Hyperbaric Spinal Ropivacaine: A Comparison to Bupivacaine in Volunteers

Background: Ropivacaine is a newly introduced local anesthetic that may be a useful alternative to low-dose bupivacaine for outpatient spinal anesthesia. However, its relative potency to bupivacaine and its dose-response characteristics are unknown. This double-blind, randomized, crossover study was designed to determine relative potencies of low-dose hyperbaric spinal ropivacaine and bupivacaine and to assess the suitability of spinal ropivacaine for outpatient anesthesia.

Methods: Eighteen healthy volunteers were randomized into three equal groups to receive one spinal administration with bupivacaine and a second with ropivacaine, of equal-milligram doses (4, 8, or 12 mg) of 0.25% drug with 5% dextrose. The duration of blockade was assessed with (1) pinprick, (2) transcutaneous electrical stimulation, (3) tolerance to high tourniquet, (4) electromyography and isometric force dynamometry, and (5) achievement of discharge criteria. Differences between ropivacaine and bupivacaine were assessed with linear and multiple regression. P < 0.05 was considered significant.

Results: Ropivacaine and bupivacaine provided dose-dependent prolongation of sensory and motor block and time until achievement of discharge criteria (R2 ranges from 0.33-0.99; P values from < 0.001 through 0.01). Spinal anesthesia with ropivacaine was significantly different from bupivacaine and was approximately half as potent for all criteria studied. A high incidence of back pain (28%; P = 0.098) was noted after intrathecal ropivacaine was given.     

Hyperbaric spinal ropivacaine for cesarean delivery: a comparison to hyperbaric bupivacaine.

We evaluated the clinical efficacy and safety of spinal anesthesia with 0.5% hyperbaric ropivacaine compared with 0.5% hyperbaric bupivacaine for elective cesarean delivery. Sixty healthy, full-term parturients were randomly assigned to receive either 12 mg of 0.5% hyperbaric bupivacaine or 18 mg of 0.5% hyperbaric ropivacaine intrathecally. There were no significant differences in demographic or surgical variables or neonatal outcomes between groups. Onset time of sensory block to T10 or to peak level was later in the Ropivacaine group (P < 0.05). The median (range) peak level of analgesia was T3 (T1-5) in the Bupivacaine group and T3 (T1-4) in the Ropivacaine group. Time for sensory block to recede to T10 did not differ between groups. Duration of sensory block was shorter in the Ropivacaine group (188.5 +/- 28.2 min vs 162.5 +/- 20.2 min; P < 0.05). Complete motor block of the lower extremities was obtained in all patients. Ropivacaine also produced a shorter duration of motor blockade than bupivacaine (113.7 +/- 18.6 min vs 158.7 +/- 31.2 min; P < 0.000). The intraoperative quality of anesthesia was excellent and similar in both groups. Side effects did not differ between groups. Eighteen milligrams of 0.5% hyperbaric ropivacaine provided effective spinal anesthesia with shorter duration of sensory and motor block, compared with 12 mg of 0.5% hyperbaric bupivacaine when administered for cesarean delivery Implications: Eighteen milligrams of 0.5% hyperbaric ropivacaine provided effective spinal anesthesia with shorter duration of sensory and motor block, compared with 12mg of 0.5% hyperbaric bupivacaine when administered for cesarean delivery.     

Hyperbaric spinal levobupivacaine: a comparison to racemic bupivacaine in volunteers.

