Ropivacaine 0.2% and Lidocaine 0.5% for Intravenous Regional Anesthesia in Outpatient Surgery

Background: A longer-acting local anesthetic agent, such as ropivacaine, may offer advantages over lidocaine for intravenous regional anesthesia. The objectives of this study were to evaluate whether the findings of volunteer investigations with intravenous regional anesthesia with ropivacaine (which have shown prolonged analgesia after release of the tourniquet) translates into improved pain control after surgery.

Methods: With Human Investigation Committee approval and a double-blind study design, 20 healthy patients with American Society of Anesthesiologists physical status I or II classification who were scheduled to undergo forearm and hand surgery were randomly assigned to administration of 40 ml of either 0.2% ropivacaine or 0.5% lidocaine for intravenous regional anesthesia. Evidence of central nervous system side effects, such as lightheadedness, tinnitus, and metallic taste, as well as cardiac arrhythmias, were evaluated and treated (if necessary) after local anesthetic administration, before and during surgery, and after release of the tourniquet until discharge from the postanesthesia care unit. Regression of sensory anesthesia in the nerve distributions of the forearm and hand was recorded. Verbal numerical pain scores were monitored and quantified until the patients were discharged to home from the postanesthesia care unit. Patient pain scores, side effect profiles, time to first oral intake, and total amount of oral analgesics were recorded 24 h postoperatively.

Results: Intravenous regional anesthesia with 0.2% ropivacaine and 0.5% lidocaine provided equivalent levels of surgical anesthesia. After release of the tourniquet, the first evidence for return of sensation in the distribution of the five peripheral nerves occurred later in the ropivacaine group (median, 20 min; range, 15-40 min) than in the lidocaine group (median, 1 min; range, 1-25 min). Verbal numerical pain scores were significantly lower at the time of admission, whereas during the remainder of the postanesthesia care unit stay and later at home, the difference in verbal numerical pain scores between the two groups was no longer statistically significant.     

Comparison of ropivacaine 0.2% and 0.25% with lidocaine 0.5% for intravenous regional anesthesia

Study ObjectiveTo compare the anesthetic effects of two different concentrations and doses of ropivacaine (0.2% and 0.25%) with those of a conventional dose of lidocaine 0.5%.DesignProspective, randomized, double-blinded, clinical investigation.SettingLarge metropolitan university hospital.Patients66 adult ASA physical status I and II patients undergoing forearm and hand surgery.InterventionsPatients were randomly allocated to three groups to receive intravenous regional anesthesia (IVRA). Study groups were: ropivacaine 0.2% (Group I, n = 22), ropivacaine 0.25% (Group II, n = 22), and lidocaine 0.5% (Group III, n = 22).MeasurementsTourniquet tolerance times and regression of sensory analgesia were noted. Verbal numerical pain scores (VNS), cumulative analgesic consumption, and side effects were recorded during surgery and postanesthesia care unit (PACU). Time to first pain medication intake and number of patients receiving analgesics in the PACU were recorded.Main ResultsAdditional tolerance times for the distal tourniquet were significantly higher in the ropivacaine 0.25% group than the other two groups. Regression of sensory anesthesia was fastest in the lidocaine group. During the PACU stay, VNSs were significantly lower in the first 20 minutes in the ropivacaine groups than the lidocaine group. Time to first intake of pain medication in the PACU was soonest in the lidocaine group. The number of patients given analgesics in the PACU was highest in the lidocaine group. The number of patients taking > two tablets of tramadol was significantly lowest in the ropivacaine 0.25% group. No serious side effects were observed in any study group.ConclusionLonger tolerance times for the distal tourniquet, prolonged analgesia after tourniquet release, and lower analgesic requirements postoperatively make ropivacaine 0.2% and 0.25% an alternative to lidocaine for IVRA.     

Bilateral Intravenous Regional Anesthesia: A New Method to Test Additives to Local Anesthetic Solutions

Background: Ketorolac, when added to lidocaine, has been shown to reduce early tourniquet pain during intravenous regional anesthesia (IVRA) in patients. Although the effectiveness of ropivacaine 0.2% for IVRA is equal to that of lidocaine 0.5% but significantly reduces central nervous system side effects after release of the tourniquet, it provides no advantage with regard to tourniquet tolerance times. Simultaneous bilateral IVRA with ropivacaine 0.2% was used to test the hypothesis that ketorolac modifies tourniquet tolerance and to test whether drug combinations can be evaluated in one study session.

