Clonidine as adjuvant for mepivacaine, ropivacaine and bupivacaine in axillary, perivascular brachial plexus block

The effect of adjuvants added to local anaesthetics for single-injection upper extremity peripheral regional anaesthesia: A systematic review with network meta-analysis of randomised trials

BACKGROUND

Peripheral regional anaesthesia is frequently used for upper extremity surgery. To prolong the duration of analgesia, adjuvants can be added to single-injection local anaesthetics. Despite attempts to compare several adjuvants in pairwise meta-analyses, a comprehensive comparison is still missing.

OBJECTIVE

The objective of this network meta-analysis was to determine the effectiveness of adjuvants in upper extremity peripheral nerve blocks.

DESIGN

A systematic review of randomised controlled trials with network meta-analyses.

DATA SOURCES

A literature search in Embase, CENTRAL, MEDLINE and Web of Science was performed up to March 2023.

ELIGIBILITY CRITERIA

Randomised trials comparing different adjuvants injected perineurally in peripheral upper extremity nerve blocks were eligible. Frequentist network meta-analysis was conducted using a random effects model with physiological saline as the comparator. The primary endpoint was the ratio of means (ROM) of the duration of analgesia.

RESULTS

The review included 242 randomised controlled trials with a total of 17 391 patients. Twenty-eight adjuvants were compared in the largest networks. Most network estimations consisted of a high proportion of direct evidence. Fourteen adjuvants increased the duration of analgesia significantly by the following factors, ROM [95% confidence interval (CI)]: dexamethasone 1.95 (1.79 to 2.13), buprenorphine 1.83 (1.51 to 2.24), butorphanol 1.84 (1.41 to 2.39), potassium chloride 1.89 (1.15 to 3.11), dexmedetomidine 1.70 (1.59 to 1.81), sufentanil 1.70 (1.27 to 2.29), ketorolac 1.68 (1.24 to 2.27), midazolam 1.55 (1.24 to 1.94), tramadol 1.52 (1.32 to 1.75), nalbuphine 1.50 (1.30 to 1.72), morphine 1.43 (1.09 to 1.88), magnesium sulfate 1.42 (1.20 to 1.67), clonidine 1.36 (1.24 to 1.50) and fentanyl 1.23 (1.08 to 1.40). Inconsistency in network meta-analysis was substantial. Overall side effect rates were low with all adjuvants.

CONCLUSION

The best interventions to prolong the duration of analgesia were dexamethasone, followed by dexmedetomidine, opioids, electrolytes, ketorolac and midazolam. There are general concerns about the quality of underlying studies and the risk of publication bias.

TRIAL REGISTRATION

PROSPERO 2018 CRD42018115722.

Effects of Clonidine as an Adjuvant to Lidocaine with Epinephrine in Ultrasound Guided Axillary Brachial Plexus Block: A Randomised Controlled Trial

This study evaluated the effects of adding adjuvant clonidine to lidocaine with epinephrine on the characteristics of ultrasound-guided axillary brachial plexus block (ABPB) for upper extremity surgery. Twenty-four patients were randomised to receive an ultrasound guided ABPB with 20 mL of lidocaine 2% with 1:200,000 epinephrine plus 2 mL of either normal saline 0.9% (Group 1) or a mixture of clonidine 1 µg/kg and normal saline 0.9% (Group 2). The outcome measures that were recorded were the overall onset time and the duration of sensory and motor block. The median (IQR) overall onset time of sensory and motor block was significantly shorter in Group 2 vs. Group 1 (5 (5–7.5) min vs. 10 (8.8–12.5) min; p < 0.001) and (5 (2.5–7.5) min vs. 7.5 (6.3–7.5) min; p = 0.001), respectively. The median (IQR) overall duration of sensory and motor block was significantly longer in Group 2 vs. Group 1 (225 (200–231) min vs. 168 (148–190) min; p < 0.001) and (225 (208–231) min vs. 168(148–186) min; p < 0.001), respectively. In ultrasound-guided ABPB, the addition of clonidine to lidocaine with epinephrine resulted in shorter onset time and prolonged duration of sensory and motor block.

Adding low concentrations of clonidine to ropivacaine for transversus abdominis plane blocks does not reduce plasma ropivacaine levels, suggesting a lack of vasoconstrictor effect

Clonidine has been used successfully to prolong the duration of action of local anaesthetics in peripheral nerve blocks, but its mechanism of action in this setting remains unclear. Some studies suggest that clonidine exerts a vasoconstrictor effect, limiting the washout of local anaesthetic from its site of deposition. We investigated this potential vasoconstrictor effect, using plasma ropivacaine concentrations as a surrogate measure of vasoconstriction, in patients who received transversus abdominis plane (TAP) blocks with and without clonidine. Eighty women undergoing laparoscopic gynaecological surgery were randomly assigned to receive one of four TAP block solutions: 0.2% ropivacaine (control), ropivacaine with clonidine 2 μg/kg (clonidine), ropivacaine with 1:400,000 adrenaline (adrenaline) or ropivacaine and a subcutaneous injection of clonidine 2 μg/kg (SC clonidine). The primary outcome was total venous plasma ropivacaine concentrations up to 6 h after the block. There were no significant differences in plasma ropivacaine concentrations between the control group and the clonidine group at any timepoint in the study, nor were there differences in either the mean maximum ropivacaine concentration ( C_max) (1.99 μg/mL versus 2.05 μg/mL, P = 0.712) or the time to maximum concentration ( T_max) (51.0 min versus 56.0 min, P = 0.537). The SC clonidine group also did not differ significantly from the controls ( C_max 2.13 μg/mL versus 1.99 μg/mL, P = 0.424; T_max 43.5 min versus 51.0 min, P = 0.201). Plasma ropivacaine concentrations in the adrenaline group were significantly lower than the controls from 10 to 90 min ( P < 0.003 for each comparison), and the C_max was less than that of the control group (1.36 μg/mL versus 1.99 μg/mL, P < 0.001) with a longer T_max (103.5 min versus 51.0 min, P = 0.001). These findings indicate that clonidine at a concentration of 1.35 μg/mL added to ropivacaine for TAP blocks did not produce a reduction in plasma ropivacaine concentrations. This suggests a lack of vasoconstrictor effect during TAP blocks. Further studies should evaluate whether vasoconstriction occurs when clonidine is used at higher concentrations or for other blocks.

