029; respectively). Those administered fentanyl in the clonidine group 105 ± 30.8 was significantly lower than that for the midazolam group 165 ± 34.5 (P = 0.0018). The percentages of patients in the calm scale were significantly higher in the clonidine group (52.5), compared to the midazolam group (17.5) (P = 0.001) in the post-operative period. VAS scores were significantly lower at one (P = 0.01) and two hours (P = 0.001) after operation in the clonidine group, compared to the midazolam group.

Conclusions

Preemptive clonidine has many marvelous advantages over midazolam, including better sedation inside the operating room and then in the post-operative care unit, lower fentanyl doses are required during surgery, more stable heart rate and blood pressure are observed during the procedure, and patients report lower post-operative pain scores.

A prospective, comparative, randomised, double blind study on the efficacy of addition of clonidine to 0.25% bupivacaine in scalp block for supratentorial craniotomies

Background and Aims:

Scalp blocks combined with general anaesthesia reduce pin and incision response, along with providing stable perioperative haemodynamics and analgesia. Clonidine has proved to be a valuable additive in infiltrative blocks. We studied the efficacy and safety of addition of clonidine 2 μg/kg to scalp block with 0.25% bupivacaine (Group B) versus plain 0.25% bupivacaine (Group A) for supratentorial craniotomies.

Methods:

Sixty patients were randomly divided into two groups to receive scalp block: Group A (with 0.25% bupivacaine) and Group B (with 0.25% bupivacaine and clonidine (2 μg/kg). Bilateral scalp block was given immediately after induction. All the patients received propofol based general anaesthesia. Intraoperatively, propofol infusion was maintained at 75 to 100 μg/kg/h up to dura closure and reduced to 50-75 μg/kg/h up to skin closure with atracurium infusion stopped at dura closure. Heart rate (HR) and mean arterial pressure (MAP) were monitored at pin insertion, at 5 minute intervals from incision till dura opening and again at 5 minute interval from dura closure up to skin closure. Fentanyl 0.5 μg/kg was given if a 20% increase in either HR and/or MAP was observed. Postoperative haemodynamics and verbal rating scores (VRS) were recorded. When the VRS score increased above 3, rescue analgesia was given. Any intraoperative haemodynamic complications were noted.

Results:

Group A showed a significant increase in haemodynamic variables during the perioperative period as compared to group B (P < 0.05). Addition of clonidine 2 μg/kg in the infiltrative block also provided significantly prolonged postoperative analgesia.

Conclusions:

Addition of clonidine to scalp block provided better perioperative haemodynamic stability and significantly prolonged analgesia.

Pain relief after ambulatory hand surgery: A comparison between dexmedetomidine and clonidine as adjuvant in axillary brachial plexus block: A prospective, double-blinded, randomized controlled study

BACKGROUND

For ages various adjuvants have been tried to prolong axillary brachial plexus block. We compared the effect of adding dexmedetomidine versus clonidine to ropivacaine for axillary brachial plexus blockade. The primary endpoints were the onset and duration of sensory and motor block and duration of analgesia.

MATERIALS AND METHODS

A total of 90 patients (20-40 years) posted for ambulatory elective hand surgery under axillary brachial plexus block were divided into two equal groups (groups ropivacaine dexmedetomidine [RD] and ropivacaine clonidine [RC]) in a randomized, double-blind fashion. In group RD (n = 45) 30 ml 0.5% ropivacaine + 100 μg of dexmedetomidine and group RC (n = 45) 30 ml 0.5% ropivacaine + 75 μg clonidine were administered in axillary plexus block. Sensory and motor block onset times and block durations, time to first analgesic use, total analgesic need, postoperative visual analog scale (VAS), hemodynamics and side-effects were recorded for each patient.