Methods: Ten healthy, unsedated volunteers received 30 ml of ropivacaine 0.2% in each upper arm with 2 ml of normal saline in one arm and 30 mg of ketorolac in the contralateral arm for IVRA. Both proximal tourniquets remained inflated for 30 min, followed by inflation of the distal tourniquets and release of the proximal ones. Verbal numeric scores for tourniquet pain were recorded for both extremities. Central nervous system side effects were graded after release of each distal tourniquet.

Results: There was no difference between the two upper extremities with regard to surgical anesthesia and tourniquet tolerance. Total tourniquet tolerance was a median of 58.5 min (range, 45-90 min) and 60.5 min (39-79 min) in the normal saline and ketorolac groups, respectively. After release of the distal tourniquets, 5 of 10 volunteers experienced mild dizziness.     

Comparison of ropivacaine 0.2% and lidocaine 0.5% for intravenous regional anesthesia in volunteers.

A longer acting local anesthetic such as ropivacaine may offer advantages over lidocaine for IV regional anesthesia (IVRA). The objective of this investigation was to determine whether the use of ropivacaine improves the quality and duration of IVRA. In a randomized, double cross-over design, 10 volunteers received lidocaine 0.5% or ropivacaine 0.2% for IVRA of the upper extremity on two separate days with a standard double-cuff technique. Sensation to pinprick, response to tetanic stimuli, and tourniquet pain were assessed on a 0-10 verbal numeric score scale at 5-min intervals throughout the period of tourniquet inflation. Motor function was evaluated by grip strength. After release of the second (distal) cuff, pinprick sensation, motor strength, and systemic side effects were evaluated at 3, 10, and 30 min. No significant differences were observed for onset times of anesthesia and times to proximal (38 +/- 3 and 36 +/- 3 min) or distal (34 +/- 13 and 36 +/- 13 min) tourniquet release after the administration of ropivacaine and lidocaine, respectively. However, postdeflation hypoalgesia and motor blockade were prolonged with ropivacaine, and postdeflation light-headedness, tinnitus, and drowsiness were more prominent with lidocaine. We conclude that ropivacaine may be an alternative to lidocaine for IVRA. It may result in prolonged analgesia and fewer side effects after tourniquet release. IMPLICATIONS: In this study, volunteers received lidocaine 0.5% or ropivacaine 0.2% for IV regional anesthesia on two study days. Ropivacaine and lidocaine provided similar surgical conditions. However, after release of the distal tourniquet, prolonged sensory blockade and fewer central nervous system side effects were observed with ropivacaine.     

Bilateral intravenous regional anesthesia: a new method to test additives to local anesthetic solutions

BACKGROUND: Ketorolac, when added to lidocaine, has been shown to reduce early tourniquet pain during intravenous regional anesthesia (i.v.RA) in patients. Although the effectiveness of ropivacaine 0.2% for i.v.RA is equal to that of lidocaine 0.5% but significantly reduces central nervous system side effects after release of the tourniquet, it provides no advantage with regard to tourniquet tolerance times. Simultaneous bilateral i.v.RA with ropivacaine 0.2% was used to test the hypothesis that ketorolac modifies tourniquet tolerance and to test whether drug combinations can be evaluated in one study session. METHODS: Ten healthy, unsedated volunteers received 30 ml of ropivacaine 0.2% in each upper arm with 2 ml of normal saline in one arm and 30 mg of ketorolac in the contralateral arm for i.v.RA. Both proximal tourniquets remained inflated for 30 min, followed by inflation of the distal tourniquets and release of the proximal ones. Verbal numeric scores for tourniquet pain were recorded for both extremities. Central nervous system side effects were graded after release of each distal tourniquet. RESULTS: There was no difference between the two upper extremities with regard to surgical anesthesia and tourniquet tolerance. Total tourniquet tolerance was a median of 58.5 min (range, 45-90 min) and 60.5 min (39-79 min) in the normal saline and ketorolac groups, respectively. After release of the distal tourniquets, 5 of 10 volunteers experienced mild dizziness. CONCLUSIONS: The addition of ketorolac to ropivacaine does not improve tourniquet tolerance. Minimal central nervous system side effects after tourniquet release suggest that a total of 60 ml ropivacaine 0.2% for bilateral i.v.RA is a useful model for comparison of i.v.RA drug combinations.     

