effect of prewarming on skin temperature changes

Conditions: Spinal Anesthesia; Hypothermia Following Anesthesia; Prewarming; Core Temperature; Urological Cancer

Summary: in this randomized prospective single-blind study,american society of anesthesiologists physical status classification system ( asa )i-ii-iii patients aged 50-80 years undergoing transurethral bladder resection will be randomly divided into two groups. first group will be covered with 41 centigrade degrees double layered cotton cloth. second group will receive active prewarming. core temperature of all patients will be monitorized via tympanic membrane. skin temperature will be monitorized from 4 different body areas. spinal anesthesia will be applied at the level of l3-l4 by a 25 gauge quincke needle with a dose of 12.5-15 mg hyperbaric bupivacaine. pinprick test will be used for sensorial block assessment. t10 sensorial block will be our goal. hemodynamic parameters will be recorded. skin temperature will be monitorized before and after spinal anesthesia and changes will be recorded. operation time, amount and temperature of irrigation fluids, transfusion requirement, discharge time from postoperative care unit will also be recorded. shivering score and thermal comfort scale will be used. the two groups will be compared for the temperature changes.

in this prospective single-blind study, patients will be divided into 2 groups with computer-based randomization technique. all patients will have a fasting time of 2 hours for clear fluid and 6 hours for solid food. patients will be taken to the premedication room before the operation. written and verbal approval will be taken from all patients. tympanic membrane will be used for core temperature measurement by citizen ear thermometer,every 15 minutes.adult skin temperature probe will be used for continuous peripheral temperature measurement from four different body areas (t1:cervical7 (c7) dermatome, t2:c6 dermatome t3:lumbar 5( l5 )dermatome, t4: l4 dermatome). the two groups will have an infusion of balanced electrolyte solution with a rate of 8 mililitre/kilogram/ hour(ml/kg/hour). patients in group i will be covered with a 41 centigrade degrees double layered cotton clothes. patients in group ii will receive active prewarming with a forced-air warming blanket (warmcare full body blanket) 30 minutes prior to the operation. 0.1 mg/kg intravenous (iv) midazolam hydrochloride will be administered for premedication. patients will be transferred to operating room, covered with warmed double layered cotton clothes. standard monitoring (pulse oximetry, noninvasive blood pressure, electrocardiography) will be applied to the patients. core temperature and 4-points skin temperature measurements will be recorded. patients will be delivered 2 liter/minute oxygen with a nasal cannula. iv hydration will be continued by room temperature balanced electrolyte solution with an infusion rate of 2mililiter/kilogram/hour. spinal anesthesia will be applied at the level of l3-l4 by a 25 gauge quincke needle with a dose of 12.5-15 mg hyperbaric bupivacaine in the sitting position. then patients will be taken supine position. hemodynamic measurements will be continued. core temperature measurements will be done every 15 minutes. peripheral skin temperature measurements will be continuous. 1st, 2nd ,3rd,4th ,5th ,6th, 7th, 8th, 9th and 10th minutes and every 5 minutes measurements will be recorded during the operation. pinprick test will be used for sensorial block assessment. t10 sensorial block will be our goal. the time for adequate sensorial block (t10) will be recorded. the patients will be repositioned (lithotomy) before the beginning of surgery. 5 mg iv ephedrine and 0.5 mg iv atropine will be administered when the blood pressure will be %80 of the baseline pressure and heart rate. operating time, amount and temperature of irrigation fluids, transfusion requirement will be recorded. all patients will be transferred to post anesthesia care unit (pacu). core temperature measurements will be continued every 15 minutes at pacu. shivering scale and thermal comfort scale will be used during and after the operation. 25 mg iv meperidine will be administered when the patient's shivering score will be more than 3. length of pacu stay will be recorded.

Eligibility criteria:
inclusion criteria: * asa i-ii-iii * 50-80 years old * patients scheduled for transurethral baldder resection exclusion criteria: * female gender * uncoordinated patients * have coagulopathy, * known allergies to drugs to be used, * patients diagnosed with severe hypovolemia * skin infection at the injection site. * body mass index greater than 35m2/kg * patients with severe endocrinological disease * patients with cardiovascular diseases * patients with severe aortic stenosis or severe mitral stenosis * patients with increased intracranial pressure

Keywords: hypothermia peripheral temperature spinal anesthesia forced-air warming