Pain management during labor: Clinical sciences

Labor is defined as the onset of regular uterine contractions that cause the cervix to efface and dilate. Pain is a natural component of labor and each person experiences it differently. Supporting your patients’ desires on how to manage their pain in labor is an important part of obstetric care, and all available options should be discussed with each patient, including non-pharmacological or pharmacological options; a combination of both; or they may choose to have no pain interventions.

Alright, let’s first talk about when your patient presents with pain during labor, and assessment of their desire for pain management intervention. Often, the options for pain management are discussed during prenatal care visits or birthing classes. Some of your patients will have specific desires and plans, while others will take a “let’s see how labor goes” approach and are open to suggestions. Remember that your patient's desires may change throughout their labor course. It’s completely okay if your patient starts out wishing to avoid all medications and then later in their labor course requests an epidural or another pharmacological option!

Okay, let’s review what can be offered when your patient desires non-pharmacological pain management. There are lots of different options to help labor pain that are non-pharmacological pain management. These include massage, movement, immersion in water during the first stage of labor, acupuncture, relaxation, aromatherapy, and hypnotherapy. These can be performed in any order and one isn’t necessarily better than another.

Some patients choose to hire a birth doula, or professional labor coach, to provide one-on-one support during labor. This can be very helpful, especially in patients who want to avoid pharmacological interventions.

Next, let’s discuss what can be offered when your patient desires pharmacological pain management. Keep in mind the difference between analgesia and anesthesia. Analgesia is when pain is reduced or relieved. Anesthesia refers to a pain-free state with or without loss of consciousness.

First, let’s talk about parenteral or systemic analgesia. These include fentanyl, morphine, nalbuphine, butorphanol, and remifentanil. There’s no great difference between these various opioids, and you will find that protocols at different facilities use different types and doses of opioids. The benefits of opioids include that they’re inexpensive and no advanced expertise is needed to administer. However, their effectiveness is limited, as they do not take away all labor pain completely and wear off after a couple of hours.

The major maternal side effects are nausea and vomiting, and you will need to monitor for respiratory depression. Also keep in mind that, since opioids cross the placenta, you’ll need to watch for changes in the fetal heart rate as well as neonatal respiratory depression.

Here’s a clinical pearl! Opioid agonist–antagonist medications, such as butorphanol and nalbuphine, should be avoided in patients who are taking an opioid agonist as part of opioid use disorder maintenance, since they can precipitate acute withdrawal.

Another analgesia option is the inhaled agent nitrous oxide, which has gained a lot of popularity recently. It’s self-administered using a mouthpiece or facemask in a 50% blend of nitrous oxide and oxygen. Benefits include maternal control over the administered amount, as well as the fact that movement is maintained, additional monitoring is not required, and its effect quickly wears off once the mask is removed. The main side effects are nausea, vomiting, dizziness, and drowsiness. Of note, it can also be used during repair of vaginal lacerations after delivery.

Next are regional or neuraxial analgesia and anesthesia options, which include an epidural or spinal. Regional and neuraxial methods vary from other options as they require placement by a qualified anesthesia provider. Epidural analgesia is administered by placing a catheter into the epidural space. Having the catheter in place allows for continuous infusion of medication that will last through labor and repair of vaginal lacerations if needed. An epidural can also be used in the case of c-section delivery by bolusing the already placed catheter with medication.