The Feinstein Institutes for Medical Research, Northwell Health System, 350 Community Drive, Manhasset, NY, 11030, USA.
School of Veterinary Medicine, Rakuno Gakuen University, Hokkaido, Japan.
J Transl Med. 2021 Nov 14;19(1):390. doi: 10.1186/s12967-021-03060-5.
Despite much evidence supporting the monitoring of the divergence of transcutaneous partial pressure of carbon dioxide (tcPCO) from arterial partial pressure carbon dioxide (artPCO) as an indicator of the shock status, data are limited on the relationships of the gradient between tcPCO and artPCO (tc-artPCO) with the systemic oxygen metabolism and hemodynamic parameters. Our study aimed to test the hypothesis that tc-artPCO can detect inadequate tissue perfusion during hemorrhagic shock and resuscitation.
This prospective animal study was performed using female pigs at a university-based experimental laboratory. Progressive massive hemorrhagic shock was induced in mechanically ventilated pigs by stepwise blood withdrawal. All animals were then resuscitated by transfusing the stored blood in stages. A transcutaneous monitor was attached to their ears to measure tcPCO. A pulmonary artery catheter (PAC) and pulse index continuous cardiac output (PiCCO) were used to monitor cardiac output (CO) and several hemodynamic parameters. The relationships of tc-artPCO with the study parameters and systemic oxygen delivery (DO) were analyzed.
Hemorrhage and blood transfusion precisely impacted hemodynamic and laboratory data as expected. The tc-artPCO level markedly increased as CO decreased. There were significant correlations of tc-artPCO with DO and COs (DO: r = - 0.83, CO by PAC: r = - 0.79; CO by PiCCO: r = - 0.74; all P < 0.0001). The critical level of oxygen delivery (DO) was 11.72 mL/kg/min according to transcutaneous partial pressure of oxygen (threshold of 30 mmHg). Receiver operating characteristic curve analyses revealed that the value of tc-artPCO for discrimination of DO was highest with an area under the curve (AUC) of 0.94, followed by shock index (AUC = 0.78; P < 0.04 vs tc-artPCO), and lactate (AUC = 0.65; P < 0.001 vs tc-artPCO).
Our observations suggest the less-invasive tc-artPCO monitoring can sensitively detect inadequate systemic oxygen supply during hemorrhagic shock. Further evaluations are required in different forms of shock in other large animal models and in humans to assess its usefulness, safety, and ability to predict outcomes in critical illnesses.
尽管有大量证据支持监测经皮二氧化碳分压（tcPCO）与动脉二氧化碳分压（artPCO）之间的差异作为休克状态的指标，但关于 tcPCO 与 artPCO 之间梯度（tc-artPCO）与全身氧代谢和血流动力学参数之间关系的数据有限。我们的研究旨在检验 tc-artPCO 可检测出血性休克和复苏期间组织灌注不足的假设。
本项在大学实验实验室进行的前瞻性动物研究使用了雌性猪。通过逐步抽血使机械通气的猪发生进行性大出血性休克。所有动物随后通过分阶段输注储存的血液进行复苏。将经皮监测器贴在耳朵上以测量 tcPCO。使用肺动脉导管（PAC）和脉搏指数连续心输出量（PiCCO）监测心输出量（CO）和几个血流动力学参数。分析了 tc-artPCO 与研究参数和全身氧输送（DO）之间的关系。
出血和输血精确地影响了预期的血流动力学和实验室数据。当 CO 降低时，tc-artPCO 水平显着升高。tc-artPCO 与 DO 和 COs 之间存在显著相关性（DO：r = -0.83，PAC 测量的 CO：r = -0.79；PiCCO 测量的 CO：r = -0.74；均 P < 0.0001）。根据经皮氧分压（阈值为 30mmHg），氧输送的临界水平为 11.72mL/kg/min。受试者工作特征曲线分析显示，tc-artPCO 用于区分 DO 的值最高，曲线下面积（AUC）为 0.94，其次是休克指数（AUC=0.78；P<0.04 与 tc-artPCO 相比），和乳酸（AUC=0.65；P<0.001 与 tc-artPCO 相比）。
我们的观察结果表明，微创 tc-artPCO 监测可以敏感地检测出血性休克期间全身氧供不足。需要在其他大型动物模型和人类中对不同形式的休克进行进一步评估，以评估其有用性、安全性和预测危重病结局的能力。
