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

The Effect of Epidural Nalbuphine Combined With Ropivacaine on Epidural Analgesia During Labor: A Multicenter, Randomized, Double-blind, Controlled Study

OBJECTIVES

The addition of a small dose of opioids during epidural labor analgesia can enhance the local analgesic effect, reduce the dose of local anaesthetic required, and minimize motor blockade. For the treatment of visceral pain, studies have shown that κ-opioid receptor agonist are more effective than μ-receptor agonists. This study compared the effectiveness of epidural nalbuphine and sufentanil in combination with ropivacaine for labor analgesia, respectively.

MATERIALS AND METHODS

We conducted a prospective, randomized, double-blind, multicentre clinical trial. Parturients who requested labor pain relief were randomly assigned to either the nalbuphine group or sufentanil group. After 5 minutes of initial dose, parturients in nalbuphine group received 10 mL 0.1% ropivacaine plus 0.3 mg/mL nalbuphine solution. The sufentanil group received the same ropivacaine dose plus 0.3 μg/mL sufentanil. The primary outcome was the duration of analgesia (the time to the first requirement for additional medication). Secondary outcomes included the ropivacaine dose per hour, and adverse reactions.

RESULTS

Between November 2018 and February 2019, 180 parturients were recruited for the study. The study showed that the duration of analgesia was shorter in the nalbuphine group as compared with the sufentanil group (P=0.040). The ropivacaine dose per hour in nalbuphine group 9.3 (2.4) mg was significantly greater versus sufentanil group 8.4 (2.5) mg (P=0.024). No serious adverse events directly associated with the analgesics were observed.

DISCUSSION

The analgesia effects of 0.3 mg/mL nalbuphine with ropivacaine are inferior to 0.3 μg/mL sufentanil with ropivacaine in labor analgesia. No serious side effects, either in the mother or in the fetus, were observed.

The 90% Effective Dose of Sufentanil for Epidural Analgesia in the Early First Stage of Labor: A Double-blind, Sequential Dose-Finding Study

PURPOSE

Epidural analgesia in the latent phase of the first stage of labor has been recognized and accepted by anesthesiologists worldwide. However, there is no unified consensus on the exact dosage of sufentanil with the combination of ropivacaine in the induction of epidural analgesia in the early first stage of labor. In this sequential dose-finding study, the 90% effective dose (ED₉₀) of sufentanil for epidural administration in the early first stage of labor was estimated to minimize the adverse effects of using higher doses.

METHODS

Forty parturients with cervical dilatation of 2 to 4 cm who requested epidural analgesia were enrolled in this study. Parturients received 15 mL of a combination of ropivacaine 13 mg and the test dose of sufentanil. The initial dose of sufentanil in epidural administration was 1 μg, and the dose of sufentanil for the next parturient was based on the response of the preceding participant as per a biased coin up-and-down design. The primary outcome was the dose of sufentanil that resulted in successful epidural administration by maintaining the parturients' visual analog scale scores at ≤30 mm in the first 15, 30, and 45 minutes of induction. The ED₉₀ and 95% CIs were estimated using isotonic regression methods and bootstrapping.

FINDINGS

The estimated ED₉₀ of sufentanil in epidural administration in the early first stage of labor was 1.91 μg (95% CI, 1.82-2.35 μg) in this sequential dose-finding study.

IMPLICATIONS

Sufentanil at a dosage of 2 μg is recommended for the administration of epidural analgesia in parturients in the early first stage of labor. ChiCTR.org.cn identifier: 1900021683.

An isobolographic analysis of diamorphine and levobupivacaine for epidural analgesia in early labour

BACKGROUND

Few data describe the pharmacological interactions between local anaesthetics and opioids. The aim of this study was to measure the median effective concentration (MEC) of diamorphine and levobupivacaine when given separately and as mixtures for epidural analgesia, and determine whether the combination is additive or synergistic.

METHODS

One hundred and twenty patients were enrolled in this prospective randomized, two-phase, double-blind study. In the first phase, 60 women were randomized to receive a fixed 20 ml volume of either levobupivacaine or diamorphine epidurally . Dosing was determined using up-down sequential allocation with testing intervals, respectively, of 0.01%w/v and 12.5 microg ml(-1). After estimations of the MEC of levobupivacaine and diamorphine, a further 60 patients were randomized in the second phase to one of the three mixtures: (a) diamorphine 70 microg ml(-1) (fixed) and levobupivacaine (testing interval 0.004%w/v, starting at 0.044%w/v); (b) levobupivacaine 0.044%w/v (fixed) and diamorphine (testing interval 7 microg ml(-1), starting at 70 microg ml(-1)); and (c) bivariate diamorphine and levobupivacaine (testing intervals of 7 microg ml(-1) and 0.004%w/v starting at 70 microg ml(-1) and 0.044% w/v respectively).