Impact of local administration of various doses of dexmedetomidine on ropivacaine-induced lumbar plexus-sciatic nerve block

The present study aimed to investigate the impact of various doses of dexmedetomidine (DEX) on ropivacaine (ROP)-induced lumbar plexus-sciatic nerve block (LSB). A total of 80 patients who underwent ankle surgery under LSB were divided into group R (applied with 30 ml 5% ROP), Dex1 (30 ml 0.5% ROP + 1 µg/kg DEX), Dex2 (30 ml 0.5% ROP + 1.5 µg/kg DEX) and Dex3 (30 ml 0.5% ROP + 2 µg/kg DEX), with 20 cases in each group. The onset time and duration of sensory and motor block, mean arterial pressure (MAP), heart rate (HR), oxygen saturation, Ramsay score, serum vascular endothelial growth factor (VEGF) level and adverse reactions in the four groups were observed. Results demonstrated that the durations of sensory and motor block in group R were shorter than those in groups Dex1-3 (P<0.01), followed by the sequence of group Dex1<Dex2<Dex3 (P<0.05). MAP and HR in groups Dex1-3 at T2-T5 were significantly lower than those in group R (P<0.01), and HR in group Dex3 at T3 and T4 was significantly lower than that in groups Dex1 and Dex2 (P<0.05). Ramsay scores in groups Dex1-3 at T2-T4 were significantly higher than those in group R (P<0.05). Serum VEGF levels in groups Dex2 and Dex3 at T2-T5 were significantly higher than those in group R (P<0.01). The incidences of over-sedation, bradycardia and dry mouth in group Dex3 were notably higher than those in the other groups. In conclusion, 1.5 µg/kg DEX exhibits a superior effect in improving ROP-induced LSB.

Clonidine used as a perineural adjuvant to ropivacaine, does not prolong the duration of sensory block when controlling for systemic effects: A paired, blinded, randomized trial in healthy volunteers

Background

Clonidine used as an adjuvant to ropivacaine have been shown to prolong the duration of peripheral nerve blocks. The mechanism of action remains unclear. We hypothesized, that clonidine used as an adjuvant to ropivacaine extends the duration of an adductor canal block (ACB) by a peripheral mechanism, compared to ropivacaine alone when controlling for systemic effects.

Methods

We conducted a paired, blinded, randomized trial in healthy volunteers. Participants received bilateral ACBs containing 20 ml ropivacaine 0.5% + 1 ml clonidine 150μg/ml in one leg and 20 ml ropivacaine 0.5% + 1 ml saline in the other leg. The primary outcome measure was duration of sensory block assessed by temperature sensation (alcohol swab). Secondary outcome measures were duration of sensory block assessed by: pinprick, maximum pain during tonic heat stimulation, warmth detection threshold and heat pain detection threshold.

Results

We enrolled 21 volunteers and all completed the trial. There was no difference in duration of sensory block assessed with an alcohol swab: Mean duration in the leg receiving ropivacaine + clonidine was 19.4h (SD 2.7) compared to 19.3h (SD 2.4) in the leg receiving ropivacaine + placebo with a mean difference of 0.1h (95% CI: -1.0 to 1.3), P = 0.83. No differences in block duration were detected when assessed by: Pinprick, mean difference 0.0 h (95% CI: -1.3 to 1.3), maximum pain during tonic heat stimulation, mean difference -0.7 h (95% CI: -2.1 to 0.8), warmth detection threshold, mean difference -0.1 h (95% CI: -1.8 to 1.6) or heat pain detection threshold, mean difference -0.2 h (95% CI: -1.7 to 1.4).

Conclusions

Administering clonidine perineurally as an adjuvant to ropivacaine in an ACB did not prolong the duration of sensory block in a setup controlling for systemic effects of clonidine.

Clonidine as an adjuvant for propranolol enhances its effect on infiltrative cutaneous analgesia in rats

Clonidine prolongs duration of analgesia when used as an adjunct to local anesthetics for infiltrative cutaneous analgesia, and propranolol produces local anesthesia. The purpose of the experiment was to evaluate clonidine as an adjuvant for propranolol on the quality and duration of cutaneous analgesia. A rat model of cutaneous trunci muscle reflex (CTMR) in response to local skin pinprick was employed to evaluate the cutaneous analgesic effect of propranolol combined with clonidine. The long-lasting local anesthetic bupivacaine was used as control. Cutaneous analgesia elicited by propranolol and bupivacaine was dose-dependent, and both propranolol (9.0μmol) and bupivacaine (1.8μmol) produced 100% nociceptive blockade. On an 50% effective dose (ED50) basis, the relative potency was bupivacaine [0.48 (0.42-0.55) μmol] greater than propranolol [2.27 (1.98-2.54) μmol] (p<0.01). Subcutaneous saline and clonidine (0.12μmol) did not produce cutaneous analgesia. The mixture of an ineffective-dose clonidine (0.12μmol) and a drug (propranolol or bupivacaine) at ED50 or ED95 increased the potency and extended the duration at producing cutaneous analgesia. The resulting data demonstrated that propranolol is less potent than bupivacaine as an infiltrative anesthetic. Clonidine as an adjuvant for propranolol or bupivacaine has a significant peripheral action in increasing the depth and duration of action on infiltrative cutaneous analgesia.

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.

Comparative evaluation of 0.75% ropivacaine with clonidine and 0.5% bupivacaine with clonidine in infraclavicular brachial plexus block

Background:

Infraclavicular brachial block with coracoids approach has gained popularity because of consistent bony landmarks and less chances of vascular puncture and pneumothorax.

Aim:

The aim of this study was to evaluate the effect of adding clonidine to bupivacaine or ropivacaine on the onset and duration of sensory and motor block and duration of analgesia in infraclavicular block.

Materials and Methods:

In a prospective randomized double-blind study, 60 patients of 18–65 years were randomly divided in to two groups of 30 each. Infraclavicular block was performed with 30 ml of 0.75% ropivacaine + 150 μg clonidine in group R and 30 ml of 0.5% bupivacaine + 150 μg clonidine in group B and were compared for onset and duration of sensory and motor block, postoperative analgesia, side-effects and complications.

