Temperature Changes and Shivering during Epidural Anesthesia in Women Undergoing Cesarian Delivery

Background: Epidural anesthesia decreases the core temperature triggering vasoconstriction and shivering, presumably by increasing apparent lower-body temperature.We therefore tested the hypothesis that epidural anesthesia in cesarian delivery patients decrease forearm-fingertip skin-surface temperature gradient and it is cause of shivering.Methods: Twenty-two healthy pregnant women were studied.Epidural anesthesia was induced by 2% lidocaine and 0.75% ropivacaine 24 ml (T4 level) at 25 o C ambient temperature.Shivering were evaluated by observation.Core temperature was recorded in the external auditory canal using a compensated infrared thermometer.Arteriovenous shunt tone was evaluated with forearmfingertip temperature gradients; gradients less than 0 were considered evidence of vasodilation.Skin-surface temperature, skintemperature gradients (forearm-fingertip, calf-toe) and the presence or absence of shivering were measured.Results: Shivering was observed in seven of twenty two patients.Sixty minutes after induction, Tympanic temperature decreased for 0.8 ± 0.1 o C in non-shivering patients and 0.9 ± 0.1 o C in shivering patients.Forearm temperature decreased for 0.2 ± 1.7 o C in non-shivering patients, but increased for 0.5 ± 0.6 o C in shivering patients.Upper limb (Forearm-fingertip) skin Temperature gradients continues the plus in non-shivering patients, but maintain minus (45 minutes after induction) in shivering patients.Low limb skin temperature is increases in both group. Conclusions:We failed to confirm our hypothesis, but for an expected reason: shivering was preceded by hypothermia and vasoconstriction in the arm.For prevention of hypothermia in epidural anesthesia, not to be monitored core temperature, but also upper limb skin temperature gradients.(Korean J Anesthesiol 2005; 49: 193∼8)