17.3: Pharmacological Pain Management
By the end of this section, you will be able to:
- Provide patient education on, administer, and monitor patients receiving analgesic medications during the process of labor and birth
- Educate the patient desiring nitrous oxide for the discomfort of labor and birth
- Explain the role of naloxone during the process of labor and birth
The laboring person determines the level of pain they are experiencing during labor. Every person has a different level of pain tolerance and should be able to request pain relief measures at any time during labor. Analgesia refers to the inability to feel pain, and the medications designed to lessen or eliminate pain without loss of consciousness are called analgesics. For persons desiring analgesia in labor, many safe options are available. The nurse provides education on different types of analgesics, their side effects, and what monitoring is required while using the analgesic. The nurse administers the analgesics as prescribed and monitors and documents the effectiveness per facility protocol.
Analgesia
Analgesia is used often for labor pain. It is important to note that all analgesics cross the placenta. Most analgesics cause a depressant effect on the laboring person and the fetus; therefore, the nurse will assess the FHR, vital signs, cervical dilation, and stage of labor prior to administering pain medication. Analgesics can be administered by many different routes: subcutaneous, intramuscular, intravenous, inhaled, and oral. In most cases, analgesics are administered intravenously (IV). This route allows faster pain relief to the laboring person. This route, however, causes a depressant effect; if too high a dose is given, it can lead to respiratory depression . Intravenously administered analgesics reach the fetus quickly and stay in the fetal system longer. If the fetus is born while the analgesic is still circulating, the fetus can exhibit depressed respirations.
Analgesia can be divided into categories. Table 17.2 lists the categories and some examples of analgesia.
| Category of Analgesia | Description | Medications |
|---|---|---|
| Tranquilizer/Amnestic |
Relieves anxiety
Rapid sedation |
Hydroxyzine (Vistaril) |
| Narcotic |
Relieves pain
Reduces anxiety Causes respiratory depression |
Fentanyl |
| Ultra-short-acting synthetic opioid |
Relieves pain
Causes respiratory depression Rapidly metabolized Does not accumulate in the fetus |
Remifentanil (Ultiva) |
| Opioid agonist-antagonist |
Relieves pain
Less respiratory depression |
Butorphanol (Stadol)
Nalbuphine (Nubain) |
| Inhaled analgesic |
Reduces anxiety
Reduces pain Rapidly reversed |
Nitrous oxide (50% N 2 O/50% O 2 ) |
Hydroxyzine
Hydroxyzine (Vistaril) is an anxiolytic that causes drowsiness and creates a feeling of calm. Hydroxyzine is commonly used in latent or early labor to relieve anxiety and allow the person to rest until active labor begins. It is not normally used during active labor. Hydroxyzine also has antihistamine properties that can cause drowsiness to aid in sleep. Side effects include dry mouth, constipation, dizziness, and headache (Brunton & Knollman, 2022). Hydroxyzine can be administered orally and intramuscularly. The nurse educates the pregnant person that they will feel relaxed and sleepy but that hydroxyzine is not a pain reliever. If the person begins to experience labor pain, they should ask the nurse what the health-care provider has ordered for pain relief.
Promethazine
Promethazine (Phenergan) is an antiemetic that is given for nausea and vomiting or in conjunction with a narcotic. It causes drowsiness and can help the laboring person sleep. Nausea and vomiting are common discomforts in labor, and promethazine can be used as treatment. Promethazine’s side effects include drowsiness, nervousness, restlessness, and dry mouth (Brunton & Knollman, 2022). Routes include oral, rectal, intramuscular (IM), and intravenous (IV). The nurse should be aware of the caustic nature of the medication and should give IM injections deep into the muscle. When administering promethazine IV push, the medication should be diluted adequately (usually with 5 to 10 mL of normal saline) and administered slowly (over 5 to 10 minutes). The nurse educates the laboring person on the side effects and encourages the person to ask for assistance when getting out of bed.
