Walking with Labor Epidural Analgesia: The Impact of Bupivacaine Concentration and a Lidocaine-Epinephrine Test Dose

Background: Regional analgesia techniques for labor that permit ambulation are popular among parturients. This study evaluated the influence of bupivacaine bolus concentration and a 3-ml 1.5% lidocaine-epinephrine test dose, on analgesic effectiveness and the ability to walk after block placement.

Methods: Using a randomized double-blind study design, epidural analgesia was initiated in 60 parturients undergoing labor as follows: Group TD/B.0625 received a 3-ml lidocaine-epinephrine test dose + 12 ml bupivacaine, 0.0625%; group TD/B.125 received a 3-ml test dose + 12 ml bupivacaine, 0.125%; group B.0625 received 15 ml bupivacaine, 0.0625% (no test dose); and group B.125 received 15 ml bupivacaine, 0.125% (no test dose). Initial boluses in all groups contained 10 [mu]g sufentanil. Bupivacaine, 0.0625%, with 0.33 [mu]g/ml sufentanil was infused throughout labor at 13.5-15 ml/h. Analgesia balance, proprioception, motor block, and patient ability to stand and walk were evaluated at various intervals.

Results: A bolus of 0.125% bupivacaine containing sufentanil, without a previous test dose, proved to be optimal with respect to analgesia and early ambulation. When a test dose was given before bupivacaine, 0.125%, fewer women walked within 1 h of block placement. Bupivacaine, 0.0625%, with sufentanil, with or without a test dose, provided inadequate analgesia, necessitating additional bupivacaine, which impaired the ability to walk. A high percentage of women in all groups (73-93%) walked at some stage during labor.     

Walking with labor epidural analgesia: the impact of bupivacaine concentration and a lidocaine-epinephrine test dose

BACKGROUND: Regional analgesia techniques for labor that permit ambulation are popular among parturients. This study evaluated the influence of bupivacaine bolus concentration and a 3-ml 1.5% lidocaine-epinephrine test dose, on analgesic effectiveness and the ability to walk after block placement. METHODS: Using a randomized double-blind study design, epidural analgesia was initiated in 60 parturients undergoing labor as follows: Group TD/B.0625 received a 3-ml lidocaine-epinephrine test dose + 12 ml bupivacaine, 0.0625%; group TD/B.125 received a 3-ml test dose + 12 ml bupivacaine, 0.125%; group B.0625 received 15 ml bupivacaine, 0.0625% (no test dose); and group B.125 received 15 ml bupivacaine, 0.125% (no test dose). Initial boluses in all groups contained 10 microg sufentanil. Bupivacaine, 0.0625%, with 0.33 microg/ml sufentanil was infused throughout labor at 13.5-15 ml/h. Analgesia balance, proprioception, motor block, and patient ability to stand and walk were evaluated at various intervals. RESULTS: A bolus of 0.125% bupivacaine containing sufentanil, without a previous test dose, proved to be optimal with respect to analgesia and early ambulation. When a test dose was given before bupivacaine, 0.125%, fewer women walked within 1 h of block placement. Bupivacaine, 0.0625%, with sufentanil, with or without a test dose, provided inadequate analgesia, necessitating additional bupivacaine, which impaired the ability to walk. A high percentage of women in all groups (73-93%) walked at some stage during labor. CONCLUSIONS: Omitting a lidocaine-epinephrine test dose and using 0.125% bupivacaine for the initial bolus should permit ambulation in the early postblock period for most parturients who elect this option.     

Combined spinal-epidural labor analgesia

Combined spinal-epidural (CSE) labor analgesia is a new neuraxial labor analgesic technique. An intrathecal injection of an opioid alone, or in combination with a local anesthetic, initiates analgesia. An epidural catheter can then be used to maintain pain relief for the duration of labor. The CSE technique combines the advantages of spinal analgesia (low drug doses, rapid onset, immediate sacral block) and epidural analgesia (titratable, able to maintain analgesia indefinitely, ability to convert to epidural anesthesia). Side effects are acceptable with attention to patient selection and technique. The initiation of CSE analgesia with either fentanyl (25 μg) or sufentanil (5.0–7.5 μg) is appropriate for early labor, or in patients for whom an acute decrease in preload is not desirable. Although an equipotent dose of sufentanil has a longer duration of analgesia than fentanyl, both drugs provide excellent analgesia and prolonged duration is of minimal clinical significance when the intrathecal dose is followed by maintenance epidural analgesia. The addition of a local anesthetic to the opioid is required to provide satisfactory analgesia once fetal descent begins. The addition of local anesthetic (usually bupivacaine 1.25–2.5 mg) allows the dose of opioid to be decreased. Markedly lower opioid doses (fentanyl 5 μg or sufentanil 1.0–2.5 μg) can then provide effective analgesia with fewer systemic side effects. Several additives have been shown to prolong the duration of analgesia of opioids and opioids plus bupivacaine, but the short increase in duration of analgesia may not be worth the increased difficulty of combining multiple drugs.     

