Liem K D, Kollée L A, Hopman J C, De Haan A F, Oeseburg B
Department of Pediatrics, University Hospital, University of Nijmegen, The Netherlands.
Acta Anaesthesiol Scand Suppl. 1995;107:157-64. doi: 10.1111/j.1399-6576.1995.tb04351.x.
To investigate the cerebrovascular response to changes in arterial CO2 tension during extracorporeal membrane oxygenation (ECMO) in normoxaemic and hypoxaemic piglets.
Four groups of six anaesthetized, paralysed and mechanically ventilated piglets: group 1-normoxaemia without ECMO, group 2-ECMO after normoxaemia, group 3-hypoxaemia without ECMO, and group 4-ECMO after hypoxaemia, were exposed successively to hypercapnia and hypocapnia. Changes in cerebral concentrations of oxyhaemoglobin (cO2Hb), deoxyhaemoglobin (cHHb), (oxidized-reduced) cytochrome aa3 (cCyt.aa3) and blood volume (CBV) were continuously measured using near infrared spectrophotometry. Heart rate, arterial O2 saturation, arterial blood pressure, central venous pressure, intracranial pressure (ICP) and left common carotid artery blood flow (LCaBF) were measured simultaneously.
Hypercapnia resulted in increased CBV, cO2Hb and ICP in all groups, while cHHb was decreased. No changes in LCaBF were found. Hypocapnia resulted in decreased cO2Hb and increased cHHb except in group 3. LCaBF decreased in all groups except group 2. CBV decreased only in groups 2 and 4. No effect on ICP was observed in any of the groups. The other variables showed no important changes either during hypercapnia or hypocapnia. ECMO after hypoxaemia resulted in a greater response of cO2Hb and cO2Hb and cHHb during hypocapnia. The effect of hypercapnia on CBV while on ECMO was greater than without ECMO.
Since cerebrovascular reactivity to CO2 remains intact during ECMO in piglets, it is important to keep arterial CO2 tension stable and in normal range during clinical ECMO.
研究在正常氧合和低氧血症仔猪体外膜肺氧合（ECMO）期间，脑血管对动脉血二氧化碳分压变化的反应。
四组，每组六只麻醉、麻痹并机械通气的仔猪：第1组为无ECMO的正常氧合组，第2组为正常氧合后进行ECMO组，第3组为无ECMO的低氧血症组，第4组为低氧血症后进行ECMO组，依次使其暴露于高碳酸血症和低碳酸血症。使用近红外分光光度法连续测量脑内氧合血红蛋白（cO2Hb）、脱氧血红蛋白（cHHb）、（氧化-还原）细胞色素aa3（cCyt.aa3）浓度和血容量（CBV）。同时测量心率、动脉血氧饱和度、动脉血压、中心静脉压、颅内压（ICP）和左颈总动脉血流量（LCaBF）。
高碳酸血症导致所有组的CBV、cO2Hb和ICP升高，而cHHb降低。未发现LCaBF有变化。低碳酸血症导致除第3组外的所有组cO2Hb降低和cHHb升高。除第2组外的所有组LCaBF均降低。仅第2组和第4组的CBV降低。在任何组中均未观察到对ICP有影响。在高碳酸血症或低碳酸血症期间，其他变量也未显示出重要变化。低氧血症后进行ECMO导致在低碳酸血症期间cO2Hb和cHHb的反应更大。在进行ECMO时，高碳酸血症对CBV的影响大于未进行ECMO时。
由于仔猪在ECMO期间脑血管对二氧化碳的反应性保持完整，因此在临床ECMO期间保持动脉血二氧化碳分压稳定并在正常范围内很重要。
