Though patients may be satisfied when PCA remifentanil is used during labor, apnea is more common with remifentanil than with epidural analgesia. (Image source: Thinkstock)

Though patients may be satisfied when PCA remifentanil is used during labor, apnea is more common with remifentanil than with epidural analgesia. (Image source: Thinkstock)

Remifentanil is a powerful opioid analgesic with a very short duration of action. The rapid onset of opioid drug effect is associated with a risk of both apnea and hypoxemia. Dr. Carolyn F. Weiniger, Department of Anesthesiology and Critical Care Medicine, Hadassah Hebrew University Medical Center, Jerusalem, Israel, and her coauthors sought to determine whether remifentanil would be better than epidural analgesia for patients in labor.  Their work, now available online in the article “A Randomized Controlled Trial of the Efficacy and Respiratory Effects of Patient-Controlled Intravenous Remifentanil Analgesia and Patient-Controlled Epidural Analgesia in Laboring Women,” will be published in a future issue of Anesthesia & Analgesia.

Women gave verbal consent as soon as they arrived in the delivery suite, though they were not enrolled in the study until they were in active labor.  Women were randomized to receive either remifentanil patient-controlled IV analgesia (PCIA) as a bolus dose of 20 mcg up to a maximum of 60 mcg as needed with a lockout interval of 1 or 2 minutes, or epidural analgesia with 15 mL of 0.1% bupivacaine with 50 mcg fentanyl followed by patient-controlled epidural analgesia infusion of 0.1% bupivacaine with 2 mcg/mL fentanyl at a basal infusion of 5 mL/h, patient-controlled bolus 10 mL, and lockout interval of 20 minutes.  Forty women were included in the study.

In both groups the intervention reduced the pain of labor. However, remifentanil was less effective than epidural anesthesia. Patient satisfaction was the same in both groups.  Only women in the remifentanil groups experienced apnea (9 events, 5 women).  Two neonates in the remifentanil group required an intervention.

It is not always be possible to insert an epidural catheter.  If the decision is to use remifentanil, close monitoring for respiratory depression is required.