Continuous infusion epidural analgesia during labor: a randomized, double-blind comparison of 0.0625% bupivacaine/0.0002% fentanyl versus 0.125% bupivacaine

The analgesic efficacy of the continuous epidural infusion of 0.0625% bupivacaine/0.0002% fentanyl was compared with the infusion of 0.125% bupivacaine alone in a randomized, double-blind study of nulliparous women. Each patient received, in sequence: 1) 3 ml of 0.5% bupivacaine with 1:200,000 epinephrine; 2) 6 ml of study solution 1 (bupivacaine-fentanyl group: 0.125% bupivacaine/0.0008% fentanyl; bupivacaine-only group: 0.25% bupivacaine alone); and 3) a continuous epidural infusion of study solution 2 at a rate of 12.5 ml/h (bupivacaine-fentanyl group: 0.0625% bupivacaine/0.0002% fentanyl; bupivacaine-only group: 0.125% bupivacaine alone). The epidural infusion was discontinued at full cervical dilatation, but patients who lacked perineal anesthesia received one or two 5-ml boluses of study solution 3 (bupivacaine-fentanyl group: 0.0625% bupivacaine alone; bupivacaine-only group: 0.125% bupivacaine alone). During the first stage of labor, 36 of 41 (88%) women in the bupivacaine-fentanyl group, and 37 of 39 (95%) women in the bupivacaine-only group, had analgesia of excellent or good quality (P = NS). During the second stage, 22 of 37 (59%) women in the bupivacaine-fentanyl group, and 23 of 35 (66%) women in the bupivacaine-only group, rated their analgesia as excellent or good (P = NS). Women in the bupivacaine-only group were more likely to have motor block at full cervical dilatation (P less than .001). There was no significant difference between groups in duration of the second stage of labor, duration of pushing, position of the vertex before delivery, method of delivery, Apgar scores, or umbilical cord blood gas and acid-base values.(ABSTRACT TRUNCATED AT 250 WORDS)     

Continuous infusion epidural analgesia in labor: the effect of adding sufentanil to 0.125% bupivacaine

The purpose of this study was to determine if the addition of sufentanil would improve the quality of analgesia obtained with 0.125% epidural bupivacaine infusions given to women in active labor. Forty healthy laboring women were randomly assigned to two equal groups. Group 1 had epidural analgesia instituted with the bolus injection of 10-15 ml 0.125% bupivacaine containing sufentanil 2 micrograms/ml, followed 30 minutes later by initiation of an epidural infusion of 0.125% bupivacaine containing sufentanil 1 microgram/ml at a rate of 10 ml/hr. Group 2 had epidural analgesia instituted with 10 or 15 ml of 0.25% bupivacaine with an epidural infusion of 0.125% bupivacaine begun 30 minutes later at a rate of 10 ml/hr. Infusion rates were altered as required to maintain an analgesic level to the tenth thoracic dermatome. Analgesia assessed by visual analog pain scores was significantly better in group 1. Significantly fewer epidural injections were required in group 1, and less motor weakness occurred in these patients. The addition of sufentanil to epidural bupivacaine infusions given in labor improves analgesia and reduces "top-up" requirements.     

