Effects of Adenine on Clotting Factors in Fresh Blood, Stored Blood, and Stored Fresh Frozen Plasma

The addition of small quantities of adenine to whole blood may prolong the useful shelf life of bank blood. The present study was undertaken to evaluate the effects of adenine on the clotting factors in blood containing ACD and CPD. Units of whole blood were collected in ACD, ACD-adenine, CPD and CPD-adenine, and each was stored 42 days under standard blood bank conditions. Samples of fresh frozen plasma containing these anticoagulants were stored three to four months at -30 C. Assays of Factors V, VIII (AHF), IX (PTC), X (Stuart Factor), fibrinogen, and prothrombin were performed on fresh blood, stored blood and stored fresh frozen plasma. The presence of small quantities of adenine did not appear to produce any appreciable alteration in the activity of the clotting factors in fresh blood. Further, adenine did not appear either to improve or worsen the survival of the procoagulants in whole blood stored 42 days or in fresh frozen plasma stored three to four months. There was significant deterioration of Factors V and VIII in whole blood stored 42 days in ACD, ACD-adenine, CPD, and CPD-adenine, but the degree of storage loss was independent of the anticoagulant employed. Factor X, fibrinogen, and prothrombin remained stable in blood stored 42 days regardless of the anticoagulant used, but Factor IX activity increased during storage possibly as the result of contact activation. Fresh frozen plasma stored three to four months showed a uniform slight loss of Factor VIII in all four anticoagulants, but Factors V, IX, X, fibrinogen, and prothrombin remained stable in stored fresh frozen plasma regardless of the anticoagulant employed.     

ADAMTS-13 levels in fresh, stored, and solvent detergent treated plasma.

BACKGROUND: ADAMTS-13 is implicated in the pathophysiology of thrombotic thrombocytopenic purpura (TTP). Plasma exchange is thought to be effective through removal of a harmful substance or provision of a required material such as ADAMTS-13. As various methods are used to prepare plasma we determined the effects of storage and solvent detergent treatment on the ADAMTS-13 levels in plasma. METHODS: Samples from fresh plasma and fresh frozen plasma (FFP) were stored at 22 degrees C and ADAMTS-13 levels were measured at 0, 12, 24, 48 and 72 h. Samples were also taken from solvent detergent treated plasma (SDP) and cryosupernatant plasma (CSP). Total protein, albumin, fibrinogen and immunoglobulins were also measured. RESULTS: In fresh plasma, the levels of both the 175 and 140 Kd subunits of von Willebrand factor were consistent at 1.38 and 1.35 OD units from 0 to 48 h indicating normal ADAMTS-13 activity. The Vitex SDP produced slightly more of the 140 Kd subunit than did Octapharma SDP which gave equivalent fragments. Cryosupernatant plasma was the same as normal plasma. None of these values changed over 48 h. There was a 28% decrease in FVIII in fresh plasma over 24 h. Fibrinogen and albumin were unchanged. CONCLUSION: ADAMTS-13 levels are not significantly decreased by storage of plasma at room temperature for up to 48 h. Both CSP and SDP also contained essentially normal levels of ADAMTS-13 and therefore could be used for treatment of patients with TTP.     

The in vivo survival of red blood cells stored in modified CPD with adenine: report of a multi-institutional cooperative effort

In order to provide data in support of licensure applications for citrate-phosphate-dextrose (CPD) supplemented with adenine, a multi- institutional cooperative effort was organized to determine survivability of red blood cells subjected to prolonged liquid storage. Two manufacturers supplied plastic multiple bag blood storage containers prefilled with modified CPD (glucose 25/ greater than the normal concentration) supplemented with adenine (17.0 to 17.3 mg per 63 ml of anticoagulant; 0.25 millimolar approximate final concentration when diluted with 450 ml of whole blood for 35 days showed a mean survival of 80.53 +/- 6.44 per cent (1 SD). Both red blood cell and supernatant plasma biochemical characteristics were comparable to those reported for whole blood stored for 21 days in either acid-citrate- dextrose (ACD) or CPD. Red blood cells from 19 units stored as concentrates for 35 days (Hct 75.03 +/− 3.74%) had a mean survival of 71.38 +/− 10.3 per cent with considerable interdonor variation in survival and interlaboratory variation in some biochemical characteristics. Red blood cells from eight units stored as concentrates (Hct 75.38 +/− 4.30%) for 28 days showed a mean survival of 83.97 +/− 6.10 per cent and biochemical characteristics comparable to those reported for red blood cell concentrates stored in CPD or ACD for 21 days. Modified CPD with adenine as formulated offers an improved anticoagulant for blood banking by extending the permissible red blood cell storage period.     

