Ropivacaine or 2% mepivacaine for lower limb peripheral nerve blocks. Study Group on Orthopedic Anesthesia of the Italian Society of Anesthesia, Analgesia, and Intensive Care

Adductor canal block combined with genicular nerve block versus local infiltration analgesia for total knee arthroplasty: a randomized noninferiority trial

OBJECTIVE

This randomized controlled and double-blind study aimed to investigate whether the analgesic effect of the adductor canal block (ACB) combined with the genicular nerve block (GNB) after total knee arthroplasty is noninferior to that of the adductor canal block combined with local infiltration analgesia (LIA).

METHODS

A total of 102 patients undergoing total knee arthroplasty under general anesthesia were included and randomly divided into: ACB + GNB and ACB + LIA groups; the ACB + LIA group received 80 mL of 0.2% ropivacaine with adrenaline 10 µg/mL for LIA, whereas the ACB + GNB group received 4 mL of 0.2% ropivacaine for the blockade of five peri-knee nerves. The primary outcome was the median difference in the visual analog scale scores at rest at 24 h between the two groups. Secondary outcomes involved the median differences in the pain scores at other time points. Other outcomes included the cumulative dosage of opioids calculated in morphine equivalents in the first 24 h and indicators related to knee joint functional recovery.

RESULTS

In total, 36 and 38 patients were included in the ACB + GNB and ACB + LIA groups, respectively. We found that the median difference (95% confidence internal) in postoperative rest pain at 24 h (noninferiority criteria, △ = 1) was - 0.5 (- 1 to 0, p = 0.002). The median difference in cumulative opioid consumption was 1 mg (- 1 to 3, p = 0.019), meeting the noninferiority criteria, △ = 7.7 mg.

CONCLUSIONS

ACB combined with GNB provides noninferior analgesia compared to ACB with LIA on the first day after total knee arthroplasty while significantly reducing local anesthetic use.

TRIAL REGISTRATION

Name of the Registry: Chinese Clinical Trial Registry; Trial Registration Number: ChiCTR2300074274; Date of Registration. August 2, 2023.

Comparison of ropivacaine, bupivacaine, and lignocaine in femoral nerve block to position fracture femur patients for central neuraxial blockade in Indian population

BACKGROUND

Patients with a fractured femur experience intense pain during positioning for neuraxial block for definitive surgery. Femoral nerve block (FNB) is therefore often given prior to positioning for analgesia. In our study, we compare the onset and quality of block of 0.25% bupivacaine, 0.5% ropivacaine, and 1.5% lignocaine for FNB in fracture femur patients.

METHODS

Seventy-five adult femur fracture patients were equally and randomly divided into three groups to receive 15 ml of either 0.25% bupivacaine (group B), 0.5% ropivacaine (group R), or 1.5% lignocaine (group L) for FNB prior to positioning for neuraxial blockade. Onset and quality of block were assessed, as well as improvement in visual analog scale (VAS) score, ease of positioning, and patient satisfaction.

RESULTS

Percentage decrease in VAS was found to be highest in group R (82.8%) followed by groups L and B. Time to achieve a VAS of less than 4 was found to be 26.2±2.4 minutes in group B, 8.5±1.9 minutes in group R, and 4.1±0.7 minutes in group L (P<0.001). In group B, 12 patients required additional fentanyl to achieve a VAS <4. Patient positioning was reported to be satisfactory in all patients in group R and L, while in B it was satisfactory in 13 (52%) patients only. Patient acceptance of FNB was 100% in group R and L, but only 64% in group B.

CONCLUSIONS

Based on our findings, 0.5% ropivacaine is a favorable choice for FNB due to early onset, ability to yield a good quality block, and good safety profile.

Effect of intravenous dexamethasone on the duration of postoperative analgesia for popliteal sciatic nerve block: a randomized, double-blind, placebo-controlled study

Background

Intravenous (IV) dexamethasone prolongs the duration of a peripheral nerve block; however, there is little available information about its optimal effective dose. This study aimed to evaluate the effects of three different doses of IV dexamethasone on the duration of postoperative analgesia to determine the optimal effective dose for a sciatic nerve block.

Methods

Patients scheduled for foot and ankle surgery were randomly assigned to receive normal saline or IV dexamethasone (2.5 mg, 5 mg, or 10 mg). An ultrasound-guided popliteal sciatic nerve block was performed using 0.75% ropivacaine (20 ml) before general anesthesia. The duration of postoperative analgesia was the primary outcome, and pain scores, use of rescue analgesia, onset time, adverse effects, and patient satisfaction were assessed as secondary outcomes.

Results

Compared with the control group, the postoperative analgesic duration of the sciatic nerve block was prolonged in groups receiving IV dexamethasone 10 mg (P < 0.001), but not in the groups receiving IV dexamethasone 2.5 mg or 5 mg. The use of rescue analgesics was significantly different among the four groups 24 h postoperatively (P = 0.001) and similar thereafter. However, pain scores were not significantly different among the four groups 24 h postoperatively. There were no statistically significant differences in the other secondary outcomes among the four groups.

Conclusions

This study demonstrated that compared to the controls, only IV dexamethasone 10 mg increased the duration of postoperative analgesia following a sciatic nerve block for foot and ankle surgery without the occurrence of adverse events.

Pectointercostal Fascial Block (PIFB) as a Novel Technique for Postoperative Pain Management in Patients Undergoing Cardiac Surgery

OBJECTIVE

To determine the efficacy of pectointercostal fascial block in relieving postoperative pain in patients undergoing cardiac surgery.

DESIGN

Single-blinded, prospective, randomized controlled trial.

SETTING

Single-center tertiary care teaching hospital.

PARTICIPANTS

A total 40 participants undergoing cardiac surgery aged 18 to 80 years.

INTERVENTIONS

Subjects were categorized into 2 groups of 20 each. In group 2 participants (interventional group), bilateral pectointercostal fascial block was given using ropivacaine injection 0.25% after completion of surgery, before shifting to the intensive care unit.

MEASUREMENTS AND MAIN RESULTS

Postoperative pain was measured after extubation at 0, 3, 6, and 12 hours, using a numeric rating scale. Pain in group 2 was significantly less and lasted for a longer duration than in group 1. Fentanyl requirement was significantly higher in group 1 (1.06 ± 0.12 µ/kg) than in group 2 (0.82 ± 0.19 µ/kg).

CONCLUSIONS

Pectointercostal fascial block is an easy and efficient technique to reduce postoperative pain after cardiac surgery.