RESULTS

Though with similar demographic profile in both groups, sensory and motor block in group RD (P < 0.05) was earlier than group RC. Sensory and motor block duration and time to first analgesic use were significantly longer and the total need for rescue analgesics was lower in group RD (P < 0.05) than group RC. Postoperative VAS value at 18 h were significantly lower in group RD (P < 0.05). Intraoperative hemodynamics were insignificantly lower in group RD (P < 0.05) without any appreciable side-effects.

CONCLUSION

It can be concluded that adding dexmedetomidine to axillary plexus block increases the sensory and motor block duration and time to first analgesic use, and decreases total analgesic use with no side-effects.

Comparison of different routes of administration of clonidine for analgesia following anterior cruciate ligament repair

Background and Aims:

A high percentage of patients undergoing arthroscopic repairs on day care basis complain of inadequate postoperative pain relief. Clonidine was evaluated for the best route as an adjuvant in regional anesthesia in anterior cruciate ligament (ACL) repair to prolong analgesia.

Material and Methods:

A prospective randomized double-blinded study was planned in a tertiary care hospital in North India in which 85 American Society of Anesthesiologists I and II patients undergoing ACL repair were enrolled. All groups received 0.5% hyperbaric bupivacaine intrathecally as in control group C. Group IT received intrathecal 1 μg/kg of clonidine along with hyperbaric bupivacaine, group IA received 0.25% bupivacaine and 1 μg/kg clonidine intra-articularly, and group NB received 0.25% bupivacaine and 1 μg/kg clonidine in femoro-sciatic nerve block (FSNB). Postoperative pain free interval and block characteristics were the primary outcomes studied.

Results:

Pain-free duration was 546.90 (±93.66) min in group NB (P < 0.001) in comparison to 234.90 (±20.99), 367.80 (±47.40) and 172.20 (±54.82) min in groups IA, IT and C, respectively. Sensory block and motor blockade in NB were 474.90 (±43.80) and 267.40 (±34.59) min, respectively, and were significantly prolonged (P > 0.001) in comparison to other groups. The mean rescue analgesic requirement and cumulative frequency of rescue analgesia were least in group NB, followed by groups IT, IA and C.

Conclusion:

Clonidine is safe and effective adjuvant with bupivacaine in prolonging analgesia through various routes employed for post knee surgery pain. The maximum prolongation of analgesia is achieved through FSNB with a risk of prolonging postanesthesia care unit stay.

Local Anesthetic Peripheral Nerve Block Adjuvants for Prolongation of Analgesia: A Systematic Qualitative Review

Background

The use of peripheral nerve blocks for anesthesia and postoperative analgesia has increased significantly in recent years. Adjuvants are frequently added to local anesthetics to prolong analgesia following peripheral nerve blockade. Numerous randomized controlled trials and meta-analyses have examined the pros and cons of the use of various individual adjuvants.

Objectives

To systematically review adjuvant-related randomized controlled trials and meta-analyses and provide clinical recommendations for the use of adjuvants in peripheral nerve blocks.

Methods

Randomized controlled trials and meta-analyses that were published between 1990 and 2014 were included in the initial bibliographic search, which was conducted using Medline/PubMed, Cochrane Central Register of Controlled Trials, and EMBASE. Only studies that were published in English and listed block analgesic duration as an outcome were included. Trials that had already been published in the identified meta-analyses and included adjuvants not in widespread use and published without an Investigational New Drug application or equivalent status were excluded.

Results

Sixty one novel clinical trials and meta-analyses were identified and included in this review. The clinical trials reported analgesic duration data for the following adjuvants: buprenorphine (6), morphine (6), fentanyl (10), epinephrine (3), clonidine (7), dexmedetomidine (7), dexamethasone (7), tramadol (8), and magnesium (4). Studies of perineural buprenorphine, clonidine, dexamethasone, dexmedetomidine, and magnesium most consistently demonstrated prolongation of peripheral nerve blocks.

Conclusions

Buprenorphine, clonidine, dexamethasone, magnesium, and dexmedetomidine are promising agents for use in prolongation of local anesthetic peripheral nerve blocks, and further studies of safety and efficacy are merited. However, caution is recommended with use of any perineural adjuvant, as none have Food and Drug Administration approval, and concerns for side effects and potential toxicity persist.

