The ideal labor analgesia should provide satisfactory maternal pain relief but not interfere with labor progression or outcome while minimizing adverse side effects to the mother and fetus. Although no single analgesia technique is ideal for all parturients, neuraxial analgesia (epidural, spinal, or combined spinal-epidural) is arguably the analgesic technique closest to the ideal for most women.
Pain in the first stage of labor is caused primarily by cervical dilation transmitted via visceral afferent fibers to the T10 to L1 spinal cord segments. As labor progresses and the fetus descends in the birth canal, pain is also caused by vaginal and perineal distension transmitted via somatic afferent fibers traveling in the pudendal nerve to the S2 to S4 spinal cord segments. The pain of cervical dilation tends to be visceral and diffuse in nature. The sacral pain is somatic and localized.
ADVANTAGES AND DISADVANTAGES OF NEURAXIAL LABOR ANALGESIA
Advantages and disadvantages of neuraxial analgesia are listed in Table 6-1. Neuraxial analgesia is the most effective form of pain relief in labor.1 However, administration of neuraxial analgesia requires the continued presence of a trained anesthesia provider. Although neuraxial labor analgesia is effective and safe in the majority of young healthy women, some women experience complications. Dense neuraxial analgesia may adversely affect the mode of vaginal delivery.
Table 6-1.Advantages and Disadvantages of Neuraxial Labor Analgesia ||Download (.pdf) Table 6-1.Advantages and Disadvantages of Neuraxial Labor Analgesia
|Advantages ||Disadvantages |
| More effective than parenteral analgesia || Procedure requires anesthesia provider |
| Improves uteroplacental blood flow || Procedure with risk of complications |
| Blunts maternal sympathetic response to pain || Medications with side effects |
| Rapid conversion from labor analgesia to surgical anesthesia for cesarean delivery || +/– Increase the rate of instrumental delivery |
| || +/– Affects duration of labor |
|Advantages ||Disadvantages |
| Lower exposure to medication than intravenous techniques || Possibility of maternal hypotension |
| Less exposure to maternal catecholamines || Possibility of uterine tachysystole (tetanic contraction) |
Alternate options for nonpharmacologic pain relief, particularly in early labor, include sterile water injections, water therapy, continuous labor support, touch and massage, and maternal movement and positioning.2,3 Systemic opioids are the most common form of pharmacologic alternative to neuraxial labor analgesia, but analgesia is incomplete and maternal and fetal respiratory depression limit the dose.
INDICATIONS AND CONTRAINDICATIONS OF NEURAXIAL LABOR ANALGESIA
Indications for Neuraxial Labor Analgesia
Neuraxial labor analgesia is an elective procedure in the majority of young, healthy parturients. If there is no contraindication, neuraxial analgesia should be provided upon request. Both the American College of Obstetricians and Gynecologists and the American Society of Anesthesiologists have endorsed the following statement: “There is no other circumstance where it is considered acceptable for an individual to experience untreated severe ...