Central nervous system side effects are less important afteriv regional anesthesia with ropivacaine 0.2% compared to lidocaine 0.5% in volunteers

PURPOSE: Following release of a double tourniquet for intravenous regional anesthesia (IVRA), ropivacaine was shown to have a longer duration of action and less central nervous system (CNS) side effects than lidocaine. This study examines the correlation of CNS side effects to plasma levels of lidocaine 0.5% and ropivacaine 0.2% when injected intravenously for IVRA. METHODS: In a double-blind, cross-over study, ten volunteers received IVRA with 40 mL ropivacaine 0.2% or lidocaine 0.5% at least four days apart. Both cuffs of a double-cuff tourniquet remained inflated until they could no longer be tolerated. The incidence, duration and intensity of CNS side effects were recorded at three, ten, and 30 min after tourniquet release and correlated with simultaneous venous blood samples. RESULTS: There was a lower incidence of CNS side effects with ropivacaine (6/10 volunteers) when compared to lidocaine (10/10 volunteers). There was also less duration of these side effects (mean +/- SD, 5.1 +/- 5.2 min vs 11.7 +/- 6.7 min). Measured total plasma levels were highest at ten minutes with ropivacaine 0.2% (1.2 +/- 0.3 microg.mL(-1)) and at three minutes with lidocaine 0.5% (1.7 +/- 0.6 microg.mL(-1)). Peak CNS symptoms correlated with measured venous plasma levels for lidocaine, but occurred earlier with ropivacaine. CONCLUSIONS: We observed a lower incidence of CNS side effects with ropivacaine as compared to lidocaine. Although ropivacaine's greater lipid solubility should, theoretically, lead to more CNS side effects, this was, likely, offset by slower release from tissues and lesser percentage of unbound (free) drug.     

Levobupivacaine 0.125% and lidocaine 0.5% for intravenous regional anesthesia in volunteers

BACKGROUND: Levobupivacaine, a long acting, amino-amide, local anesthetic, may offer advantages over lidocaine for intravenous regional anesthesia (IVRA). The objective of this investigation was to compare levobupivacaine to lidocaine for IVRA. METHODS: After institutional review board approval and informed consent, eight unpremedicated male American Society of Anesthesiologists (ASA) I-II volunteers received 40 ml of levobupivacaine 0.125% or lidocaine 0.5% for IVRA on separate days. Onset and regression of sensory anesthesia by pinprick, transcutaneous electrical stimulation (TES), and of motor function were tested before, during, and after release of the tourniquet. Central nervous system and cardiac side effects were evaluated after local anesthetic administration and tourniquet release. The tourniquet remained inflated for 30-45 min. RESULTS: Intravenous regional anesthesia with either agent provided surgical anesthesia. Sensory anesthesia to pinprick (lateral antebrachial cutaneous nerve) was faster with lidocaine at median 1.5 min. versus 12.5 min with levobupivacaine. Loss of sensation to TES occurred at median 22.5 and 27.5 min for lidocaine and levobupivacaine, respectively. Loss of motor function occurred earlier after lidocaine administration. After release of the tourniquet, return of sensation to TES, pinprick (ulnar nerve), and return of motor function occurred later with levobupivacaine at median 25, 15, and 21.25 versus 10, 4.5, and 10 min with lidocaine. Central nervous system side effects were absent in volunteers given levobupivacaine, but five of eight volunteers given lidocaine experienced mild side effects. No cardiac events were noted. CONCLUSIONS: Levobupivacaine 0.125% may be an alternative to lidocaine 0.5% for IVRA. Longer lasting analgesia after release of the tourniquet may be caused by a more profound and prolonged tissue binding effect of levobupivacaine.     

Comparison of anesthetic effect between 0.375% ropivacaine versus 0.5% lidocaine in forearm intravenous regional anesthesia