Levobupivacaine is the isolated S-enantiomer of bupivacaine and may be a favorable alternative to spinal bupivacaine. However, its clinical efficacy relative to bupivacaine and its dose-response characteristics, in spinal anesthesia, must first be known. This double-blinded, randomized, cross-over study was designed to compare the clinical efficacy of hyperbaric levobupivacaine and bupivacaine for spinal anesthesia. Eighteen healthy volunteers were randomized into three equal groups to receive two spinal anesthetics, one with bupivacaine and the other with levobupivacaine, of equal-milligram doses (4, 8, or 12 mg). We assessed blockade quality and duration with pinprick, transcutaneous electrical stimulation, thigh tourniquet, abdominal and quadriceps muscle strength, modified Bromage scale, and time until achievement of discharge criteria. Sensory and motor block were similar between the same doses of levobupivacaine and bupivacaine (P > 0.56 to 0.86). For example, in the 12-mg groups of levobupivacaine versus bupivacaine, mean duration of tolerance to transcutaneous electrical stimulation at T12 was 100 min for both. The duration of motor block at the quadriceps was 71 versus 73 min, and time until achievement of discharge criteria was 164 min for both. Hyperbaric spinal levobupivacaine has equivalent clinical efficacy to racemic bupivacaine for spinal anesthesia in doses from 4 to 12 mg. IMPLICATIONS: Hyperbaric spinal levobupivacaine has equivalent clinical efficacy to hyperbaric spinal bupivacaine over the 4-12-mg ranges.     

A comparison of intrathecal plain solutions containing ropivacaine 20 or 15 mg versus bupivacaine 10 mg

Ropivacaine, which blocks sensory nerve fibers more readily than motor fibers, is considered to be less potent than bupivacaine. Our hypothesis was that, when used in spinal anesthesia for day surgery, ropivacaine 15 and 20 mg would provide faster motor recovery than bupivacaine 10 mg. This prospective, randomized, double-blinded study included 90 ambulatory lower-extremity surgery patients who received 2 mL of ropivacaine 1%, ropivacaine 0.75%, or bupivacaine 0.5%. Motor block was tested with the Bromage scale, and sensory block was tested with pinprick. Ropivacaine 15 mg provided faster recovery of motor block (150 min) than did bupivacaine 10 mg (210 min; P = 0.005), but the median duration of sensory block at T10 (140 min) did not differ significantly from that with bupivacaine 10 mg (140 min). The median duration of sensory block at T10 was significantly longer with ropivacaine 20 mg (170 min) than with bupivacaine 10 mg (140 min; P = 0.005), but the median recovery from motor block (210 min) did not differ significantly. We conclude that the duration of sensory block of ropivacaine was two thirds and the duration of motor block was half when compared with bupivacaine, with calculations based on the duration-per-milligram of the local anesthetic.     

Determination of the full dose-response relation of intrathecal bupivacaine, levobupivacaine, and ropivacaine, combined with sufentanil, for labor analgesia

BACKGROUND: Ropivacaine and levobupivacaine are local anesthetics that produce less motor block and greater sensory-motor separation when compared with equal milligram doses of bupivacaine. Although minimum local analgesic concentration studies suggested that they are less potent than bupivacaine, full dose-response studies have not been performed. The current trial describes the dose-response relation of levobupivacaine, ropivacaine, and bupivacaine, combined with sufentanil, when used for intrathecal labor analgesia. METHODS: Four hundred fifty term parturients in active labor were included in this double-blind, randomized trial. Combined spinal-epidural anesthesia was performed, and ropivacaine, levobupivacaine, or bupivacaine was intrathecally administered in a dose of 1.0, 1.5, 2.0, 2.5, 3.0, or 3.5 mg, always combined with 1.5 microg sufentanil. Patients were considered responders to spinal analgesia if the visual analog scale score for pain was less than 25 mm within 15 min and the visual analog scale score remained less than 25 mm for 45 min. Patient demographics, obstetric data, maternal side effects, and fetal and neonatal well-being were noted. Group-specific dose-response curves were constructed using a probit regression model. RESULTS: The ED95 of bupivacaine was 3.3 mg (95% confidence interval, 2.9-4.1). The ED95s of ropivacaine and levobupivacaine were 4.8 mg (95% confidence interval, 4.0-6.7) and 5.0 mg (95% confidence interval, 4.1-7.0), respectively. Racemic bupivacaine was significantly more potent than ropivacaine (P=0.0027) and levobupivacaine (P=0.0006). Ropivacaine and levobupivacaine were of similar potency (P=0.91). CONCLUSIONS: This full dose-response study suggests that ropivacaine and levobupivacaine are of similar potency, whereas bupivacaine is more potent than both other drugs.     