Results:

Significant differences were observed in the time for onset of sensory block (5.80 ± 5.12 min in group R and 4.87 ± 1.46 min in group B, P < 0.05); onset of motor block (11.37 ± 2.66 min in group R and 9.60 ± 1.78 min in group B, P < 0.05); duration of sensory and motor block (10.07 ± 0.91 and 9.03 ± 0.89 h in group R and 12.50 ± 1.14 and 10.67 ± 1.18 h in group B respectively, P < 0.01) and duration of analgesia (15.30 ± 1.39 h in group R and 18.07 ± 1.66 h in group B). No significant difference was observed in hemodynamics, sedation, side-effects and complications.

Statistical Analysis:

Variables were compared using Chi-square test for nonparametric data and Student's t-test for parametric data.

Conclusion:

Addition of clonidine to bupivacaine lead to early onset and prolonged duration of sensory and motor block with prolonged analgesia as compared to the addition of clonidine to ropivacaine.

Clonidine as an adjuvant to ropivacaine-induced supraclavicular brachial plexus block for upper limb surgeries

Background and Aims:

Ropivacaine is a new amide, long acting, pure S-enantiomer, local anesthetic, with differential blocking effect. The addition of clonidine to local anesthetic improves the quality of peripheral nerve blocks. This study was conducted to evaluate the effect of clonidine on characteristics of ropivacaine-induced supraclavicular brachial plexus block.

Material and Methods:

A total of 60 adult patients were randomly recruited to two groups of 30 each: Group I: 30 ml 0.75% ropivacaine + 1 ml normal saline. Group II: 30 ml 0.75% ropivacaine + 1 mcg/kg clonidine diluted to 1 ml with normal saline.

Results:

The onset of sensorimotor block was earlier in Group II (4.36 ± 0.81 min for sensory block and 9.83 ± 1.12 min for motor block) than in Group I (4.84 ± 0.65 min for sensory block and 10.85 ± 0.79 min for motor block). The duration of both sensory and motor block were significantly prolonged by clonidine (P < 0.001). The duration of analgesia was also prolonged in patients receiving clonidine (613.10 ± 51.797 min vs. 878.33 ± 89.955 min). Although incidence of hypotension and bradycardia was higher in Group II when compared to Group I, it was not clinically significant.

Conclusions:

Ropivacaine 0.75% is well-tolerated and provides effective surgical anesthesia as well as relief of postoperative pain. Clonidine as an adjuvant to ropivacaine significantly enhances the quality of supraclavicular brachial plexus block by faster onset, prolonged duration of sensory and motor block and improved postoperative analgesia, without associated adverse effects at the dose used.

Addition of clonidine or lignocaine to ropivacaine for supraclavicular brachial plexus block: a comparative study

INTRODUCTION

Clonidine is used with local anaesthetics to improve analgesia. However, the improvement conferred when clonidine is used together with ropivacaine is controversial. Thus, the present study aimed to evaluate the improvement in analgesia when clonidine is used together with ropivacaine for supraclavicular brachial plexus block.

METHODS

This was a prospective, randomised, double-blind controlled study. A total of 75 patients who were scheduled to undergo supraclavicular block were randomly assigned into three groups (i.e. clonidine, lignocaine and control groups) of 25. Patients in all three groups received 20 mL of 0.75% ropivacaine. In addition to that, patients in the clonidine group received 1 mL of clonidine (150 μg) plus 9 mL of saline, patients in the lignocaine group received 10 mL of 2% lignocaine with adrenaline (1:200,000), and patients in the control group received 10 mL of saline. The characteristics of anaesthesia and analgesia for these three groups were assessed.

RESULTS

The addition of 2% lignocaine with adrenaline to ropivacaine led to earlier onset of the sensory block (by 4.88 mins), but no increase in the duration of analgesia when compared to analgesia using ropivacaine alone. The addition of clonidine to ropivacaine led to earlier onset of sensory and motor blocks (by 2.88 mins and 3.28 mins, respectively), as well as an increased duration of sensory and motor blocks (by 222.64 mins and 192.92 mins, respectively) when compared to analgesia using ropivacaine alone. The total duration of analgesia was increased by 208.24 mins with clonidine when compared to analgesia using ropivacaine alone. There were no significant differences in sedation score and no side effects in all three groups.

CONCLUSION

When compared to the use of ropivacaine alone, the addition of 150 μg clonidine to ropivacaine for brachial plexus block achieved earlier analgesic onset and improved duration of analgesia, without unwanted side effects.

Additives to local anesthetics for peripheral nerve blocks or local anesthesia: a review of the literature

SUMMARY 

A multitude of studies have focused on individual additives to local anesthetics and their effect on quality, onset, duration, spread and selectivity, as well as the potential toxic effects of their use. This review aims to give a broad overview of the current evidence in this developing field, based on beneficial and adverse effects of these drugs. We discuss the limitations of the available data and hope to convey implications and future perspectives for clinicians and researchers alike.

Clonidine as an adjuvant for ultrasound guided supraclavicular brachial plexus block for upper extremity surgeries under tourniquet: A clinical study

Background and Aims:

Clonidine has been used as an adjuvant to local anesthetic to extend the duration of block. The present study was aimed to compare the onset and duration of sensory and motor blockade of 0.75% ropivacaine alone or in combination with clonidine during ultrasound guided supraclavicular brachial plexus block for upper extremity surgeries under tourniquet.

Materials and Methods:

Sixty four adult American Society of Anesthesiologist grade 1 and 2 patients, scheduled for upper extremity surgeries were randomized to receive either 19.8 mL of 0.75% ropivacaine with 0.2 mL of normal saline (Group R) or 0.2 mL (30 μg) of clonidine (Group RC) in supraclavicular block. Onset and duration of sensory and motor blockade was compared. The hemodynamic variability, sedation, respiratory adequacy and any other adverse effects were also recorded.

Result:

Ultrasound helped to visualize the nerves, needle and spread of local anesthetic at the brachial plexus block site. There was no statistically significant difference in the onset of sensory and motor blockade between the groups. Surgical anesthesia was achieved at the mean time of 20 min in all patients. Prolonged post-operative analgesia (mean duration 956 min) was observed in RC group as compared with R group (736 min). No complication of technique or adverse effect of ropivacaine and clonidine was reported.