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.

Interscalene brachial plexus block for shoulder arthroscopic surgery: Prospective randomised controlled study of effects of 0.5% ropivacaine and 0.5% ropivacaine with dexamethasone

BACKGROUND AND AIMS

Various adjuvants have been used to prolong the duration of local anaesthetic action after peripheral and regional nerve blocks. We evaluated the effect of dexamethasone on the duration of pain relief in shoulder arthroscopic surgeries performed under interscalene brachial plexus using ropivacaine as local anaesthetic.

METHODS

After Ethical Committee approval and informed consent from patients we performed a prospective, randomised, comparative study on patients scheduled for arthroscopic shoulder surgery under interscalene block (ISB). Patients in ropivacaine group (Group R) received 30 ml of 0.5% ropivacaine plus 2 ml normal saline (n = 50) and dexamethasone-ropivacaine (Group RD) received 0.5% ropivacaine 30 ml plus 8 mg dexamethasone (4 mg/ml) (n = 50). Duration of analgesia, onset of sensory and motor block, success and failure of block, and complications were recorded and compared. Computer software SPSS version-16 (SPSS Inc., Chicago, Illinois, USA) was used for statistical analysis. Chi-square test and Student's t-test were used and P < 0.05 was considered as significant.

RESULTS

The mean duration of analgesia in Group RD was 1103.72 ± 296.027 min and in Group R it was 551.54 ± 166.92 min (P = 0.0001). Onset of sensory block in Group RD was 12.24 ± 1.88 min and in Group R was 13.48 ± 1.81 min (P = 0.5170). Onset of motor block in Group RD was 16.24 ± 2.04 min and in Group R was 17.76 ± 2.21 min (P = 0.2244). Onset of surgical anaesthesia in Group RD was19.46 ± 1.86 min and in Group R was 20.84 ± 1.71 min (P = 0.0859).

CONCLUSION

Dexamethasone significantly prolonged duration of analgesia of ropivacaine during ISB used for arthroscopic surgeries of shoulder. Dexamethasone when mixed with ropivacaine had no effect on the onset of sensory and motor effects of ISB with ropivacaine.

Effect of dexmedetomidine as adjuvant in ropivacaine-induced supraclavicular brachial plexus block: A prospective, double-blinded and randomized controlled study

Background and Aims:

Different additives have been used to prolong brachial plexus block. We evaluated the effect of adding dexmedetomidine to ropivacaine for supraclavicular brachial plexus blockade. The primary endpoints were the onset and duration of sensory and motor block and duration of analgesia.

Materials and Methods:

A total of 84 patients (20-50 years) posted for elective forearm and hand surgery under supraclavicular brachial plexus block were divided into two equal groups (Group R and RD) in a randomized, double-blind fashion. In group RD (n = 42) 30 ml 0.5% ropivacaine +1 ml (100 μg) of dexmedetomidine and group R (n = 42) 30 ml 0.5% ropivacaine +1 ml normal saline were administered in supraclavicular block. Sensory and motor block onset times and block durations, time to first analgesic use, total analgesic need, postoperative visual analog scale (VAS), hemodynamics and side-effects were recorded for each patient.

Results:

Though with similar demographic profile in both groups, sensory and motor block in group RD (P < 0.05) was earlier than group R. Sensory and motor block duration and time to first analgesic use were significantly longer and the total need for rescue analgesics was lower in group RD (P < 0.05) than group R. Post-operative VAS value at 12 h were significantly lower in group RD (P < 0.05). Intra-operative hemodynamics were significantly lower in group RD (P < 0.05) without any appreciable side-effects.

Conclusion:

It can be concluded that adding dexmedetomidine to supraclavicular brachial plexus block increases the sensory and motor block duration and time to first analgesic use, and decreases total analgesic use with no side-effects.

