Intrathecal Ropivacaine for Labor Analgesia

Programmed intermittent epidural bolus as an ideal method for labor analgesia: a randomized controlled trial

BACKGROUND

Although programmed intermittent epidural bolus (PIEB) is effective for labor analgesia, an appropriate flow rate has not been established. Therefore, we investigated the analgesic effect based on different epidural injection flow rates.

METHODS

Nulliparous women scheduled for spontaneous labor were enrolled in this randomized trial. After injection of intrathecal 0.2% ropivacaine 3 mg with fentanyl 20 μg, participants were randomized to three study groups. Epidural analgesics, 10 ml during one hour, were administered with patient controlled epidural analgesia as follows (0.2% ropivacaine 60 ml, fentanyl 180 μg, and 0.9% saline 40 ml): continuous (n = 28, 10 ml/h for continuous infusion), PIEB (n = 29, 240 ml/h for bolus infusion of 10 ml), or manual (n = 28, 1200 ml/h for bolus injection of 10 ml). The primary outcome was hourly consumption of the epidural solution. The time interval between labor analgesia and the first breakthrough pain was investigated.

RESULTS

The median (Q1, Q3) hourly consumption of epidural anesthetics was significantly different among the groups (continuous: 14.3 [8.7, 16.9] ml, PIEB: 9.4 [6.2, 9.8] ml, manual: 8.6 [7.6, 9.9] ml; P < 0.001). The time to breakthrough pain for the PIEB group was longer than that for the other groups (continuous: 78.5 [35.8, 185.0] min, PIEB: 200.0 [88.5, 441.5] min, manual: 60.5 [37.3, 162.0] min, P = 0.027).

CONCLUSIONS

PIEB, with a low-flow rate, provided more adequate labor analgesia than a continuous epidural infusion or manual injection with a high-flow rate.

A biased coin up-and-down sequential allocation trial to determine the ED90 of intrathecal sufentanil combined with ropivacaine 2.5 mg for labor analgesia

Purpose

To determine the 90 percent effective dose (ED90) of intrathecal sufentanil combined with ropivacaine 2.5 mg for labor analgesia and observe its safety for parturients and neonates.

Methods

We conducted a prospective, double-blind, biased coin up-and-down study. We injected a fixed 2.5 mg ropivacaine combined with a designated dose of sufentanil intrathecally to observe the labor analgesic effect. The initial dose of sufentanil was assigned 1.0 μg, and the remaining doses were assigned as per the biased coin up-and-down method. The criterion of successful response was defined as VAS ≤ 30 mm after intrathecal injection at 10 min. Safety was evaluated in terms of maternal and neonatal outcomes.

Results

The ED90 dose of intrathecal sufentanil combined with ropivacaine 2.5 mg (0.1%, 2.5 mL) was 2.61 μg (95% CI, 2.44 to 2.70 μg) by isotonic regression. No respiratory depression, hypotension, or motor block was observed. Thirty-one (77.5%) parturients complained of pruritus, and 14 (35.0%) suffered nausea and vomiting. Three neonates reported a 1 min Apgar score of ≤7, and none reported a 5 min Apgar score of ≤7.

Conclusion

The ED90 of intrathecal sufentanil combined with ropivacaine 2.5 mg for labor analgesia was 2.61 μg. The dose is safe for parturients and neonates.

Polyanalgesic Consensus Conference 2012: recommendations for the management of pain by intrathecal (intraspinal) drug delivery: report of an interdisciplinary expert panel

INTRODUCTION

The use of intrathecal (IT) infusion of analgesic medications to treat patients with chronic refractory pain has increased since its inception in the 1980s, and the need for clinical research in IT therapy is ongoing. The Polyanalgesic Consensus Conference (PACC) panel of experts convened in 2000, 2003, and 2007 to make recommendations on the rational use of IT analgesics based on preclinical and clinical literature and clinical experiences.

METHODS

The PACC panel convened again in 2011 to update the standard of care for IT therapies to reflect current knowledge gleaned from literature and clinical experience. A thorough literature search was performed, and information from this search was provided to panel members. Analysis of published literature was coupled with the clinical experience of panel members to form recommendations regarding the use of IT analgesics to treat chronic pain.

RESULTS

After a review of literature published from 2007 to 2011 and discussions of clinical experience, the panel created updated algorithms for the rational use of IT medications for the treatment of neuropathic pain and nociceptive pain.