Determination of the Full Dose-Response Relation of Intrathecal Bupivacaine, Levobupivacaine, and Ropivacaine, Combined with Sufentanil, for Labor Analgesia

Background: Ropivacaine and levobupivacaine are local anesthetics that produce less motor block and greater sensory-motor separation when compared with equal milligram doses of bupivacaine. Although minimum local analgesic concentration studies suggested that they are less potent than bupivacaine, full dose-response studies have not been performed. The current trial describes the dose-response relation of levobupivacaine, ropivacaine, and bupivacaine, combined with sufentanil, when used for intrathecal labor analgesia.

Methods: Four hundred fifty term parturients in active labor were included in this double-blind, randomized trial. Combined spinal-epidural anesthesia was performed, and ropivacaine, levobupivacaine, or bupivacaine was intrathecally administered in a dose of 1.0, 1.5, 2.0, 2.5, 3.0, or 3.5 mg, always combined with 1.5 [mu]g sufentanil. Patients were considered responders to spinal analgesia if the visual analog scale score for pain was less than 25 mm within 15 min and the visual analog scale score remained less than 25 mm for 45 min. Patient demographics, obstetric data, maternal side effects, and fetal and neonatal well-being were noted. Group-specific dose-response curves were constructed using a probit regression model.

Results: The ED95 of bupivacaine was 3.3 mg (95% confidence interval, 2.9-4.1). The ED95s of ropivacaine and levobupivacaine were 4.8 mg (95% confidence interval, 4.0-6.7) and 5.0 mg (95% confidence interval, 4.1-7.0), respectively. Racemic bupivacaine was significantly more potent than ropivacaine (P = 0.0027) and levobupivacaine (P = 0.0006). Ropivacaine and levobupivacaine were of similar potency (P = 0.91).     

罗哌卡因和布比卡因用于老龄患者下肢手术麻醉中的对比研究

【摘要】 目的 探讨在老龄患者下肢手术的麻醉中等效剂量罗哌卡因和布比卡因麻醉效果以及对手术的影响。方法 选择拟行股骨颈骨折手术老龄患者50例,随机分为罗哌卡因组(R组)和布比卡因组(B组)。两组均采用腰硬联合麻醉(CSEA),分别给予0.5%罗哌卡因2.5 mL和0.5%布比卡因2.5 mL注入蛛网膜下腔。术中麻醉效应不足时硬膜外给予2%利多卡因。术中监测呼吸循环状况,评估麻醉效果,并观察不良反应。结果 两组麻醉效果,最高阻滞平面及不良反应的差异无统计学意义(P>0.05),B组的血压下降更加明显(P<0.05),R组下肢感觉阻滞起效更慢,持续时间更短(P<0.05),下肢运动阻滞程度显著低于B组(P<0.05)。结论 罗哌卡因和布比卡因在老龄患者下肢手术的腰硬联合麻醉都有效,罗哌卡因对循环系统影响更小,运动神经阻滞更轻且恢复迅速,更适合老龄患者下肢手术麻醉中的应用。     

