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.     

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.     

Comparison of coagulation factor XIII content and concentration in cryoprecipitate and fresh-frozen plasma

BACKGROUND: For patients with plasma coagulation factor XIII (pFXIII) deficiency, recommended means of replacement include infusions of fresh‐frozen plasma (FFP), cryoprecipitate, or (where available) factor (F)XIII concentrates. Quantitative differences in pFXIII concentration in FFP and cryoprecipitate are not well defined and were, therefore, the subject of this study. STUDY DESIGN AND METHODS: FFP and cryoprecipitate (10 bags each from blood group O donors) were analyzed to quantify pFXIII activity and antigen. Coagulation FVIII, fibrinogen, and von Willebrand factor (VWF) were also quantitated. RESULTS: Mean (±SD) pFXIII activity in cryoprecipitate and FFP bags was 60 ± 30 and 288 ± 77 U per bag, respectively, and pFXIII antigen and activity levels were concordant. Other comparisons (mean ± SD) between cryoprecipitate and FFP, respectively, were as follows: coagulation FVIII activity, 133 ± 37 and 265 ± 83 U per bag; fibrinogen content (Clauss kinetic assay), 183 ± 44 and 725 ± 199 mg per bag; VWF antigen content, 181 ± 53 and 218 ± 70 U per bag; VWF ristocetin cofactor activity, 168 ± 34 and 221 ± 65 U per bag; VWF collagen‐binding activity, 164 ± 40 and 208 ± 71 U per bag; and fluid (plasma) volumes per bag, 21.3 ± 2.7 and 245 ± 29 mL. CONCLUSION: In contrast to other cryoprecipitable coagulation proteins, pFXIII is only mildly enriched in cryoprecipitate when compared with FFP (approx. two‐ to threefold). Although both products can provide effective pFXIII replacement, FFP may be preferred when infusion volume is not a major consideration and pFXIII concentrates are not available. VWF is substantially enriched in cryoprecipitate (approx. ninefold compared with its concentration in FFP), with VWF activity content exceeding that of FVIII by approximately 26 percent on average.     

Refreezing previously thawed fresh-frozen plasma. Stability of coagulation factors V and VIII:C

With the growth in autologous blood programs and the increased scrutiny of the indications for transfusion of fresh-frozen plasma (FFP), an increase has been seen in the number of occasions on which FFP was requested and thawed but then not transfused. The coagulation properties of FFP units that were refrozen and then rethawed were therefore studied. Fifty-eight units of plasma were studied, with each experimental unit of FFP paired with an identical control unit. Experimental units were frozen, stored at -65 degrees C, thawed, stored at 1 to 6 degrees C for various periods of time up to 24 hours, and then refrozen, stored at -65 degrees C, rethawed, and stored again in the refrigerator for up to 24 hours. Control units were frozen once at the time the experimental units were first frozen and thawed once at the time of the second thaw of the experimental units. Aliquots of plasma were sampled periodically and were later batch-tested for prothrombin time (PT), activated partial thromboplastin time (aPTT), and factor V and VIII:C activity. The results of coagulation testing of the twice-frozen plasmas were always within the normal range. There was a slight but statistically valid prolongation of the PT and aPTT and a decrease in the factor V and VIII:C levels for twice-frozen plasma compared with control plasma. The greatest decline occurred in the level of factor VIII:C. The measured deterioration in coagulation of twice-frozen FFP is unlikely to be of clinical importance. Refreezing FFP may eventually prove useful for rare donor, autologous, and massive transfusion programs.     

内镜下氩离子凝固术治疗Barrett食管疗效的探讨

目的 探讨内镜下氩离子凝固术(APC)联合抑酸剂埃索美拉唑镁治疗Barrett食管的临床疗效.方法 对23例经病理证实的Barrett食管行内镜下氩离子凝固术(APC),治疗间隔为2周,直至病理证实复层鳞状上皮完全修复,术后给予抑酸剂埃索美拉唑镁20 mg/次,2次//d口服,共3个月,术后第6个月及1年进行内镜及组织学随访.结果 17例经1次APC根除,4例经2次APC根除,2例经3次APC根除,平均烧灼次数为1.3次.全部病例于治疗后6个月均获得治愈,4例于治疗后1年出现化生的柱状上皮黏膜岛,治疗总有效率为82.6%.7例出现剑突或胸骨后疼痛,经口服埃索美拉唑镁后症状缓解.结论 BE的内镜下APC联合抑酸剂埃索美拉唑治疗安全有效,但仍有一定比例的复发与残留.     

Thawing of fresh-frozen plasma with a new microwave oven

In the Federal Republic of Germany fresh-frozen plasma (FFP) is still the most important therapeutic agent for acquired coagulation disorders. However, thawing by waterbath (WB) requires about 30 minutes, which is too slow in emergency situations and carries the risk of bacterial contamination of the FFP. There are conflicting data about the use of microwaves for thawing. Therefore, we examined a new microwave oven (MWO; 2450 +/- 50 MHz), which was developed with our cooperation and allows thawing of FFP in 5 minutes, heating FFP to a surface temperature of 21.5 degrees C. A shaking WB (30 min, 37 degrees C) was also used in parallel for comparison. We measured activated partial thromboplastin time (aPTT), nonactivated PTT (NaPTT), fibrinogen, factors VIII:C, X, and XI, fibrinopeptide A, beta-thromboglobulin (beta-TG), thrombin-AT III-complexes, factor VIII-related antigen, C3c, C4, and the plasticizer di(2-ethylhexyl)phthalate (DEHP) in 84 units of FFP as paired samples from 42 double aphereses. Immediately after thawing there was no significant difference in the coagulation test results of FFP with low-cell contamination, regardless of the thawing procedure. Two hours later, after storage at room temperature, FFP thawed by MWO showed even less change than that thawed by WB (NaPTT, p less than 0.01; FX, p less than 0.01). The differences became more evident in comparison with FFP with higher cell contamination and could be observed immediately after thawing (FVIII:C p less than 0.001; FXI, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