A Randomized Controlled Trial Assessing the Effect of a Continuous Subcutaneous Infusion of Local Anesthetic Following Elective Surgery to the Great Toe

Local anesthetic use for wound infusions, single injection, and continuous nerve blocks for postoperative analgesia is well established. No study has investigated the effect of a continuous block of the saphenous and superficial peroneal nerves at the level of the ankle joint following first ray surgery. A double blind randomized controlled trial was designed. One hundred patients with hallux valgus and rigidus requiring surgical correction were recruited and randomized to receive a postoperative continuous infusion at the ankle of normal saline or ropivacaine for 24 hours. Pain scores were recorded on postoperative days 1 and 7. There were more females than males. Follow-up was 100%. There were no significant differences in demographic data between the 2 randomized groups. There was no significant difference between the absolute visual analog scale scores on day 1 (P = .14) and day 7 (P = .16); nor was there a significant difference in reduction in scores between days 1 and 7 (P = .70). This study has shown no benefit to postoperative analgesia with the use of a continuous infusion of ropivacaine at the ankle. We, therefore, cannot currently recommend its use in the way described. Further studies may still identify a role for continuous local anesthetic infusions at the ankle to improve postoperative analgesia.

LEVELS OF EVIDENCE

Level I : Prospective randomised control trial.

A double-blind randomized controlled trial comparing dexamethasone and clonidine as adjuvants to a ropivacaine sciatic popliteal block for foot surgery

Background and aims

A popliteal block is effective in managing postoperative pain for foot surgery, but since the duration of analgesia is limited following a single-shot popliteal fossa block technique, methods to prolong effective postoperative analgesia are mandatory. The aim of this study was to assess the effect of adjuvants to ropivacaine on the duration of sensory and motor block.

Methods

In this double-blind randomized placebo-controlled study, we evaluated the analgesic effect of clonidine or dexamethasone (DXM) when added to ropivacaine for hallux valgus surgery. After obtaining institutional ethics research board approval and written informed consent, a total of 72 patients were randomly allocated. Fifty-seven of these patients were statistically analyzed. All patients received an ultrasound-guided single-shot popliteal fossa block with 30 mL of ropivacaine 0.75%, supplemented with saline, clonidine 100 µg, or DXM 5 mg. The primary end point was time to first pain sensation. Secondary end points were time to complete sensory and motor block regression.

Results

Compared to saline, duration to first pain sensation was prolonged by 9 hours (mean ± standard deviation: 31±9 hours) (42%) in the DXM group (P=0.024) and by 6 hours (28±10 hours) (27%) in the clonidine group (P=0.024). Compared to saline, DXM prolonged both complete sensory and motor blockade by 12 hours (25±7 hours) (46%) and 13 hours (36±6 hours) (55%), respectively, while clonidine prolonged complete sensory and motor blockade by 7 hours (30±7 hours) (27%) and 2 hours (22±5 hours) (10%), respectively. DXM prolonged sensory block regression time by 6 hours (21±7 hours) (41%) and clonidine by 2 hours (17±6 hours) (13%) compared to the control group (P=0.006). Similarly, DXM prolonged motor block regression by 7 hours (25±7 hours) (46%) and clonidine by 4 hours (21±4 hours) (19%) (P<0.0001).

Conclusion

Addition of DXM and clonidine to ropivacaine significantly prolonged the duration of postoperative sensory and motor block.

Do the Concentration and Volume of Local Anesthetics Affect the Onset and Success of Infraclavicular Anesthesia?

Background:

Although local anesthesia is a suitable method for upper limb surgeries, there is debate regarding the effects of appropriate dosing.

Objectives:

In the current study, we investigated the effects of the concentration and volume of a local anesthetic on the beginning and quality of anesthesia during upper limb orthopedic surgeries.

Patients and Methods:

This double-blinded, randomized, clinical trial was conducted on 60 patients aged between 18 and 85 years candidated for upper limb orthopedic operations. The patients were equally and randomly distributed into two groups (n = 30). Under ultrasound imaging guidance, the first group received 7 mL of 2% lidocaine and the second group 10 mL of 1.3% lidocaine into the brachial plexus cords. The onset of block and the level of sensory and motor block were documented for each nerve territory.

Results:

The onset of sensory and motor block was significantly shorter in the 1.3% lidocaine group than in the 2% lidocaine group (P ≤ 0.05). The success rate of sensory and motor block was not different. The quality (completeness) of sensory block for the musculocutaneous nerve and that of motor block for the radial nerve were significantly better in the 1.3% lidocaine group than in the 2% lidocaine group.

Conclusions:

The volume of the injected anesthetic accelerated the onset of sensory and motor block without affecting the rate of success in our patients.

Minimum effective concentration of bupivacaine for axillary brachial plexus block guided by ultrasound

INTRODUCTION

The use of ultrasound in regional anesthesia allows reducing the dose of local anesthetic used for peripheral nerve block. The present study was performed to determine the minimum effective concentration (MEC90) of bupivacaine for axillary brachial plexus block.

METHODS

Patients undergoing hand surgery were recruited. To estimate the MEC90, a sequential up-down biased coin method of allocation was used. The bupivacaine dose was 5 mL for each nerve (radial, ulnar, median, and musculocutaneous). The initial concentration was 0.35%. This concentration was changed by 0.05% depending on the previous block; a blockade failure resulted in increased concentration for the next patient; in case of success, the next patient could receive or reduction (0.1 probability) or the same concentration (0.9 probability). Surgical anesthesia was defined as driving force ≤ 2 according to the modified Bromage scale, lack of thermal sensitivity and response to pinprick. Postoperative analgesia was assessed in the recovery room with numeric pain scale and the amount of drugs used within 4h after the blockade.

RESULTS

MEC90 was 0.241% [R(2): 0.978, confidence interval: 0.20-0.34%]. No patient, with successful block, reported pain after 4h.

CONCLUSION

This study demonstrated that ultrasound guided axillary brachial plexus block can be performed with the use of low concentration of local anesthetics, increasing the safety of the procedure. Further studies should be conducted to assess blockade duration at low concentrations.

0.5% levobupivacaine versus 0.5% ropivacaine: Are they different in ultrasound-guided sciatic block?

Context and Aims:

Little is known about onset and duration of sciatic block after 0.5% levobupivacaine (Levo) versus 0.5% ropivacaine (Ropi) for ultrasound-guided technique. We assessed these parameters in the ultrasound-guided block, to know for the practice.

Setting and Design:

A comparative randomized double-blind study was conducted in the University Hospital.

Materials and Methods:

Were included 35 adults of ASA I-II, scheduled for foot surgery, presenting clear imaging of their sciatic nerve at mid-thigh. A volume of 20 mL of either 0.5% Levo or 0.5% Ropi were injected around the sciatic nerve at mid-thigh using ultrasound guidance (out of the plane) followed by placement of a catheter to use, if necessary, for perioperative analgesia. A femoral single shot block was systematically performed to block the saphenous nerve. The onset times until complete foot block (primary outcome) and the sensory and motor block duration (secondary outcome) were assessed using Wilcoxon test. Values were expressed as medians (1^st-3^rd quartile).