RESULTS

The MEC estimates from the first phase were 143.8 microg ml(-1) (95% CI 122.2-165.3) for diamorphine and 0.083%w/v (95% CI 0.071-0.095) for levobupivacaine. In the second phase, the MEC and interaction index (gamma) of the three combinations were: diamorphine 65.5 microg ml(-1) (56.8-74.2), gamma = 0.99; levobupivacaine 0.041%w/v (0.037-0.049), gamma = 0.98; and for the fixed combination diamorphine 69.5 microg ml(-1) (60.5-78.5) and levobupivacaine 0.044%w/v (0.039-0.049), gamma = 1.02.

CONCLUSION

The combination of diamorphine and levobupivacaine is additive and not synergistic when used for epidural analgesia in the first stage of labour.

[Patient-controlled epidural analgesia for labour: in practice]

OBJECTIVES

Update on patient controlled epidural analgesia for labour.

STUDY DESIGN

Literature review of the recent data on local anaesthetics, additional analgesics and of publications on the various protocols used.

DATA COLLECTION

Pubmed database was checked with the following key words: PCEA, labour, opioids, clonidine. The abstracts of the ASA meetings from 2000 to 2005 were also examined.

RESULTS

Patient controlled epidural analgesia (PCEA) is the method of choice for optimal labour pain management. The advantages of this technique are numerous. Some of them are established: consistent reduction in overall local anathetic requirement, less motor blockade, safety of the technique and team workload reduction. A better adequacy with the analgesic requirements and an increase in overall patient satisfaction are frequently retrieved, provided that the choice of the analgesics and the PCEA parameters are adequately chosen.

CONCLUSION

The use of PCEA improves the quality of analgesic management offered to the parturients who are more and more willing to have a "more natural" childbirth. The PCEA gives them more autonomy and, in fine, enables them to better enjoy this unique event. The main barrier to a more widespread diffusion of PCEA in many institutions remains the financial issue, although a well-selected device and low cost disposables allow a reduction of indirect costs by decreasing care giver workload.

Ropivacaine and Fentanyl Concentrations in Patient-Controlled Epidural Analgesia During Labor: A Volume-Range Study

We enrolled nulliparous women in induced labor in a randomized study to determine whether increasing the concentration of the solution used in a patient-controlled epidural analgesia (PCEA) device was required as labor progressed. Patients were assigned to 6 groups (n = 25 in each group), receiving ropivacaine/fentanyl in concentrations of either 0.1%/0.5 microg/mL or 0.2%/1 microg/mL via a PCEA pump. Three groups received boluses of 12, 16, or 20 mL dilute solution in early labor (uterine contractions every 3 min and 4-cm cervical dilation) then 6, 8, and 10 mL concentrated solution in late labor. Three other groups received boluses of 12, 16, or 20 mL dilute solution during both periods. The lockout interval was 25 min. The primary outcome was time until the first request for staff-administered analgesia supplement. Hourly assessments included pain scores on a visual analog scale (VAS) graded from 0 to 10, satisfaction scores, arterial blood pressure, motor block intensity, and the upper sensory level of epidural anesthesia. Patients, midwives, and the observer were unaware of study solutions and PCEA settings. The maximum pain score was defined as the highest score experienced by each patient during each period. Duration of analgesia was defined as the time from the start of each period to the first injection of rescue analgesia and was compared using a survival analysis. There were no differences among the groups with regard to demographic and obstetric variables, arterial blood pressure, motor block intensity, upper sensory level, or satisfaction scores. At least 75% of the women rated their satisfaction as either good or excellent during each period. During late labor, the maximum pain score was lower in the group receiving 20 mL dilute solution compared with the group receiving 6 mL concentrated solution. Maximum pain score was not significantly different between 20 mL dilute solution and 10 mL concentrated solution (difference between VAS values = -0.4; 95% confidence limits, -1.599 and 0.799; P = 0.5055). During late labor, the duration of analgesia was longer in groups receiving 20 mL dilute solution (99 +/- 4 min) (mean +/- SD) than in those receiving 12 mL (77 +/- 30 min) and 16 mL (80 +/- 23 min). Duration of analgesia did not differ between groups receiving 20 mL and 10 mL (92 +/- 23 min) or between groups receiving 12 mL and 6 mL (78 +/- 30 min) of each respective solution. Duration of analgesia was longer in the groups receiving 8 mL concentrated solution (94 +/- 16 min) than in those receiving 16 mL dilute solution. We concluded that 0.1%/0.5 microg/mL ropivacaine/fentanyl was effective throughout labor when 20 mL was injected with each PCEA demand. With 16 mg ropivacaine and 8 microg fentanyl, the duration of analgesia was prolonged by doubling the concentration when labor became active. When 12 mg ropivacaine and 6 microg fentanyl were injected at each demand, analgesia was less satisfactory and doubling the concentration was not clinically effective. These results suggest that the effectiveness of PCEA is dependent on drug mass rather than the volume or concentration administered with each successful pump demand.