Clotting Factor Activity in Cryoprecipitates and Supernatant Plasma Prepared from Blood Collected into ACD, ACD-Adenine, CPD, and CPD-Adenine and from Plasma Collected by Plasmapheresis

Adenine has been used to prolong the survival of stored erythrocytes, and thus extend the storage period of blood. It seemed desirable to investigate the effect of this additive on the procoagulants of plasma that full use of cryoprecipitates and other plasma fractions could be made from blood drawn into an adenine-enriched anticoagulant. Eight units of whole blood were drawn into each of four anticoagulants: ACD, ACD-adenine, CPD, and CPD-adenine. Cryoprecipitates were prepared from each unit of fresh plasma according to a modification of Pool's method. Assays for fibrinogen, prothrombin, and factors V, VII, VIII, IX, and X were performed on the cryoprecipitates and on the supernatant plasma drawn off the cryoprecipitates. Adenine did not alter the expected yield of factor VIII (AHF) in the cryoprecipitate. There was slight to moderate loss of factor V and fibrinogen, respectively, in the supernatant plasma, but prothrombin and factors VII, IX, and X were unaffected by the procedure. Assays also revealed good AHF activity in each unit of plasma from a double plasmapheresis; therefore, both units are satisfactory for use in preparing cryoprecipitates.     

Effect of gamma irradiation with 30 Gy on the coagulation system in leukoreduced fresh-frozen plasma

BACKGROUND: The aim of this study was to investigate the effect of gamma irradiation with 30 Gy on the coagulation system in leukoreduced fresh-frozen plasma (FFP). STUDY DESIGN AND METHODS: In 74 FFP units that had been stored for 352 +/- 103 days below -30 degrees C, the following variables were determined in parallel in an irradiated and not irradiated half: prothrombin time (PT); activated partial thromboplastin time (APTT); thrombin time; antithrombin III; protein C; protein S; von Willebrand factor antigen; ristocetin cofactor; plasminogen-alpha(2)-antiplasmin; the coagulation factors fibrinogen, factor (F)II, FV, FVII, VIII, F IX, FX, FXI, FXII, FXIII, and activated factor XII (FXIIa); D-dimer; fibrin monomer; thrombin-antithrombin complex; prothrombin fragment 1 + 2 (F1+2); plasmin-alpha(2)-antiplasmin complexes (PAPs); and platelet factor 4. The FVII activity ratio was assayed to quantify activation of FVII. RESULTS: Irradiation with 30 Gy resulted in a reduction of APTT (35.0 +/- 4.1 sec vs. 34.4 +/- 4.1 sec; p = 0.00000006) and PT (89.8 +/- 8.2% vs. 90.7 +/- 8.0%; p = 0.002) and a significant increase of the activities of the coagulation factors FII, FV, FVII, F IX, FX, and FXII. FVIII activity decreased from 118 +/- 31 to 116 +/- 32 percent (p = 0.02). Activation of the coagulation system was shown by an increase in the FVII activity ratio (1.19 +/- 0.29 vs. 1.31 +/- 0.34; p = 0.0000001), FXIIa (0.81 +/- 0.50 ng/mL vs. 0.90 +/- 0.51 ng/mL; p = 0.006), and F1+2 (1.19 +/- 0.20 nmol/L vs. 1.24 +/- 0.20 nmol/L; p = 0.000005) after irradiation with 30 Gy, whereas an increase of PAP (16.2 +/- 11.5 ng/mL vs. 20.2 +/- 12.0 ng/mL; p = 0.0004) demonstrated activation of the fibrinolytic system. No negative influence of irradiation with 30 Gy on inhibitors of coagulation was observed. CONCLUSION: Gamma irradiation of leukoreduced FFPs with 30 Gy results in a significant but very weak activation of the coagulation and fibrinolytic system in FFPs.     