Conclusion:

Clonidine as an adjuvant to ropivacaine for ultrasound guided supraclavicular brachial plexus enhanced duration of post-operative analgesia. There was no incidence of vessel puncture or pneumothorax.

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

Background:

The role of clonidine as an adjuvant to local anesthetic agents in brachial plexus block (BPB) has been extensively studied. However, till date there has been no consensus about the ideal dose of clonidine for this purpose. This study was carried out to evaluate two doses of clonidine-1 and 2 g/kg, added to 0.5% bupivacaine, with regard to onset and duration of sensorimotor blockade, hemodynamic effects, postoperative analgesia, and adverse effects.

Materials and Methods:

Sixty adult patients undergoing upper limb surgeries were randomly allocated into two groups. Thirty patients received 1 g/kg clonidine (group I) and the rest received 2 g/kg clonidine (group II) added to 30 mL of 0.5% bupivacaine through nerve stimulator-guided supraclavicular BPB. The onset and duration of sensorimotor blockade, hemodynamic variables, duration of analgesia, level of sedation, and adverse effects was assessed.

Results:

The onset of sensorimotor block was earlier in group II (9.9 ± 4.1 min for sensory block and 13.2 ± 6.7 min for motor block) than in group I (15.9 ± 6.8 min for sensory block and 18.5 ± 7.8 min for motor block). The duration of analgesia was also prolonged in patients receiving the higher dose (21.0 ± 2.96 h vs. 14.9 ± 3.0 h). Although hemodynamics remained comparable in both the groups, incidence of hypotension and bradycardia was higher in group II as compared to group I. The sedation was clinically and statistically more in group II patients (43% vs. 17%).

Conclusion:

Higher dose of clonidine in BPB hastens the onset, prolongs the duration of sensorimotor blockade and postoperative analgesia without significant hemodynamic alterations. It also causes more sedation, which although ensures patient comfort in most cases, but might be undesirable in certain situations.

Clonidine as an adjuvant in axillary brachial plexus block for below elbow orthopedic surgeries: A comparison between local and systemic administration

Background:

Axillary brachial plexus block for below elbow orthopedic surgery provides a safe and low-cost technique with the advantage of prolonged postoperative analgesia. Clonidine, with selective partial agonist activity on α₂ adrenergic receptors, has significantly demonstrated its role in this regard as an adjuvant to local anesthetics. The current study compares the locally administered clonidine with systemically administered control group in terms of onset and duration of sensory block, motor block, and analgesia; hemodynamic variability; sedation; and other side effect profile.

Materials and Methods:

Seventy patients (ASA I or II) scheduled for below elbow orthopedic surgeries were randomly allocated in equal numbers to receive either 30 ml of 0.5% plain bupivacaine with 150 μg (1 ml) of inj. clonidine locally in the axillary sheath and 1 ml of normal saline (NS) subcutaneously (Group L) or 30 ml of 0.5% plain bupivacaine with 1 ml of NS locally and 150 μg (1 ml) of inj. clonidine subcutaneously (Group S). Standard monitoring of vital parameters was done. Duration of sensory and motor block, analgesia, hemodynamic changes, and any adverse effects were observed and recorded for different duration up to 24 h.

Results:

Duration of sensory block (625 ± 35 min), motor block (690 ± 38 min), and analgesia (930 ± 45 min) was significantly longer in Group L than in Group S [sensory block (480 ± 30 min), motor block (535 ± 25 min), and analgesia (720 ± 30 min)] (P < 0.05). Significant alteration of heart rate, systolic blood pressure and diastolic blood pressure, and mean arterial pressure in Group S was observed compared to Group L (P < 0.05). Side effects like nausea and vomiting were comparable, but highly significant sedation score (χ² = 47.75 and 49.51 at 120 and 240 min, respectively; P < 0.01) was observed between the two groups.

Conclusion:

Compared to systemic administration, local clonidine as an adjuvant in axillary block resulted in significant prolongation of duration of sensory and motor blockade, and analgesia without any hemodynamic alteration, probably by locally mediated mechanism of action.

Clonidine does not improve quality of ropivacaine axillary brachial plexus block in children

BACKGROUND

The addition of clonidine to peripheral nerve blocks is controversial in children.

OBJECTIVE

The aim of our study was to evaluate the effect of clonidine added to ropivacaine in pediatric axillary brachial plexus block (ABPB).

METHODS

Children aged 1-6 years, scheduled to undergo forearm or hand surgery, were recruited into this prospective, double-blind controlled trial. Patients were randomly allocated to receive an ABPB either with ropivacaine 0.2% 0.4 ml · kg(-1) plus saline in 1 ml (RS) or ropivacaine 0.2% 0.4 ml · kg(-1) plus clonidine 1 μg · kg(-1) in 1 ml (RC). Primary endpoints were quality of postoperative analgesia as assessed by pain scores and total 24-h postoperative analgesia requirements. Secondary outcomes were time to first analgesia request and duration of motor blockade.

RESULTS

Sixty patients were recruited (n = 30 per group) into the study. Pain scores were comparable throughout the first 24 h between the two groups. Ten children in the (RS) and six in (RC) groups required supplementary analgesia during the first 24 h (P = 0.24). Children who required further analgesia did so after 288 ± 94 min in the (RS) and 437 ± 204 min in the (RC) group (P = 0.06). There was no difference in the duration of motor block [186 ± 71 and 154 ± 56 min, P = 0.12 for (RS) and (RC), respectively].

CONCLUSION

Ropivacaine (0.2% 0.4 ml · kg(-1) ) for ABPB provides sufficient postoperative analgesia in children scheduled for forearm or hand surgery. The addition of clonidine to ABPB does not improve overall postoperative analgesia but may increase the time to first analgesia request.