BACKGROUND AND OBJECTIVES: Ropivacaine was shown to provide superior postblock analgesia to lidocaine in intravenous regional anesthesia (IVRA) in voluntary studies. The objective of this study was to compare the anesthesia efficacy, postblock analgesia, and local anesthetic-related side effects between ropivacaine and lidocaine when forearm IVRA was used. METHODS: Fifty-one patients undergoing outpatient hand surgery were randomized to receive forearm IVRA with either ropivacaine 0.375% or lidocaine 0.5%. The volume was 0.4 mL/kg up to 25 mL. Sensation to pinching by forceps and motor function was assessed at 5-minute intervals up to 15 minutes. After tourniquet deflation, verbal pain rating score (VRPS) at 15-minute intervals for the first 2 hours and time for first analgesic in the first 24 hours were evaluated. RESULTS: Eleven patients were excluded from the study with 20 patients remaining in each group. Onset time of anesthesia (6.5 +/- 2.9 minutes v 8.0 +/- 4.1 minutes for lidocaine and ropivacaine groups, respectively) and motor block were similar. In the postoperative period, VPRS was significantly lower in the ropivacaine group in the first 60 minutes (median, 0; P <.05) with significantly more patients in the ropivacaine group pain free (VPRS, 0) up to the first 90 minutes (P >.05). More patients in lidocaine group requested analgesic in the first 2 hours postblock, and only patients in the lidocaine group required supplemental IV morphine in the recovery room. Twenty-four hour analgesic consumption was the same. No local anesthetic-related side effects were observed. CONCLUSIONS: We conclude that 0.375% ropivacaine provides effective anesthesia and superior postoperative analgesia compared with 0.5% lidocaine when forearm IVRA is used.     

Comparison of ropivacaine and lidocaine for intravenous regional anesthesia in volunteers: a preliminary study on anesthetic efficacy and blood level.

BACKGROUND: Ropivacaine may be useful for intravenous regional anesthesia, but its anesthetic effectiveness and toxicity have not been evaluated. METHODS: Two doses of ropivacaine (1.2 and 1.8 mg/kg) and one dose of lidocaine (3 mg/kg) were compared for intravenous regional anesthesia in 15 volunteers. An arm tourniquet was inflated for 30 min after injection and then deflated in two cycles. Sensory block was measured by response to touch, cold, pinprick, and transcutaneous electric stimulation, and motor function was measured by hand grip strength and muscle power. Median, ulnar, radial, and musculocutaneous nerve functions were tested before local anesthetic injection and then at 5-min intervals until blocks resolved. The plasma ropivacaine and lidocaine concentrations were determined from arterial and venous blood samples drawn from the unanesthetized arm. RESULTS: Sensory and motor blocks were complete within 25 min and 30 min, respectively, in all three treatment groups. However, recovery of sensory and motor block after tourniquet release was slowest in the high-dose ropivacaine group. Anesthesia to pinprick and transcutaneous electric stimulation was sustained in all the volunteers in the high-dose ropivacaine group for 55 min and 85 min, respectively, whereas complete recovery was observed in the lidocaine group (P = 0.008) and partial recovery in the low-dose ropivacaine group (P < 0.05) during the same period. Motor block also was sustained in the high-dose ropivacaine group for 70 min, which was significantly longer than in the lidocaine group (P < 0.05). All volunteers (five of five) given lidocaine and one volunteer given high-dose ropivacaine reported light-headedness and hearing disturbance during tourniquet release when the arterial plasma lidocaine and ropivacaine concentrations were 4.7+/-2.1 microg/ml (mean) and 2.7 micro/ml, respectively. CONCLUSION: Compared with lidocaine, intravenous regional anesthesia with ropivacaine appears to be comparable but has longer-lasting residual anesthesia.     

Levobupivacaine 0.125% and Lidocaine 0.5% for Intravenous Regional Anesthesia in Volunteers

Background: Levobupivacaine, a long acting, amino-amide, local anesthetic, may offer advantages over lidocaine for intravenous regional anesthesia (IVRA). The objective of this investigation was to compare levobupivacaine to lidocaine for IVRA.

Methods: After institutional review board approval and informed consent, eight unpremedicated male American Society of Anesthesiologists (ASA) I-II volunteers received 40 ml of levobupivacaine 0.125% or lidocaine 0.5% for IVRA on separate days. Onset and regression of sensory anesthesia by pinprick, transcutaneous electrical stimulation (TES), and of motor function were tested before, during, and after release of the tourniquet. Central nervous system and cardiac side effects were evaluated after local anesthetic administration and tourniquet release. The tourniquet remained inflated for 30-45 min.

Results: Intravenous regional anesthesia with either agent provided surgical anesthesia. Sensory anesthesia to pinprick (lateral antebrachial cutaneous nerve) was faster with lidocaine at median 1.5 min. versus 12.5 min with levobupivacaine. Loss of sensation to TES occurred at median 22.5 and 27.5 min for lidocaine and levobupivacaine, respectively. Loss of motor function occurred earlier after lidocaine administration. After release of the tourniquet, return of sensation to TES, pinprick (ulnar nerve), and return of motor function occurred later with levobupivacaine at median 25, 15, and 21.25 versus 10, 4.5, and 10 min with lidocaine. Central nervous system side effects were absent in volunteers given levobupivacaine, but five of eight volunteers given lidocaine experienced mild side effects. No cardiac events were noted.     