Results:

Except for two delayed sciatic blocks in each group, the onset time otherwise was 35 min (20-60) in Ropi versus 40 min (30-60) in Levo, P = 0.5. Sensory block lasted longer in Levo, 17 h (14-27) compared with 15 h (10-17) in Ropi, P = 0.04. No significant between-group difference was found with motor block durations, 15 h (12-18) in Levo and 15 h (12-16) in Ropi, P = 0.3.

Conclusion:

No difference of onset times was found in ultrasound-guided sciatic block whether using Levo or Ropi. Levo induced a longer-lasting sensory block.

Pain Management for Elective Foot and Ankle Surgery: A Systematic Review of Randomized Controlled Trials

Pain after foot and ankle surgery can significantly affect the postoperative outcomes. We performed a systematic review of randomized controlled trials assessing postoperative pain after foot and ankle surgery, because the surgery will lead to moderate-to-severe postoperative pain, but the optimal pain therapy has been controversial. A systematic review of randomized controlled trials in English reporting on pain after foot and ankle surgery in adults published from January 1946 to February 2013 was performed. The primary outcome measure was the postoperative pain scores. The secondary outcome measures included supplemental analgesic requirements and other recovery outcomes. With 953 studies identified, 45 met the inclusion criteria. The approaches improving pain relief (reduced pain scores or opioid requirements) included peripheral nerve blocks, wound infiltration, intravenous dexamethasone, acetaminophen, nonsteroidal anti-inflammatory drugs, cyclooxygenase-2 selective inhibitors, and opioids. Wound instillation, intra-articular injection, and intravenous regional analgesia had variable analgesia. The lack of homogeneous study design precluded quantitative analyses. Optimal pain management strategies included locoregional analgesic techniques plus acetaminophen and nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 selective inhibitors, with opioids used for "rescue," and 1 intraoperative dose of parenteral dexamethasone. Popliteal sciatic nerve blocks would be appropriate when expecting severe postoperative pain (extensive surgical procedure), and ankle blocks and surgical incision infiltration would be appropriate when expecting moderate postoperative pain (less extensive and minimally invasive surgical procedures). Additional studies are needed to assess multimodal analgesia techniques.

Comparative evaluation of ropivacaine and lignocaine with ropivacaine, lignocaine and clonidine combination during peribulbar anaesthesia for phacoemulsification cataract surgery

Background:

Peribulbar block is the most common type of local anaesthesia administered for cataract surgery, and continuous efforts are on to find a long-acting local anaesthetic (LA) drug with the safest pharmacological profile.

Objectives:

A double-blind, prospective and randomized study was carried out in our institute to compare the anaesthetic effects of ropivacaine with the combination of ropivacaine and clonidine in administration of peribulbar block for phacoemulsification cataract surgery.

Methods:

A total of 200 patients of both sexes aged 50–80 years of American Society of Anaesthesiologists grade I and II, scheduled for phacoemulsification cataract surgery under monitored anaesthesia care, were enrolled for the study. Patients were assigned into two groups of 100 each; ropivacaine group (R) and ropivacaine clonidine group (RC). Group R received 10 mL of LA solution containing 5 mL of 2% lignocaine, 5 mL of 0.75% ropivacaine and 100 units of hyaluronidase while group RC received 8 mL of a similar mixture with the addition of clonidine 1 μg/kg and saline to make a total volume of 10 mL. Heart rate (HR), mean arterial pressure (MAP), pulse oximetry (SpO₂), respiratory rate (RR), intraocular pressure (IOP), eye muscle movement scores and quality of peribulbar block were observed and recorded throughout the study period at regular intervals. At the end of the research project, the data was compiled systematically and was subjected to statistical analysis using the ANOVA test with post hoc significance for continuous variables and Chi-square test for qualitative data. Value of P<0.05 was considered significant and P<0.0001 as highly significant.

Results:

Demographic characteristics, SpO₂ and RR were comparable in both the groups. Mean HR and MAP were also comparable after a significant variation in the first 2–3 min (P<0.05). Onset and establishment of sensory and motor blocks were significantly earlier in the RC group (P<0.05). IOP decreased significantly during the first 6–7 min in the RC group after the administration of the peribulbar block. Duration of analgesia was prolonged in the RC group (6.5±2.1 h) as compared with the R group (4.2±1.8 h). The side-effect profile revealed a higher incidence of nausea, vomiting, headache and dizziness in Group R, while a considerably higher incidence of dry mouth was observed in Group RC.

Conclusions:

Addition of clonidine to ropivacaine not only decreases the total volume of LA to be used but also augments early onset and prolonged offset of sensory analgesia as well as provides smooth operating conditions with a good sedation level as well by providing a wider safety margin of LA.

A comparison of sartorius versus quadriceps stimulation for femoral nerve block: a prospective randomized double-blind controlled trial

BACKGROUND

Femoral nerve block is widely used for regional anesthesia and analgesia in many lower limb operations. Peripheral nerve stimulation of the femoral nerve may elicit 1 of 2 responses: contraction of the sartorius muscle through stimulation of its muscular branch or contraction of the quadriceps muscle through stimulation of its respective muscular branches. Historically, a quadriceps response has been preferred. We hypothesized that the success of femoral nerve block using a sartorius muscle evoked motor response is equivalent to that using quadriceps muscle twitch response. This prospective randomized double-blind controlled trial compared sartorius or quadriceps muscle evoked motor response as the end point for stimulation for femoral nerve block.

METHODS

Seventy-two patients scheduled for primary unilateral total knee arthroplasty were randomly assigned to undergo femoral nerve block using either the sartorius or the quadriceps evoked muscle response as an end point of stimulation. Motor block of the femoral and sensory block of the femoral, saphenous, and lateral femoral cutaneous nerves were assessed. The primary outcome was the quality of motor and sensory block of the femoral nerve 30 minutes after injection of 20 mL of 0.5% ropivacaine. Secondary outcomes were duration of femoral nerve block, time required to perform the nerve block, total dose of hydromorphone patient-controlled analgesia, and postoperative pain by visual analog score 24 hours after block insertion. In addition, the spread of local anesthetic and the position of the needle in relation to the femoral nerve were assessed by means of ultrasonography.

RESULTS

There were no statistically significant differences in the proportion of patients with either complete alone or complete and partial block combined between quadriceps and sartorius groups 30 minutes after block insertion; femoral nerve (P = 0.49; P = 0.13), the saphenous nerve (P = 0.64; P = 0.21), or the lateral femoral cutaneous nerves (P = 0.2; P = 0.35). Patient-controlled analgesia hydromorphone consumption was significantly higher in the group that underwent sartorius muscle stimulation ([mean ± SD] 4.9 ± 3.6 mg [range, 0-13.2 mg] vs 3.1 ± 2.7 mg [range, 0-10.0 mg]; P = 0.024).