Comparison of fentanyl and sufentanil as adjuncts to bupivacaine for labor epidural analgesia

Study ObjectiveTo compare the clinical efficacy of theoretically equipotent doses of fentanyl and sufentanil, each in combination with bupivacaine, for patient-controlled epidural analgesia (PCEA) for labor.DesignSingle-blinded, randomized study.SettingUniversity hospital.Patients48 ASA physical status I and II term parturients in active labor, with cervical dilatation equal to or less than 5 cm, and requesting epidural analgesia.InterventionsPatients received a loading dose of 10 mL of 0.125% bupivacaine with either 30 μg of fentanyl or 5 μg of sufentanil. PCEA was maintained with 0.0625% bupivacaine with either fentanyl two μg/mL or sufentanil 0.35 μg/mL. The PCEA settings were: bolus 5 mL, lockout 10 minutes, infusion 10 mL/hr, and maximum dose 40 mL/hr. Standardized rescue doses of bupivacaine were administered as necessary.MeasurementsThe bupivacaine requirement in mg/hr was calculated from the time of initiation of the epidural until the patient had had 4 to 6 hours of PCEA. The hourly pain score, sensory and motor block, and side effects were documented. Overall patient satisfaction was assessed at the end of the study.Main ResultsThe mean (standard deviation) bupivacaine requirement was 12.4 mg/hr (3.2) and 11.0 mg/hr (2.4) for the fentanyl and sufentanil groups, respectively (P = 0.08). There was evidence of higher maternal satisfaction (P = 0.01), and weak evidence of lower pain scores (P = 0.10) in the sufentanil group. The side effects were similar in both groups.ConclusionsAt the assumed equipotent sufentanil to fentanyl ratio of 6:1, there is some evidence that sufentanil is clinically superior to fentanyl as an adjunct to bupivacaine in labor epidurals, although the advantages are subtle.     

Comparison of fentanyl and sufentanil in combination with bupivacaine for patient-controlled epidural analgesia during labor

STUDY OBJECTIVES: To compare the efficacy of fentanyl plus bupivacaine with sufentanil plus bupivacaine for treatment of pain during labor and delivery using patient-controlled epidural analgesia (PCEA). DESIGN: Prospective, double-blind, clinical investigation. SETTINGS: University-affiliated hospital. PATIENTS: 226 ASA physical status I and II laboring patients. INTERVENTIONS: Patients were randomized to receive 0.125% bupivacaine with fentanyl (2 micro g.ml(-1)) or 0.125% bupivacaine with sufentanil (0.25 micro g.ml(-1)) through PCEA. MEASUREMENTS: Maternal analgesia assessed by visual analog scale was recorded before epidural block, 1 and 3 hours after epidural block, at full cervical dilation, and at delivery. Motor blockade assessed by Bromage scale was recorded at delivery. MAIN RESULTS: Nine patients in group fentanyl, and 11 in group sufentanil were excluded from the study. Overall analgesia was good and no difference was observed between the two groups. Total boluses of 4 mL bupivacaine-opioid administered and the number of supplementary top-up injections of 5 mL 0.25% bupivacaine were similar in both groups. In group sufentanil, motor blockade and pruritus were significantly lower than in group fentanyl. Nausea was not recorded in any patients. Mode of delivery was similar in both groups, i.e., cesarean section, vacuum or forceps, or spontaneous vaginal delivery. No difference was observed in Apgar scores. CONCLUSIONS: Sufentanil is preferable to fentanyl during bupivacaine PCEA as there is less incidence of motor blockade and pruritus.     

Dose-dependent Reduction of the Minimum Local Analgesic Concentration of Bupivacaine by Sufentanil for Epidural Analgesia in Labor

Background: The minimum local analgesic concentration (MLAC) has been defined as the median effective local analgesic concentration in a 20-ml volume for epidural analgesia in the first stage of labor. The aim of this study was to determine the local anesthetic-sparing efficacy of epidural sufentanil by its effect on the MLAC of bupivacaine.

Methods: In this double-blind, randomized, prospective study, 147 parturients at Results: The MLAC of bupivacaine alone was 0.104% wt/vol (95% CI, 0.090 - 0.117). The addition of sufentanil at doses of 0.5 [micro sign]g/ml, 1 [micro sign]g/ml, and 1.5 [micro sign]g/ml resulted in significant reductions (P < 0.0001) in the MLAC of bupivacaine to 0.048% wt/vol (95% CI, 0.030 - 0.065), 0.021% wt/vol (95% CI, 0 - 0.055), and 0.009% wt/vol (95% CI, 0 - 0.023), respectively.     

