Alternatives to neuraxial analgesia for labor.

PURPOSE OF REVIEW: Although millions of parturients profit from neuraxial analgesia for labor, there are far more of those who do not have this choice for one reason or another. They need alternative ways to relieve labor pain. RECENT FINDINGS: Paracervical block gives less efficient analgesia compared with single-shot spinal in a sample of multiparae at active labor but is associated with better umbilical artery pH. Use of a neurostimulator may increase success in pudendal block. It is possible to reduce nitrous oxide occupational exposure by a developed scavenging system. Intravenous remifentanil gives less efficient pain relief than epidural analgesia. The maternal satisfaction, however, may be comparable. SUMMARY: Paracervical block with modern technique is a viable option for selected cases. It is rapid and does not affect the course of labor, but its efficacy is only modest. Pudendal block can be used in the second stage of labor or for episiotomy tear repair and pain. Intravenous remifentanil is currently becoming an established method, although its safety is still an issue. Nitrous oxide is a useful method to be used alone or together with the other methods.

Remifentanil in obstetric analgesia: a dose-finding study.

UNLABELLED: IV patient-controlled analgesia (PCA) with remifentanil is a new approach in systemic opioid analgesia during labor. We determined the minimum effective dose of IV remifentanil by increasing the PCA bolus from 0.2 microg/kg with 0.2 microg/kg increments during a 60-min study period until the analgesia was considered adequate by the parturient. Twenty healthy parturients with singleton pregnancies participated in the study during the first stage of labor. Remifentanil hydrochloride was given IV via PCA over 1 min with a lockout time of 1 min. The parturient started the PCA bolus at the first subjective sign of uterine contraction. All 17 patients who completed the study reached adequate pain relief. The median effective PCA bolus was 0.4 microg/kg and consumption was 0.066 microg x kg(-1) x min(-1), with wide individual variation (0.2-0.8 microg/kg and 0.027-0.207 microg x kg(-1) x min(-1), respectively). The pain scores were reduced by a median of 4.2 (25th-75th percentiles, 3.1-5.2; P < 0.001) on an 11-point numeric scale. Although there was a wide individual variation in the dose required, remifentanil seems effective for labor analgesia. However, maternal oxygen desaturation, sedation, and reduced fetal heart rate beat-to-beat variability were observed frequently. There was wide individual variation in the dose required for effective labor analgesia. Potentially serious side effects, which were observed frequently during remifentanil analgesia, may limit remifentanil's use in obstetrics. IMPLICATIONS: We determined the minimum effective dose of patient-controlled IV remifentanil for labor analgesia. There was wide individual variation in the dose required for effective labor analgesia. Potentially serious side effects, which were observed frequently during remifentanil analgesia, may limit its use in obstetrics.