Hyperbaric spinal for elective Cesarean section--ropivacaine vs bupivacaine

PURPOSE: To compare hyperbaric spinal ropivacaine to hyperbaric spinal bupivacaine for elective cesarean delivery in a prospective, randomized, double blinded study. METHODS: With the University Ethics Committee approval, 66 parturients for elective cesarean deliveries received either 15 mg of hyperbaric ropivacaine (N = 33) or 11.25 mg of hyperbaric bupivacaine (N - 33) with 0.1 mg of preservative-free morphine and 0.01 mg fentanyl. The sensory and motor blockades were assessed at 3, 6, and 9 min after injection. The APGAR scores, umbilical cord gases, intra-operative side effects and the total duration of motor and sensory blockade, were recorded. RESULTS: The two groups had similar demographics, and similar times for sensory block to T6 and Bromage score 3 motor blockade. The median levels of sensory blockade were T3 and T2 for the ropivacaine and bupivacaine groups respectively. Duration of sensory block was shorter in the ropivacaine group (174 +/- 24 min vs 217 +/- 46 min; P < 0.001). Duration of motor block was shorter in the ropivacaine group (85 +/- 26 vs 159 +/- 56 min; P < 0.001). The obstetricians rated intra-operative anesthesia as excellent in both groups. None of neonates had Apgar scores less than 7. There was no difference in cord gases between the two groups. Side effects did not differ between the two groups. The ropivacaine patients expressed significantly higher satisfaction levels (P < 0.016). DISCUSSION: 15 mg of hyperbaric ropivacaine with 0.1 mg morphine and 0.01 mg fentanyl provided excellent anesthesia for cesarean delivery. The advantages of hyperbaric ropivacaine consist of faster regression of the block and higher patient satisfaction.     

A prospective, randomized, double-blind comparison of unilateral spinal anesthesia with hyperbaric bupivacaine, ropivacaine, or levobupivacaine for inguinal herniorrhaphy

In 60 patients undergoing inguinal hernia repair, we compared the clinical profile of unilateral spinal anesthesia produced with either 8 mg of hyperbaric bupivacaine 0.5% (n = 20), 8 mg of hyperbaric levobupivacaine 0.5% (n = 20), or 12 mg of hyperbaric ropivacaine 0.5% (n = 20). The study drug was injected slowly through a 25-gauge Whitacre directional needle and patients maintained the lateral decubitus position for 15 min. The onset time and intraoperative efficacy were similar in the three groups. The maximal level of sensory block on the operative and nonoperative sides was T6 (T12-5) and L3 (/[no sensory level detectable]-T4) with bupivacaine, T8 (T12-5) and L3 (/-T3) with levobupivacaine, T5 (T10-2) and T11 (/-T3) with ropivacaine (P = 0.11, P = 0.23, respectively). Complete regression of spinal anesthesia occurred after 166 +/- 42 min with ropivacaine, 210 +/- 63 min with levobupivacaine, and 190 +/- 51 min with bupivacaine (P = 0.03 and P = 0.04, respectively); however, no differences were observed in time for home discharge (329 +/- 89 min with bupivacaine, 261 +/- 112 min with levobupivacaine, and 332 +/- 57 min with ropivacaine [P = 0.28]). We conclude that 8 mg of levobupivacaine or 12 mg of ropivacaine are acceptable alternatives to 8 mg of bupivacaine when limiting spinal block at the operative side for inguinal hernia repair.     

Spinal ropivacaine or bupivacaine for cesarean delivery: a prospective, randomized, double-blind comparison

