8.9: Local Anesthetics: Clinical Application as Epidural Anesthesia
Epidural anesthetics are administered in the fat-filled epidural space, the outermost part of the spinal canal. This technique is commonly employed for pain management and anesthesia during lower abdomen and pelvis surgeries or labor and delivery.
Since epidural anesthetics can be infused through an epidural catheter, all types of drugs, including short-acting ones, can be administered. Chloroprocaine and lidocaine are examples of short and long-duration anesthetics, respectively. Bupivacaine is the drug of choice if prolonged anesthesia is required for surgeries. Lower concentrations of bupivacaine are used to provide analgesia during labor. Adding vasoconstrictors like epinephrine reduces systemic toxicity while prolonging the anesthesia duration. A significant difference between spinal and epidural anesthesia is that no differential sympathetic blockade is observed in epidural anesthesia.
Potential risks and complications associated with epidural anesthesia include dural puncture, infection, nerve damage, and systemic toxicity from local anesthetics (LA). High concentrations of LA in plasma during labor can result in the LAs crossing the placenta and entering fetal circulation. This results in neonatal depression during delivery.