Evaluation of Magnesium as an adjuvant in Ropivacaine-induced supraclavicular brachial plexus block: A prospective, double-blinded randomized controlled study

Objective:

Different additives have been used to prolong brachial plexus block. We evaluated the effect of adding magnesium sulfate to ropivacaine for supraclavicular brachial plexus blockade. The primary endpoints were the onset and duration of sensory and motor block and duration of analgesia.

Methods:

One hundred patients (25–55 years) posted for elective forearm and hand surgeries under supraclavicular brachial plexus block were divided into two equal groups (Groups RM and RN) in a randomized, double-blind fashion. In group RM (n = 50), 30 ml 0.5% ropivacaine plus 150 mg (in 1 ml 0.9% saline) magnesium sulfate and in group RN (n = 50), 30 ml 0.5% ropivacaine plus 1 ml normal saline were administered in supraclavicular block. Sensory and motor block onset times and block durations, time to first analgesic use, total analgesic need, postoperative visual analog scale (VAS), hemodynamic variables, and side effects were recorded for each patient.

Findings:

Though with similar demographic profile and block (sensory and motor) onset time, the sensory and motor block duration and time to first analgesic use were significantly longer and the total need for rescue analgesics was lower in group RM (P = 0.026) than group RN. Postoperative VAS values at 24 h were significantly lower in group RM (P = 0.045). Intraoperative hemodynamics was comparable among two groups and no appreciable side effect was noted throughout the study period.

Conclusion:

It can be concluded from this study that adding magnesium sulfate to supraclavicular brachial plexus block may increase the sensory and motor block duration and time to first analgesic use, and decrease total analgesic needs, with no side effects.

Analgesic efficacy of transversus abdominis plane block in providing effective perioperative analgesia in patients undergoing total abdominal hysterectomy: A randomized controlled trial

Background and Aims:

Transversus abdominis plane (TAP) block has been shown to provide postoperative pain relief following various abdominal and inguinal surgeries, but few studies have evaluated its analgesic efficacy for intraoperative analgesia. We evaluated the efficacy of TAP block in providing effective perioperative analgesia in total abdominal hysterectomy in a randomized double-blind controlled clinical trial.

Materials and Methods:

A total of 90 adult female patients American Society of Anesthesiologists physical status I or II were randomized to Group B (n = 45) receiving TAP block with 0.25% bupivacaine and Group N (n = 45) with normal saline followed by general anesthesia. Hemodynamic responses to surgical incision and intraoperative fentanyl consumption were noted. Visual analog scale (VAS) scores were assessed on the emergence, at 1, 2, 3, 4, 5, 6 and 24 h. Time to first rescue analgesic (when VAS ≥4 cm or on demand), duration of postoperative analgesia, incidence of postoperative nausea-vomiting were also noted.

Results:

Pulse rate (95.9 ± 11.2 bpm vs. 102.9 ± 8.8 bpm, P = 0.001) systolic and diastolic BP were significantly higher in Group N. Median intraoperative fentanyl requirement was significantly higher in Group N (81 mcg vs. 114 mcg, P = 0.000). VAS scores on emergence at rest (median VAS 3 mm vs 27 mm), with activity (median 8 mm vs. 35 mm) were significantly lower in Group B. Median duration of analgesia was significantly higher in Group B (290 min vs. 16 min, P = 0.000). No complication or opioid related side effect attributed to TAP block were noted in any patient.

Conclusion:

Preincisional TAP block decreases intraoperative fentanyl requirements, prevents hemodynamic responses to surgical stimuli and provides effective postoperative analgesia.

Noteworthy literature in regional anesthesia 2013

The regional anesthesia literature was quite active in the calendar year 2013. In typical fashion, the literature was composed of articles representing neuraxial analgesia, peripheral nerve blocks, patient outcomes, regional anesthesia adjuvant medications, and patient safety. The goal of this article is to summarize and present the most relevant articles from each of these arenas.