0.5% versus 1.0% 2-chloroprocaine for intravenous regional anesthesia: a prospective, randomized, double-blind trial

In this randomized prospective double-blind study we tested the hypothesis that compared with 40 mL chloroprocaine 0.5%, 40 mL chloroprocaine 1% results in an earlier onset to analgesia duration and improves distal tourniquet tolerance in 150 patients undergoing forearm surgery under IV regional anesthesia using a double-cuff technique, switching from the proximal to the distal cuff was performed if pain scores increased above 4 of 10. Switching to the distal cuff resulted in pain scores below 4 in 69% of patients in the 0.5% group and in 88% of patients in the 1% group (P = 0.047). In addition, both groups differed in the sustained effect on distal tourniquet pain (P = 0.020). Time between injection and onset to analgesia duration was 13 +/- 1 min in the 0.5% group and 11 +/- 1 min in the 1% group (P = 0.0006). On release of the tourniquet, signs of systemic local anesthetic toxicity occurred in 6 patients of the 0.5% group and 28 of the 1% group (P < 0.0001). We conclude that chloroprocaine 1% resulted in an earlier onset of analgesia and improved distal tourniquet tolerance. However, these beneficial effects must be weighed against a fourfold increase in side effects. IMPLICATIONS: Compared to a standard dose of 40 mL 0.5% chloroprocaine, 40 mL 1% chloroprocaine resulted in an earlier onset of analgesia duration and improved distal tourniquet tolerance during IV regional anesthesia. These beneficial effects must be weighed against a fourfold increase in signs of systemic local anesthetic toxicity.     

Comparison of Ropivacaine and Lidocaine for Intravenous Regional Anesthesia in Volunteers: A Preliminary Study on Anesthetic Efficacy and Blood Level

Background: Ropivacaine may be useful for intravenous regional anesthesia, but its anesthetic effectiveness and toxicity have not been evaluated.

Methods: Two doses of ropivacaine (1.2 and 1.8 mg/kg) and one dose of lidocaine (3 mg/kg) were compared for intravenous regional anesthesia in 15 volunteers. An arm tourniquet was inflated for 30 min after injection and then deflated in two cycles. Sensory block was measured by response to touch, cold, pinprick, and transcutaneous electric stimulation, and motor function was measured by hand grip strength and muscle power. Median, ulnar, radial, and musculocutaneous nerve functions were tested before local anesthetic injection and then at 5-min intervals until blocks resolved. The plasma ropivacaine and lidocaine concentrations were determined from arterial and venous blood samples drawn from the unanesthetized arm.

Results: Sensory and motor blocks were complete within 25 min and 30 min, respectively, in all three treatment groups. However, recovery of sensory and motor block after tourniquet release was slowest in the high-dose ropivacaine group. Anesthesia to pinprick and transcutaneous electric stimulation was sustained in all the volunteers in the high-dose ropivacaine group for 55 min and 85 min, respectively, whereas complete recovery was observed in the lidocaine group (P = 0.008) and partial recovery in the low-dose ropivacaine group (P < 0.05) during the same period. Motor block also was sustained in the high-dose ropivacaine group for 70 min, which was significantly longer than in the lidocaine group (P < 0.05). All volunteers (five of five) given lidocaine and one volunteer given high-dose ropivacaine reported light-headedness and hearing disturbance during tourniquet release when the arterial plasma lidocaine and ropivacaine concentrations were 4.7 +/- 2.1 [micro sign]g/ml (mean) and 2.7 [micro sign]/ml, respectively.     

Adding clonidine to lidocaine for intravenous regional anesthesia prevents tourniquet pain.