A Double-blind Comparison of 0.125% Ropivacaine with Sufentanil and 0.125% Bupivacaine with Sufentanil for Epidural Labor Analgesia

Background: This study intends to evaluate the benefits of the administration of intermittent bolus doses of ropivacaine (0.125%) compared with bupivacaine (0.125%) after addition of sufentanil for analgesia during labor.

Methods: One hundred thirty American Society of Anesthesiologists physical status 1 or 2 parturients were studied. The 90 initial patients were assigned randomly to receive 10 ml bupivacaine, 0.125%, plus 7.5 [micro sign]g sufentanil (initial bupivacaine 0.125% group) or ropivacaine, 0.125%, plus 7.5 [micro sign]g sufentanil (ropivacaine 0.125% group). Forty additional patients were recruited and received 0.125% bupivacaine plus 7.5 [micro sign]g sufentanil (additional bupivacaine 0.125% group) or 0.100% bupivacaine plus 7.5 [micro sign]g sufentanil (additional bupivacaine 0.100% group). The duration of analgesia, visual analogue scores for pain, motor blockade (using a six-point modified Bromage scale), patient satisfaction scores, nausea, pruritus, heart rate, and blood pressure were recorded.

Results: Bupivacaine 0.125% and ropivacaine 0.125% coadministered with sufentanil provided rapid and complete analgesia. Onset of analgesia occurred after +/- 15 min and lasted +/- 90 min. After the third epidural injection, patients in the ropivacaine group experienced significantly less severe motor blockade than patients in the initial bupivacaine 0.125% group. At this point, 93% of the patients in the ropivacaine group were free from motor impairment versus 66% in the bupivacaine group (P < 0.05). Comparable levels of motor blockade were obtained in both additional groups. Patients' evaluation of their analgesia was worst in the bupivacaine 0.100% group.     

Efficacy of ropivacaine, bupivacaine, and levobupivacaine for labor epidural analgesia

STUDY OBJECTIVE: To compare analgesic efficacy and intensity of motor block with continuous infusions of ropivacaine, bupivacaine, and levobupivacaine in combination with fentanyl for labor epidural analgesia. DESIGN: Prospective, randomized, double-blinded study. SETTING: Labor and delivery suite at Magee Womens Hospital, Pittsburgh, PA. PATIENTS: 162 ASA physical status I and II, full-term, primiparous women. INTERVENTIONS: All patients received epidural labor analgesia. Epidural medication consisted of an initial bolus of 8 mL local anesthetic with fentanyl (100 microg) followed by an infusion at 12 mL/h of local anesthetic with 2 microg/mL fentanyl. Patients were allocated to one of three groups, as follows: group 1 received bolus and infusion of bupivacaine 0.125%, group 2 received bolus and infusion of levobupivacaine 0.125%, and group 3 received a bolus of ropivacaine 0.2% and infusion of ropivacaine 0.1%. MEASUREMENTS: Maternal vital signs, pain visual analog scale (VAS) score, sensory levels, and motor block (Bromage score) were recorded every hour. Duration of first and second stage of labor and mode of delivery were also recorded. RESULTS: There were no statistically significant differences in pain VAS or Bromage motor scores among the three groups of patients at any of the measured time intervals. The time to achieve T10 sensory level and patient comfort was shorter in the ropivacaine (9.35 +/- 4.96 min) and levobupivacaine (9.56 +/- 4.71 min) groups than the bupivacaine (11.89 +/- 7.76 min) group, although this difference did not reach a statistically significant level (P = 0.06). The second stage was significantly shorter in the bupivacaine group, lasting 81.27 +/- 63.3 min, compared with the ropivacaine group (121.69 +/- 86.5 min) and the levobupivacaine (115.5 +/- 83.6 minutes) group (P = 0.04). CONCLUSION: There are no significant differences in pain VAS and Bromage scores between 0.1% ropivacaine, 0.125% bupivacaine, and 0.1% levobupivacaine given for labor epidural analgesia.     

Effect of Intravenous versus Epidural Fentanyl on the Minimum Local Analgesic Concentration of Epidural Bupivacaine in Labor

Background: The minimum local analgesic concentration (MLAC) has been defined as the median effective local analgesic concentration (EC50) in a 20-ml volume for epidural analgesia in the first stage of labor. The aim of this study was to determine the relative local anesthetic sparing efficacies of intravenous and epidural fentanyl by comparison of their effects on the MLAC of bupivacaine.