CONCLUSION

Our study demonstrated that using sartorius or quadriceps evoked muscle twitch as an end point of stimulation was associated with an equivalent degree of femoral nerve block.

Estimation and pharmacodynamic consequences of the minimum effective anesthetic volumes for median and ulnar nerve blocks: a randomized, double-blind, controlled comparison between ultrasound and nerve stimulation guidance

BACKGROUND

Nerve stimulation and ultrasound guidance are the most popular techniques for peripheral nerve blocks. However, the minimum effective anesthetic volume (MEAV) in selected nerves for both techniques and the consequences of decreasing the local anesthetic volume on the pharmacodynamic characteristics of nerve block remain unstudied. We designed a randomized, double-blind controlled comparison between neurostimulation and ultrasound guidance to estimate the MEAV of 1.5% mepivacaine and pharmacodynamics in median and ulnar nerve blocks.

METHODS

Patients scheduled for carpal tunnel release were randomized to ultrasound guidance (UG) or neurostimulation (NS) groups. A step-up/step-down study model (Dixon method) was used to determine the MEAV with nonprobability sequential dosing based on the outcome of the previous patient. The starting dose of 1.5% mepivacaine was 13 and 11 mL for median and ulnar nerves at the humeral canal. Block success/failure resulted in a decrease/increase of 2 mL. A blinded physician assessed sensory blockade at 2-minute intervals for 20 minutes. Block onset time and duration were noted.

RESULTS

The MEAV50 (SD) of the median nerve was lower in the UG group 2 (0.1) mL (95% confidence interval [CI] = [1, 96] to [2, 04]) than in the NS group 4 (3.8) mL (95% CI = [2, 4] to [5, 6]) (P = 0.017). There was no difference for the ulnar nerve between UG group 2 (0.1) mL (95% CI = [1, 96] to [2, 04]) and NS group 2.4 (0.6) mL (95% CI = [2, 1] to [2, 7]). The duration of sensory blockade was significantly correlated to local anesthetic volume, but onset time was not modified.

CONCLUSION

Ultrasound guidance selectively provided a 50% reduction in the MEAV of mepivacaine 1.5% for median nerve sensory blockade in comparison with neurostimulation. Decreasing the local anesthetic volume can decrease sensory block duration but not onset time.

Comparative evaluation of ultrasound-guided continuous infraclavicular brachial plexus block with stimulating catheter and traditional technique: a prospective-randomized trial

BACKGROUND

Secondary catheter failure has been reported in up to 40% of patients with continuous peripheral nerve blocks resulting in failure to provide pain relief after the initial block wears off. Introduction of stimulating catheters as well as ultrasound for regional anaesthesia has facilitated correct placement of catheter tip, closer to the plexus. This randomized study was conducted to compare the efficacy of continuous infraclavicular brachial plexus blocks using non-stimulating catheter, stimulating catheter and ultrasound-guided catheter placement with nerve stimulation assistance.

METHODS

Patients undergoing elective hand surgery were randomly allocated to receive continuous infraclavicular brachial plexus block using non-stimulating catheter [group traditional nerve stimulation (TR)], stimulating catheter [group stimulating catheter (ST)] or ultrasound-guided catheter placement with nerve stimulation assistance [group ultrasound guidance with nerve stimulation assistance (US)]. Motor and sensory blocks were assessed every 5 min and primary block success was determined at 30 min. After resolution of the primary block, threshold stimulating current and resulting response, spread of drug on re-injection as seen ultrasonographically and the capacity to re-establish block was documented. Complications and need for supplement was noted.

RESULTS

The primary block success was significantly higher in the US group [96% US, 58% ST, 59% TR (P=0.0005)]. Secondary catheter failure was significantly lower in the US group [9% US, 17% ST, 86% TR (P<0.0001)]. Axillary nerve was blocked more predictably in the US group (100% US, 79% ST, 50% TR (P=0.0003).

CONCLUSION

In this study, ultrasound guidance with nerve stimulation assistance significantly improved primary success and reduced secondary catheter failure in continuous infraclavicular brachial plexus blocks.

Similar analgesic effect after popliteal fossa nerve blockade with 0.375% and 0.75% bupivacaine

This study tested the hypothesis that increasing the concentration of bupivacaine from 0.375 to 0.75% would increase the duration of postoperative analgesia by 3 h. Seventy patients scheduled for hospital admission after foot or ankle surgery gave consent to enter this prospective randomized trial. Patients were randomly assigned to receive a popliteal fossa block (posterior approach) using 30 cc of either 0.375% or 0.75% bupivacaine, with epinephrine. Patients also received a neuraxial anesthetic and postoperative intravenous patient-controlled analgesia. Patient characteristics, duration of analgesia, pain scores, use of analgesic medications, and side effects of analgesic therapy were determined. Duration of analgesia was similar with both concentrations of bupivacaine (0.375% 14 +/- 8 h, 0.75% 13 +/- 6 h; mean +/- SD). Pain scores were the same for both groups on the first postoperative day (3 of 10 at rest, 5 with therapy). Analgesic use and side effects attributable to pain management did not differ between groups. In conclusion, postoperative analgesia was not affected by the concentration of bupivacaine used for the nerve block. There was no benefit to increasing the concentration of bupivacaine above 0.375% for single-injection popliteal fossa nerve blockade when performed for postoperative analgesia.

A Modified Mid-Femoral Approach to the Sciatic Nerve Block: A Correlation Between Evoked Motor Response and Sensory Block

BACKGROUND

The lateral sciatic mid-femoral block (LSMF), proved to be reliable, safe, and effective on both branches of the sciatic nerve with a single injection. However, we do not know which component of the sciatic nerve (the tibial [T] or the common peroneal [CP]) produces a better success rate when performing a LSMF with a single injection technique. In this prospective study we compared the success rate of the T motor response with the CP motor response.

METHODS

Ninety-five patients undergoing ankle or foot surgery were enrolled. Thirty milliliters of 0.475% ropivacaine was injected at the first evoked motor response, either T or CP, with a minimal intensity between 0.3 and 0.5 mA.

RESULTS

Seventy-two patients were included in group T and 23 in group CP. The block was considered a success when a complete sensory block of the sciatic nerve was obtained. The success rate was 90% (65) for the T response and 70% (16) for the CP response (P < 0.05). Time to perform the block (CP: 4.5 +/- 3 min vs T: 4.5 +/- 4 min; P = NS) as well as sensory and motor onset times were not significantly different between groups. No complications were observed in either group.

