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)     

A New Rapid Method for Thawing Fresh Frozen Plasma

The use of fresh frozen plasma (FFP) often results in unused thawed units because of the time required to thaw FFP prior to use. A rapid thawing technique was studied, utilizing a microwave oven. Resultant levels of coagulation factors were compared with conventional slow thawing in a 37 C water bath. Mean prefreezing, rapid thaw and conventional thaw values were fibrinogen 246, 223, 238 mg/100 ml; prothrombin 101, 103, 105 per cent; factor V; 102, 79, 86 per cent; factor VIII 94, 77, 75 per cent; factor IX 103, 92, 90 per cent; factors VII/X 101, 107, 103 per cent; and factor × 84, 79, 82 per cent. No significant differences existed between rapid thawing and conventional thawing for any coagulation factor studied. Average thawing times were five minutes for rapid thawing (RT) and 25 minutes for conventional thawing. Although careful establishment of thawing time is required for each oven, microwave thawing permits better utilization of FFP for surgery and speeds delivery in emergencies, without destroying coagulation proteins.     

Stability of solvent/detergent-treated plasma and single-donor fresh-frozen plasma during 48 h after thawing.

The aim of this study was to compare the quality of solvent/detergent (SD) treated plasma, Octaplas, and single-donor fresh-frozen plasma (FFP) units during 48-h storage after thawing. Octaplas bags of different blood groups and individual FFP units were thawed and stored at either +4 degrees C or at room temperature (RT) for 48 h. Samples drawn during the observation period were investigated on various coagulation factor and protease inhibitor activities using standard coagulation and chromogenic assays. The generation of FVIIa was followed as a marker of coagulation factor activation. All investigated coagulation factors and protease inhibitors were stable for at least 8h during storage of Octaplas at +4 degrees C. FVIII levels started to decline earlier in FFP than in Octaplas at both storage temperatures. Stored Octaplas OD660 values were more stable during the storage period than FFP OD660 values, whereas VWF multimeric patterns were comparably stable in both types of plasma. In conclusion, this stability study has demonstrated that thawed Octaplas maintains its high quality, even with a time safety margin, for 8 h at +4 degrees C and for 6 h at RT. In general, there was more variability in coagulation factor levels among different FFP units compared with different Octaplas batches.     

Coagulant stability and sterility of thawed S/D-treated plasma

BACKGROUND: Units of frozen S/D-treated plasma (SDP) must be transfused within 24 hours after thawing. To avoid waste, an attempt was made to determine how long SDP could be therapeutically effective after thawing and storing it at 20 degrees C. STUDY DESIGN AND METHODS: The microbiologic safety and the activity of labile coagulation factors were evaluated in units stored at 20 degrees C of thawed SDP units and FFP within 24 hours of collection (FFP24). Five SDP and FFP24 samples of each ABO blood group were cultured and assayed for coagulation factors daily over 5 days. Assays included FV, FVII, FVIIa, FVIII, F IX, FXI, protein S, antiplasmin, fibrinogen, prothrombin times (PTs), and activated partial thromboplastin times (aPTTs). RESULTS: None of the 80 bacterial cultures demonstrated growth under either aerobic or anaerobic conditions. FV, FVIII, F IX, FXI, fibrinogen, and the aPTT appeared to be stable in both thawed FFP24 and SDP. The PT increased slightly in thawed FFP24 and insignificantly in SDP. FVII decreased slightly in FFP24 but remained in the normal range, and FVIIa was low and constant. FVII was increased in SDP and FVIIa was markedly increased. Protein S decreased from initial normal values in FFP24 to very low values. Protein S was very low immediately after thawing in the SDP and continued to decline. Antiplasmin was normal and stable in thawed FFP24 but was low in SDP and remained constant after thawing. CONCLUSION: Sterile SDP that is stored at 20 degrees C provides sufficient coagulant activity of labile FV and FVIII to transfuse it for up to 5 days after thaw. Caution is warranted by decreases in Protein S and antiplasmin, clinical evidence of coagulopathy in some recipients of SDP, and a recent manufacturer's warning.     