Methods: In this double-blind, randomized, prospective study, 84 parturients at <= 7-cm cervical dilation who requested epidural analgesia were allocated to one of two groups. After lumbar epidural catheter placement, 20 ml bupivacaine (n = 44) or bupivacaine with 3 [mu]g/ml (60 [mu]g) fentanyl (n = 40) was administered. The plain bupivacaine group then received 60 [mu]g intravenous fentanyl. The bupivacaine-fentanyl group received intravenous saline. The concentration of bupivacaine was determined by the response of the previous patient in that group to a higher or lower concentration using up-down sequential allocation. Analgesic efficacy was assessed using 100-mm visual analog pain scores, with <= 10 mm within 30 min defined as effective.

Results: The MLAC of bupivacaine-intravenous fentanyl was 0.064% wt/vol (95% confidence interval, 0.049-0.080), and the MLAC of bupivacaine-epidural fentanyl was 0.034% wt/vol (95% confidence interval, 0.017-0.050). Epidural fentanyl significantly increased the analgesic potency of bupivacaine by a factor of 1.88 (95% confidence interval, 1.09-3.67) compared with intravenous fentanyl. The epidural fentanyl group demonstrated significantly higher dermatomal spread (P = 0.0064) and increased pruritus (P = 0.01).     

A comparison of opioid solutions for patient-controlled epidural analgesia

Sixty patients took part in a randomised, double-blind study to compare the analgesic and side effects of three opioid-containing solutions for patient-controlled epidural analgesia following abdominal surgery. Patients in group 1 received a solution containing bupivacaine 0.125% with fentanyl 10μg. ml⁻¹, group 2 bupivacaine 0.125% with diamorphine 125μg. ml⁻¹, group 3 pethidine 2.5 mg. ml⁻¹. All groups received 4 ml.h⁻¹ background infusion and 3 ml boluses every 20 min if necessary. There were no significant differences between the groups in visual analogue scale pain scores (p = 0.537) or volumes of solution used at 24 h (p = 0.351) or 48 h (p = 0.105). Motor block was significantly higher in group 2 (p < 0.004) and pruritis occurred significantly less in group 3 (p < 0.05). We conclude that these three solutions produce equivalent analgesia but that pethidine 2.5 mg. ml⁻¹ may be associated with fewer side effects.     

A double-blind comparison of 0.125% ropivacaine with sufentanil and 0.125% bupivacaine with sufentanil for epidural labor analgesia

BACKGROUND: This study intends to evaluate the benefits of the administration of intermittent bolus doses of ropivacaine (0.125%) compared with bupivacaine (0.125%) after addition of sufentanil for analgesia during labor. METHODS: One hundred thirty American Society of Anesthesiologists physical status 1 or 2 parturients were studied. The 90 initial patients were assigned randomly to receive 10 ml bupivacaine, 0.125%, plus 7.5 microg sufentanil (initial bupivacaine 0.125% group) or ropivacaine, 0.125%, plus 7.5 microg sufentanil (ropivacaine 0.125% group). Forty additional patients were recruited and received 0.125% bupivacaine plus 7.5 microg sufentanil (additional bupivacaine 0.125% group) or 0.100% bupivacaine plus 7.5 microg sufentanil (additional bupivacaine 0.100% group). The duration of analgesia, visual analogue scores for pain, motor blockade (using a six-point modified Bromage scale), patient satisfaction scores, nausea, pruritus, heart rate, and blood pressure were recorded. RESULTS: Bupivacaine 0.125% and ropivacaine 0.125% coadministered with sufentanil provided rapid and complete analgesia. Onset of analgesia occurred after +/-15 min and lasted +/-90 min. After the third epidural injection, patients in the ropivacaine group experienced significantly less severe motor blockade than patients in the initial bupivacaine 0.125% group. At this point, 93% of the patients in the ropivacaine group were free from motor impairment versus 66% in the bupivacaine group (P<0.05). Comparable levels of motor blockade were obtained in both additional groups. Patients' evaluation of their analgesia was worst in the bupivacaine 0.100% group. CONCLUSIONS: Ropivacaine 0.125% with sufentanil affords reliable analgesia with minimal motor blockade.     