BACKGROUND AND OBJECTIVES: The aim of this prospective, randomized, double-blinded study was to compare clinical efficacy and safety of ropivacaine and bupivacaine given intrathecally in combination with morphine for cesarean delivery. METHODS: With ethical committee approval and a written informed consent, 60 women scheduled for elective cesarean delivery under spinal anesthesia were randomly allocated to receive spinal anesthesia with either 20 mg ropivacaine plus 0.1 mg morphine (n = 30) or 15 mg bupivacaine plus 0.1 mg morphine (n = 30). Profile of spinal block (onset and recovery times), cardiovascular effects, and quality of postoperative analgesia (patient-controlled morphine) were recorded by a blinded observer. RESULTS: The onset time of motor block was shorter after bupivacaine (8 +/- 2 min) than after ropivacaine (12 +/- 5 minutes) (P <.05), whereas duration of both sensory and motor blocks was longer after bupivacaine (139 +/- 37 minutes and 254 +/- 76 minutes) than after ropivacaine (112 +/- 27 minutes and 211 +/- 48 minutes) (P <.01 and P <.05, respectively). No differences in intraoperative quality of anesthesia and clinical hypotension requiring ephedrine administration were observed between the two groups. Postoperative analgesia was similarly effective in both groups; however median consumption of patient-controlled morphine during the first 24 hours after surgery was higher in patients of group Ropivacaine (5 mg; range, 0 to 18 mg) than in patients of group Bupivacaine (2 mg; range, 0 to 7 mg) (P <.01). CONCLUSION: Spinal anesthesia produced with 20 mg ropivacaine plus 0.1 mg morphine is as effective and safe as that provided by 15 mg bupivacaine plus 0.1 mg morphine, with an earlier recovery of sensory and motor functions after surgery.     

Intrathecal low-dose bupivacaine versus lidocaine for in vitro fertilization procedures

BACKGROUND AND OBJECTIVES: Recent controversy with the use of intrathecal lidocaine has prompted the search for suitable ambulatory surgery alternatives. The purpose of our study was to evaluate the clinical utility of intrathecal low-dose bupivacaine for outpatient transvaginal oocyte retrieval. METHODS: Forty women enrolled and completed our prospective, randomized, double-blinded study of intrathecal hyperbaric bupivacaine 3.75 mg (0.5 mL of 0.75%) with fentanyl 25 microg versus hyperbaric lidocaine 30 mg (2.0 mL of 1.5%) with fentanyl 25 microg. Onset and level of sensory and motor block; time to ambulation, urination, and discharge; and intra- and postoperative complications (hypotension, pruritus, nausea, emesis, postdural puncture headache, post spinal pain syndrome [PSPS]) were recorded. Data were evaluated using analysis of variance, chi-squared, and Mann-Whitney U tests, with P <.05 considered significant. RESULTS: In demographically similar groups, no differences were noted in times to onset and recovery of sensory and motor function, or complications; however, times to voiding and discharge were significantly longer in the bupivacaine group. Four and 2 patients in the bupivacaine and lidocaine groups, respectively, required intravenous analgesic supplementation. One patient in the lidocaine group experienced PSPS. CONCLUSIONS: Although prolongation to voiding and discharge was observed, intrathecal hyperbaric bupivacaine 3.75 mg with fentanyl 25 microg is a viable anesthetic for oocyte retrieval.     

Intrathecal hyperbaric bupivacaine 3 mg + fentanyl 10 microg for outpatient knee arthroscopy with tourniquet

BACKGROUND: Combination of local anesthetic and opioid enables the use of less spinal anesthetic and increases the success of anesthesia. Intrathecal opioid does not prolong motor recovery and thus should not delay discharge home. We hypothesized that 3 mg of hyperbaric bupivacaine with 10 microg of fentanyl permits fast-tracking or shorter stay in post anesthesia care unit (PACU), and earlier discharge home, compared with 4 mg of hyperbaric bupivacaine. METHODS: In this double-blind study, 100 outpatients undergoing knee arthroscopy received randomly either 4 mg of bupivacaine (B4) or 3 mg of bupivacaine + 10 microg fentanyl (B3F) intrathecally. The volume of 0.8 ml was injected at the L2/3 interspace over a 2-min period. A lateral decubitus position was maintained for 10 min. The sensory block was recorded by using thermal stimuli, and motor block was assessed according to a modified Bromage scale. Fast-tracking criteria were complete recovery of motor block, sensory block Th12 or lower and stable vital signs. RESULTS: One block (1%) failed. Motor recovery was faster in the B3F group: 60% of the patients recovered in 80 min or less compared with 28% in group B4 (P = 0.002). The PACU-time was shorter: 36 (10-103) vs. 55 (10-140) min, respectively (P = 0.005). Seventeen (B3F) vs. nine patients (B4) could bypass PACU (NS). Time to discharge home was similar in both groups. In the B3F group, 75% of the patients developed pruritus. CONCLUSION: Both solutions produced reliable spinal anesthesia for outpatient knee arthroscopy. The PACU-time was shorter in the bupivacaine-fentanyl group, but both groups reached home-readiness equally.     

