Antithrombin replacement during extracorporeal membrane oxygenation

Heparin remains the predominant anticoagulant during extracorporeal membrane oxygenation (ECMO). Heparin acts by potentiating the anticoagulant effect of antithrombin (ATIII). Acquired ATIII deficiency, common in pediatric patients requiring ECMO, may result in ineffective anticoagulation with heparin. ATIII replacement may result in increased bleeding. Our objective is to determine ATIII's effect on anticoagulation and blood loss during ECMO. A retrospective chart review was performed of all patients at Children's Hospital of Wisconsin who received ATIII while supported on ECMO in 2009. ATIII activity levels, heparin drip rate, and activated clotting times (ACT) were compared before, 4, 8, and 24 h after ATIII administration. Chest tube output and packed red blood cell (pRBC) transfusion volume were compared from 24 h before ATIII administration to 24 h after. Twenty-eight patients received ATIII as a bolus dose during the course of 31 separate times on ECMO support. The median age of these patients was 0.3 years (range 1 day-19.5 years). ATIII activity increased significantly at 8 and 24 h after administration. No significant difference was noted in heparin drip rate, ACT levels, chest tube output, or pRBC transfusion volume. ATIII administration resulted in higher ATIII activity levels for 24 h without a significant effect on heparin dose, ACT, or measures of bleeding.     

Antithrombin deficiency and its relationship to severe burns

Antithrombin (AT) is an important endogenous anticoagulant and exhibits marked anti-inflammatory properties. To evaluate the incidence of AT deficiency in severe burn and its correlation to the variables of the abbreviated burn severity index (ABSI), length of hospital stay (LOS) and mortality we collected data on the substitution of human plasma-derived AT concentrate in 201 consecutive patients suffering from severe burn. One hundred and eight patients (54%) developed AT deficiency during their hospitalisation and, according to our institutional practice, received substitution therapy by continuous infusion to maintain physiological plasma activity (70-120%). The mean administered dose served as a measure of AT deficiency. The percentage of patients in an AT deficient state was highest within the first 5 days after injury. It was 26% on day 1 and between 38% and 41% on days 2-5 and thereafter decreased constantly over time. A multiple regression analysis between the dependent variable mean administered dose of AT concentrate and the independent variables age, total body surface area burned (TBSA), gender, inhalation injury (INHAL), full thickness burn (FTB), LOS and mortality was performed. Age, gender and FTB showed no significant influence on the development of AT deficiency. Increasing TBSA and INHAL clearly increase the risk of developing AT deficiency (p-values 0.0001 and 0.037). The analysis also identified AT deficiency as an independent predictor of LOS and mortality (p-values 0.036 and 0.003). Development of AT deficiency is a frequent event after burn with significant correlation to TBSA and INHAL, increased mortality rates and longer hospital stays.     

深静脉血栓患者血浆蛋白Z水平的研究

目的研究深静脉血栓(DVT)患者的血浆蛋白Z(PZ)水平,探讨DVT和PZ的相关性。方法采用酶联免疫吸附检测(ELISA)法测定68例DVT患者和55名健康人的蛋白Z水平;采用发色法测定蛋白C(PC),抗凝血酶(AT);采用凝固法测定蛋白S(PS)活性。结果DVT组PZ、PC、PS、AT水平分别为:PZ(1.31±0.60)mg/L,PC(123±25)%,PS(54±23)%,AT(114±17)%;健康对照组PZ、PC、PS、AT水平分别为:PZ(1.11±0.51)mg/L,PC(135±26)%,PS(68±17)%,AT(130±8)%。两组PZ水平无显著性差异(P>0.05);两组PC,PS,AT活性有显著性差异(P<0.05)。DVT组男性和女性PZ水平分别为(1.34±0.61)mg/L和(1.27±0.60)mg/L,健康对照组男性和女性PZ水平分别为(1.09±0.55)mg/L和(1.12±0.49)mg/L,不同性别之间PZ水平无显著性差异(P>0.05)。结论DVT患者和健康人的PC,PS和AT水平有显著性差异,DVT和PC,PS和AT水平具有相关性。DVT患者和健康人的PZ水平无显...     

纤维蛋白（原）降解产物对发色底物法测定抗凝血酶活性的影响

目的　探讨纤维蛋白 (原 )降解产物 (FDP)、D 二聚体 (DD)对发色底物法测定抗凝血酶活性 (AT :A)的影响。方法　留取 31例体检正常标本和 85例FDP、DD可能增高的患者标本 ,分别用发色底物法测定AT :A ,免疫比浊法测定抗凝血酶抗原 (AT :Ag) ,ELISA法测定其FDP、DD含量。再将正常混合血浆与高FDP、DD浓度的异常混合血浆以不同比例混合后同上法分别测定其AT :A、AT :Ag、FDP及DD的含量。 结果　AT :A除肝硬化组外其余各组与对照组比较差异均无显著性 (P >0 .0 5 ) ,而AT :Ag含量各组均显著低于对照组 ;AT :A与AT :Ag含量的比值均明显高于对照组 ,其比值增高的幅度与FDP、DD的浓度呈正相关。结论　FDP、DD对发色底物法测定AT :A结果有影响。临床应用中 ,若同时测定AT :A和AT :Ag含量 ,更能明确反映该指标的临床意义。     

儿童感染性疾病凝血指标检测的临床意义

目的探讨儿童感染性疾病中,凝血功能变化对感染的诊断及转归的意义。方法取患儿感染期标本,分别以凝固法、发色底物法、免疫胶体金法等检测凝血酶原时间（PT）、活化部分凝血活酶时间（APTT）、纤维蛋白原含量（FIB）、凝血酶时间（TT）、抗凝血酶活性（AT：A）、D-二聚体（DD）等凝血及抗凝指标。结果感染患儿的凝血指标与正常对照组儿童间差异有统计学意义,特别是AT：A与DD的结果在弥散性血管内凝血（D IC）组与非D IC组中差异有统计学意义。结论各凝血指标特别是AT：A和DD的检测可作为D IC前期诊断和预后评估的指标。     

A case of antithrombin replacement using recombinant human antithrombin in an adult patient supported with extracorporeal membrane oxygenation

In the critically ill patient on extracorporeal life support, antithrombin production and activity can be decreased and may require replacement to therapeutic levels in order to maintain appropriate anticoagulation and prevent thrombosis.