A randomized controlled double-blinded prospective study of the efficacy of clonidine added to bupivacaine as compared with bupivacaine alone used in supraclavicular brachial plexus block for upper limb surgeries

We compared the effects of clonidine added to bupivacaine with bupivacaine alone on supraclavicular brachial plexus block and observed the side-effects of both the groups. In this prospective, randomized, double-blinded, controlled trial, two groups of 25 patients each were investigated using (i) 40 ml of bupivacaine 0.25% plus 0.150 mg of clonidine and (ii) 40 ml of bupivacaine 0.25% plus 1 ml of NaCl 0.9, respectively. The onset of motor and sensory block and duration of sensory block were recorded along with monitoring of heart rate, non-invasive blood pressure, oxygen saturation and sedation. It was observed that addition of clonidine to bupivacaine resulted in faster onset of sensory block, longer duration of analgesia (as assessed by visual analogue score), prolongation of the motor block (as assessed by modified Lovett Rating Scale), prolongation of the duration of recovery of sensation and no association with any haemodynamic changes (heart rate and blood pressure), sedation or any other adverse effects. These findings suggest that clonidine added to bupivacaine is an attractive option for improving the quality and duration of supraclavicular brachial plexus block in upper limb surgeries.

Brachial plexus blocks: infusions and other mechanisms to provide prolonged analgesia

PURPOSE OF REVIEW

Regional anesthesia has numerous benefits for upper extremity surgery such as improved analgesia, opioid sparing and reduced side effects. However, many of these advantages are lost after block regression. Recently, several strategies such as continuous ambulatory local anesthetic infusions and adjuvants that may potentiate analgesia after a brachial plexus block have been described and investigated. This review will highlight and place in context this recent work.

RECENT FINDINGS

Current investigations have demonstrated that brachial plexus analgesia can be extended by combining existing solutions and technology. This has been most evident in the use of ambulatory continuous peripheral nerve blocks such as the interscalene, infraclavicular and axillary approaches. Accomplishing this safely in an outpatient setting requires the use of basic infusion pumps, patient education and a mechanism for follow-up after discharge. This strategy has prolonged pain relief and facilitated major operations on an outpatient basis. An alternative to this strategy is to combine adjuvants such as opioids, clonidine, ketamine and neostigmine to potentiate the effects of local anesthetics. These additives have had mixed results. The most promising solutions are the alpha-2-adrenergic agonists but further investigation is necessary to confirm their efficacy and quantify their appropriate dose and side effects.

SUMMARY

The advances and techniques recently described demonstrate that prolonging analgesia after brachial plexus blocks is possible. This may be accomplished via several different approaches and mechanisms resulting in improved patient analgesia and side effects.

Clonidine--a potent analgesic adjuvant

PURPOSE OF REVIEW

The alpha(2)-adrenoceptor agonist clonidine is one of the most widely investigated substances in anaesthesia and pain therapy. Recently, numerous experimental and clinical studies have allowed a better understanding of its underlying mechanisms of action and interactions with other analgesic drugs.

RECENT FINDINGS

Several experimental studies have shown that clonidine may improve the analgesic effect of anti-inflammatory agents and also have significant peripheral antinociceptive effects. Volunteer and clinical studies have demonstrated analgesic effects of clonidine after systemic administration, whereas local administration of plain clonidine (e.g. intra-articular, intravenous regional) showed only limited clinical efficacy. The major clinical place of clonidine may thus be as an adjuvant to other analgesics, as shown in a number of studies in which clonidine has been investigated in combination with local anaesthetics, opioids and ketamine. An increasing number of studies have now investigated clonidine in paediatric patients and have demonstrated that the effects are generally similar to those in adults. Furthermore, it seems that in paediatric patients the side-effects of clonidine are predictable and of limited clinical importance.

SUMMARY

During the past decade clonidine has been investigated as an adjuvant for general and regional anaesthesia and in the postoperative period. There is no doubt that clonidine improves analgesia after systemic, spinal or peripheral opioids, and prolongs the analgesic action of most local anaesthetics. The side-effects of usual doses of clonidine are predictable. Given the clinical experience of an increasing number of hospitals, clonidine should no longer be considered an experimental drug, but a useful addendum to the pharmacological armamentarium.

The Effects of Clonidine on Postoperative Analgesia After Peripheral Nerve Blockade in Children

BACKGROUND

The effect of clonidine on the duration of sensory blockade after peripheral nerve blockade is controversial. We evaluated the effects of clonidine on the duration of sensory and motor block and analgesia time in children who underwent a variety of peripheral nerve blocks.

METHODS

We reviewed the regional anesthesia database that contains data on children who underwent an infraclavicular, lumbar plexus, femoral, fascia iliaca or sciatic nerve block for postoperative analgesia at The Children's Hospital of Philadelphia between October 2002 and December 2005. Patients were prospectively followed after the nerve block.

RESULTS

Two hundred fifteen patients (47%) received either bupivacaine or ropivacaine local anesthetic (LA) and 220 (53%) a combination of local anesthetic and clonidine (LAC). The duration of sensory block was significantly longer in the LAC (17.2 +/- 5 h) compared with that in the LA group (13.2 +/- 5 h) (P = 0.0001). The increase in duration was independent from the type of peripheral nerve block, local anesthetic used and operation performed. The motor block duration was significantly longer in the LAC group (9.6 +/- 5 vs 4.3 +/- 4 h, P = 0.014). Two patients in the LAC and one in the LA group experience prolonged numbness (max 72 h). No paresthesia or dysesthesia was observed.

CONCLUSION

The addition of clonidine to bupivacaine and ropivacaine can extend sensory block by a few hours, and increase the incidence of motor blocks.

Does clonidine 50 μg improve cervical plexus block obtained with ropivacaine 150 mg for carotid endarterectomy? A randomized, double-blinded study

STUDY OBJECTIVE

To evaluate the effects of adding 50 microg clonidine to 150 mg ropivacaine for superficial cervical plexus block in patients undergoing elective carotid endarterectomy (TEA).

DESIGN

Randomized, double-blind study.

SETTING

Departments of Anesthesia and Vascular Surgery of a university hospital.

PATIENTS

40 ASA physical status II and III patients undergoing elective TEA during superficial cervical plexus block.

INTERVENTIONS

Superficial cervical plexus block was placed using 20 mL of 0.75% ropivacaine alone (Ropi group, n = 20) or with the addition of 50 microg clonidine (Ropi-Clonidine group, n = 20). If required, analgesic supplementation was given with local infiltration with 1% lidocaine and intravenous fentanyl (50-microg boluses). Nerve block profile, need for intraoperative analgesic supplementation, and time to first analgesic request were recorded.

