Effects of Desflurane and Sevoflurane on Somatosensory Evoked Potentials in Patients Undergoing Neurosurgery / 昆明医科大学学报

ABSTRACT

Objective To compare the effects of desflurane and sevoflurane on somatosensory evoked potentials (SEP) in patients undergoing spine neurosurgery. Methods Thirty patients with ASA grades I-Ⅱand undergoing spinal deformity orthopaedic surgery were selected and divided into two groups desflurane group and sevoflurane group (n=30) . Bispectral index (BIS),the state of muscle relaxation, SEP and hemodynamics were monitored during operation. By maintaining the BIS in the range of 35-45,the state of muscle relaxation disappeared and hemodynamic became stable. Adjust the concentration of anesthetic step by step from 0 to 0.3, 0.6 and 0.9 maximum alveolar concentrations (MAC), then inhaled different concentrations of drugs. Record the incubation period and amplitude of SEP before inhaling anesthetics (based on the value), in the moment of achieving each inhaled concentration ( T1, T2 and T3) , and the moment that the inhaled anesthetics blows completely (regression value) . The percentages of T1, T2, T3, and the regression value compared with basic value were calculated.Results Compared with the basic value, T1, T2 and T3 of left arm, left leg and right leg in desflurane group, T2 and T3 of right arm in desflurane group, T2 and T3 of left arm, left leg and right arm in sevoflurane group,and T2 and T3 of right leg in sevoflurane group showed incubation period delaying ( <0.05) . And the incubation period extended along with the increase of inhaled anesthetics dosage. Compared with the basic value,T1,T2 and T1 of left arm and left leg in desflurane group,T1 of right arm in desflurane group, T1 and T2 of right leg in desflurane, T3 of left arm in sevoflurane group, T1 and T3 in left leg in sevoflurane group had decreased amplitude ( < 0.05), especially T1. Compared with desflurane, sevoflurane showed a weaker inhibition effect on the incubation period and amplitude of T1,T2,T3 of left arm and left leg,T2 and T3 of right arm and right leg, and the amplitude of T1 of right leg ( < 0.05) . Conclusion Both of desflurane and sevoflurane have inhibition effect on SEP. The inhibition effect gradually strengthens along with the increasing of dose. The inhibition effect of desflurane is stronger than sevoflurane.