急性期出血性頭蓋内病変に対してのニトログリセリンによる企図的降圧療法と頭蓋内圧の変化

Intentional Hypotention Therapy Induced by Nitroglycerin and the Changes of the Intracranial Pressure for Acute Hemorrhagic Intracranial Lesions

I．はじめに

　出血性頭蓋内病変（高血圧性脳内出血及びくも膜下出血）では，出血初期には反応性の高血圧を示すことが多く，再出血により急激な神経学的症状の悪化をみる症例を少なからず経験する．そのため急性期には積極的な降圧療法が必要と思われる．現在，低血圧麻酔や術中高血圧などのコントロールに使われている降圧剤は，トリメタファン，ニトロプルシッド，プロスタグランジン，ニフェジピン，ニトログリセリンである．このうちニトログリセリンは，不安定狭心症や急性心不全等の心疾患の治療に用いられているが，脳外科領域においては頭蓋内圧を上昇させるため，急性期の出血性病変には，むしろ禁忌といわれている^3-5,7,8）．しかし実際，術中に降圧薬として使用した際，頭蓋内手術操作が頭蓋内圧亢進のため困難と感じられたこともない．ニトログリセリン投与後の頭蓋内圧の変化についての報告は，麻酔下もしくは，正常頭蓋内圧の症例においての報告がほとんどであり^3,4,7,8），実際に頭蓋内圧亢進の症例において使用した報告は数少ない．今回，われわれは，急性期にニトログリセリンを用いて企図的降圧療法を行い，良好な結果を得たので文献的考察を加え報告する．

It is reported that nitroglycerin (NTG) induces the elevation of intracranial pressure (ICP). Because of it, the use of NTG in patients exhibiting the increased ICP especially in the neurosurgical field is thought to be avoided. However, these reported cases dealt with normal patients. Few cases under the condition of ex-actly increased intracranial pressure were studied. Our 31 patients of the hemorrhagic intracranial lesion (sub-arachnoid hemorrhage and hypertensive intracranial hemorrhage) at the acute stage were treated by NTG infusion as an antihypertensive drug, and the ICP was measured using the epidural pressure transducer. The 31 patients were divided into three groups. Group 1 consists of the 14 patients exhibiting normal ICP ( ＜ 15mmHg). Group 2 consists of 9 patients showing ele-vated ICP (15mmHg≦ Group 3 consists of 8 patients treated with glycerol before the NTG infusion.

Group 1 demonstrates a statistically significant eleva-tion of ICP corresponding with the blood pressure de-pression. Group 2 showed no significant elevation of it. Group 3 disclosed no remarkable elevation of it both in the elevated ICP cases and the normal ICP cases. As mentioned above, the intravenous NTG caused a re-markable increase of ICP in the normal compliance of the intracranial contents and no elevation of ICP in the poor compliance. We conclude that NTG can be used for blood pressure control at an acute stage even in hemorrhagic intracranial lesion as antidepressor.