MEASUREMENTS AND MAIN RESULTS

Median (range) onset time was 10 minutes (5-25 min) in the Ropi group and 5 minutes (5-20 min) in the Ropi-Clonidine group (P < 0.05). Intraoperative consumption of both 1% lidocaine and fentanyl was higher in patients of the Ropi group (15 mL [0-25 mL] and 250 microg [50-300 microg]) than in patients of the Ropi-Clonidine group (8 mL [0-20 mL] and 0 microg [0-150 microg]; P < 0.05 and P < 0.05, respectively). First postoperative analgesic request occurred after 17 hours (10-24 hrs) in the Ropi group and 20 hours (10-24 hrs) in the Ropi-Clonidine group (P > 0.05).

CONCLUSIONS

Adding 50 microg clonidine to 150 mg ropivacaine for superficial cervical plexus block shortened the onset time and improved the quality of surgical anesthesia in patients undergoing elective TEA.

Ropivacaine: a review of its use in regional anaesthesia and acute pain management

Ropivacaine (Naropin) is the pure S(-)-enantiomer of propivacaine, and is a long-acting amide local anaesthetic agent, eliciting nerve block via reversible inhibition of sodium ion influx in nerve fibres. Ropivacaine is a well tolerated regional anaesthetic effective for surgical anaesthesia as well as the relief of postoperative and labour pain. The efficacy of ropivacaine is similar to that of bupivacaine and levobupivacaine for peripheral nerve blocks and, although it may be slightly less potent than bupivacaine when administered epidurally or intrathecally, equi-effective doses have been established. Clinically adequate doses of ropivacaine appear to be associated with a lower incidence or grade of motor block than bupivacaine. Thus ropivacaine, with its efficacy, lower propensity for motor block and reduced potential for CNS toxicity and cardiotoxicity, appears to be an important option for regional anaesthesia and for the management of postoperative and labour pain.

The effects of clonidine added to mepivacaine for paronychia surgery under axillary brachial plexus block

We hypothesized that onset of sensory block is delayed in infected versus healthy tissues within the same nerve distribution after axillary brachial plexus block (ABPB) and that clonidine added to mepivacaine would enhance anesthesia and postoperative analgesia. Forty-one outpatients undergoing thumb/index paronychia surgery under ABPB were randomly assigned to receive in a double-blind fashion 400 mg mepivacaine plus either 100 microg clonidine (clonidine group, n = 21) or 2 mL saline (placebo group, n = 20). Onset of sensory block in the infected area was delayed compared with healthy areas of the same nerve distribution (24.7 +/- 5.5 min versus 21.3 +/- 7.2; P = 0.02 for median and 21.6 +/- 7.8 min; P = 0.04 for radial) within the placebo group. In the clonidine group, when compared to placebo i) onset of sensory block in both the median and radial nerve territories was accelerated (11.1 +/- 5.6 and 10.5 +/- 5.2 versus 21.3 +/- 7.2 and 21.6 +/- 7.8 min, respectively; P < 0.001), ii) onset of sensory block in the region of infection was accelerated (9.1 +/- 1.9 versus 24.7 +/- 5.5 min; P < 0.001), iii) duration of anesthesia (275 +/- 75 versus 163 +/- 57; P = 0.04) and time to first analgesic requirement (279 +/- 87 versus 197 +/- 84 min; P = 0.002) were prolonged with decreased visual analog scale scores at this time (30 +/- 18 versus 70 +/- 24; P < 0.001), and iv) verbal numeric rating scores were decreased at 24 h (1.7 +/- 2.2 versus 4.1 +/- 3.0; P = 0.002) and 48 h (0.1 +/- 0.5 versus 1.5 +/- 2.4; P = 0.01) postoperatively. Our findings suggest that in the setting of distal infected tissue surgery under ABPB infected tissues are resistant to anesthesia compared with healthy areas within the same nerve distribution and clonidine added to mepivacaine enhances both anesthesia and postoperative analgesia.

Clonidine as an adjuvant for lidocaine in axillary brachial plexus block in patients with chronic renal failure

BACKGROUND

Clonidine is often used as an adjuvant for local anaesthetics in regional anaesthesia; however, its effects on axillary block in chronic renal failure patients have not been investigated. These effects were the focus of this study.

METHODS

Twenty-eight adult chronic renal failure patients (ASA physical status III) scheduled for arteriovenous fistula construction were studied in a prospective, randomized, double-blind, controlled design. All axillary block procedures were performed by the same anaesthesiologist using the nerve stimulator technique. The control group received 40 ml of lidocaine (10 mg ml(-1)) combined with 1 ml of saline, and the clonidine group received 40 ml of lidocaine (10 mg ml(-1)) mixed with 150 microg of clonidine. Characteristics of the patients and the blocks were recorded, in addition to data on the nerves stimulated, intraoperative haemodynamic parameters, and sedative and analgesic requirements.

RESULTS

The onset time for sensory blockade was longer in the clonidine group than in the controls (P = 0.013), and both motor and sensory blocks lasted longer in the clonidine group (P = 0.004, P < 0.001, respectively). In addition, the clonidine group had lower mean arterial pressures, heart rates and higher sedation scores compared to the controls (P < 0.05 for all).

CONCLUSION

Use of clonidine (150 microg) as adjuvant for lidocaine in axillary blocks for arteriovenous fistula construction in chronic renal failure patients prolongs blockade, decreases both heart rates and blood pressures and provides sedative effects.

Role of Analgesic Adjuncts in Postoperative Pain Management

Postoperative pain remains a major problem. A multi-modal analgesic approach is recommended to optimize pain management and reduce opiate-related adverse effects. Several analgesic adjuncts have been investigated, and many have proved to have a useful analgesic effect. This article reviews the literature regarding use of analgesic adjuncts in the perioperative period.