Spinal 2-chloroprocaine: a comparison with small-dose bupivacaine in volunteers

Ambulatory surgery continues to increase nationwide. Because spinal lidocaine is associated with transient neurologic symptoms, many clinicians have switched to small-dose bupivacaine for outpatient spinal anesthesia. However, bupivacaine often produces inadequate surgical anesthesia and has an unpredictable duration. Preservative-free 2-chloroprocaine (2-CP) has reemerged as an alternative for outpatient spinal anesthesia. We designed this double-blind, randomized, crossover, volunteer study to compare 40 mg of 2-CP with small-dose (7.5 mg) bupivacaine with measures of pinprick anesthesia, motor strength, tolerance to tourniquet and electrical stimulation, and simulated discharge criteria. Peak block height (2-CP average T7 [range T3-10]; bupivacaine average T9 [range T4-L1]), regression to L1 (2-CP 64 +/- 10 versus bupivacaine 87 +/- 41 min), and tourniquet tolerance (2-CP 52 +/- 11 versus bupivacaine 60 +/- 27 min) did not differ between drugs (P = 0.15, 0.12, and 0.40, respectively). However, time to simulated discharge (including time to complete block regression, ambulation, and spontaneous voiding) was significantly longer with bupivacaine (2-CP 113 +/- 14, bupivacaine 191 +/- 30 min, P = 0.0009). No subjects reported transient neurologic symptoms or other side effects. We conclude that spinal 2-CP provides adequate duration and density of block for ambulatory surgical procedures, and has significantly faster resolution of block and return to ambulation compared with 7.5 mg of bupivacaine.     

A low dose of plain or hyperbaric bupivacaine for unilateral spinal anesthesia

BACKGROUND AND OBJECTIVES: Unilateral spinal anesthesia may be advantageous, especially in the outpatient setting. A low dose of anesthetic solution, pencil-point needle, low speed of intrathecal injection, and a lateral position have been reported to facilitate the production of unilateral distribution of spinal anesthesia. We compared the effects of plain and hyperbaric bupivacaine in attempting to obtain a unilateral spinal anesthesia for patients undergoing outpatient knee arthroscopy. METHODS: Sixty patients were randomly allocated to 2 groups to receive either 1.2 mL (6 mg) of plain 0.5% bupivacaine (group 1; n = 30) or 1.2 mL (6 mg) of hyperbaric 0.5% bupivacaine in 8% glucose (group 2; n = 30). Drugs were administered at the L2-3 interspace with the patient in the lateral position. Patients remained in this position for 20 minutes before being turned supine for the operation. Spinal block was assessed by pinprick and modified Bromage scale and compared between the operated and nonoperated sides. RESULTS: There was a significant difference between the operated and nonoperated side in both groups at all testing times, but a more unilateral spinal block was achieved with hyperbaric bupivacaine. Unilateral motor and sensory block was observed in 25 patients in group 2 (83%) and in 11 patients in group 1 (37%) (P <.01). The hemodynamic changes were minimal, since hypotension occurred only in 5.0% and bradycardia in 1.7% of all patients. CONCLUSION: In conclusion, the spinal anesthesia in both groups are suitable alternatives for adult outpatient knee arthroscopies, but hyperbaric bupivacaine provides us with a more unilateral spinal block.     