CONCLUSION

We conclude that the evoked motor response of the T branch is associated with a higher success rate than a CP response using the modified LSMF block.

Parasacral Sciatic Nerve Block: Does the Elicited Motor Response Predict the Success Rate?

BACKGROUND

In this prospective, randomized, double-blind study, we compared the tibial and the peroneal evoked motor response with regard to efficacy of sciatic nerve block using the parasacral approach.

METHODS

Twenty-six ASA I-III patients scheduled for elective lower limb surgery were randomized to receive a parasacral sciatic block, using a nerve stimulator technique seeking either a tibial (n = 14) or peroneal (n = 12) motor response. After the evoked motor response was obtained, a solution of 10 mL 2% lidocaine with epinephrine and 10 mL 0.75% ropivacaine (actual final concentration of epinephrine, 1/160,000) was slowly injected through the needle. Sensory and motor blocks were assessed every 5 min for 30 min by an anesthesiologist blinded to the elicited motor response. If the block was not complete 30 min after injection of the local anesthetics, it was considered as failed, and general anesthesia was supplemented.

RESULTS

Time to perform the block and level of minimal and maximal stimulation were not different between groups. The success rate of complete block was significantly higher in the tibial compared to the peroneal group (11 of 14 vs 2 of 12; P = 0.002).

CONCLUSIONS

Eliciting a tibial motor response predicts a higher success rate than eliciting a peroneal motor response with parasacral sciatic nerve block.

Ropivacaine versus lidocaine in digital nerve blocks: a prospective study

BACKGROUND

Ropivacaine is a relatively new long-acting amide local anesthetic. Since its introduction in 1996, it has been used for subcutaneous infiltration; epidural, intrathecal, and peripheral nerve block surgery; and postoperative analgesia. However, it has never been used for digital blocks. This prospective, randomized, double-blind study compares the digital block results following the administration of 2.5 ml of 0.75% ropivacaine solution and 2.5 ml of 2% lidocaine solution.

METHODS

From March of 1999 to March of 2001, 70 adult patients who underwent immediate reconstruction for traumatic injuries of the digits were prospectively randomized into two groups. Group A (n = 35) received 2.5 ml 0.75% ropivacaine and group B (n = 35) received 2.5 ml of 2% lidocaine for digital anesthesia. Onset time of anesthetic action, duration of anesthesia, time until first postoperative requirement for pain medication, and digital-brachial artery systolic blood pressure index were recorded and evaluated. Local vascular effects were observed visually.

RESULTS

No side effects were observed. Lidocaine had the quickest onset of anesthesia, with a mean time of 1.3 minutes (range, 1 to 2.7 minutes). Ropivacaine had a mean onset time of 4.5 minutes (range, 3.5 to 5.5 minutes). The mean duration of postoperative anesthesia for lidocaine was 2.4 hours (range, 1.4 to 4 hours), compared with 21.5 hours for ropivacaine and less requirement for analgesics during the first 24 postoperative hours (p < 0.05) (range, 19 to 23 hours). No significant difference was found between the digital-brachial artery systolic blood pressure index of group A compared with group B.

CONCLUSIONS

Ropivacaine can be used effectively as a local anesthetic for digital nerve blocks. It can be used for prolonged operations (>1.5 hours) without additional injections and can provide long-lasting postoperative analgesia.

Minimum effective anesthetic concentration (MEAC) for sciatic nerve block: subgluteus and popliteal approaches

BACKGROUND

We tested the hypothesis that using a subgluteus approach to the sciatic nerve requires a lower concentration of mepivacaine to obtain complete anesthesia as compared with the popliteal approach.

METHODS

With midazolam premedication (0.05 mg kg(-1) iv), 48 patients undergoing hallux valgus repair were randomly allocated to receive a sciatic nerve block using either a posterior popliteal (group Popliteal, n = 24) or subgluteus (group Subgluteus, n = 24) approach with 30 mL of local anesthetic injected after elicitation of plantar flexion of the foot with a current <or= 0.5 mA. A 20G catheter was inserted for 2-4 cm to supplement the block if required. The concentration of the injected solution was varied for consecutive patients using the up-and-down staircase method according to the response of the previous patient (initial concentration: 1%; up-and-down steps: 0.1%). Successful nerve block was defined as complete loss of pinprick sensation in both tibial and common peroneal nerve distributions with concomitant inability to perform plantar or dorsal flexion of the foot 30 min after injection.

RESULTS

The minimum effective anesthetic concentration of mepivacaine resulting in complete block of the sciatic nerve in 50% of cases (ED(50)) was 0.95% +/- 0.014% (95% confidence intervals [CI(95)]: 0.77%-1.12%) in group Subgluteus and 1.53% +/- 0.453% (CI(95): 0.96%-2.00%) in group Popliteal (P = 0.026). The ED(95) for adequate nerve block calculated with probit transformation and logistic regression analysis was 1.12% (CI(95): 0.71%-1.99%) in group Subgluteus and 1.98% (CI(95): 1.39%-2.31%) in group Popliteal.

CONCLUSION

A subgluteus approach to the sciatic nerve facilitates a reduction of the minimum effective concentration of local anesthetic required to produce an effective surgical block within 30 min after the injection as compared with the posterior popliteal approach.

Lateral trans-biceps popliteal block for elective foot and ankle surgery performed after induction of general anesthesia

BACKGROUND

The purpose of this study was to determine safety and efficacy of lateral transtendinous popliteal blocks performed after induction of general anesthesia for intraoperative and postoperative pain control in elective foot and ankle surgery.

METHODS

The charts of 475 consecutive patients were retrospectively reviewed. The technique was a lateral transtendinous popliteal block under nerve stimulator direction (described in the text). Patient records were retrospectively evaluated from the postanesthesia care unit, as well as at followup on postoperative day 1 and weeks 2, 6, and 12.

RESULTS

The block was complete in 398 patients (83.7%). An incomplete block was found in 77 patients (16.2 %). In the incomplete category, 21 patients (4.4%) had no pain but some motor function, 32 patients (6.5%) reported mild to moderate pain, and 24 patients (5.3%) had severe pain. The average block duration was 16.5 hours. There were no adverse effects documented in any patient at followup.

CONCLUSIONS

Lateral popliteal nerve block after induction of general anesthesia appears to be safe and effective for intraoperative and postoperative pain control in elective foot and ankle surgery.

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.

