Hyperventilation-induced tetany associated with epidural analgesia for labor.

We report a case of painful carpo-pedal spasm associated with the initiation of epidural analgesia for labor. The patient, an otherwise healthy primigravida in early labor at term, was experiencing severe hyperventilation as a result of inappropriate use of the Lamaze breathing technique. Bilateral carpo-pedal spasm occurred, and produced severe pain. Resolution of symptoms coincided with onset of effective epidural labor pain relief. A diagnostic challenge was presented to the anesthesiologist, as the symptoms could have been consistent with subdural block, local anesthetic toxicity, high sensory level of analgesia or eclamptic neuro-excitation activity.