Coagulation parameters of thawed fresh-frozen plasma during storage at different temperatures

Once thawed, fresh-frozen plasma (FFP) should be used, according to guidelines, within 24 h. In hospital practice, this may be associated with wastage. This study has been performed to investigate the coagulation levels of thawed quarantine FFP as used in the Netherlands. Five units of quarantine FFP, obtained by plasmapheresis, were thawed and by sterile docking divided into satellite bags (SB). SB 2-4 were stored at room temperature (RT) for, respectively, 1, 3 and 6 h and SB 5-9 at 4 degrees C for 6, 12 and 24 h and 1 and 2 weeks. At each time point, activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen, factor V (FV), factor VIII (FVIII) and ADAMTS13 activity were measured. During storage at RT for up to 6 h, no major differences were found in the levels of FV, PT, fibrinogen and ADAMTS13 activity. FVIII activity showed a decrease of 16% and the APTT was prolonged by 6%. During storage at 4 degrees C for 2 weeks, FV and FVIII were reduced by 35 and 45%, respectively. The APTT and PT were prolonged by 17 and 15%, respectively. Fibrinogen was decreased by 8%. No change in ADAMTS13 activity was found. FFP stored at RT for 6 h or at 4 degrees C for 2 weeks can provide sufficient support for adequate haemostasis except for patients with a known deficiency for FVIII and can be used for plasmapheresis in patients with thrombotic thrombocytopenic purpura (TTP).     

The effect of methylene blue phototreatment on plasma proteins and in vitro coagulation capability of single-donor fresh-frozen plasma

BACKGROUND: Photodynamic virus inactivation of fresh-frozen plasma (FFP) may result in its impaired coagulation capability. STUDY DESIGN AND METHODS: Double-volume plasmapheresis samples from 11 donors were divided in pairs of 250 mL. One group underwent methylene blue (MB) phototreatment (MB-FFP). The other group was treated according to the standards of the American Association of Blood Banks for preparation and storage of FFP. Parameters of hemostasis and clinically important plasma proteins were tested in native plasma, thawed MB-FFP, thawed FFP, and twice-frozen and thawed FFP (FFP-II). RESULTS: Mean activities of factor V (73.4 vs. 94.5%; p < 0.01), factor VIII (58.1 vs. 86.7%; p < 0.001), and fibrinogen (1.8 vs. 2.8 g/L; p < 0.001) were reduced in MB-FFP as compared to those in FFP. The comparison of MB-FFP to FFP-II revealed reduced activities of factor VIII (58.1 vs. 85.2%; p < 0.001) and fibrinogen (1.8 vs. 2.8 g/L; p < 0.001) but no changes in factor V. Activated partial thromboplastin time in MB-FFP was prolonged beyond the upper normal range (+5.3 sec; p < 0.001) and prothrombin time increased in MB-FFP versus FFP (+0.96 sec; p < 0.001). CONCLUSION: MB phototreatment reduces the in vitro coagulation capacity of FFP, most likely as a result of the effects of an additional freezing and thawing procedure and photooxidation-induced protein damage.     

Modification of fresh-frozen plasma transfusion practices through educational intervention

The effect of an educational program designed to address misconceptions about the perioperative transfusion of fresh-frozen plasma (FFP) was examined. Results of a baseline audit of FFP use were compared to those of a study subsequent to the educational process. Statistical analysis of the data revealed that the decrease in the number of patients transfused with FFP, from 32 of 2077 operative cases in Group A (baseline) to 18 of 2540 operative cases in Group B (after education), was significant (p less than 0.01). Analysis of the justifications given for transfusion of FFP revealed that the increase in acceptable indications from 47 percent in Group A to 78 percent in Group B was also significant (p less than 0.05). There was no significant difference between the two groups in units of FFP transfused per patient (Group A, 3.66 +/- 3.2, vs. Group B, 2.47 +/- 1.7) or red cells (Group A, 2.84 +/- 5.2, vs. Group B, 5.22 +/- 4.4), and the patterns of platelet transfusion were similar in the two groups. There was a significant difference in the postoperative partial thromboplastin time (Group A, 38.2 +/- 8.7 vs. Group B, 56.3 +/- 24 seconds, p less than 0.01) but no significant difference in postoperative prothrombin time (Group A, 14.1 +/- 2.6 vs. Group B, 15.4 +/- 3.3 seconds). It can be concluded that an educational program designed to address misconceptions in transfusion practice can alter physician performance and thereby reduce the inappropriate use of FFP.     

