Obstetric analgesia and anesthesia

Obstetric analgesia and anesthesia refer to the multiple techniques used to alleviate pain associated with labor and delivery. Analgesia is relief of pain without loss of consciousness. Regional analgesia implies partial sensory blockade, with or without partial motor blockade, over a specific region of the body. Regional anesthesia is the loss of sensation, motor function, and reflex activity over a specific region of the body. Regional blocks used for labor or vaginal delivery or both include lumbar epidural, caudal epidural, spinal, paracervical block, lumbar sympathetic block, pudendal block, and perineal infiltration. In the past, lumbar epidural analgesia often resulted in significant relaxation of skeletal muscle. In contemporary practice, many physicians administer dilute solutions of local anesthetic, with or without an opioid, which typically result in little or no motor blockade. General anesthesia results in a loss of consciousness. Systemic agents capable of producing anesthesia may produce modest analgesia when administered in low concentrations. The term balanced anesthesia refers to a technique in which a combination of drugs is used to provide hypnosis, amnesia, analgesia, and skeletal muscle relaxation, while exposing the fetus to small amounts of anesthetic agents.