红细胞参数在危重病患者液体管理中的作用

Relevance of erythrocyte parameters on fluid management in critical care

目的探讨红细胞参数与中心静脉压（CVP）及血容量的关系，以期指导重症患者的液体管理。方法①试验1：持续观察1例重症患者38d，记录其每日早晨的CVP和红细胞参数[红细胞计数（RBC）、血红蛋白（Hb）、红细胞比容（HCT）]等；将所测CVP值（emH2O，1emH20=0．098kPa）分为3组（〈8组、8～10组、〉10组），比较各组的红细胞参数，分析其与CVP的相关性。同时获取其“最佳”CVP（即血容量最合适的情况下）及与之对应的“最佳”红细胞参数（血液既未被稀释，也未被浓缩）。②试验2：观察另1例重症患者，分析其“最佳”CVP，确定其“最佳”红细胞参数值。在怀疑其血容量可能不足或过度的情况下，立即检测其红细胞参数，如果所测数值与“最佳”红细胞参数差异较大，予以扩充血容量或利尿，否则寻找其他原因或继续观察。分别比较扩容或利尿治疗前后的CVP。结果①试验1：CVP〉10组的RBC（×109／L）、Hh（g/L）、HCT均较CVP〈8组和CVP8～10组显著降低（RBC：3．05±0．32比3．59±0．25、3．42±0．24，Hb：85-3±6．8比104．2±3．6、97．5±4．9，HCT：0．271±0．023比0．321±0．015、0．309±0．019，均P〈0．01）；CVP8～10组的Hb也显著低于CVP〈8组（97．5±4．9比104．2±3．6，P〈0．01）。CVP与RBC、Hb、HCT均呈负相关，相关系数（r值）分别为-0．735、-0．903、-0．822（均P〈0．01）；RBC、Hb、HCT之间呈高度正相关，r值分别为0．804、0．931、0．863（均P〈0．01）。患者CVP为8～10cinH2O时生命体征较为平稳，故将此值定为“最佳”CVP；据此确定的“最佳”红细胞参数RBC为3．43×109／L、Hb为97．4g／L、HCT为0．310。②试验2：该患者的“最佳”CVP也为8～10omH2O，对应的“最佳”红细胞参数Hb为105g／L。在Hb较“最佳”Hh显著升高组中，经过扩容后其CVP明显升高（8．29±1．80比5．86±1．57，P〈0．05）；在Hb较“最佳”Hb显著降低组中，经过利尿后其CVP显著降低（8．80±2．39比12．20±1．92，P〈0．05）。结论红细胞各参数与CVP呈显著负相关，“最佳”CVP对应的“最佳”红细胞参数值可能具有指导危重病患者液体管理的作用。

Objective To manage fluid therapy in severely ill patients through investigating the relationship between erythrocyte parameters and central venous pressure （CVP） and its denoted blood volume. Methods The research project was divided into two parts. Part I ： CVP and concurrent erythroeyte parameters ~red blood count （ RBC ）, hemoglobin （ Hb ）, haematocrit （ HCT ） were serially recorded in a severely ill patient every morning for 38 days. The obtained values of CVP （cm H20, 1 cm H20=0.098 kPa） were divided into three groups （〈8 group, 8-10 group, 〉 10 group ）, then erythrocyte parameters of each period were compared to obtain the relationship among them. At the same time,＂the best＂ CVP （blood volume was in suitable state） and ＂the best＂ erythrocyte parameters （accordingly the blood was not be diluted or concentrated） were obtained. Part II ： ＂the best＂ CVP and corresponding ＂the best＂ erythrocyte parameters were determined in another patient. When the patient＇s blood volume was in doubt, detected her erythrocyte parameters right away. If the variance between the ＂practical＂ and ＂the best＂ values was notable, blood volume replenishment or diureses were performed. Then the resulting CVP of fluid expansion or diuresis before and after the treatment were compared, or else other influencing factors should be seeked. Results Part I ： the values of RBC （ x 109/L）, Hb （g/L） and HCT in group CVP〉 10 were lower than those of group CVP〈8 and CVP 8-10 （RBC： 3.05±0.32 vs. 3.59±0.25, 3.42±0.24; Hb： 85.3 ±6.8 vs. 104.2±3.6, 97.5 ±4.9; HCT： 0.271 ±0.023 vs. 0.321 ±0.015, 0.309 ±0.019, all P〈0.01 ）, and Hb in group CVP 8-10 was lower than group CVP 〈8 （97.5 ±4.9 vs. 104.2 ±3.6, P〈0.01 ）. CVP was negatively correlated with RBC, Hb and HCT, and coefficients of correlation （r value） were -0.735, -0.903 and -0.822, respectively （all P〈0.01 ）, and positive correlations were found among RBC, Hb and HCT, with r value 0.804, 0.931 and 0.863, respectively （all P〈0.01 ）. The patient＇s vital signs were stable when CVP was 8 to 10 cm HzO, therefore it was assigned as ＂the best＂ CVP, and the corresponding ＂the best＂ erythrocyte parameters were determined （RBC was 3.43 x 109/L, Hb was 97.4 g/L, HCT was 0.310）. Part 1] ： ＂the best＂ CVP of the this patient was 8 to 10 cm H20 too, accordingly ＂the best＂ erythrocyte parameter in term of Hb was 105 g/L. The CVP was obviously elevated in the group in which Hb was higher than ＂the best＂ Hb subsequent to fluid expansion （8.29 ±1.80 vs. 5.86 ±1.57, P〈0.05）, and the CVP was obvious lowered in the group which Hb was lower than ＂the best＂ Hb through diuresis （8.80 ±2.39 vs. 12.20 ±1.92, P〈O.05）. Conclusion CVP was negatively correlated with erythrocyte parameters, ＂the best＂ erythrocyte parameters accompanying ＂the best＂ CVP would probably guide fluid therapy best in severely ill patients.