A comparison of factor VIII activity in cryoprecipitates prepared from ACD and CPD plasma

In an attempt to develop a method to produce a cryoprecipitate with a predictable Factor VIII potency, several variables were studied and statistically analyzed. These included the hematocrit, age, blood group and Rh type of the donor; possible epinephrine release; the degree of lipemia, volume, pH and Factor VIII activity of the donor plasma; the volume of cryoprecipitates, its Factor VIII activity and the per cent yield; and the Factor VIII activity of the supernatant plasma. Cryoprecipitates were prepared by the method of Pool and Shannon from the plasmas of 40 random male donors, half the bloods being drawn in ACD and half in CPD. None of the variables had a significant influence on the per cent yield of activity, although the mean values obtained suggest that the per cent yield of Factor VIII activity in the cryoprecipitates prepared from CPD plasmas is higher than in those prepared from ACD plasma. Although the per cent yield of Factor VIII in cryoprecipitates prepared from CPD plasma is not significantly different from that of ACD plasma, the mean total units of Factor VIII activity is significantly higher in CPD cryoprecipitates. It also was confirmed that a higher per cent Factor VIII activity in the donor results in a relatively higher activity in the cryoprecipitate. The data indicate that if CPD plasma collected from donors having above a certain minimum per cent activity were used for cryoprecipitate production, one could be assured of having a minimum of 100 units of Factor VIII activity per bag.     

Activity of clotting factors in fresh-frozen plasma during storage at 4°C over 6 days

BACKGROUND: Fresh-frozen plasma (FFP) requires thawing, which delays availability. We investigated clotting factor activity and bacterial contamination of FFP when stored at 4°C ± 2°C for 6 days.
STUDY DESIGN AND METHODS: Plasma of 20 healthy plasma donors was sampled, frozen, and analyzed at baseline and repeatedly over a period of 6 days after thawing. The activity of fibrinogen, Factor (F)II, FV, FVII, FVIII, F IX, FX, XI, FXII, FXIII, antithrombin III (ATIII), von Willebrand factor antigen (VWF-Ag), protein C (PC), and free protein S (FPS) were determined and analyzed over time.
RESULTS: Immediately after thawing there was a significant decrease of fibrinogen (−9%), FII (−7%), FV (−14%), FVII (−12%), FX (−11%), FXIII (−20%), PC (−7%), and ATIII (−4%), whereas FVIII (+8%), F IX (+1%), FXI (+11%), FXII (−1%), FPS (−1%), and VWF-Ag (−6%) remained stable without significant change. Over 6 days after thawing fibrinogen, ATIII (+2%) and VWF-Ag (+2%) remained stable whereas FXII (+2%), FXIII (+6%), and PC (+3%) changed significantly over time and increased at the end. FII (−8%), FV (−16%), FVII (−31%), FVIII (−47%), F IX (−12%), FX (−10%), FXI (−25%), and FPS (±0%) changed also significantly over time and decreased at the end. All clotting factors and inhibitors remained within the reference range requested by quality assurance regulations. No FFP bag showed bacterial contamination.
CONCLUSION: This provides evidence for maintaining quality of thawed FFP and may improve rapid availability in emergency situations and reduce cost for health care givers.     

Comparison of fresh frozen plasma with a standardized serum protein solution following therapeutic plasma exchange in patients with autoimmune disease: a prospective controlled clinical trial.

