頭蓋内圧充進に対するhemodilutionの効果—赤血球増加症に合併した脳梗塞症例の検討

HEMODILUTIONAL THERAPY IN RAISED INTRACRANIAL PRESSURE: OBSERVATIONS IN A CASE OF CEREBRAL INFARCTION ASSOCIATED WITH POLYCYTHEMIA VERA

　抄録　血液ヘマトクリット（Ht）値の著明な高値を呈した赤血球増加症に，重篤な出血性脳梗塞を合併した症例を経験した。本症例に対して，硬膜外脳圧計を留置し，持続的に頭蓋内圧（ICP）の観察を行ない，臨床症状，Ht値，　CTの経時的な変化と比較検討した。本症例の病態には血液粘度亢進によるhemostasis，出血性梗塞による脳浮腫およびICP亢進が関与し，高度の脳血流低下が推定されたため，マンニトール投与に加え，間歇的な瀉血が行なわれた。瀉血によるhemodilutionにより臨床症状とICPレベルは著明に改善され，Htの上昇時にこれらは悪化した。すなわち，　hemorheologicalな要因による脳血流の改善がICP値に関与し，病態変化に影響を与えるものと考えられた。

A 36-year-old man presented with sudden onset of hemorrhagic cerebral infarction in association with polycythemia vera. On admission this patient manifested semicomatous state and left hemiplegia which were gradually progressed. X ray CT de-monstrated a severe hemorrhagic infarction in right MCA territory accompanying marked shift of midline structures. Cerebral angiograms repre-sented occlusion of right MCA showing floating emboli in the internal carotid. Hematocrit value was found to be high as 61.2 per cent. Elevated ICP levels were noted by means of epidural pres-sure monitoring. Deterioration of patient status was considered to be based on impairment of cerebral circulation due to hemostasis by elevated blood viscosity. In addition to administration of mannitol solution, intermittent exsanguinations, 1000 ml in total amount, were performed and hematocrit levels were corrected by hemodilution. Consciousness level was remarkably improved in accordance with reduction of ICP, which well corresponded to values of hematocrit. Level of ICP and tissue perfusion are convinced to be strongly affected by hemorheological factor in the state of raised ICP.