Median effective local anesthetic doses of plain bupivacaine and ropivacaine for spinal anesthesia administered via a spinal catheter for brachytherapy of the lower abdomen

BACKGROUND AND OBJECTIVES: Continuous spinal anesthesia via a spinal catheter allows adjusting the duration and extent of anesthesia to surgical needs, maintenance of hemodynamic stability, and good postoperative analgesia. This study was designed to determine the median effective local anesthetic dose of plain ropivacaine and bupivacaine administered intrathecally for interstitial brachytherapy of the lower abdomen using the Dixon up-and-down method. METHODS: Forty patients were randomly allocated to receive either intrathecal bupivacaine 5 mg per mL or ropivacaine 10 mg per mL via a 24-gauge spinal catheter at the L3-4 interspace. The initial dose was 10 mg of bupivacaine or 20 mg of ropivacaine; the dosing intervals were 1 mg and 2 mg, respectively. Doses for subsequent patients were determined by the response of the previous patient in that group. Successful anesthesia was defined as a loss of sensation to a cold stimulus at the T6 level and full motor blockade within 20 minutes after administration of the local anesthetic. RESULTS: The median effective local anesthetic dose for intrathecal bupivacaine was 11.2 mg (95% confidence interval [CI], 10.3-12.1) and 22.6 mg for ropivacaine (95% CI, 20.5-24.6). A relative analgesic potency ratio of 0.50 (95% CI, 0.44-0.56) was calculated between the median effective local anesthetic dose of intrathecal bupivacaine and ropivacaine. CONCLUSIONS: Bupivacaine and ropivacaine are appropriate for continuous spinal anesthesia for interstitial radiation therapy procedures of the lower abdomen. In the dose-ranges investigated, intrathecal ropivacaine is approximately half as potent as bupivacaine.     

罗哌卡因在临床麻醉中的应用进展

随着对布比卡因致命性心脏毒性作用的认识，新型局部麻醉药罗哌卡因在临床上有越来越多的使用趋势。本文就罗哌卡因的理化特性及其临床应用进展作一综述。     

Selective spinal anesthesia: a comparison of hyperbaric bupivacaine 4 mg versus 6 mg for outpatient knee arthroscopy.

IMPLICATIONS: A low-dose (4 mg), low-volume (0.8 mL), low-flow (2 min) technique with hyperbaric bupivacaine toward the dependent side oriented injection and maintenance of the lateral decubitus position for 10 min produced selective spinal anesthesia with rapid recession of motor block and early discharge home.     

Intrathecal ropivacaine for ambulatory surgery.

BACKGROUND: The rationale of this study was to evaluate intrathecal ropivacaine for ambulatory surgery. METHODS: One hundred fifty patients with American Society of Anesthesiologists physical status 1 scheduled for knee arthroscopy were studied. Patients were randomly assigned to receive 4 ml of one of five isobaric intrathecal solutions: Patients in group 1 (n = 30) received 8 mg of bupivacaine; patients in group 2 (n = 30) received 8 mg ropivacaine; patients in group 3 (n = 30) received 10 mg ropivacaine; patients in group 4 (n = 30) received 12 mg ropivacaine; and patients in group 5 (n = 30) received 14 mg ropivacaine. The level and duration of sensory anesthesia were recorded along with the intensity and duration of motor block. Patients were interviewed to identify transient neurologic symptoms. RESULTS: Intrathecal ropivacaine 10 mg produced shorter sensory anesthesia and motor blockade than bupivacaine 8mg (152 +/- 44 min and 135 +/- 41 min vs. 181 +/- 44 min and 169 +/- 52 min, mean +/- SD; P < 0.05). However, the quality of intraoperative analgesia was significantly lower in the 10-mg ropivacaine group (P < 0.05). Ropivacaine 12 mg produced sensory and motor block almost comparable to bupivacaine 8 mg. Ropivacaine 14 mg produced sensory and motor block comparable to ropivacaine 12 mg but significantly increased the time to void. No sign of transient radicular irritation were noted. CONCLUSION: Intrathecal ropivacaine 12 mg is approximately equivalent to bupivacaine 8 mg. At this dose, ropivacaine offers no significant advantage compared with bupivacaine.     