Minimum analgesic doses of fentanyl and sufentanil for epidural analgesia in the first stage of labor

In this study, we sought to determine the minimum analgesic doses and relative potencies of fentanyl and sufentanil when they are used as the sole epidural analgesic during the first stage of labor. Nulliparous parturients (n = 66) in spontaneous labor at term gestation and requesting epidural analgesia were enrolled into this prospective, double-blinded, randomized, sequential-allocation study. Each woman received fentanyl or sufentanil diluted with 0.9% wt/vol saline to a volume of 10 mL. The initial dose was arbitrarily chosen to be 125 microg for fentanyl and 25 microg for sufentanil, with subsequent doses being determined by the response of the previous patient (testing interval, 5 microg for fentanyl and 1 microg for sufentanil). Efficacy was accepted if the visual analog score decreased to < or =10 mm on a 100-mm scale within 30 min. The minimum analgesic dose or median effective dose was 21.1 microg (95% confidence interval [CI], 20.2-21.9 microg) for sufentanil and 124.2 microg (95% CI, 118.1-130.6 microg) for fentanyl (P < 0.0001). The sufentanil/fentanyl potency ratio was 5.9 (95% CI, 5.6-6.3). In conclusion, we have established the equivalent doses and relative potencies of fentanyl and sufentanil for epidural analgesia in the first stage of labor. IMPLICATIONS: This study determined the minimum analgesic doses of fentanyl and sufentanil for epidural anesthesia in the first stage of labor. The sufentanil/fentanyl potency ratio was 5.9. This ratio may be used to establish the equivalent doses for fentanyl and sufentanil for epidural analgesia in labor.     

The dose-range effects of sufentanil added to 0.125% bupivacaine on the quality of patient-controlled epidural analgesia during labor

To determine the minimal sufentanil concentration required to improve the quality of patient-controlled epidural analgesia during labor, we compared the efficacy of a combination of 0.125% bupivacaine with 1:800,000 epinephrine and different concentrations of sufentanil in a double-blinded randomized study. Concentrations were no sufentanil (n = 66), 0.078 microg/mL sufentanil (n = 65), 0.156 microg/mL sufentanil (n = 65), 0.312 microg/mL sufentanil (n = 65), and 0.468 microg/mL sufentanil (n = 67). The patient-controlled epidural analgesia setting was a 12-mL bolus dose and a 25-min lockout interval. Pain was scored at 5-6 cm, 7-8 cm, and full cervical dilation by using a 10-cm visual analog scale. At full cervical dilation, the pain scores were lower in the groups receiving a solution of at least 0.156 microg/mL sufentanil. Few differences were observed when using the larger concentrations, except for increased pruritus intensity. The duration of labor and the mode of delivery were similar in each group. Rescue analgesia, which consisted of 6 mL of 0.25% bupivacaine, was infrequent and comparable between groups. The use of the pump did not differ between groups. Adding a small concentration of sufentanil to 0.125% bupivacaine for patient-controlled epidural analgesia during labor improved the quality of analgesia but did not modify the bupivacaine requirement. Reducing the sufentanil concentrations to 0.156 microg/mL decreased the pruritus intensity without reducing analgesia. Implications: Adding a small concentration of sufentanil to 0.125% bupivacaine for patient-controlled epidural analgesia during labor improved the quality of analgesia but did not modify the bupivacaine requirement. Reducing the sufentanil concentrations to 0.156 microg/mL decreased the pruritus intensity without reducing analgesia.     

A comparison of epidural infusions in the combined spinal/epidural technique for labor analgesia

We compared the clinical effects of three epidural infusions initiated after subarachnoid medication was administered as part of the combined spinal/epidural technique for labor analgesia. Fifteen minutes after administering subarachnoid fentanyl 25 microg and 1 mL of bupivacaine 0.25%, and 5 min after an epidural test dose of 3 mL of bupivacaine 0.25%, women were randomized to receive an epidural infusion of saline, bupivacaine 0.125%, bupivacaine 0.0625%, or bupivacaine 0.04% with epinephrine 1:600,000. All epidural infusions were started at 10 mL/h, and all except the Saline Group also received fentanyl 2 microg/mL. The end point of the study was delivery or request for additional medication for analgesia. We found that time until request for additional analgesia was longest in women who received bupivacaine 0.125% (median duration, 300 min) versus saline (median duration, 118 min) (P = 0.0001) and was intermediate for bupivacaine 0.0625% and bupivacaine 0.04% (median duration, 162 and 180 min, respectively) (P = 0.0001 versus saline). Women who received bupivacaine 0.125% had the most motor block. We conclude that all the bupivacaine-based infusions we tested maintained the analgesia from subarachnoid medication longer than saline, with the longest duration, but the most motor block, from bupivacaine 0.125%. IMPLICATIONS: In this prospective, randomized, and double-blinded study we found that initiating an epidural infusion of bupivacaine 0.125% with fentanyl 2 microg/mL at 10 mL/h 15 min after subarachnoid fentanyl 25 microg with 1 mL of bupivacaine 0.25%, followed by an epidural test dose of 3 mL of bupivacaine 0.25%, maintained the analgesia for longer but with more motor block than with either bupivacaine 0.04% or bupivacaine 0.0625%.     

