ヘマトクリットの脳マイクロ循環と深度の低温バイパス中の組織酸素化に対する効果
L F Duebener1, T Sakamoto, S Hatsuoka
1Department of Cardiac Surgery, Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Circulation
|September 25, 2001
まとめ
低体温心肺バイパス (CPB) 中の高血圧値 (Hct) を維持すると,脳組織の酸素供給が改善され,白血球の活性化が低下します. 重度の血液希釈 (10% Hct) は,CPB中に小循環と酸素供給を損なう.
科学分野:
- 心血管科学の研究について
- 神経科学は神経科学である.
- イントラバイタル顕微鏡検査
背景:
- 低熱性心肺バイパス (CPB) 中の血液希釈は,微循環を改善することを目的としています.
- CPB中の血液希釈のための最適の血液クリット (Hct) レベルは未決定のままです.
研究 の 目的:
- 脳の微循環と組織の酸素化に対する異なる血中濃度 (Hct) の影響を調査する.
- 低熱性CPBおよび深度の低熱性循環停止 (DHCA) 中の10%,20%,30%のHctで脳の微循環と酸素を評価する.
主な方法:
- 頭蓋骨の窓を持つブタの生体内顕微鏡モデルを使用しました.
- フルオレスセイン-イソチオシアネート-デクストランを用いた機能毛細血管密度 (FCD) の評価.
- 毛細血管後の静脈における白血球の粘着とロールを測定し,組織酸素化のためのNADHレベルを測定した.
主要な成果:
- 機能性毛細血管密度 (FCD) は,DHCA後の早期再注血中の10%Hctと比較して30%Hctで有意に高かった.
- 重度の血液希釈 (10% Hct) は,ローリング白血球の増加と関連しており,これは30% Hct.と比較した.
- NADH測定は,冷却段階で10%Hctで脳組織の酸素化が不十分であることを示した.
結論:
- 高血圧値 (30%) は脳マイクロ循環を損なわず,DHCA後の白血球内皮細胞活性化を低下させる.
- 重度の血液希釈 (10% Hct) は,低熱性CPBの間,不十分な脳組織の酸素供給につながります.
- 低熱性CPBでは,特にDHCAが使用されている場合,低血圧値よりも30%の血圧値が推奨されます.
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