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Abstract：
Monitoring for thrombosis and hemolysis is crucial for patients under extracorporeal or mechanical circulatory support, but it can be costly. We investigated correlations between hemolysis index (HI) and plasma-free hemoglobin (PFH) levels on one hand, and between the HI and plasma lactate dehydrogenase (LDH) levels on the other, in critically ill patients with and without extracorporeal or mechanical circulatory support. Additionally, we calculated the cost reductions if monitoring through HI were to replace monitoring through PFH or plasma LDH. In a single-center study, HI was compared with PFH and plasma LDH levels in blood samples taken for routine purposes in critically ill patients with and without extracorporeal or mechanical circulatory support. A cost analysis, restricted to direct costs associated with each measurement, was made for an average 10-bed ICU. This study included 147 patients: 56 patients with extracorporeal or mechanical circulatory support (450 measurements) and 91 patients without extracorporeal or mechanical circulatory support (562 measurements). The HI correlated well with PFH levels (r = 0.96; p < 0.01) and poorly with plasma LDH levels (r = 0.07; p < 0.01) in patients with extracorporeal or mechanical circulatory support. Similarly, HI correlated well with PFH levels (r = 0.97; p < 0.01) and poorly with plasma LDH levels (r = -0.04; p = 0.39) in patients without extracorporeal or mechanical circulatory support. ROC analyses demonstrated a strong performance of HI, with the curve indicating excellent discrimination in the whole cohort (area under the ROC of 0.969) as well as in patients under ECMO or mechanical circulatory support (area under the ROC of 0.988). Although the negative predictive value of HI for predicting PFH levels > 10 mg/dL was high, its positive predictive value was found to be poor at various cutoffs. A simple cost analysis showed substantial cost reduction if HI were to replace PFH or plasma LDH for hemolysis monitoring. In conclusion, in this cohort of critically ill patients with and without extracorporeal or mechanical circulatory support, HI correlated well with PFH levels, but poorly with plasma LDH levels. Given the high correlation and substantial cost reductions, a strategy utilizing HI may be preferable for monitoring for hemolysis compared to monitoring strategies based on PFH or plasma LDH. The PPV of HI, however, is unacceptably low to be used as a diagnostic test.
摘要：
监测血栓形成和溶血对于体外或机械循环支持下的患者至关重要。但成本很高.我们一方面调查了溶血指数（HI）和无血浆血红蛋白（PFH）水平之间的相关性，在HI和血浆乳酸脱氢酶（LDH）水平之间，在有或没有体外或机械循环支持的危重病人。此外,我们计算了如果通过HI监测取代通过PFH或血浆LDH监测的成本降低.在单中心研究中，在有或没有体外或机械循环支持的危重患者中，将HI与常规目的血液样本中的PFH和血浆LDH水平进行了比较。成本分析，仅限于与每次测量相关的直接成本，是为平均10张床的ICU制造的。这项研究包括147名患者：56名接受体外或机械循环支持的患者（450次测量）和91名没有体外或机械循环支持的患者（562次测量）。在体外或机械循环支持患者中，HI与PFH水平相关良好（r=0.96；p<0.01），而与血浆LDH水平相关较差（r=0.07；p<0.01）。同样，在没有体外或机械循环支持的患者中，HI与PFH水平相关良好（r=0.97；p<0.01），而与血浆LDH水平相关较差（r=-0.04；p=0.39）。ROC分析证明了HI的强劲表现，曲线表明，在整个队列（ROC下面积为0.969）以及接受ECMO或机械循环支持（ROC下面积为0.988）的患者中，差异都很好。尽管HI对预测PFH水平>10mg/dL的阴性预测值很高，发现其阳性预测值在各种截止时间都很差。简单的成本分析表明，如果HI代替PFH或血浆LDH进行溶血监测，成本将大大降低。总之,在这个有或没有体外或机械循环支持的危重患者队列中，HI与PFH水平相关性很好，但血浆LDH水平较差。鉴于高度相关性和大幅降低成本，与基于PFH或血浆LDH的监测策略相比,利用HI的策略对于监测溶血可能是优选的。HI的PPV,然而,用作诊断测试是不可接受的低。
