氟醚静脉麻醉脊髓血流量的变化.ppt

Spinal Cord Blood Flow Change by Intravenous Midazolam During Isoflurane Anesthesia,Tomoki Nishiyama, MD, PhD By Corallibra,Background,Midazolam has been used for general anesthesia and sedation during local anesthesia or artificial ventilation. It has become clear that midazolam has an analgesic property mediated by GABA receptors in the spinal cord. Therefore, it is important to know the effects of midazolam on spinal cord blood flow.,Methods,anesthesia,maintain,ventilation,Methods,Midline skin incision, L1-5 were removed, and the spinal cord was exposed. A platinum was inserted stereotaxically into the spinal cord to a depth of 1 mm at 2 mm lateral to the midline at L2. Spinal cord blood flow was measured eith the hydrogen clearance method. Statistical analysis was performed with repeated-measures analysis of variance,Results,Arterial blood gas values before the study drug treatment without any difference. Arterial blood pressure decreased during the first 30 min after MID 2 and 4mg/Kg Heart rate did not change.,Results,Spinal cord blood flow increased significantly for 90 min after MID 1 mg/Kg and for 15 min after MID 2mg/Kg.,Discussion,Spinal cord blood flow was increased by the smallest dose of IV midazolam used (1 mg/kg) without any changes in arterial blood pressure The largest dose (4 mg/kg) did not induce any changes in spinal cord blood flow but decreased arterial blood pressure,Discussion,Spinal cord blood flow increased as ETco2 increased, but it did not change with mean arterial blood pressure between 50 and 135 mmHg or with Pao2 more than 40 mmHg (arterial blood pressure was in the range of autoregulation),Discussion,Spinal cord blood flow might change similarly to cerebral blood flow Bolus midazolam (0.15 mg/kg) decreased cerebral blood flow, but mean arterial blood pressure also decreased,Discussion,Isoflurane increased spinal cord blood flow within the arterial blood pressure range of 90130mmHg The decrease in arterial blood pressure in the midazolam 2 and 4 mg/kg groups may have decreased spinal cord blood flow during isoflurane anesthesia that masked the increase otherwise caused by midazolam,Discussion,However, in patients, midazolam is often coadministered with other anesthetics To know the effects of midazolam, isoflurane should be discontinued,Conclusion,A smaller dose of midazolam (1 mg/kg) increased spinal cord blood flow without changes in arterial blood pressure, but a larger dose (4 mg/kg) did not change s