The effect of hypertonic saline solution on vasodilatation of superior sagittal sinus using magnetic resonance imaging in normovolenmic dogs

一些动物研究已经证明了高渗盐水（HSS）对脑血流量、颅内压和脑含水量的有益作用。本研究旨在使用磁共振成像研究（1）在犬脑血管扩张和脑脊液减少方面，小体积HSS是否上级右旋糖酐，以及（2）在犬脑血管扩张方面，小体积含6%右旋糖酐70的7.2%高渗盐水溶液（HSD）是否上级甘露醇。HSS使垂体垂直切面上的上级窦横截面积明显扩大，中脑边缘垂直切面上的脑脊液面积明显减少，其作用强于右旋糖酐40。然而，接受右旋糖酐40的狗的相对血浆体积在t=30分钟后显著高于HSS组（p<0.001）。研究2：犬经右头静脉分别以5 mL/kg等渗盐水（ISS）、20%甘露醇或HSD（20 mL/kg/h）静脉滴注，作为对照。在液体输注前即刻（前）和开始液体输注后每15分钟采集一次静脉血样，直至120分钟。采集每份血样后，立即进行T1和T2加权磁共振成像记录。HSD灌注后即刻，犬的上级矢状窦横截面积明显大于其他各组（p<0.001），达到术前的2.09±0.25倍。因此，5 mL/kg的HSD在降低犬CSF方面可能优于等体积的甘露醇上级。

Several animal studies have demonstrated the beneficial effects of hypertonic saline (HSS) on cerebral blood flow, intracranial pressure and brain water content. This study aimed to investigate, using magnetic resonance imaging, (1) whether a small volume of HSS is superior to dextran in vasodilatation of cerebral vessels and reduction of cerebrospinal fluids in dogs, and (2) whether a small volume of 7.2% hypertonic saline solution with 6% dextran 70 (HSD) is superior to mannitol in vasodilatation of encephalic vessels in the dogs.STUDY 1 : HSS induced significant expansion of the cross-section of superior sugittal sinus at the vertical section of pituitary and a decrease in cerebrospinal fluid area at the vertical section of epencephalic limbic more than dextran 40 did. However, the relative plasma volume in the dog received dextran 40 was significantly higher after t=30 min than the HSS group (p<0.001). Therefore, it is suggested that HSS might be superior to colloid solution in improving of cerebral circulation, whereas dextran 40 is superior to HSS in expanding systemic circulation in dogs.STUDY 2: The dogs were assigned to receive 5 mL/kg of isotonic saline solution (ISS) as control, 20% mannitol or HSD infusion at a flow rate of 20 mL/kg/hours via right cephalic vein. Venous blood samples were collected immediately before fluid infusion (pre) and every 15 minutes until 120 minutes after the initiation of fluid infusion. Immediately after collection of each blood sample, T1 and T2-weighted magnetic resonance imaging recordings were undergone. Immediately after HSD infusion, the area of the cross-section of superior sagittal sinus was significantly greater than that of beagles in the other groups (p<0.001), reaching the 2.09±0.25 times pre-value. Therefore, it is suggested that 5 mL/kg of HSD might be superior to isovolume of mannitol in reducing CSF in the dog.