临床实验室指标判断肾病综合征患者低血容量的诊断价值

Diagnostic value of clinical laboratory indexes in judging the hypovolemia in patients with nephrotic syndrome

目的评估临床实验室指标在判断肾病综合征（NS）患者低血容量时的诊断价值，以选择出高准确度的判断指标。方法入选健康成年男女受试者各50例，用吲哚菁绿-脉搏染料光密度（ICG-PDD）测定法检测血容量，获得正常值范围及判断低血容量的划界值。用ICG-PDD法检测81例NS患者血容量，根据ICG—PDD判断低血容量的划界值分为低血容量组（21例）及非低血容量组（60例），比较两组患者临床实验室指标，筛选出差异有统计学意义的指标。用受试者工作特征（ROC）曲线评估临床及实验室指标对判断低血容量的诊断价值，从中筛选出准确度高的指标。结果（1）ICG—PDD判定成年人低血容量的划界值为：男性〈52．9ml／kg，女性〈52．5ml／kg。（2）临床实验室指标判断低血容量的诊断价值：用直立位心率（OHR）增快〉10次／min；钠排泄分数（FENa）〈1；跨。肾小管钾梯度（TTKG）〉60％；血尿素氮／血肌酐比率（BUN／Scr）〉20和尿比重（SG）〉1．020等指标来判断NS患者的低血容量时，单独1项或2项指标联合判断的准确度为中度。联合3项指标，即OHR增快＋FENa＋BUN／Scr、FENa＋BUN／Scr＋SG、OHR增快＋TTKG＋BuN／Scr或OHR增快＋FENa＋TTKG来判断低血容量准确度可达到高度。结论ICG．PDD法判定中国成年NS患者低血容量的划界值为男性〈52．9ml／kg，女性为〈52．5ml／kg，联合3项临床实验室指标判定NS患者低血容量的准确度较高。

Objective To evaluate the diagnostic value of clinical laboratory indexes on judgment of hypovolemia in the patients with nephrotic syndrome （NS）. Methods The blood volume of each 50 cases of healthy adult men and women was assessed with indocyanine greenpulse dye densitometry （ICG-PDD）. The normal range of blood volume and the cut-off value of hypovolemia were determined. The blood volume of 81 patients with NS was also measured with ICG-PDD and then these patients were divided into the hypovolemic group （21 cases） and the non-hypovolemic group （60 cases） according to the cut- off value of hypovolemia. The test data of clinical laboratory indexes of the patients in the two groups were compared, and the indexes with statistic difference were screened out. Their diagnostic values on judgment of hypovolemia were evaluated by receiver operating characteristic （ROC） curve analysis, and finally the indexes with high judgment accuracy were selected. Results （1）The cut-off values of hypovolemia are 〈 52.9 ml/kg for the male and 〈 52.5 ml/kg for the women, which were determined with ICG-PDD. （2）The five clinical laboratory indexes, including orthostatic heart rate （OHR） increase 〉 10 bit per minute, fractional excretion of sodium （FENa） 〈 1, transtubular potassium gradient （TTKG） 〉 60%, blood urea nitrogen/serum creatinine ratio （BUN/Scr） 〉 20, and urine specific gravity （SG） 〉 1.020, were used to judge the hypovolemia in NS patients in this study. ROC curve analysis showed that the diagnostic accuracy in judgment of hypovolemia by one index or two indexes combination only belonged to medium level. However, the diagnostic accuracy in judgment of hypovolemia by the following three indexes combination, i.e. OHR inerease＋FeNa＋BUN/Scr, FeNa＋ BUN/Scr ＋ SG, OHR increase ＋ TTKG ＋ BUN/Scr, or ORG increase ＋ FeNa ＋ TTKG, reached high level. Conclusion This study obtained the cutoff value of Chinese adults hypovolemia are 〈 52.9 ml/kg for the male and 〈 52.5 ml/kg for the women, which are determined with ICG-PDD, through evaluation we recommend applying the above four specific combinations of three indexes for diagnosis of hypovolemia in NS patients.