Changes of Blood Glucose and Insulin under Different Fentanyl Dosage in Neonates and Infants Undergoing Open Heart Surgery / 대한마취과학회지

Background: Hyperglycemia during cardiopulmonary bypass may increase the incidence and severity of neurologic deficits that may result from cerebral ischemia. Moderate hyperglycemia has been noted to occur in pediatric patients undergoing cardiac surgery despite measures such as eliminating dextrose from the CPB clear pump priming solution and from the intra-operative iv fluids. To ameliorate the hormonal and hemodynamic stress responses during cardiac surgery in neonates, infants and children, high dose fentanyl anesthesia is widely used. The authors wished to determine prospectively whether fentanyl dosage is associated with reduced blood glucose or not in pediatric patients undergoing cardiac surgery. METHODS: Twenty four pediatric patients undergoing cardiac surgery were allocated randomly into 3 groups who received 25 g/kg fentanyl, 50 g/kg fentanyl or 75 g/kg fentanyl before CPB. The changes of plasma glucose and insulin levels were observed after sternotomy, on bypass, 30 min after bypass, off bypass, and the end of the operation. RESULTS: Blood glucose levels were not increased after sternotomy, but significantly increased at bypass to the end of the operation in all fentanyl dosage groups. Plasma insulin level increased, but statistically not significant. Different fentanyl dosage (25~75 g/kg) is not associated with differences in blood glucose level. CONCLUSION: At a dosage of 25~75 g/kg fentanyl anesthesia during pediatric open heart surgery were associated with no differences and below 250 mg/dl of blood glucose level and no significant changes in insulin level.

Spinal Anesthesia with 0.5% Plain Bupivacaine: Effects of Patient's Posture and the Temperature of Bupivacaine / 대한마취과학회지

BACKGROUND: Many factors determine the distribution of local anesthetics in the subarachnoid space. These major factors are dosage of local anesthetics, baricity of local anesthetics, position of patient, contour of vertebral column. The temperature of local anesthetics alters the baricity of local anesthetics. At 20oC, the density of 0.5% plain bupivacaine is 1.0003 and generally act as isobaric solution in the CSF. As its temperature lowers, its baricity increases. METHODS: Forty patients (A.S.A I and II) scheduled for lower extremity operation under spinal anesthesia were randomized into four groups; group I (37oC 0.5% bupivacaine, sitting position), group II (37oC 0.5% bupivacaine, 15o head-down position), group III (4oC 0.5% bupivacaine, sitting position), group IV (4oC 0.5% bupivacaine, 15o head-down position). The patients were placed in the sitting position (Group I, III) or lateral decubitus (Group II, IV) and dural puncture was performed at the L3-4 interspace using a midline approach (25-gauge Quincke spinal needle). A free flow of clear cerebrospinal fluid was obtained before administration of drug (37oC 0.5% bupivacaine in Group I, II and 4oC 0.5% bupivacaine in Group III, IV). Patients remained in the sitting position or 15o head-down position for 3 minutes after injection. Patients in each group received a solution that had been previously equilibrated in a stove to 37oC and in a refrigerator to 4oC for more than 1 day. Syringes used to administer the bupivacaine solution were also equilibrated to 37oC and 4oC, respectively. We checked sensory block level using pin-prick test at every 5 minutes. RESULTS: There was statistic significance in sensory block level between Group I, IV and Group II, III. The maximum sensory block level and the time to maximum cephalad spread of analgesia was the T4 level and 9.6 minutes in Group I, the T5 level and 13.5 minutes in Group IV compared to the T9 level and 21 minutes in Group II, the T10 level and 18 minutes in Group III. CONCLUSIONS: The temperature of 0.5% plain bupivacaine affects sensory block level and time to block. It is concluded that the temperature of the injected solution plays an important role in the sensory spread of 0.5% plain bupivacaine.