Tourniquet pain often complicates the use of the pneumatic tourniquet during surgical procedures performed under IV regional anesthesia. Clonidine-containing local anesthetic solutions have better analgesic properties than plain solutions when used for spinal, epidural, or peripheral blocks. We tested the hypothesis that the addition of clonidine may improve the quality of IV regional anesthesia, especially tourniquet tolerance. Forty patients were allocated randomly in a double-blinded, randomized study to receive 40 mL of 0.5% lidocaine and either 1 mL of isotonic saline or clonidine (150 microg). A double-cuffed tourniquet was kept inflated until patients complained of pain, leading to release of the distal cuff. Pain at the tourniquet site, at the surgical site, and in the distal part of the arm was rated on a visual analog scale (VAS) and a verbal rating scale (VRS) every 15 min during tourniquet placement and every 15 min for 1 h after tourniquet deflation. Motor blockade, sedation, arterial pressure, and heart rate were also recorded. VAS and VRS scores were significantly lower in the clonidine group 30 and 45 min after tourniquet inflation. The tolerance for the distal tourniquet was also significantly longer in the clonidine group (median [range]: 22 [10-40] vs 10 [5-20] min; P < 0.05); motor blockade was comparable between the two groups. Pain was not different in the two groups after tourniquet release. The clonidine group experienced a higher degree of sedation. We conclude that clonidine improves tourniquet tolerance when added to a local anesthetic solution. IMPLICATIONS: A 150-microg dose of clonidine added to lidocaine improved tourniquet tolerance during IV regional anesthesia.     

Intravenous regional anesthesia using lidocaine and clonidine.

BACKGROUND: Clonidine has been added to local anesthetic regimens for various peripheral nerve blocks, resulting in prolonged anesthesia and analgesia. The authors postulated that using clonidine as a component of intravenous regional anesthesia (IVRA) would enhance postoperative analgesia. METHODS: Forty-five patients undergoing ambulatory hand surgery received IVRA with lidocaine, 0.5%, and were assigned randomly and blindly to three groups. The control group received intravenous saline, the intravenous clonidine group received 1 microg/kg clonidine intravenously, and the IVRA clonidine group received 1 microg/kg clonidine as part of the IVRA solution. After their operations, the patients' pain and sedation scores and analgesic use were recorded. RESULTS: Patients in the IVRA clonidine group had a significantly longer period of subjective comfort when they required no analgesics (median [range]) for 460 min (215-1,440 min), compared with 115 min (14-390 min) for the control group and 125 min (17-295 min) for the intravenous clonidine group (P<0.0001). The patients who received IVRA with clonidine reported significantly lower pain scores 1 and 2 h after tourniquet deflation compared with the other groups, and they required no fentanyl in the postanesthesia care unit. They also required fewer analgesic tablets (325 mg acetaminophen with 30 mg codeine) in the first 24 h (2+/-1, mean +/- SD) compared with the other two groups, 5+/-1 tablets (control) and 4+/-2 tablets (intravenous clonidine) (P<0.0001). No significant postoperative sedation, hypotension, or bradycardia developed in any of the patients. CONCLUSION: The addition of 1 microg/kg clonidine to lidocaine, 0.5%, for IVRA in patients undergoing ambulatory hand surgery improves postoperative analgesia without causing significant side effects during the first postoperative day.     

An evaluation of the analgesic efficacy of intravenous regional anesthesia with lidocaine and ketorolac using a forearm versus upper arm tourniquet

Intravenous regional anesthesia (IVRA) using a forearm tourniquet may be a potentially safer technique compared with using an upper arm tourniquet. Ketorolac is a useful adjuvant to lidocaine for IVRA. In this study, we assessed the analgesic efficacy of administering IVRA lidocaine and ketorolac with either a forearm or upper arm tourniquet for outpatient hand surgery. Upper arm IVRA was established using 40 mL of a solution containing 200 mg of lidocaine and ketorolac 20 mg (0.5 mg/mL). Forearm IVRA was established using 20 mL of a solution containing 100 mg of lidocaine and ketorolac 10 mg (0.5 mg/mL). Onset and duration of sensory block as well as postoperative pain and analgesic use were recorded. The patients who received forearm IVRA had a significantly longer period during which they required no analgesics (701 +/- 133 min) compared with 624 +/- 80 min for the upper arm IVRA ketorolac patients (P = 0.032). Onset of sensory block was similar between the two groups; however, recovery of sensation was significantly longer in the Forearm IVRA (22 +/- 5 min) group compared with the Upper Arm IVRA (13 +/- 3 min) group (P < 0.05). There were no differences in postoperative analgesic use or pain scores between the two groups. We conclude that forearm IVRA with lidocaine and ketorolac provides safe and effective perioperative analgesia for patients undergoing ambulatory hand surgery. This technique results in a longer duration of sensory block and prolonged postoperative analgesia compared with upper arm IVRA while using one-half the doses of both lidocaine and ketorolac. IMPLICATIONS: Forearm tourniquet intravenous regional anesthesia (IVRA) with 50% less lidocaine and ketorolac provides for both a longer duration of sensory block and prolonged postoperative analgesia compared with upper arm IVRA.     

