Liem K D, Kollée L A, Klaessens J H, Geven W B, Festen C, De Haan A F, Oeseburg B
Department of Pediatrics, University of Nijmegen, The Netherlands.
Pediatr Res. 1995 Jul;38(1):124-9. doi: 10.1203/00006450-199507000-00022.
The objective of this study was to investigate changes of cerebral oxygenation and hemodynamics related to opening of the bypass bridge during veno-arterial extracorporeal membrane oxygenation (ECMO). Ten newborn infants and 12 piglets were studied during opening of the bridge for 10 and 1 s, respectively. Changes in cerebral concentration of oxyhemoglobin (cO2Hb), deoxyhemoglobin (cHHb), (oxidized-reduced) cytochrome aa3 (cCyt.aa3), and blood volume (CBV) were continuously measured by near infrared spectrophotometry. Heart rate, arterial O2 saturation (saO2), and mean arterial blood pressure (MABP) were measured simultaneously. In the piglets, central venous pressure (CVP), intracranial pressure (ICP), and left common carotid artery blood flow (CaBF) were also measured. Opening of the bridge for 10 s in the infants resulted in a significant decrease in MABP, saO2, and cO2Hb, whereas cHHb increased. CBV did not change significantly. In piglets biphasic changes were observed for MABP, CaBF, cO2Hb, and CBV, showing an initial decrease followed by a smaller increase. cHHb and CVP showed reverse biphasic changes. ICP increased but saO2 was unchanged. In all cases heart rate and cCyt.aa3 did not change significantly. Opening of the bridge for 1 s resulted in minor changes in only a few variables. In conclusion, opening of the bridge resulted in a decrease of CBV and cerebral O2 supply due to a decrease of cerebral blood flow, followed by a compensatory increase of cerebral O2 extraction and vasodilatation. The return of oxygenated blood after reclosing resulted in an increase of CBV with overcompensation of cerebral O2 supply.
本研究的目的是调查在静脉-动脉体外膜肺氧合（ECMO）期间与搭桥开放相关的脑氧合和血流动力学变化。分别在10名新生儿和12只仔猪搭桥开放10秒和1秒期间进行了研究。通过近红外分光光度法连续测量脑氧合血红蛋白（cO2Hb）、脱氧血红蛋白（cHHb）、（氧化-还原）细胞色素aa3（cCyt.aa3）和血容量（CBV）的变化。同时测量心率、动脉血氧饱和度（saO2）和平均动脉血压（MABP）。在仔猪中，还测量了中心静脉压（CVP）、颅内压（ICP）和左颈总动脉血流量（CaBF）。新生儿搭桥开放10秒导致MABP、saO2和cO2Hb显著降低，而cHHb升高。CBV无显著变化。在仔猪中，观察到MABP、CaBF、cO2Hb和CBV呈双相变化，显示出最初下降随后较小幅度上升。cHHb和CVP呈反向双相变化。ICP升高但saO2不变。在所有情况下，心率和cCyt.aa3无显著变化。搭桥开放1秒仅导致少数变量有轻微变化。总之，搭桥开放导致脑血流量减少，进而导致CBV和脑氧供应减少，随后脑氧摄取和血管扩张出现代偿性增加。重新闭合后含氧血的回流导致CBV增加，脑氧供应过度代偿。