The aim of the study was the comparison of the influence of fresh frozen plasma (FFP) (Freiburg, Germany) and Biseko, Biotest Pharma GmbH (Dreieich, Germany), as a plasma substitute (a standardized, virus inactivated human serum protein solution) on the coagulation factors, inhibitors, proteins, and complement factors in the plasma of autoimmune disease patients following membrane plasma separation. Patients (n = 24) with autoimmune disease were randomized to receive either FFP or Biseko for membrane plasma separation therapy. During each plasma exchange, 100% of the plasma volume was replaced by the respective substitute. Plasma exchange volume was performed once daily for 3 days. Target test parameters of the coagulation system were fibrinogen, fibrinopeptide A, factor VIII (FVIIIC), von Willebrand factor antigen (vWFAg), partial thromboplastin time (PTT), thromboplastin time (Quick value), and antithrombin (AT III). The immunoglobulins were IgG, IgA, and IgM and C-reactive protein (CRP). The thrombocytes were platelet factor 4 (PF4), and complement factors were C3 and C4. Biseko was well tolerated with 1 mild adverse drug reaction (ADR) (n = 1) while FFP gave rise to ADR on 7 occasions (n = 4). Statistically significant differences in the 2 groups were observed for fibrinogen, PTT, Quick value, and AT III. From the clinical point of view, all fluctuations and differences in parameter levels remained clinically silent. The differences had no clinical consequences. Reflecting on a potential decrease in the risk of infections in comparison to FFP therapy and the lower rate of adverse drug reactions, it is possible to postulate an advantage of Biseko for plasma exchange therapy.     

Comparison of von Willebrand factor antigen, von Willebrand factor-cleaving protease and protein S in blood components used for treatment of thrombotic thrombocytopenic purpura

Replacement of normal levels of von Willebrand factor-cleaving protease (VWF:CP, ADAMTS13) activity from infused plasma is important in plasma exchange (PEX) for the treatment of thrombotic thrombocytopenic purpura (TTP) patients. We have studied the VWF:CP activity, VWF multimer distribution, VWF:Ag, protein S (PS) activity and free PS antigen levels in fresh frozen plasma (FFP), cryosupernatant (CSP) and virally inactivated components treated with methylene blue/light (MB) or solvent detergent (SD) processes. VWF:CP activity was normal in all components tested and was retained following overnight storage at room temperature. CSP and SD plasma contained reduced levels of the highest molecular weight VWF multimers. Protein S activity was reduced below the normal range in SD plasma, but within the normal range for the other components tested. Virally inactivated SD- and MB-treated plasma may be an effective alternative to FFP and CSP in PEX for TTP. Reduced PS activity in SD plasma may predispose to venous thromboembolism, especially if infused in large volumes.     

普通冰冻血浆与新鲜冰冻血浆部分血浆组分的比较

目的:比较普通冰冻血浆(FP)和新鲜冰冻血浆(FFP)中血浆组分的差异。方法:随机选择北京市红十字血液中心提供的FP和FFP各20份,血浆融化后即刻分别检测凝血因子、纤溶系统及抗凝蛋白指标等12种血浆组分,即活化的部分凝血活酶时间(APTT)、凝血酶原时间(PT)、凝血因子Ⅷ(FⅧ)活性、凝血因子Ⅴ(FⅤ)活性、纤维蛋白原(FIB)水平、血管性血友病因子裂解蛋白酶(ADAMTS-13)活性、血管性血友病因子(v WF)活性、D-二聚体(D-dimer,DD)、纤维蛋白降解产物(fibrin degradation products,FDP)、抗凝血酶(antithrombin,AT)、蛋白C(protein C,PC)、蛋白S(protein S,PS),并进行比较分析。结果:与FFP相比,FP中APTT明显延长(t=3.428,P<0.01),PT延长(z=-2.140,P<0.05),FⅧ活性明显降低(t=-3.372,P<0.01),但均在参考区间内;PS活性降低(t=-2.458,P<0.05);两种血浆中其余组分的差异无统计学意义(P>0.05)。结论:与FFP相比,FP缺乏某些凝血因子和抗凝蛋白,但可替代FFP应用于部分疾病的治疗。     

Shelf-life of bank blood and stored plasma with special reference to coagulation factors

