Epidural Fentanyl for 2nd Stage Labor Analgesia

The objective is to evaluate if high-dose epidural fentanyl (100 micrograms) is more
effective at providing pain relief during the late first stage (>8 cm cervical dilation) and
second stage of labor until the time of delivery compared to low-dose epidural fentanyl (20
micrograms). In this study, anesthetic care will be provided to a subject by an experienced
anesthesia provider according to standard hospital care. If the subject has adequate pain
relief from the continuous epidural infusion, then a study investigator will record the
verbal pain score and document any other side effects at hourly intervals beginning at >8cm
cervical dilation, but no additional epidural medications will be administered. If pain
relief becomes inadequate during the late first or second stage of labor (>8cm cervical
dilation) and a manual epidural bolus is required, then the subject will be randomly assigned
to one of two groups (like flipping a coin): one group will receive lower dose epidural
fentanyl (20 micrograms) combined with local anesthetic; and one group will receive
higher-dose epidural fentanyl (100micrograms) combined with the same amount of local
anesthetic. Both doses are used frequently on labor and delivery and are considered to be
safe based on available evidence. If there is not sufficient pain relief from the epidural
medication given, then an experienced anesthesia provider will assess if another epidural
dose may be effective and this additional epidural medication will be given at the discretion
of the anesthesia provider. An experienced anesthesia provider will be available at all times
during the study to assess pain and provide epidural medications. All patients participating
in the study will have their pain scores assessed every hour as soon as the cervical dilation
is noted to be >8cm; at the time of randomization; and at 10, 20, 30 and 60 minutes after the
epidural dose is administered. The presence of any side-effects such as itching, shivering,
nausea, vomiting, low blood pressure, slow respiratory rate or lower extremity muscle
weakness will also be collected at hourly intervals as soon as the cervical dilation is noted
to be >8cm. Subject satisfaction (1-100 rating scale) with anesthetic care provided will be
assessed on postpartum day # 1 during routine follow-up visit.

Inclusion Criteria:

1. Nulliparous women

2. Spontaneous labor

3. A single vertex presentation fetus at term (38-42 weeks)

4. Effective labor epidural analgesia with continuous epidural infusion established

5. Provide written consent to participate in the study.

Exclusion Criteria:

1. Multigravida women

2. Multigestation pregnancies

3. Patients being treated/managed for chronic pain

4. Allergies or significant adverse reactions to local anesthetic or opioid medications

5. Inadequate or unsatisfactory labor epidural analgesia

6. Patients with history of spine abnormalities or spine surgery

7. Non-English speaking

8. Prisoners

9. Age less than 18 years old