Intravenous but Not Perineural Clonidine Prolongs Postoperative Analgesia After Psoas Compartment Block with 0.5% Levobupivacaine for Hip Fracture Surgery

We evaluated the systemic and local effects of clonidine as an analgesic adjunct to psoas compartment block (PCB) with levobupivacaine. In a randomized, prospective, double-blind trial, 36 patients requiring hip fracture surgery received PCB and general anesthesia. Patients were randomized into three groups. Each patient received PCB with 0.4 mL/kg of levobupivacaine 0.5%. The control group (group L) received IV saline, the systemic clonidine group (group IC) received IV clonidine 1 mug/kg, and the peripheral clonidine group (group C) received IV saline and PCB with clonidine 1 microg/kg. The interval from time of completion of block injection to first supplementary analgesic administration was longer in group IC compared with group L (mean +/- sd, 13.4 +/- 6.1 versus 7.3 +/- 3.6 h; P = 0.03). There was no difference between group C and group L (10.3 +/- 5.9 versus 7.3 +/- 3.6 h; P > 0.05). The groups were similar in terms of 24 h cumulative morphine and acetaminophen consumption. There were no significant differences among groups regarding postoperative adverse effects (bradycardia, hypotension, sedation, and nausea). We conclude that IV but not perineural clonidine (1 microg/kg) prolongs analgesia after PCB without increasing the incidence of adverse effects.

Adding clonidine to the induction bolus and postoperative infusion during continuous femoral nerve block delays recovery of motor function after total knee arthroplasty

We evaluated the effects of adding clonidine for continuous peripheral nerve infusions. Sixty patients undergoing total knee arthroplasty under combined single-injection sciatic block and continuous femoral infusion were randomly allocated to three groups: block induction with 0.75% ropivacaine followed by 0.2% ropivacaine (group control; n = 20); block induction with 0.75% ropivacaine and 1 microg/kg clonidine followed by 0.2% ropivacaine (group cloni-bolus; n = 20), and block induction with 0.75% ropivacaine and 1 microg/kg clonidine followed by 0.2% ropivacaine with 1 microg/mL clonidine (group cloni-infusion; n = 20). After surgery, continuous femoral infusion was provided with a patient-controlled infusion pump (basal infusion rate, 6 mL/h; incremental dose, 2 mL; lockout time, 15 min). The median (range) onset time of surgical block was 15 min (5-30 min) in group control, 10 min (5-35 min) in group cloni-bolus, and 10 min (5-30 min) in group cloni-infusion (P = 0.07). No differences were reported among groups in the degree of pain measured with the visual analog scale. The total consumption of local anesthetic solution after a 24-h infusion was 170 mL (144-220 mL) in group control, 169 mL (144-260 mL) in group cloni-bolus, and 164 mL (144-248 mL) in group cloni-infusion (P = 0.51); after the second day of infusion, total consumption was 168 mL (144-200 mL) in group control, 156 mL (144-288 mL) in group cloni-bolus, and 150 mL (144-210 mL) in group cloni-infusion (P = 0.48). Hemodynamic profiles and sedation were similar in the three groups. Motor function impairment after 48 h of infusion was observed in 27% of cloni-infusion patients but in only 6% of both the control and cloni-bolus groups (P = 0.05). We conclude that adding clonidine 1 microg/mL to local anesthetic for continuous femoral nerve block does not improve the quality of pain relief but has the potential for delaying recovery of motor function.

Tramadol as adjunct to psoas compartment block with levobupivacaine 0.5%: a randomized double-blinded study

BACKGROUND

Tramadol has been administered peripherally to prolong analgesia after brachial plexus and neuraxial blocks. Our aim was to evaluate the systemic and perineural effects of tramadol as an analgesic adjunct to psoas compartment block (PCB) with levobupivacaine.

METHODS

In a randomized, prospective, double-blinded trial, 60 patients (ASA I-III), aged 49-88 yr, undergoing primary total hip or knee arthroplasty underwent PCB and subsequent bupivacaine spinal anaesthesia. Patients were randomized into three groups. Each patient received PCB with levobupivacaine 0.5%, 0.4 ml kg(-1). The control group (group L, n=21) received i.v. saline, the systemic tramadol group (group IT, n=19) received i.v. tramadol 1.5 mg kg(-1) and the perineural tramadol group (group T, n=20) received i.v. saline and PCB with tramadol 1.5 mg kg(-1). Postoperatively patients received regular paracetamol 6-hourly and diclofenac sodium 12-hourly. Time to first morphine analgesia, 24-hour morphine consumption, sensory block, pain and sedation scores and haemodynamic parameters were recorded.

RESULTS

Time (h) to first morphine analgesia was similar in the three groups [mean (SD)]: group L, 11.2 (6.6); group T, 14.5 (8.0); group IT, 14.6 (6.8); P=0.35. Twenty-four-hour cumulative morphine (mg) consumption was also similar in the three groups [group L, 21.9 (10.1); group T, 19.8 (6.7), group IT, 16.5 (9.5)], as were durations of sensory and motor block. There were no differences in the incidence of adverse effects except that patients in group IT were more sedated at 14 h than group L (P=0.02).

CONCLUSION

We conclude that our data do not support a clinically important local anaesthetic or peripheral analgesic effect of tramadol as adjunct to PCB with levobupivacaine 0.5%.

Clonidine as an adjuvant to local anaesthetic axillary brachial plexus block: a randomized, controlled study

BACKGROUND

We compared the effects of clonidine added to levobupivacaine and bupivacaine on axillary brachial plexus block as well as the effectiveness of levobupivacaine alone compared with bupivacaine alone.

METHODS

In this prospective, randomized, controlled, double-blind trial, four groups of 20 patients each were investigated, using (i) 40 ml of levobupivacaine 0.5% plus 0.150 mg of clonidine, (ii) 40 ml of levobupivacaine 0.5% plus 1 ml of NaCl 0.9%, (iii) 40 ml of bupivacaine 0.5% plus 0.150 mg of clonidine, and (iv) 40 ml of bupivacaine 0.5% plus 1 ml of NaCl 0.9%, respectively. The onset of motor and sensory block and duration of sensory block were recorded.

RESULTS

There was no significant difference in duration between groups, but a significantly higher variance (P<0.001) was found in the two groups with clonidine than in the two groups without.

CONCLUSIONS

These findings suggest responder and non-responder behaviour is a result of the addition of clonidine.

Regional anesthesia for outpatient surgery

In summary, regional techniques offer significant advantages in the outpatient setting. They can avoid the side effects of nausea, vomiting, and pain that frequently delay discharge or cause admission. They can also provide prolonged analgesia as well as offer, with the use of continuous catheters, the promise of a pain-free perioperative period. The choice of drugs must be carefully adjusted, especially with neuraxial techniques. Despite frequently requiring some additional time at the outset, regional techniques have consistently been shown to provide competitive discharge times and costs when compared with general anesthesia. They deserve a prominent place in outpatient surgery.

