Conrad S A, Zwischenberger J B, Eggerstedt J M, Bidani A
Department of Medicine, Louisiana State University Medical Center, Shreveport 71130-3932.
Artif Organs. 1994 Nov;18(11):840-5. doi: 10.1111/j.1525-1594.1994.tb03333.x.
The intravascular oxygenator (IVOX) has undergone both animal and clinical trials. Data from the animal studies have demonstrated that the device is capable of transferring up to approximately 100 ml/min of oxygen and carbon dioxide. Initial data from the human trials suggest that gas transfer, although approaching these levels, varied widely in patients with respiratory failure. We studied the factors affecting gas exchange in 26 patients with severe acute respiratory failure who underwent intravenacaval support of gas exchange with IVOX. The patients underwent monitoring of IVOX gas transfer rates, hemodynamics, blood gases, and ventilation parameters at scheduled intervals following device insertion. All devices functioned following implantation. The mean value for O2 transfer was 64 +/- 21 SD ml/min (range 15-114 ml/min) and for CO2 transfer was 48 +/- 17 ml.min-1 (range 14-112 ml/min). CO2 transfer correlated positively with device surface area, cardiac output, and mixed venous Pco2 and negatively with duration of implantation. O2 transfer did not correlate with any patient factors probably due to error inherent in the measurement of this variable. Independent measurements of IVOX gas transfer by respiratory gas exchange in a subset of patients with normal values of mixed venous Pco2 were in good agreement with the routine measurements and indicated that the device provided up to 26% of gas exchange requirements in this subset. We conclude that IVOX transfers clinically useful amounts of oxygen and carbon dioxide in vivo. Factors that influence gas transfer include device surface area, PvCO2, cardiac output, and duration of implantation. Optimization of these factors (such as with permissive hypercapnea) could result in enhanced performance in vivo.
血管内氧合器（IVOX）已进行了动物试验和临床试验。动物研究数据表明，该装置能够输送高达约100毫升/分钟的氧气和二氧化碳。人体试验的初步数据表明，尽管气体交换接近这些水平，但在呼吸衰竭患者中差异很大。我们研究了26例严重急性呼吸衰竭患者在接受IVOX进行腔静脉内气体交换支持时影响气体交换的因素。在装置植入后，按预定间隔对患者进行IVOX气体传输速率、血流动力学、血气和通气参数的监测。所有装置植入后均能正常工作。氧气传输的平均值为64±21标准差毫升/分钟（范围为15 - 114毫升/分钟），二氧化碳传输的平均值为48±17毫升·分钟⁻¹（范围为14 - 112毫升/分钟）。二氧化碳传输与装置表面积、心输出量和混合静脉血二氧化碳分压呈正相关，与植入持续时间呈负相关。氧气传输与任何患者因素均无相关性，这可能是由于该变量测量中存在的误差所致。在混合静脉血二氧化碳分压值正常的部分患者中，通过呼吸气体交换对IVOX气体传输进行的独立测量与常规测量结果高度一致，表明该装置在这部分患者中可提供高达26%的气体交换需求。我们得出结论，IVOX在体内能传输临床上有用量的氧气和二氧化碳。影响气体传输的因素包括装置表面积、混合静脉血二氧化碳分压、心输出量和植入持续时间。对这些因素进行优化（如采用允许性高碳酸血症）可能会提高其在体内的性能。