Anesthetic Efficacy of Different Ropivacaine Concentrations for Inferior Alveolar Nerve Block

This study was conducted on 72 American Society of Anesthesiologists class 1 patients scheduled for extraction of a mandibular third molar after inferior alveolar nerve block. Each patient was randomly administered one of the following ropivacaine concentrations: 0.75%, 0.5%, 0.375%, or 0.25% (18 patients per group). Onset of block (mean +/- SD) was rapid for both 0.75% (1.4 +/- 0.4 minutes) and 0.5% (1.7 +/- 0.5 minutes) ropivacaine but significantly slower for the 0.375% (4.2 +/- 2.5 minutes) and 0.25% (10.7 +/- 3.0 minutes) concentrations. Tooth extraction was performed successfully with the 0.5% and 0.75% concentrations, and supplemental injections were not required. Second injections, however, were required with 0.375% ropivacaine. Anesthesia was unsuccessful in 13 patients given 0.25% ropivacaine even after 3 injections. The mean durations of soft tissue anesthesia were 3.3 +/- 0.3 hours and 3.0 +/- 0.3 hours for the 0.75% and 0.5% concentrations, but significantly shorter with more dilute concentrations. The duration of analgesia showed a similar pattern, with the 0.75% and 0.5% concentrations producing prolonged analgesia of 6.0 +/- 0.4 hours and 5.6 +/- 0.4 hours. These results indicate that 0.5% and 0.75% concentrations were effective for intraoral nerve blockade, with both a rapid onset and prolonged duration of pain control.

What Is the Minimum Effective Volume of Local Anesthetic Required for Sciatic Nerve Blockade? A Prospective, Randomized Comparison Between a Popliteal and a Subgluteal Approach

For sciatic nerve blockade, no study has defined the optimal volume of local anesthetic required to block the nerve. The current, prospective, randomized investigation was designed to find a minimum volume of 1.5% mepivacaine required to block the sciatic nerve using the subgluteal and posterior popliteal approaches. A total of 56 patients undergoing foot surgery were randomly assigned to receive sciatic nerve block by means of a posterior subgluteal (group subgluteal, n = 28) or a posterior popliteal (group popliteal, n = 28) approaches. All blocks were performed with the use a nerve stimulator (stimulating frequency, 2 Hz, intensity 1.5-0.5 mA) and a perineural stimulating catheter. In all patients, plantar flexion of the foot was elicited at <0.5 mA, to maintain consistency among groups. The volume of local anesthetic used in each patient was based on the modified Dixon's up-and-down method. Complete anesthesia was defined as complete loss of pinprick sensation in the sciatic nerve distribution with concomitant inability to perform plantar or dorsal flexion of the foot 20 min after injection. The mean volume of local anesthetic required to block the sciatic nerve was 12 +/- 3 mL in the subgluteal group and 20 +/- 3 mL in the popliteal group (P < 0.05). The ED95 for adequate block of the sciatic nerve was 17 mL in the subgluteal group and 30 mL in the popliteal group. The authors conclude that a larger volume of local anesthetic is necessary to block the sciatic nerve at a more distal site (popliteal approach) as compared with a more proximal level (subgluteal approach).

Evaluation of femoral nerve blockade following inguinal paravascular block of Winnie: are there still lessons to be learnt?

Lower limb peripheral nerve blocks are used to provide surgical anaesthesia or postoperative analgesia. Anatomical texts imply that femoral and saphenous nerve blocks be evaluated by sensory testing of the skin overlying the anterior aspect of the thigh, and the medial aspect of the foot, respectively. We have mapped the distribution of anaesthesia in 25 adults following femoral nerve blockade, performed using the inguinal paravascular technique of Winnie. There was substantial interindividual variation in the area of anaesthesia. Only the skin overlying the middle third of the medial thigh was consistently blocked in 100% of patients. The distribution of anaesthesia conformed to anatomical text descriptions in 24% of cases. We conclude that demonstration of complete quadriceps paralysis confirms femoral nerve blockade. Failing that, sensory evaluation of a femoral nerve block should involve testing the skin of the middle third of the medial aspect of the thigh. The skin overlying the anteromedial aspect of the middle third of the leg should be evaluated for saphenous nerve block.

Does the Site of Injection Distal to the Greater Trochanter Make a Difference in Lateral Sciatic Nerve Blockade?

The two components of the sciatic nerve become more distant from one another in their course down the lower limb. This may have clinical implications if a small volume of local anesthetic is used with a single injection technique. In this prospective, randomized, double-blind study, we compared two different injection sites, 20 cm and 30 cm distal to the greater trochanter, in terms of onset time and success rate of sciatic nerve blockade after a single injection of 20 mL of 1.5% mepivacaine. Fifty patients undergoing foot surgery were randomly allocated to receive a lateral sciatic nerve blockade using one of 2 levels: 20 cm distal to the greater trochanter (group proximal; n = 25) and 30 cm distal to the greater trochanter (group distal; n = 25). Twenty milliliters of 1.5% mepivacaine was injected after a flexion plantar response was obtained at <0.5 mA. Time required for onset of sensory and motor blockade of the foot was recorded. Success rate was defined as complete sensory and motor blockade in all sciatic nerve distributions associated with a pain-free surgery. Onset of complete sensory and motor blockade was faster in group proximal (12 +/- 7 min and 15 +/- 8 min, respectively) compared with group distal (19 +/- 9 min and 23 +/- 9 min; P < 0.05). Group proximal also had a more frequent success rate compared with group distal (88% versus 56%, respectively; P < 0.05). It is concluded that in lateral sciatic nerve blockade, a more proximal approach to the sciatic nerve predicts a shorter onset time and more frequent success than a more distal injection site when a single injection and a small volume of local anesthetic is used.

IMPLICATIONS

In lateral sciatic nerve blockade, a more proximal approach to the sciatic nerve provides shorter onset times and more frequent success than a more distal injection site when a single injection of 20 mL of mepivacaine 1.5% is used.

Sciatic nerve block with 0.5% levobupivacaine, 0.75% levobupivacaine or 0.75% ropivacaine

BACKGROUND AND OBJECTIVE

This prospective, randomized, double-blind study was conducted to evaluate the onset time and duration of sciatic nerve block produced with 0.5% levobupivacaine, 0.75% levobupivacaine and 0.75% ropivacaine.

METHODS

Forty-five healthy patients undergoing hallux valgus repair were randomly allocated to receive sciatic nerve block with levobupivacaine 0.5% (n=15), levobupivacaine 0.75% (n=15) or ropivacaine 0.75% 20 mL (n=15). A femoral nerve block was also performed with mepivacaine 2% 15 mL to cover pain related to the thigh tourniquet. A blinded observer recorded the onset time and duration of sciatic nerve block.

RESULTS

The median (range) onset time was 5 (5-40) min with 0.75% levobupivacaine, 30 (5-60) min with 0.5% levobupivacaine and 20 (5-50) min with 0.75% ropivacaine (P = 0.02 and P = 0.12, respectively). Mean (25-75 percentiles) first request for pain medication occurred after 13 (11-14) h with 0.75% ropivacaine, 18 (15-19) h with 0.75% levobupivacaine and 16 (13-20) h with 0.5% levobupivacaine (P = 0.002 and P = 0.002, respectively). Rescue tramadol after surgery was required by three patients in the 0.75% levobupivacaine group, eight patients in the 0.5% levobupivacaine group and nine patients in the 0.75% ropivacaine group (P = 0.05).