接受运动处方干预老年人凝血与纤溶系统的变化

目的:以引发血栓性疾病的因素-血液凝血和纤维蛋白溶解系统(简称纤溶系统)为切入点,观察体育运动对老年人血液凝血和纤溶系统的影响。方法:实验于2006-07/2007-05在江西师范大学完成。从普查中随机选择健康不锻炼老年人52名,男27名,女25名,年龄在61～74岁之间,平均年龄(68.7±5.4)岁。受试对象大多数从事教育工作,经健康检测,所有受检老人无慢性肝肾疾病、无糖尿病及高血压、冠心病、无出血及血栓性疾病,男性至少戒烟3年以上或不吸烟。从52名中随机抽取27名为不锻炼组,男14名,女13名;另25名为运动处方组,男性13名,女性12名。运动处方:运动形式为步行快走,运动强度为最大心率的60%,每次运动持续时间为40min,隔日1次,每周三四次,运动周期半年。采用组间比较实验方法,观察与分析运动处方组和不锻炼组血液凝血和纤溶系统指标差异。检测组织型纤溶酶原激活物活性、纤溶酶活性、6-酮-前列环素含量、血栓烷B2含量、α2抗纤溶酶活性和纤维蛋白原含量。结果:52名受试者均进入结果分析。体育锻炼不仅增加了组织型纤溶酶原激活物活性、纤溶酶活性,同时还能降低了α2抗纤溶酶活性、纤维蛋白原含量和血栓烷B2含量;运动对于老年人血液凝血和纤溶系统能力的影响无明显的性别差异。结论:长期体育运动有助于提高老年人纤溶活性,加速纤维蛋白的降解,最终能有效地预防血栓的形成。     

Effect of therapeutic plasma exchange on coagulation parameters in patients on warfarin

Therapeutic plasma exchange (TPE) without plasma replacement results in coagulation factor removal. Warfarin decreases the activity of vitamin K dependent coagulation factors. The combined effect of TPE and warfarin on the coagulation system has not been studied. A prospective, observational study was conducted in patients undergoing TPE while on warfarin. One plasma volume TPEs were performed on the COBE Spectra Apheresis System (Terumo BCT, Lakewood, CO) with 5% albumin. International normalized ratio (INR), fibrinogen, and factor II activity were obtained pre and post procedure. Eight patients underwent 121 TPEs that met study criteria with pre and post data. The average pre values were INR 2.09 ± 0.58, fibrinogen 263 ± 76 mg/dl, and factor II 29 ± 16% and the average post values were INR 4.12 ± 1.44, fibrinogen 105 ± 31 mg/dl, and factor II 13 ± 7%. The pre‐INR was ≥2.00 for 55% of TPEs. The pre value (Y₀) predicts the post value (Y) by the following equations Y = ?0.54 + 2.21Y₀, Y =12.10 + 0.35Y_0, and Y =1.83 + 0.39Y₀ for INR, fibrinogen, and factor II respectively. In conclusion, pre procedure laboratory values can predict the post laboratory values for patients on warfarin receiving single plasma volume TPE with albumin replacement. The post‐INR is approximately twice the pre‐INR. At normal and mildly elevated pre‐INR, the effect of TPE on the INR is less marked. A single plasma volume TPE decreases the plasma level by ～65% for fibrinogen and 60% for factor II. J. Clin. Apheresis 29:75–82, 2014. © 2013 Wiley Periodicals, Inc.     

Clinical use of fresh-frozen plasma in neonatal intensive care unit

Recommendations for FFP use in neonates are based on a very limited amount of data, and not on well-designed randomized controlled trials. This retrospective study was performed to analyze our experience with FFP use in neonatal intensive care unit (NICU). From January 2006 until August 2011 a total of 80 neonates were identified as having been treated with FFP. The most common indication for FFP use was prolonged PT or aPTT, representing 32.8% of all usages of FFP. Following FFT treatment PT and aPTT normalized in 42% and 60% patients, respectively. Our results suggest that FFP were often used in acceptable indications in NICU.     

Inactivation of human immunodeficiency virus by gamma radiation and its effect on plasma and coagulation factors

The inactivation of HIV by gamma-radiation was studied in frozen and liquid plasma; a reduction of the virus titer of 5 to 6 logs was achieved at doses of 5 to 10 Mrad at -80 degrees C and 2.5 Mrad at 15 degrees C. The effect of irradiation on the biologic activity of a number of coagulation factors in plasma and in lyophilized concentrates of factor VIII (FVIII) and prothrombin complex was examined. A recovery of 85 percent of the biologic activity of therapeutic components present in frozen plasma and in lyophilized coagulation factor concentrates was reached at radiation doses as low as 1.5 and 0.5 Mrad, respectively. As derived from the first-order radiation inactivation curves, the radiosensitive target size of HIV was estimated to be 1 to 3 MDa; the target size of FVIII was estimated to be 130 to 160 kDa. Gamma radiation must be disregarded as a method for the sterilization of plasma and plasma-derived products, because of the low reduction of virus infectivity at radiation doses that still give acceptable recovery of biologic activity of plasma components.