HYPERTHERMIA RELATED TO EPIDURAL ANALGESIA DURING LABOR

Although hypothermia has been reported during epidural anesthesia perf ormed for non-obstetrical surgery or cesarean section, epidural analge sia for labor may lead to hyperthermia. Its incidence, time-course and intensity are influenced by multiple factors including site of measur ement, duration of labor preceding epidural analgesia and perhaps ambi ent temperature and occurrence of shivering. During the first 2-5 h of epidural analgesia, a significant increase in temperature is not usua lly observed. Then, if labor is prolonged (mostly in primiparas), temp erature may increase at a rate of 0.07-0.15 degrees C per hour. Imbala nce between reduced heat loss during epidural analgesia and labor-indu ced heat production has been implicated but impairment of central temp erature regulation cannot be excluded. This hyperthermia is usually of mild intensity (< 38 degrees C) and occurs in the absence of any infe ctious process; maternal and fetal consequences are also usually absen t and treatment is probably unnecessary. However, fetal tachycardia ma y occur and the potential for a deleterious effect on the fetus remain s controversial. Various measures for cooling the mother have been pro posed but their efficacy has not been evaluated. The recognition that epidural analgesia may provoke hyperthermia may help to avoid inapprop riate use of antibiotics or fetal extraction.