CHAPTER 60 Obstetric Analgesia and Anesthesia
1 What are the most commonly used parenteral opioids for labor analgesia? Which side effects are of special concern to the parturient?
Table 60-1 summarizes commonly used parenteral opioids and their side effects. In general, intravenous medications help the parturient tolerate labor pain but do not provide complete analgesia. The incidence of side effects and efficacy of analgesia are dose dependent. Maternal sedation and nausea are common. Opioids easily cross the placenta and may cause a decrease in fetal heart rate variability. In addition, intravenous opioids may cause neonatal respiratory depression and neurobehavioral changes.
2 What advantages does PCA offer over conventional intermittent bolus dosing?
Patient-controlled analgesia (PCA) has been associated with greater patient satisfaction, less risk of maternal respiratory depression, less need for antiemetic use, and better pain relief despite lower drug doses. PCA is especially useful if epidural anesthesia is contraindicated or not available. The most experience has been gained with meperidine and fentanyl using the regimens noted in Table 60-1.