Spinal anesthesia with hyperbaric levobupivacaine and ropivacaine for outpatient knee arthroscopy: a prospective, randomized, double-blind study

To compare unilateral spinal block produced with small doses of hyperbaric ropivacaine with that produced by 2 doses of hyperbaric levobupivacaine, we randomly allocated 91 ASA physical status I-II outpatients undergoing knee arthroscopy to receive unilateral spinal anesthesia with 7.5 mg of hyperbaric ropivacaine 0.5% (group Ropi-7.5, n = 31) or either 7.5 mg (group Levo-7.5, n = 30) or 5 mg (group Levo-5, n = 30) of hyperbaric levobupivacaine 0.5%. Spinal anesthesia was performed at the L3-4 interspace using a 25-gauge Whitacre spinal needle. The lateral decubitus position was maintained for 15 min after injection. Strictly unilateral sensory block was present in 73%, 50%, and 61% of cases in groups Ropi-7.5, Levo-7.5, and Levo-5, respectively, 30 min after injection (P = 0.40), and unilateral motor block was observed in 94%, 93%, and 83% in groups Ropi-7.5, Levo-7.5, and Levo-5, respectively (P = 0.31). One patient of group Ropi-7.5 required general anesthesia to complete surgery, and fentanyl supplementation was required in one patient of group Ropi-7.5 (3%) and one patient of group Levo-5 (3%) (P = 0.42). The median (range) time for spinal block resolution was shorter in group Ropi-7.5 (135 [126-154] min] than in group Levo-7.5 (162 [148-201] min) (P = 0.04); whereas home discharge was shorter in groups Ropi-7.5 (197 [177-218] min) and Levo-5 (197 [187-251] min) as compared with group Levo-7.5 (238 [219-277] min) (P = 0.02 and P = 0.04, respectively). We conclude that 7.5 mg of 0.5% hyperbaric ropivacaine and 5 mg of 0.5% hyperbaric levobupivacaine provide adequate spinal block for outpatient knee arthroscopy, with a faster home discharge as compared with 7.5 mg of 0.5% hyperbaric levobupivacaine.     

Comparison of ropivacaine and bupivacaine for intrathecal anesthesia during outpatient arthroscopic surgery

STUDY OBJECTIVE: To compare the effects of intrathecal ropivacaine with bupivacaine in a dose ratio of 2:1 for outpatient arthroscopic knee surgery. DESIGN: Randomized, single-blinded study. SETTING: University-affiliated hospital. PATIENTS: 90 patients scheduled for outpatient arthroscopic knee surgery. INTERVENTIONS: Patients were randomized and assigned in single-blinded fashion to receive a 3-mL solution of either 15 mg of isobaric ropivacaine (group R; n = 45) or 7.5 mg of isobaric bupivacaine (group B; n = 45) through a 27-gauge Quincke spinal needle at the L(3) to L(4) interspace, while placed in the lateral decubitus position. MEASUREMENTS: Onset and offset times for sensory and motor block; highest level of sensory block; duration of the sensory and motor block; first ambulation, urination, and discharge time; mean arterial pressure; and heart rate were all recorded. MAIN RESULTS: Onset time for sensory block (mean +/- SD) to L1 and time until sensory block regressed to L2 were shorter in group R. Complete motor block occurred in 40 patients with ropivacaine and 45 patients with bupivacaine. First ambulation and first urination and discharge times were similar between the two groups. Cephalad spread of sensory block was higher with ropivacaine (P < 0.05). The median (range) upper sensory level obtained with bupivacaine was T11 (T6-L1) and T8 (T6-T10) with ropivacaine. Hemodynamic changes were similar between the groups (P > 0.05). CONCLUSION: Isobaric ropivacaine 15 mg provided a higher sensory block level and shorter sensorial onset and offset times than did 7.5 mg of isobaric bupivacaine.