Sharma A S, Weerwind P W, Bekers O, Wouters E M, Maessen J G
Department of Cardiothoracic Surgery, CARIM, Maastricht University Medical Center, PO box 5800, 6202 AZ, Maastricht, the Netherlands.
Department of Clinical Chemistry, Maastricht University Medical Center, Maastricht, the Netherlands.
Intensive Care Med Exp. 2016 Dec;4(1):2. doi: 10.1186/s40635-016-0076-3. Epub 2016 Jan 16.
Extracorporeal carbon dioxide removal (ECCO2R) has been gaining interest to potentially facilitate gas transfer and equilibrate mild to moderate hypercapnic acidosis, when standard therapy with non-invasive ventilation is deemed refractory. However, concern regarding the effectiveness of low-flow CO2 removal remains. Additionally, the prospect to steadily reduce hypercapnia via low-flow ECCO2R technique is limited, especially with regional anticoagulation which potentially reduces the risk of bleeding. Therefore, an in vivo study was conducted to determine the efficacy of CO2 removal through a modified renal dialysis unit during the carbon dioxide dialysis study using systemic and regional anticoagulation.
The acute study was conducted for 14 h in landrace pigs (51 ± 3 kg). CO2 removal using a diffusion membrane oxygenator substituting the hemoconcentrator was provided for 6 h. Blood and gas (100 % O2) flows were set at 200 and 5 L/min, respectively. Anticoagulation was achieved by systemic heparinization (n = 7) or regional trisodium citrate 4 % (n = 7).
The CO2 transfer was highest during the initial hour and ranged from 45 to 35 mL/min, achieving near eucapnic values. Regional and systemic anticoagulation were both effective in decreasing arterial pCO2 (from 8.9 ± 1.3 kPa to 5.6 ± 0.8 kPa and from 8.6 ± 1.0 kPa to 6.3 ± 0.7 kPa, p < 0.05 for both groups, respectively). Furthermore, pH improved (from 7.32 ± 0.08 to 7.47 ± 0.07 and from 7.37 ± 0.04 to 7.49 ± 0.01, p < 0.05) for both regional and systemic anticoagulation groups, respectively. Upon ceasing CO2 dialysis, hypercapnia ensued. The liver and kidney function test results were normal, and scanning electron microscopy analysis revealed only some cellular and fibrin adhesion on the oxygenator fibre in the heparin group.
CO2 dialysis utilizing either regional or systemic anticoagulation showed to be safe and effective in steady transfer of CO2 and consequently optimizing pH.
当无创通气的标准治疗被认为无效时，体外二氧化碳清除（ECCO2R）越来越受到关注，因为它可能有助于气体交换并平衡轻至中度高碳酸血症性酸中毒。然而，对于低流量二氧化碳清除的有效性仍存在担忧。此外，通过低流量ECCO2R技术稳步降低高碳酸血症的前景有限，尤其是在采用局部抗凝以降低出血风险的情况下。因此，进行了一项体内研究，以确定在使用全身和局部抗凝的二氧化碳透析研究中，通过改良的肾透析装置清除二氧化碳的效果。
在长白猪（51±3千克）中进行了为期14小时的急性研究。使用替代血液浓缩器的扩散膜氧合器进行6小时的二氧化碳清除。血液和气体（100%氧气）流量分别设置为200和5升/分钟。通过全身肝素化（n = 7）或局部4%柠檬酸钠（n = 7）实现抗凝。
最初一小时内二氧化碳转移最高，范围为45至35毫升/分钟，达到接近正常碳酸水平的值。局部和全身抗凝在降低动脉血二氧化碳分压方面均有效（分别从8.9±1.3千帕降至5.6±0.8千帕和从8.6±1.0千帕降至6.3±0.7千帕，两组p均<0.05）。此外，局部和全身抗凝组的pH值均有所改善（分别从7.32±0.08升至7.47±0.07和从7.37±0.04升至7.49±0.01，p<0.05）。停止二氧化碳透析后，出现高碳酸血症。肝功能和肾功能测试结果正常，扫描电子显微镜分析显示肝素组仅在氧合器纤维上有一些细胞和纤维蛋白粘附。
采用局部或全身抗凝的二氧化碳透析在稳定转移二氧化碳并因此优化pH值方面显示出安全有效。