Storage of thawed plasma for a liquid plasma bank: impact of temperature and methylene blue pathogen inactivation

BACKGROUND: Rapid transfusion of fresh‐frozen plasma (FFP) is desired for treating coagulopathies, but thawing and issuing of FFP takes more than 40 minutes. Liquid storage of plasma is a potential solution but uncertainties exist regarding clotting factor stability. We assessed different storage conditions of thawed FFP and plasma treated by methylene blue plus light (MB/light) for pathogen inactivation. STUDY DESIGN AND METHODS: Fifty thawed apheresis plasma samples (approx. 750 mL) were divided into three subunits and either stored for 7 days at 4°C, at room temperature (RT), and at 4°C after MB/light treatment. Clotting factor activities (Factor [F] II, FV, FVII through FXIII, fibrinogen, antithrombin, von Willebrand factor antigen, Protein C and S) were assessed after thawing and on Days 3, 5, and 7. Changes were classified as “minor” (activities within the reference range) and “major” (activities outside the reference range). RESULTS: FFP storage at 4°C revealed major changes for FVIII (median [range], 56% [33%‐114%]) and Protein S (51% [20%‐88%]). Changes were more pronounced when plasma was stored at RT (FVIII, 59% [37%‐123%]; FVII, 69% [42%‐125%]; Protein S, 20% [10%‐35%]). MB/light treatment of thawed FFP resulted in minor changes. However, further storage for 7 days at 4°C revealed major decreases for FVIII (47% [12%‐91%]) and Protein S (49% [18%‐95%]) and increases for FVII (150% [48%‐285%]) and FX (126% [62%‐206%]). CONCLUSION: Storage of liquid plasma at 4°C for 7 days is feasible for FFP as is MB/light treatment of thawed plasma. In contrast, storage of thawed plasma for 7 days at RT or after MB/light treatment at 4°C affects clotting factor stability substantially and is not recommended.     

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).     

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.     

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.     

Stability of factors V and VIII in thawed fresh frozen plasma units

Factors V and VIII, commonly regarded as unstable in unfrozen plasma, were assayed at various intervals up to 24 hours using plasma from 20 thawed fresh frozen plasma (FFP) units. Comparisons were made between units stored at 4 and 25 C. The mean factor V value did not significantly change during the postthaw test period. Mean factor VIII activity prior to freezing was 121 per cent, dropped to 89 per cent four hours after thawing, and gradually decreased to 67 per cent at 24 hours. There was no difference between those units stored at 4 C and those stored at 25 C after thawing; therefore, refrigeration does not appear necessary for factor V or VIII stability up to 24 hours after thawing.     

Comparison and stability of ADAMTS13 activity in therapeutic plasma products

BACKGROUND: The von Willebrand factor (VWF)-cleaving protease, ADAMTS13, is often deficient in cases of thrombotic thrombocytopenic purpura (TTP). The primary treatment of TTP is therapeutic plasma exchange (TPE) utilizing a variety of plasma products that help restore ADAMTS13 activity. However, multiple replacement products are available to choose from. Thawed plasma products have a variable refrigerated shelf life depending on the product type; stability of ADAMTS13 in thawed products stored at 1 to 6 degrees C has not been determined. STUDY DESIGN AND METHODS: ADAMTS13 activity was measured in three types of plasma products and cryoprecipitate. Fresh-frozen plasma (FFP) aliquots and cryoprecipitate-poor plasma (CPP) products were produced from 10 whole-blood (WB) donations. Twenty-four-hour plasma products were manufactured from 10 additional WB donations. ADAMTS13 activity in these products at time of thaw and after 5 days of storage at 1 to 6 degrees C was measured with a modified version of the FRETS-VWF73 fluorogenic assay. ADAMTS13 activity at time of thaw was measured in 10 units of cryoprecipitate and five related CPP products. RESULTS: ADAMTS13 is present in similar amounts in FFP, CPP, and 24-hour plasma products. Storage at 1 to 6 degrees C for up to 5 days did not significantly diminish ADAMTS13 activity. The concentration of ADAMTS13 in cryoprecipitate was significantly higher than that observed in plasma products. CONCLUSION: FFP, CPP, and 24-hour plasma products should be equally effective for ADAMTS13 restoration through TPE and should remain so for the duration of the shelf life of the thawed products.     