Adding dexmedetomidine to lidocaine for intravenous regional anesthesia

Dexmedetomidine is approximately 8 times more selective toward the alpha-2-adrenoceptors than clonidine. It decreases anesthetic requirements by up to 90% and induces analgesia in patients. We designed this study to evaluate the effect of dexmedetomidine when added to lidocaine in IV regional anesthesia (IVRA). We investigated onset and duration of sensory and motor blocks, the quality of the anesthesia, intraoperative-postoperative hemodynamic variables, and intraoperative-postoperative pain and sedation. Thirty patients undergoing hand surgery were randomly assigned to 2 groups to receive IVRA. They received 40 mL of 0.5% lidocaine and either 1 mL of isotonic saline (group L, n = 15) or 0.5 microg/kg dexmedetomidine (group LD, n = 15). Sensory and motor block onset and recovery times and anesthesia quality were noted. Before and after the tourniquet application at 5, 10, 15, 20, and 40 min, hemodynamic variables, tourniquet pain and sedation, and analgesic use were recorded. After the tourniquet deflation, at 30 min, and 2, 4, 6, 12, and 24 h, hemodynamic variables, pain and sedation values, time to first analgesic requirement, analgesic use, and side effects were noted. Shortened sensory and motor block onset times, prolonged sensory and motor block recovery times, prolonged tolerance for the tourniquet, and improved quality of anesthesia were found in group LD. Visual analog scale scores were significantly less in group LD in the intraoperative period and 30 min, and 2, 4, and 6 h after tourniquet release. Intra-postoperative analgesic requirements were significantly less in group LD. Time to first analgesic requirements was significantly longer in group LD in the postoperative period. We conclude that the addition of 0.5 microg/kg dexmedetomidine to lidocaine for IVRA improves quality of anesthesia and perioperative analgesia without causing side effects. IMPLICATIONS: This study was designed to evaluate the effect of dexmedetomidine when added to lidocaine for IV regional anesthesia. This is the first clinical study demonstrating that the addition of 0.5 microg/kg dexmedetomidine to lidocaine for IV regional anesthesia improves quality of anesthesia and intraoperative-postoperative analgesia without causing side effects.     

Intravenous Regional Anesthesia Using Lidocaine and Clonidine

Background: Clonidine has been added to local anesthetic regimens for various peripheral nerve blocks, resulting in prolonged anesthesia and analgesia. The authors postulated that using clonidine as a component of intravenous regional anesthesia (IVRA) would enhance postoperative analgesia.

Methods: Forty-five patients undergoing ambulatory hand surgery received IVRA with lidocaine, 0.5%, and were assigned randomly and blindly to three groups. The control group received intravenous saline, the intravenous clonidine group received 1 [mu]g/kg clonidine intravenously, and the IVRA clonidine group received 1 [mu]g/kg clonidine as part of the IVRA solution. After their operations, the patients' pain and sedation scores and analgesic use were recorded.

Results: Patients in the IVRA clonidine group had a significantly longer period of subjective comfort when they required no analgesics (median [range]) for 460 min (215-1,440 min), compared with 115 min (14-390 min) for the control group and 125 min (17-295 min) for the intravenous clonidine group (P < 0.0001). The patients who received IVRA with clonidine reported significantly lower pain scores 1 and 2 h after tourniquet deflation compared with the other groups, and they required no fentanyl in the postanesthesia care unit. They also required fewer analgesic tablets (325 mg acetaminophen with 30 mg codeine) in the first 24 h (2 +/- 1, mean +/- SD) compared with the other two groups, 5 +/- 1 tablets (control) and 4 +/- 2 tablets (intravenous clonidine) (P < 0.0001). No significant postoperative sedation, hypotension, or bradycardia developed in any of the patients.     