CONCLUSIONS

We conclude that 0.75% levobupivacaine provides a shorter onset time than 0.5% levobupivacaine and a longer duration of postoperative analgesia than both 0.5% levobupivacaine and 0.75% ropivacaine with reduced need for rescue analgesia after surgery.

Peripheral Nerve Blocks and Continuous Catheter Techniques

Peripheral nerve blocks provide intense, site-specific analgesia and are associated with a lower incidence of side effects when compared with many other modalities of postoperative analgesia. Continuous catheter techniques further prolong these benefits. These advantages can facilitate a prompt recovery and discharge and achieve significant perioperative cost savings. This is of tremendous value in a modern health care system that stresses cost-effective use of resources and a continued shift toward shorter hospital stay as well as outpatient surgery.

Continuous lateral popliteal block with stimulating catheters

Foot surgery often induces severe postoperative pain. Sciatic nerve block is a good alternative for its treatment. We report two cases of continuous lateral popliteal sciatic nerve block using two different stimulating catheters. The lateral approach may offer some advantages. Stimulating catheters may be useful to verify correct catheter tip positioning. This technique seem to be easy to use and provided excellent pain relief.

Plantar Flexion Seems More Reliable than Dorsiflexion with Labat???s Sciatic Nerve Block: A Prospective, Randomized Comparison

Labat's classic approach to the sciatic nerve has not been able to show which motor response of the foot provides a more frequent rate of complete sensory and motor block. In this prospective, randomized, double-blind study, we compared plantar flexion with dorsiflexion with regard to onset time and efficacy of sciatic nerve block using the classic posterior approach. A total of 80 patients undergoing hallux valgus repair were randomly allocated to receive sciatic nerve block after evoked plantar flexion (n=40) or dorsiflexion (n=40). Twenty milliliters of 0.75% ropivacaine was injected after the motor response was elicited at <0.5 mA. Success rate was defined as complete sensory and motor block in all sciatic nerve distributions associated with a pain-free surgery. Time required for onset of sensory and motor block of the foot was recorded. Success was more frequent after elicited plantar flexion (87.5%) than dorsiflexion (55%; P <0.05). Onset of complete sensory and motor block of the foot was faster after elicited plantar flexion (10 +/- 10 min and 13 +/- 10 min, respectively) compared with dorsiflexion (20 +/- 11 min and 24 +/- 12 min; P <0.05). We conclude that plantar flexion of the foot predicts a shorter onset time and a more frequent success rate than dorsiflexion with Labat's classic posterior sciatic nerve block.

Anaesthetic Agents for Advanced Regional Anaesthesia

Interest in the use of regional anaesthesia, particularly peripheral nerve blocks (PNBs) and continuous PNBs, has increased in recent years. Accompanying this resurgence in interest has been the development of new local anaesthetics and additives designed to enhance block duration and quality. This manuscript provides a literature-based review on accepted uses of local anaesthetics and adjuncts for a variety of regional anaesthesia techniques. A brief review of local anaesthetic pharmacodynamics describes the action of these drugs in preventing nerve depolarisation, thus blocking nerve impulses. Toxic adverse effects of local anaesthetics, specifically CNS and cardiac manifestations of excessive local anaesthetic blood concentrations and the direct neurotoxic properties of local anaesthetics, are discussed generally and specifically for many commonly used local anaesthetics. Clinically useful ester and amide local anaesthetics are evaluated individually in terms of their physical properties and toxic potential. How these properties impact on the clinical uses of each local anaesthetic is explored. Particular emphasis is placed on the long-acting local anaesthetic toxic potential of racemic bupivacaine compared with levobupivacaine and ropivacaine, which are both levorotatory stereoisomers. Guidelines for using ropivacaine and mepivacaine, based on the authors' experience using advanced regional anaesthesia in a busy practice, is provided. Finally, epinephrine (adrenaline), clonidine and other local anaesthetic additives and their rationale for use is covered along with other future possibilities.

Is a double-injection technique superior to a single injection in posterior subgluteal sciatic nerve block?

BACKGROUND AND OBJECTIVES

Currently, no information is available on the effects of a double-injection technique on onset time and efficacy following subgluteal sciatic nerve blockade. We hypothesized that the success rate and time to onset of subgluteal nerve block following a double-injection technique would be superior to that after a single injection.

METHODS

Fifty ASA I or II patients undergoing foot or ankle surgery randomly received a single or double injection subgluteal sciatic nerve block. Group S (n=25) received a single injection of 30 ml of 0.75% ropivacaine to the sciatic nerve. In Group D (n = 25), 15 ml of the same solution was injected to each sciatic nerve component. Completion of sensory and motor blockade, and patient acceptance, was evaluated by a blinded anesthesiologist.

RESULTS

Complete sensory and motor blockade of the foot was achieved faster with the double injection (7.4 [5.9-8.8] min and 12.3 [10.4-14.2] min, respectively) than with the single-injection technique (12.5 [10.7-14.3] min and 18.8 [16.7-21.0] min, respectively) (P<0.001 and P<0.001, respectively). Success rate and acceptance were similar in both groups. Severe or moderate discomfort during the procedure was less frequent after a single injection (P = 0.013).

CONCLUSIONS

Both the single- and double-injection technique for subgluteal sciatic nerve blockade resulted in acceptable anesthesia in most patients. The double injection generated a faster onset of anesthesia than the single injection. However, the double-injection technique caused more patient discomfort during establishment of the nerve block.

The Effects of Three Different Approaches on the Onset Time of Sciatic Nerve Blocks with 0.75% Ropivacaine

We studied three different injection techniques of sciatic nerve block in terms of block onset time and efficacy with 0.75% ropivacaine. A total of 75 patients undergoing foot surgery were randomly allocated to receive sciatic nerve blockade by means of the classic posterior approach (group classic; n = 25), a modified subgluteus posterior approach (group subgluteus; n = 25), or a lateral popliteal approach (group popliteal; n = 25). All blocks were performed with the use of a nerve stimulator (stimulation frequency, 2 Hz; intensity, 2-0.5 mA) and 30 mL of 0.75% ropivacaine. Onset of nerve block was defined as complete loss of pinprick sensation in the sciatic nerve distribution with concomitant inability to perform plantar or dorsal flexion of the foot. In the three groups, an appropriate sciatic stimulation was elicited at <0.5 mA. The failure rate was similar in the three groups (group popliteal: 4% versus group classic: 4% versus group subgluteus: 8%). The onset of nerve block was slower in group popliteal (25 +/- 5 min) compared with group classic (16 +/- 4 min) and group subgluteus (17 +/- 4 min; P < 0.001). There was no significant difference in the onset of nerve block between group classic and group subgluteus. No differences in the degree of pain measured at the first postoperative administration of pain medication were observed among the three groups. We conclude that the three approaches resulted in clinically acceptable anesthesia in the distribution of the sciatic nerve. The subgluteus and classic posterior approaches generated a significantly faster onset of anesthesia than the lateral popliteal approach.

