Epidural analgesia for labor: safety and success

Abstract

Safe and successful provision of epidural analgesia for labor requires an understanding of the risks of the technique and attention to detail when performing the technique. The frequency of the commonest complication of epidural analgesia, accidental dural puncture, can probably best be minimized by regular practice of the technique. Some catheters, intended for the epidural space, will find themselves intrathecal, intravascular, or subdural. Although such misplacements probably cannot be prevented, their consequences can be minimized by careful, incremental injection of small doses of local anesthetic. The traditional epidural “test dose” of 45 mg of lidocaine and 15 μg of epinephrine can have undesired effects when injected intrathecally, intravenously, or epidurally. Successful epidural analgesia requires first placing a catheter in the epidural space. The combined spinal epidural technique is a very reliable way to accomplish this task. Subsequently, an appropriate dose of drug must be injected or infused by using an effective delivery system. Continuous infusion of ultra-dilute solutions of local anesthetics and opioids will relieve labor pain in some women, but the frequent need for supplemental medications severely limits their efficacy. Patient-controlled epidural analgesia, using slightly more concentrated local anesthetic solutions produces excellent analgesia with less local anesthetic and less need for rescue medication than continuous infusion techniques.