Whole blood and plasma drawn into plastic bags containing citrate- phosphate-dextrose (CPD) and stored at 4 degrees C for various periods were studied for variations of coagulation factor and fibrinolytic activity. The blood was collected and processed in the conventional way. The most labile component, factor VIII coagulant activity, decreased to about 50 percent of its original value within the first 24 hours in whole blood, but thereafter, it decreased more slowly. Storage of whole blood for 6 hours at 4 degrees C had an insignificant effect on VIII coagulant activity; an even slower decrease was found for factor VIII coagulant antigen. The major fall in VIII coagulant activity occurred between 6 and 24 hours of whole blood storage. Factor VIII-related antigen remained normal for about 1 week, but on further storage showed signs of proteolytic degradation. In plasma, there was a successive decrease in VIII coagulant activity with its minimum level (about 50% decrease as compared with the original level) after 7 to 14 days of storage. All other factor VIII activities in plasma remained unchanged throughout the study. Factor V retained its activity for about 1 week in the whole blood. Factors II, VII, IX, X, XII, XIII and fibrinogen did not fall below normal during a storage period of 35 days, nor was there any indication of increased fibrinolytic activity in either whole blood or plasma. Storage of whole blood and plasma at 4 degrees C for 1 to 2 weeks seems to have relatively little effect on the levels and function of various coagulation components with the possible exception of factor VIII coagulant activity.     

Intensive blood and plasma exchange for treatment of coagulopathy in meningococcemia

Eight pediatric patients with fulminant meningococcemia, purpura, and disseminated intravascular coagulation who by multiple prognostic scoring systems were anticipated to have a poor outcome underwent intensive plasma exchange (IPE) or whole blood exchange (WBE) in addition to standard medical therapy. IPE/WBE was initiated shortly after admission with a mixture of both fresh frozen plasma and cryoprecipitate as the replacement solution. All IPE procedures were performed using a continuous flow system and a red cell prime. The mean fibrinogen level increased from 62 to 192 mg/dl, the prothrombin time (PT) decreased from a mean of 32.4 seconds to 15.1 seconds, and the mean activated partial thromboplastin time (APTT) decreased from 89.5 seconds to 40.1 seconds following completion of the initial IPE/WBE. There was a corresponding improvement in all coagulation factor levels but only slight improvement in antithrombin III (ATIII) and protein C levels. Seven of eight patients survived (87.5%) their initial presentation with the sole early death attributed to meningitis with cerebral edema. Mean fluid balance after the procedure was + 10.8 ± 5.87 cc/kg. There were no significant bleeding or cardiovascular complications during the procedure. There was no clinical or radiographic evidence of fluid overload after the procedure. This experience demonstrates that IPE/WBE may be conducted safely in critically ill, unstable pediatric patients and is effective in rapidly improving coagulopathy without fluid overload.     

Effect of fresh-frozen plasma transfusion on prothrombin time and bleeding in patients with mild coagulation abnormalities

BACKGROUND: Fresh-frozen plasma (FFP) is frequently transfused to patients with mild prolongation of coagulation values under the assumption that FFP will correct the coagulopathy. There is little evidence to support this practice, however. To determine the effect of FFP on coagulation variables and correlation with bleeding in patients with mildly prolonged coagulation values, a prospective audit of all FFP transfusions at the Massachusetts General Hospital between September 2, 2004, and September 30, 2005, was performed. STUDY DESIGN AND METHODS: All patients transfused with FFP for a pretransfusion prothrombin time (PT) between 13.1 and 17 seconds (international normalized ratio [INR], 1.1-1.85) and with a follow-up PT-INR within 8 hours of transfusion were included. Of 1091 units of FFP transfused, follow-up coagulation values within 8 hours were available for 121 patients (324 units). RESULTS: Transfusion of FFP resulted in normalization of PT-INR values in 0.8 percent of patients (95% confidence interval [CI], 0.0020-0.045) and decreased the PT-INR value halfway to normalization in 15.0 percent of patients (95% CI, 0.097-0.225). Median decrease in PT was 0.20 seconds (median decrease in INR, 0.07). Pretransfusion PT-INR, partial thromboplastin time, platelet count, and creatinine values had no correlation with red blood cell loss. CONCLUSION: It is concluded that transfusion of FFP for mild abnormalities of coagulation values results in partial normalization of PT in a minority of patients and fails to correct the PT in 99 percent of patients.     