Butorphanol
Butorphanol (Stadol) is an opioid agonist-antagonist used for moderate to severe pain in labor. It can be given intramuscularly or intravenously. It causes sedation and decreased pain. Side effects include dizziness, confusion, nausea, constipation, respiratory depression, and withdrawal syndrome (Brunton & Knollman, 2022). Because of the medication’s antagonist property, persons dependent on opiates can have withdrawal symptoms when taking butorphanol. The nurse should assess the person’s social history prior to administering the medication. The nurse educates the laboring person and partner on the side effects and explains the need for assistance when getting out of bed.
Nalbuphine
Nalbuphine (Nubain) is an opioid agonist-antagonist used for moderate to severe pain in labor. Side effects include dizziness, nausea, respiratory depression, and urinary retention (Brunton & Knollman, 2022). It should not be given to persons with substance use disorder, as it can precipitate withdrawal. It is normally given intramuscularly or intravenously, but can also be administered subcutaneously. As with butorphanol, the nurse must assess the person’s social history regarding opioid dependency and signs of opioid withdrawal prior to administering. The nurse explains the side effects and encourages the person to call for assistance when getting out of bed.
Fentanyl
Fentanyl is a potent opioid used to treat moderate to severe pain. It can be administered through an epidural catheter or intravenously. Side effects include nausea, bradycardia, hypotension, sedation, peripheral vasodilation, and potentially fatal respiratory depression (Brunton & Knollman, 2022). Some institutions require a continuous pulse oximeter to be used to monitor oxygen saturation while using this opioid. The nurse should keep an opioid antagonist readily available in case of overdose and respiratory depression. The nurse educates the laboring person and partner on the side effects and the importance of calling for assistance when getting out of bed.
Pain Relief Expectations
The beliefs and perceptions of the person experiencing childbirth influence their subjective labeling and response to the process of labor and birth as well as any decisions made within the health-care setting. Pain is part of the labor and birth process, and culture influences a person’s perception and communication of their pain. Laboring persons of various cultures may express their pain by vocalization or no expression at all and, when asked what their level of pain is, may state the pain is a low level. Culture or individual choice will dictate what the person chooses to relieve the pain and discomfort of the labor and birth process. These choices are based on the interaction of psychologic, social, and physiologic factors. Understanding and respecting individual choices for pain relief is essential to culturally competent nursing care (Mousa et al., 2018).
Nitrous Oxide
Nitrous oxide (N 2 O) is a tasteless, odorless gas that works by releasing neurotransmitters that act like opioids in the brain and by altering pain perception in the dorsal horn of the spinal cord (Broughton et al., 2020). N 2 O is used for labor analgesia in all stages of labor and is safe for the laboring person and the fetus. N 2 O does not cause a sedating effect on the fetus, as narcotic analgesia does, and has a rapid onset and clearance. The safe concentration for labor analgesia is 50% N 2 O to 50% oxygen. A machine permanently set at this setting is used to blend the gases; the setting cannot be changed. The gas is inhaled through a mask held only by the laboring person. The gas is not free flowing. The person must place the mask firmly against the face to develop negative pressure to inhale the gas. The laboring person is in control of how much and how often to use the gas. Laboring persons describe feeling relaxed with mild pain relief. The common side effects are nausea, vomiting, and dizziness. The nurse educates the person and support person that the mask must be held only by the laboring person, the gas takes several breaths to become effective, and the person must breathe through the contractions to make it effective. Opioids used in conjunction with N 2 O can cause an increased risk for respiratory depression and are therefore not recommended.
Naloxone
Naloxone ( Narcan ) is the antidote to opioids. It rapidly replaces opioids by binding to opioid receptors and blocking the opioid from reattaching. This reverses the respiratory depression caused by opioid overdose. On the labor and delivery unit, naloxone is readily available because of the narcotics being administered for pain relief. Naloxone can be administered to the laboring person if their respirations are shallow or their oxygen saturation is low (Vallerand & Sanoski, 2023). It can be given to the newborn if respirations are slow, crying is weak, or color is poor. Opioids rapidly cross the placenta and enter the fetal circulation. If the opioid has not metabolized and cleared from the fetal circulation, the newborn can experience respiratory depression. In this case, the newborn may be given naloxone to reverse the opioid-related respiratory depression. If the birthing person is opioid dependent, naloxone should not be administered to the newborn due to possible seizure activity. The nurse monitors for respiratory depression in the laboring person, newly delivered person, and neonate when naloxone is administered.