单纯罗哌卡因与罗哌卡因复合舒芬太尼在硬膜外分娩镇痛中的比较

目的比较单纯罗哌卡因与罗哌卡因复合舒芬太尼在硬膜外分娩镇痛中的有效性和安全性。方法选择要求硬膜外分娩镇痛的产妇481例,年龄18~45岁,ASAⅠ级,随机分为两组,硬膜外分别给予0.125%罗哌卡因(R组,n=241)或0.125%罗哌卡因复合0.3μg/ml舒芬太尼(RS组,n=240)。记录产程中NRS疼痛评分及VAS镇痛满意度评分,产妇Bromage运动评分及不良反应情况,以及新生儿Apgar评分及脐带血气分析。结果最终纳入产妇346例,R组164例,RS组182例。第一产程NRS评分RS组2.2分(IQR 1.8~2.7分),明显低于R组2.4分(IQR 2~2.8分)(P0.001),第二产程两组NRS评分差异无统计学意义。两组VAS镇痛满意度差异无统计学意义。分娩镇痛相关不良反应发生率RS组47.2%,R组37.7%,两组差异无统计学意义。RS组1 min的Apgar评分≤7分的比例为5.5%,明显高于R组1.2%(P0.05)。结论单纯罗哌卡因用于硬膜外分娩镇痛与罗哌卡因复合舒芬太尼效果相似,但产妇不良反应更少,新生儿1 min的Apgar评分≤7分的比例更低。     

A comparison of epidural analgesia with 0.125% ropivacaine with fentanyl versus 0.125% bupivacaine with fentanyl during labor

We previously found that the extent of an epidural motor block produced by 0.125% ropivacaine was clinically indistinguishable from 0.125% bupivacaine in laboring patients. By adding fentanyl to the 0. 125% ropivacaine and bupivacaine solutions in an attempt to reduce hourly local anesthetic requirements, we hypothesized that differences in motor block produced by the two drugs may become apparent. Fifty laboring women were randomized to receive either 0. 125% ropivacaine with fentanyl 2 microg/mL or an equivalent concentration of bupivacaine/fentanyl using patient-controlled epidural analgesia (PCEA) with settings of: 6-mL/hr basal rate, 5-mL bolus, 10-min lockout, 30-mL/h dose limit. Analgesia, local anesthetic use, motor block, patient satisfaction, and side effects were assessed until the time of delivery. No differences in verbal pain scores, local anesthetic use, patient satisfaction, or side effects between groups were observed; however, patients administered ropivacaine/fentanyl developed significantly less motor block than patients administered bupivacaine/fentanyl. Ropivacaine 0.125% with fentanyl 2 microg/mL produces similar labor analgesia with significantly less motor block than an equivalent concentration of bupivacaine/fentanyl. Whether this statistical reduction in motor block improves clinical outcome or is applicable to anesthesia practices which do not use the PCEA technique remains to be determined. Implications: By using a patient-controlled epidural analgesia technique, ropivacaine 0.125% with fentanyl 2 microg/mL produces similar analgesia with significantly less motor block than a similar concentration of bupivacaine with fentanyl during labor. Whether this statistical reduction in motor block improves clinical outcome or is applicable to anesthesia practices which do not use the patient-controlled epidural analgesia technique remains to be determined.     