CONCLUSIONS

The advent of new algorithmic tracks for neuropathic and nociceptive pain is an important step in improving patient care. The panel encourages continued research and development, including the development of new drugs, devices, and safety recommendations to improve the care of patients with chronic pain.

Efficacy of patient-controlled epidural analgesia after initiation with epidural or combined spinal-epidural analgesia

BACKGROUND

The aim of the present study was to compare the efficacy of patient-controlled epidural analgesia after initiation with either epidural or combined spinal-epidural analgesia.

METHODS

Forty ASA I parturients at 37-42 weeks' gestation and cervical dilatation <6 cm were randomly allocated to receive either epidural analgesia (group EA) or combined spinal-epidural analgesia (group CSEA). Analgesia was initiated with a 7-mL epidural bolus 0.1% bupivacaine containing fentanyl 50 mug (group EA, n=20) or with intrathecal fentanyl 20 mug (group CSEA, n=20). In both groups, analgesia was provided by a 5-mL bolus on demand via PCEA with a 10-min lock-out interval and a 15-mL/h limit.

RESULTS

No significant differences were observed in the rate of cervical dilatation, delivery type or duration of delivery between the groups. The time to first analgesic demand was shorter in the CSEA than in the EA group. Total bupivacaine dose was comparable in both groups, but total fentanyl dose in group CSEA was significantly lower than that of group EA because of the initial dose used for the induction of EA and CSEA. The incidence of pruritus in group CSEA was significantly higher than in group EA.

CONCLUSION

Both regional analgesia techniques followed by demand-only PCEA provided efficient pain relief for labor without changing the duration of labor or rate of cesarean section.

New local anesthetics. Are they worth the cost?

Epidural analgesia that uses dilute concentrations of bupivacaine with fentanyl or sufentanil provides excellent analgesia, good sensory-motor discrimination, and minimal toxicity and is inexpensive. The new local anesthetic agents, ropivacaine and levobupivacaine, offer potential improvements in the risk of toxicity when administered in large doses but probably no important clinical difference when used in dilute concentrations for labor analgesia. After accounting for the potency difference, ropivacaine offers little or no motor-sparing advantage over bupivacaine. Currently, epidural anesthesia with concentrated bupivacaine is rarely used for cesarean section, so there is little indication for the newer anesthetic agents in this setting either. The authors believe that large difference in cost cannot be justified on the basis of currently available data.

Newer techniques of labor analgesia

In maternity units in which central neuraxial techniques are frequently used, newer methods of epidural drug delivery (continuous infusion, patient-controlled) are well established and combined spinal-epidural analgesia is commonly used. Continuous spinal analgesia has reemerged as a useful approach after accidental dural puncture. Lumbar sympathetic block has been revisited and the safety of paracervical nerve block improved. The analgesic properties of systemic opioid in labor are poor, but PCIA at least has psychological benefits and allows rapid drug titration. PCIA is again under investigation because of the potent antinociceptive effects of the short-acting mu-opioid agonist, remifentanil. The premixing of nitrous oxide and a subanesthetic concentration of volatile anesthetic for patient-controlled administration has been tested under control of midwifery staff and without direct medical supervision.

Continuous spinal analgesia for labor pain in a parturient with aortic stenosis

Aortic stenosis in pregnancy carries a high fetal and maternal morbidity and mortality. Spinal analgesia/anesthesia is considered by many to be contraindicated in these patients. The rapid onset of sympathetic block induces hypotension, which can result in myocardial hypoperfusion and myocardial ischemia. We describe a case of moderate to severe aortic stenosis, diagnosed during pregnancy, in which pain relief during labor and delivery was managed using a continuous spinal catheter. Pure intrathecal opioid analgesia was used initially to maintain hemodynamic stability. However after two bolus administrations of sufentanil, analgesia was further maintained using ropivacaine and sufentanil. A spinal catheter was chosen to provide reliable anesthesia, which could be extended rapidly for cesarean section.

Regional anesthesia for obstetrics

The practice of administration of labor analgesia has undergone dramatic changes this decade. This is largely attributable to unparalleled interest in the field by many dedicated and capable investigators around the world. Through their efforts, this decade has witnessed the introduction of new techniques (pencil point needles, CSE, PCEA, ultradilute epidural regimens) that have permitted us to come closer than ever to realizing the goal of complete relief from the pain and suffering of labor while safeguarding the well-being of mother and child and minimizing effects on the labor process. Neuraxial anesthetic techniques and modern multimodal analgesic approaches to postoperative pain relief now minimize the effects of cesarean delivery on maternal satisfaction and participation in the birth process.