Comparison of ADAMTS13 and Von Willebrand factor levels and activities,and plasminogen levels,in plasma products currently available for the treatment of thrombotic thrombocytopenic purpura in South Africa

Objective

Thrombotic thrombocytopenic purpura (TTP) results from a deficiency in the Von Willebrand factor (VWF) cleaving protease, ADAMTS13. Treatment involves plasma exchange (PEX) therapy with either fresh frozen plasma (FFP), cryosupernatant (CSP) or solvent/detergent-treated plasma (SDP), available in South Africa as Bioplasma FDP. The aim of the study was to generate in vitro data on these products, and to explore possible differences between the products that may offer treatment advantages.

红细胞悬液与血浆不同比例输注对急性创伤患者凝血功能、纤溶功能及血栓弹力图监测结果的影响

目的 探讨大量输血时,红细胞悬液与血浆不同比例输注对急性创伤患者凝血功能、纤溶功能及血栓弹力图(TEG)监测结果的影响.方法 荣县人民医院收治的120例需要大量输血的患者,按入院24h内输注新鲜冰冻血浆(FFP)与红细胞悬液(SRBC)的比例,以100 ml:1U为比例单位,将患者分为低比例组(FFP:SRBC=1:3...     

Study of three patients with thrombotic thrombocytopenic purpura exchanged with solvent/detergent-treated plasma: is its decreased protein S activity clinically related to their development of deep venous thromboses?

Solvent/detergent treated plasma (S/DP) has reduced protein S activity (about 0.5 units/mL) as compared with fresh frozen plasma (FFP). When used as replacement fluid for repetitive therapeutic plasma exchange (PEX), e.g., in patients with thrombotic thrombocytopenic purpura (TTP), S/DP could lead to lowered protein S levels and, possibly, risk of hypercoagulable complications. We describe three patients with TTP who had low functional protein S (FPS) levels during PEX for TTP. Each developed one or more deep vein thromboses (DVTs) while receiving 100% S/DP or 50% S/DP and 50% cryosupernatant plasma (CSP) as replacement fluid. FPS levels rose when 100% CSP was substituted for S/DP. Our observations suggest that use of S/DP alone or in 50% combination with CSP as replacement fluid in PEX for TTP may lead to difficulty in maintaining safe FPS levels. Determination of risk of resulting clinically significant thrombotic events requires further study.     

Effect of 24-hour whole-blood storageon plasma clotting factors

BACKGROUND: The current requirements for the preparation of fresh-frozen plasma within 8 hours of whole-blood collection were designed to maintain clotting factor activities. These requirements, however, limit the production of fresh-frozen plasma in a large blood center. There are few data on the effect of the extension of CPD whole-blood storage to 24 hours on clotting factor activity. STUDY DESIGN AND METHODS: A 500-mL unit of whole blood was collected from 10 volunteer donors. At 1 hour after collection, a plasma sample was separated by centrifugation, and each unit was equally divided into 2 half-units, with 1 half-unit stored at 4 degrees C (range, 1-6 degrees C) and 1 half-unit stored at 22 degrees C (range, 20-24 degrees C) for 8 hours after collection. Each half-unit was then placed at 4 degrees C for further storage for 16 hours. At 8 and 24 hours after collection, plasma samples were separated from each half-unit. All plasma samples were frozen at -18 degrees C. Factors V, VII, VIII, and X; fibrinogen; antithrombin III; protein C; and protein S were measured. RESULTS: No significant changes were noted in factors V, VII, and X; fibrinogen; antithrombin III; protein C; and protein S over the 24-hour storage period. Factor VIII in both half-units was significantly reduced, by 13 percent, from the baseline sample as compared to the level in the 8-hour storage sample (p<0.05). Factor VIII was further reduced by 15 to 20 percent after the 24-hour storage period (p<0.05). CONCLUSION: The coagulation factor activity for all factors measured, with the exception of factor VIII, showed no significant change over the 24-hour storage period. Factor VIII was significantly decreased by 13 percent in 8-hour storage and by an additional 15 to 20 percent in 24-hour storage. For clinical situations not requiring the replacement of factor VIII only, 24-hour frozen plasma has properties comparable to those of fresh-frozen plasma.