IMPLICATIONS

There is no clinical reason for increasing the concentration of the patient-controlled epidural analgesia (PCEA) solution when labor becomes active provided that an effective dose is already being administered with each demand. The quality of PCEA depends on the drug mass given with each demand rather than the concentration of the pump solution.

Ropivacaine 0.15% plus sufentanil 0.5 microg/mL and ropivacaine 0.10% plus sufentanil 0.5 microg/mL are equivalent for patient-controlled epidural analgesia during labor

We compared the administration of 0.15% ropivacaine plus 0.5 microg/mL of sufentanil with that of 0.10% ropivacaine plus 0.5 microg/mL of sufentanil for labor analgesia with patient-controlled epidural analgesia (PCEA) to determine whether a decreased concentration of ropivacaine could produce equally effective analgesia. One-hundred-thirty healthy pregnant women at term were randomized in a double-blinded fashion. The PCEA settings were as follows: 12-mL initial bolus, 5-mL bolus dose, 5-min lockout interval, and 10 mL/h basal infusion. Patient demographics and labor characteristics were comparable in both groups. No differences were observed for pain scores, maternal satisfaction, volume of anesthetic solution administered, number of boluses requested and delivered, need for supplemental boluses, mode of delivery, motor block, side effects, or Apgar scores. Patients in the 0.10% ropivacaine group used significantly less drug than those in the 0.15% group (mean, 57 mg; 95% confidence interval, 50.5-63.5 mg; versus mean, 88.0 mg; 95% confidence interval, 74.4-93.3 mg, respectively; P < 0.0001). Ropivacaine 0.10% plus 0.5 microg/mL of sufentanil administered via PCEA for labor analgesia is equally effective as ropivacaine 0.15% plus 0.5 microg/mL of sufentanil, with a 30% local anesthetic-sparing effect and a 40% reduction in cost. However, this reduction in local anesthetic is not associated with a decrease in the incidence of motor block, side effects, or instrumental deliveries.

IMPLICATIONS

Ropivacaine 0.10% plus 0.5 microg/mL of sufentanil given via patient-controlled epidural anesthesia for labor analgesia is equally as effective as ropivacaine 0.15% plus 0.5 microg/mL of sufentanil, with a 30% local anesthetic-sparing effect and a 40% reduction in cost. This reduction in ropivacaine concentration is not associated with a decrease in the incidence of motor block, side effects, or instrumental deliveries.

Neuraxial opioids for labour analgesia: analgesic efficiency and effect on labour

Neuraxial opioids have changed the practice of obstetric anaesthesia and analgesia dramatically. Excellent analgesia with minimal side effects started an era of ever increasing numbers of women who opt for the 'painless birth experience'. Several papers have been reported during 2001 that examine analgesic efficacy, maternal side effects, and effect on foetal well-being of epidural and spinal opioids. Foetal bradycardia following intrathecal opioid analgesia, an increasingly popular technique, has attracted particular attention over the past few years. The present review addresses recently reported work that, according to the author, is key to this field.

Combined spinal-epidural analgesia for labor: breakthrough or unjustified invasion?

The combined spina-epidural (CSE) technique has become increasingly popular for labor analgesia. The advantages of the CSE include more rapid onset of analgesia, reduced total drug dosage, minimal or no motor blockade, and increased patient satisfaction. CSE has also been associated with more rapid cervical dilation when compared to epidural analgesia in nulliparous women in early labor. Despite these potential advantages, the indications for CSE versus epidural analgesia remain unclear and controversial. This review should allow better understanding of the benefits and risks of this technique, and bearing in mind that no ultimate neuraxial analgesic exists, it would seem that CSE should be considered a major breakthrough in the management of labor analgesia.