| Anesthesia-induced mild hypothermia increases the risk of blood loss and wound infection, and it causes shivering. Thirty to 60% of parturients who receive spinal or epidural anesthesia during Cesarean delivery suffer from hypothermia, and maternal hypothermia induces hypothermia of the newborn . Horn et al. showed that forced-air prewarming for 15 minutes before anesthesia induction prevented the development of hypothermia in patients undergoing Cesarean delivery during epidural anesthesia and prevented the development of hypothermia in the newborn .Although it was shown that intravenous (IV) infusion of warmed fluids helped to prevent hypothermia during major abdominal surgery and ambulatory gynecological anesthesia, the Association of periOperative Registered Nurses (AORN) Recommended Practices Committee recommended that warmed infusion should be considered only if a large volume (ie, more than two L/hr) is administered . Administration of a large volume of warm crystalloid (one L/15 min) reduced the incidence of shivering. However, the effects of warmed infusion on maternal and neonatal temperature, and neonatal outcome such as umbilical pH and Apgar scores, have not been determined. Although preloading of a large volume of crystalloid before spinal anesthesia for prevention of maternal hypotension is not recommended, colloid administration before spinal anesthesia, even a relatively small dose (5-10mL/kg), may decrease the incidence of maternal hypotension. After volume preloading, 100% of the colloid remains in the vascular space, while only 25% of the crystalloid does so. Thus, the difference in temperature of a colloid that had been preloaded before spinal anesthesia may produce a difference in maternal and neonatal core temperatures and improve neonatal outcome.We thus hypothesized that intravenous infusion of pre-warmed colloid followed by a warm crystalloid solution before spinal anesthesia and during surgery may prevent the development of maternal and neonatal shivering, and influence neonatal outcome in pregnant women undergoing Cesarean section during spinal anesthesia.Objective: To determine whether intravenous infusion of pre-warmed colloid followed by pre-warmed crystalloid solution change the parturients' temperature for Cesarean section and effect the neonatal outcome.Design: Randomized, placebo-controlled study.Patients: 60 parturients scheduled to undergo elective Cesarean section during spinal anesthesia.Method:Patients assigned to the warmed fluid group (n=30) received pre-warmed colloid HES with average molecular weight of 130,000 daltons and substitution ratio of 0.38-0.45, followed by pre-warmed crystalloid (kept in warmed storage maintained at 39°C before surgery). Patients assigned to the unwarmed fluid group (n=30) received non-warmed fluid group (kept in room maintained at 19°C). All patients received 400 mL HES before spinal anesthesia followed by another 300 mL before delivery of the newborn. After completion of a 1,000 mL infusion of colloid fluid, Lactate Ringer's solution was infused until the end of surgery.Measurements:⑴Core temperature measured at the rectal, Peripheral temperature measured at forearm and fingertip skin temperatures were recorded just after arrival at the operating room (baseline), after administration of spinal anesthesia (spinal), at incision (incision), at delivery of the newborn (delivery), and at 15, 30, and 45 minutes after delivery.⑵CalculatingΔT= forearm skin temperature-fingertip skin temperature.ΔT>0 indicate peripheral vasoconstric- tion.⑶Rectal temperature of the baby at one minute after delivery, and umbilical artery pH and BE value were evaluated.⑷Apgar scores at one and 5 minutes after delivery.⑸Hb were recorded before and after surgery. CalculatingΔHb = Hb before surgery- Hb after surgery, comparing the whole blood loss between the parturients of two groups.⑹Comparing the incidence of shivering between the parturients of two groups.Results: Core temperature was significantly higher in the warmed fluid group from the time of delivery to 45 minutes after delivery. Apgar scores at one minute after delivery were significantly higher and umbilical arterial pH were normal in the warmed fluid group.ΔHb were less in the warmed fluid group.ΔT1>0 andΔT2>0 in the non-warmed fluid group.Conclusion: Intravenous infusion of pre-warmed intravenous colloid followed by crystalloids maintained core temperature during Cesarean section and induced higher Apgar scores and normal umbilical arterial pH. The whole blood loss of parturients were less in the warmed fluid group. Forearm skin temperature were higher than fingertip skin temperature at the time of spinal anesthesia (spinal), at the time of incision (incision) in the non-warmed fluid group, indicating peripheral vasoconstriction. |
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