Brachial plexus block

PURPOSE OF REVIEW

In recent years there has been a renewed interest in regional anesthesia, particularly peripheral nerve blockade, in order not only to improve the patient's well being, but also to meet the requirements of modern orthopedic surgery. These requirements include appropriate conditions to perform early and efficient rehabilitation.

RECENT FINDINGS

The upper extremity is well designed for the practice of the perineural catheter technique, since we have three main approaches, interscalene, infraclavicular and axillary, which allow all territories involved in specific surgical procedures to be blocked with only one shot or catheter. Recent developments have focused on modification of traditional technical approaches, improving the safety of the procedure, finding a more efficient way to administer the local anesthetic through the perineural catheter, and examining new indications and modes of performing regional anesthesia.

SUMMARY

Early rehabilitation is currently a key point for the success of orthopedic surgery. The rapid development of peripheral nerve blockade gives the anesthesiologist the means to face this new challenge.

Clonidine in paediatric anaesthesia

PURPOSE OF REVIEW

This review aims to summarize results of recently published studies concerning clonidine application in paediatric anaesthesia, to analyse trends in these studies, and to discuss perspectives of the perioperative use of clonidine for children.

RECENT FINDINGS

Reassessment of clonidine premedication has revealed that oral clonidine is inferior to midazolam for preoperative sedation. Oral or intravenous clonidine has been successfully used for the prevention of sevoflurane-induced agitation during emergence from anaesthesia. Peripheral injection or caudal (epidural) administration of clonidine prolonged the duration and enhanced the quality of postoperative analgesia by local anaesthetics without severe side effects. However, some negative results concerning potentiation of postoperative analgesia with clonidine have been reported.

SUMMARY

Clonidine may be less favored than midazolam as premedication for children because of inferior clonidine-induced sedation. Additional comparative studies are required, however, to confirm this finding. On the other hand, clonidine-induced analgesia may well be useful and find wide application in paediatric anaesthesia. Prospective multicentre trials using a larger number of patients will be needed to verify the usefulness of caudal clonidine for postoperative pain relief. Prophylactic use of clonidine against sevoflurane-induced agitation may represent a new and promising application. Assessment of the efficacy of clonidine in potentiating regional anaesthesia/analgesia by local anaesthetics in children also needs more investigation. Moreover, it may be worthwhile to try new successful applications demonstrated in adults for paediatric anaesthesia.

Anaesthesia for treating distal radial fracture in adults

BACKGROUND

Fracture of the distal radius is a common clinical problem, particularly in older white women with osteoporosis. Anaesthesia is usually provided during manipulation of displaced fractures or during surgical treatment.

OBJECTIVES

To examine the evidence for the relative effectiveness of the main methods of anaesthesia (haematoma block, intravenous regional anaesthesia (IVRA), regional nerve blocks, sedation and general anaesthesia) as well as associated physical techniques and drug adjuncts used during the management of distal radial fractures in adults.

SEARCH STRATEGY

We searched the Cochrane Musculoskeletal Injuries Group specialised register (January 2002), the Cochrane Controlled Trials Register (The Cochrane Library Issue 4, 2001), MEDLINE (1966 to October 2001), EMBASE (1988 to 2001 Week 48), Current Controlled Trials (December 2001) and reference lists of articles.

SELECTION CRITERIA

Randomised or quasi-randomised clinical trials evaluating relevant interventions for these injuries (see Objectives). We excluded pharmacological trials comparing drug dosages and, with one exception, different drugs in the same class. Also excluded were trials reporting only pharmacokinetic and/or physiological outcomes.

DATA COLLECTION AND ANALYSIS

All trials meeting the selection criteria were independently assessed by the three reviewers for methodological quality. Data were extracted independently by two reviewers. Quantitative data are presented using relative risks or mean differences together with 95 per cent confidence limits. Only very limited pooling of results from comparable trials was possible.

MAIN RESULTS

The 18 included studies involved at least 1200, mainly female and older, patients with fractures of the distal radius. All studies had serious methodological limitations, notably in the frequent failure to assess clinically important and longer-term outcomes. Five trials provided evidence that, when compared with haematoma block, IVRA provided better analgesia during fracture manipulation and enabled better and easier reduction of the fracture, with some indication of a reduced risk of later redislocation or need for re-reduction. In contrast, haematoma block was quicker and easier to perform and less resource intensive. There was inadequate evidence of relative effectiveness of different methods of anaesthesia only examined within single trials: nerve block versus haematoma block; intravenous sedation versus haematoma block; general anaesthesia versus haematoma block; general anaesthesia versus sedation; and general anaesthesia versus haematoma block and sedation. None of the three trials evaluating three different physical aspects of anaesthesia (injection site of, or extra tourniquet, for IVRA; and technique for brachial plexus block) provided conclusive evidence for the effectiveness and safety of the novel technique. Six trials examined the use of drug adjuncts. The addition of two different muscle relaxants and one analgesic was tested for IVRA; one sedative and hyaluronidase for haematoma block; and clonidine for brachial plexus block. All trials evaluating adjuncts failed to provide evidence on eventual clinical outcome. A seriously flawed study comparing bupivacaine with prilocaine for IVRA gave some insight on the potential confounding effects of treatment by different doctors on patient outcome.

REVIEWER'S CONCLUSIONS

There was insufficient robust evidence from randomised trials to establish the relative effectiveness of different methods of anaesthesia, different associated physical techniques or the use of drug adjuncts in the treatment of distal radial fractures. There is, however, some indication that haematoma block provides poorer analgesia than IVRA, and can compromise reduction. Given the many unresolved questions over the management of these fractures, we suggest an integrated programme of research, which includes consideration of anaesthesia options, is the way forward.

Regional anaesthesia for orthopaedic surgery

Recently, there has been considerable interest in regional anaesthetic techniques, particularly in peripheral nerve blockade, for orthopaedic limb surgery. Many traditional nerve-block techniques have been significantly modified to improve their role in both in-patient and out-patient surgery. The introduction of long-acting local anaesthetic with a better safety profile as well as better equipment for continuous nerve blockade has further increased the use of such techniques in the provision of postoperative analgesia. The recent developments described in this review are likely to result in wider use of these techniques in years to come.