IMPLICATIONS

Comparing three different approaches to the sciatic nerve with 0.75% ropivacaine, the classic and subgluteal approaches exhibited a faster onset time of sensory and motor blockade than the lateral popliteal approach.

The anterior combined approach via a single skin injection site allows lower limb anesthesia in supine patients

PURPOSE

Lower limb anesthesia (LLA) requires the combination of, at least, three-in-one and sciatic nerve (SCN) blocks. Anterior approaches are easier to perform with minimal discomfort in supine patients, specially for traumatology. Feasibility of a single needle entry combined approach is reported.

CLINICAL FEATURES

The combined landmark was applied in 119 ASA I and II patients (32-68 yr) scheduled for surgery below the knee. Needle (nerve stimulation applied through a single 150-mm long b-bevelled insulated needle) was inserted at the midpoint between the two classical approaches. Thirty and 15 mL of 0.5% ropivacaine were injected close to the femoral and the SCN, respectively. During the following 45 min, the extent of sensory block and knee and ankle motor block were assessed. Landmarks were determined within 1.7 min (0.7-2.2 min). The entire procedure was performed within 4.2 min (2.9-7.1 min) from the determination of the landmark to the SCN infiltration. The three-in-one technique was successful in 89.9% while SCN was successful in 94.9%. Femoral and tibial nerves were always blocked. Blockade of the posterior cutaneous femoral nerve was observed in 78% of patients. The extent and the quality of the sensory block always allowed surgery. Additional iv sedation was needed in 32.6% of patients. Motor block (adapted Bromage's scale > 2) was observed in the femoral (98.3%), the obturator (84.8%), the tibial (97.4%) and the common peroneal (85.7%) nerve distributions. No important adverse effects were recorded.

CONCLUSION

The anterior combined approach via a single needle entry represents a technically easy and reliable technique to perform LLA in the supine patient.

Perioperative pain control

There are many options for perioperative pain control available to surgeons. Given these options, adequate levels of analgesia should be achieved and maintained in all surgical patients. Data suggest that analgesia may be improved by combining different analgesic approaches. To avoid high-dose requirements, dose-dependent adverse effects, and potential toxicity associated with reliance on one agent or technique, "balanced" or multimodal analgesic regimens have been advocated. A multimodal recovery program consists of three major components: (1) early mobilization, (2) complete perioperative analgesia, and (3) early oral nutrition. The goal of multimodal programs is to accelerate patient rehabilitation and reduce hospital stays. Balanced multimodal programs are the present and future of perioperative pain control and will enhance patient care.

Infragluteal-parabiceps sciatic nerve block: an evaluation of a novel approach using a single-injection technique

Clinical use of the sciatic nerve block (SNB) has been limited by technical difficulties in performing the block using standard approaches, substantial patient discomfort during the procedure, or the need for two injections to block the tibial and peroneal nerves. In this report, we describe a single-injection method for SNB using an infragluteal-parabiceps approach, where the nerve is located along the lateral border of the biceps femoris muscle. SNB was performed in the prone or lateral decubitus position. The needle was positioned (average depth, 56 +/- 15 mm) to the point where plantar flexion (53%) or inversion (45%) of the ipsilateral foot was obtained at < or =0.4 mA. Levobupivacaine 0.625% with epinephrine (1:200:000) was administered at a dose of 0.4 mL/kg. The procedure was completed in 6 +/- 3 min. Discomfort during block placement was treated with fentanyl 50-100 microg in 24% of patients. Complete sensory loss and motor paralysis occurred in 92% of subjects at a median time of 10 (range, 5-25) min after injection. Compared with plantar flexion, foot inversion was associated with a more frequent incidence (86% versus 100%), and shorter latency for both sensory loss and motor paralysis of the peroneal, tibial, and sural nerves. There were no immediate or delayed complications. We conclude that the infragluteal-parabiceps approach to SNB is reliable, efficient, safe, and well tolerated by patients.

IMPLICATIONS

Sciatic nerve block using the infragluteal-parabiceps approach produces sensory loss and motor paralysis after a single 0.4 mL/kg injection of levobupivacaine 0.625% with epinephrine (1:200,000) in >90% of patients. The approach is reliable, uses consistent soft-tissue landmarks, is not typically painful, and does not produce significant complications.

A double-blinded, randomized comparison of either 0.5% levobupivacaine or 0.5% ropivacaine for sciatic nerve block

To compare intraoperative and postoperative clinical properties of levobupivacaine and ropivacaine for sciatic nerve block, 50 ASA physical status I and II patients undergoing hallux valgus repair received a femoral nerve block with 15 mL of 2% mepivacaine. They were then randomly allocated in a double-blinded fashion to receive a sciatic nerve block with either 0.5% levobupivacaine (n = 25) or 0.5% ropivacaine (n = 25). An independent blinded observer evaluated the onset time of surgical anesthesia as well as the quality of the surgical block and postoperative analgesia. The median (range) onset time of surgical block at the sciatic nerve distribution was 30 min (5-60 min) with levobupivacaine and 15 min (5-60 min) with ropivacaine (P = 0.63). Four patients (two patients in each group) received a supplementary ankle block by the surgeon just before the beginning of surgery. All four patients also received IV fentanyl supplementation, but in three of them, propofol infusion was required to complete surgery (two in the Levobupivacaine group [8%] and one in the Ropivacaine group [4%]; P = 0.99). In six patients of the Levobupivacaine group (24%) and five patients of the Ropivacaine group (20%), IV fentanyl supplementation was required to complete surgery (P = 0.99). No differences in the time to recovery of sensory and motor function were observed between the two groups, whereas median (range) duration of postoperative analgesia was 16 h (8-24 h) with levobupivacaine and 16 h (8-24 h) with ropivacaine (P = 0.83). We conclude that 0.5% levobupivacaine and 0.5% ropivacaine provide comparable surgical anesthesia and postoperative analgesia.

IMPLICATIONS

No studies have compared the clinical properties of levobupivacaine with those of ropivacaine when providing sciatic nerve block for hallux valgus repair. Results from this prospective, randomized, double-blinded study demonstrate that 20 mL of either 0.5% levobupivacaine or 0.5% ropivacaine provide comparable surgical block with prolonged postoperative analgesia.