Effect of intravenous versus epidural fentanyl on the minimum local analgesic concentration of epidural bupivacaine in labor

BACKGROUND: The minimum local analgesic concentration (MLAC) has been defined as the median effective local analgesic concentration (EC50) in a 20-ml volume for epidural analgesia in the first stage of labor. The aim of this study was to determine the relative local anesthetic sparing efficacies of intravenous and epidural fentanyl by comparison of their effects on the MLAC of bupivacaine. METHODS: In this double-blind, randomized, prospective study, 84 parturients at < or = 7-cm cervical dilation who requested epidural analgesia were allocated to one of two groups. After lumbar epidural catheter placement, 20 ml bupivacaine (n = 44) or bupivacaine with 3 microg/ml (60 microg) fentanyl (n = 40) was administered. The plain bupivacaine group then received 60 microg intravenous fentanyl. The bupivacaine-fentanyl group received intravenous saline. The concentration of bupivacaine was determined by the response of the previous patient in that group to a higher or lower concentration using up-down sequential allocation. Analgesic efficacy was assessed using 100-mm visual analog pain scores, with < or = 10 mm within 30 min define as effective. RESULTS: The MLAC of bupivacaine-intravenous fentanyl was 0.064% wt/vol (95% confidence interval, 0.049-0.080), and the MLAC of bupivacaine-epidural fentanyl was 0.034% wt/vol (95% confidence interval, 0.017-0.050). Epidural fentanyl significantly increased the analgesic potency of bupivacaine by a factor of 1.88 (95% confidence interval, 1.09-3.67) compared with intravenous fentanyl. The epidural fentanyl group demonstrated significantly higher dermatomal spread (P = 0.0064) and increased pruritus (P = 0. 01). CONCLUSIONS: Epidural fentanyl significantly reduced the MLAC of bupivacaine when compared with intravenous fentanyl for the parturients in this study. The significantly enhanced local anesthetic sparing, dermatomal level, and pruritus with epidural fentanyl suggest a primarily spinal site of action.     

不同浓度罗哌卡因复合舒芬太尼在硬膜外阶梯式分娩镇痛中的应用

目的观察不同浓度罗哌卡因复合舒芬太尼硬膜外阻滞在产程潜伏期阶梯式分娩镇痛中的效果。方法选择2015年2~4月单胎头位初产妇210例,随机分为七组,每组30例。1组:0.125%罗哌卡因+0.5μg/ml舒芬太尼;2组:0.075%罗哌卡因+0.5μg/ml舒芬太尼(宫口开3cm),0.125%罗哌卡因+0.5μg/ml舒芬太尼(宫口开≥3cm);3组:0.1%罗哌卡因+0.5μg/ml舒芬太尼(宫口开3cm),0.125%罗哌卡因+0.5μg/ml舒芬太尼(宫口开≥3cm);4组:0.15%罗哌卡因+0.5μg/ml舒芬太尼;5组:0.075%罗哌卡因+0.5μg/ml舒芬太尼(宫口开3cm),0.15%罗哌卡因+0.5μg/ml舒芬太尼(宫口开≥3cm);6组:0.1%罗哌卡因+0.5μg/ml舒芬太尼(宫口开3cm),0.15%罗哌卡因+0.5μg/ml舒芬太尼(宫口开≥3cm);7组:0.125%罗哌卡因+0.5μg/ml舒芬太尼(宫口开3cm),0.15%罗哌卡因+0.5μg/ml舒芬太尼(宫口开≥3cm)。观察各组VAS评分、产程时间、产后出血量、Bromage评分以及产后不良反应,同时观察新生儿Apgar评分。结果七组产妇镇痛后各时间点的VAS评分差异无统计学意义。2、3组潜伏期时程较1组明显缩短(P0.05),5、6组较4组明显缩短(P0.05)。4组活跃期时程较1组明显延长(P0.05)。2、3组出血量较1组明显减少(P0.05),5、6、7组出血量较2组明显增多(P0.05),同样也明显多于3组(P0.05)。2、3组产妇运动神经阻滞较1组轻微,且5、6、7组产妇运动神经阻滞较4组也明显减弱(P0.05)。各组产妇产后不良反应及新生儿Apgar评分差异无统计学意义。结论产程潜伏期应用0.075%或0.1%罗哌卡因+0.5μg/ml舒芬太尼,活跃期应用0.125%罗哌卡因+0.5μg/ml舒芬太尼,镇痛效果确切,对产程干扰小,产后出血量少,不影响产妇下肢活动,并且对母婴安全无明显影响。