Compartment syndrome following intravenous regional anesthesia

PURPOSE: To present two cases of upper extremity compartment syndrome following intravenous regional anesthesia. CLINICAL FEATURES: Case 1: A 57-yr-old man presented for surgical release of a left-hand Dupuytren's contracture. The procedure was performed under iv regional anesthesia with 360 mg lidocaine and sedation with 150 microg fentanyl and 1.5 mg midazolam. Tourniquet time was 107 min at a pressure of 260 mmHg using three different tourniquet sites. Within minutes of tourniquet release, increased forearm muscle tension, hand anesthesia, pallor, and limited motor function developed. Serum CK and myoglobin levels rose. Myoglobinuria was present. Several fasciotomies and aggressive fluid therapy were performed. Patient made almost full recovery. Case 2: A 73-yr-old woman with controlled hypertension had Dupuytren fasciotomy of her right hand under iv regional anesthesia with 200 mg lidocaine and sedation using 75 microg fentanyl and 1.5 mg midazolam. Tourniquet time was 64 min at a pressure of 250 mmHg using three different tourniquet sites. The patient complained of pain at the iv site during injection of local anesthetic, third tourniquet inflation and after deflation of tourniquet. Thirty minutes after arrival in PACU, her fingers were bluish. She complained of pain and swelling of the forearm. Under general anesthesia, fasciectomy was performed. Myoglobin and CPK levels rose. CPK MB was high but troponin was negative. Three days later she developed pulmonary embolism. She was heparinized and subsequently discharged home. She recovered completely. CONCLUSION: Compartment syndrome may have a rapid and severe onset. Etiology of our cases is still not established. We postulate that increased tissue pressure may be the cause. The anesthesiologists must be aware of compartment syndrome during regional anesthesia.     

Forearm rescue cuff improves tourniquet tolerance during intravenous regional anesthesia

BACKGROUND AND OBJECTIVES: Tourniquet pain during intravenous regional anesthesia (IVRA) of the upper limb is common and can limit tourniquet inflation time. We hypothesize that a forearm rescue cuff is better tolerated than the traditional rescue cuff of a double-cuff tourniquet. METHODS: After Institutional Review Board (IRB) approval and informed consent, 10 healthy unmedicated volunteers took part in a prospective, randomized, cross-over study. Following inflation of the proximal tourniquet cuff on the upper arm, a standardized IVRA with 0.5% lidocaine, 0.6 mL/kg was administered. When the volunteer complained of tourniquet pain, or at 30 minutes, the initial cuff was changed to a rescue cuff. During session A, the rescue cuff was the traditional distal cuff of the double-cuff tourniquet. During session B, a single forearm cuff was used. When the volunteer experienced the same level of tourniquet pain, the rescue cuff was deflated and the study session ended. The tourniquet time for the rescue cuff, the visual analog scale (VAS) pain score, and the incidence and duration of side effects were recorded. RESULTS: The forearm rescue cuff was tolerated significantly longer than the arm rescue cuff (49 +/- 15 v 29 +/- 11 minutes, 95% confidence interval [CI] 7 to 32 minutes, P 相似文献   

Quantitative comparison of leakage under the tourniquet in forearm versus conventional intravenous regional anesthesia

We compared the quantitative leakage between forearm and conventional IV regional anesthesia (IVRA). Forearm IVRA remains unpopular because of the theoretical risk of local anesthetic leakage through the interosseous vessels. IVRA was simulated on the forearm or arm during two separate, randomized sessions using a double tourniquet in 14 volunteers. A radiolabeled substance, DISIDA (99m Tc-disofenin) with a structure similar to lidocaine, was injected instead of local anesthetic. Volumes of 0.4 mL/kg (maximum 25 mL), were used for forearm IVRA and 0.6 mL/kg (maximum 45 mL) for conventional IVRA. A gamma camera recorded radioactivity levels in the limb distal to the tourniquet every 30 s while the tourniquet was inflated (25 min) and for 20 min postdeflation. The leakage of radiolabeled substance during inflation was similar in both groups, 6%+/-12% (mean +/- SD) from the forearm and 10%+/-20% from the upper arm. After deflation, mean loss of radioactivity was higher in conventional IVRA, 70%+/-7% vs 57%+/-11% and 82%+/-5% vs 69%+/-11% at 3 and 20 min, respectively (P < 0.001). We conclude that forearm IVRA results in tourniquet leakage comparable to conventional IVRA and is potentially safer because the required dose of local anesthetic is smaller. IMPLICATIONS: Using a tourniquet on the forearm for IV regional anesthesia does not increase the risk of drug leakage. This is potentially a safer technique compared with conventional IV regional anesthesia because a much smaller dose of local anesthetic is required.