Measurement of serum and plasma osmolality in healthy young humans--influence of time and storage conditions.

BACKGROUND: The precise measurement of osmolality is crucial in the differential diagnosis of disorders of water balance. Storage conditions, and freezing and thawing of serum or plasma samples before osmometry may influence the accuracy of measured values. METHODS: A series of serum and plasma samples of 25 healthy young individuals were stored under different conditions at different temperatures (room temperature (22 degrees C), 7 degrees C, -21 degrees C, -78 degrees C) for up to 56 days. Before freezing a protein-stabilizing agent (bacitracin) was added to one part of the samples. Osmolality was examined using the freezing point method. RESULTS: At room temperature osmolality was stable for up to 3 days but showed a tendency toward an increase that was significant on day 14. In contrast, at 7 degrees C an initial significant decrease in serum osmolality occurred (day 1), which was followed by a slow increase. Serum samples stored at -21 degrees C showed a significantly lower osmolality on the 14th day compared to baseline. Adding bacitracin before freezing reduced this decrease by more than half, but the deviation was still significant. In samples stored at -78 degrees C no significant alteration of osmolality from baseline was observed over the observation period of 56 days if samples were thawed in a 37 degrees C water bath. CONCLUSION: Immediate measurement of osmolality is most reliable in order to obtain accurate values, although storing at room temperature does not influence osmolality significantly during the first 3 days. If storage is necessary for longer, samples should be stored at -78 degrees C and must be thawed quickly (at 37 degrees C). Under these conditions reliable values can be obtained from frozen serum or plasma. Storage at 7 degrees C is not recommended. If samples are stored at -21 degrees C the addition of a protein-stabilizing agent may be useful.     

Analysis of prolonged storage on coagulation Factor (F)V,FVII, and FVIII in thawed plasma: is it time to extend the expiration date beyond 5 days?

BACKGROUND: According to AABB standards, fresh‐frozen plasma (FFP) should be thawed at 30 to 37°C and expire after 24 hours. An increase in the aggressive management of trauma patients with thawed plasma has heightened the risk of plasma waste. One way to reduce plasma waste is to extend its shelf life, given that the full range of therapeutic efficacy is maintained. We evaluated the effect of prolonged storage at 1 to 6°C on the activity of Factor (F)V, FVII, and FVIII in plasma thawed at 37 or 45°C. STUDY DESIGN AND METHODS: Group O plasma from healthy donors (n = 20) was divided into 10 pairs and frozen and stored at not more than ?18°C. One sample from each pair was thawed at 37 or 45°C, and all were stored at 1 to 6°C. Samples were analyzed for FV, FVII, and FVIII activity on Days 0, 5, 10, 15, and 20. RESULTS: Plasma thawing time was 17% less at 45°C than at 37°C. No differences were observed between thawing groups in coagulation activity of FV, FVII, and FVIII during the 20‐day storage period (p > 0.12). In both groups, the activity of FV and FVIII decreased over time but remained within a normal range at 10 days. CONCLUSION: Although levels of plasma clotting factors are reduced in storage, therapeutic levels of FV and FVIII are maintained in thawed plasma stored for up to 10 days at 1 to 6°C. Thawing of FFP at 45°C decreases thawing time but does not affect the activity of FV, FVII, and FVIII.     

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.     

Vitamin K-dependent coagulation factors and fibrinogen levels in FFP remain stable upon repeated freezing and thawing

BACKGROUND: FFP is considered adequate for transfusion up to 24 hours after thawing and is currently used most often to replace deficient clotting factors, such as in warfarin overdose. We set to examine the levels of vitamin K-dependent factors (i.e., prothrombin, FVII, F IX, FX), as well as fibrinogen, upon twice freezing and thawing of FFP. If factor levels in refrozen FFP remain within normal limits, this component can possibly be transfused, thus avoiding wastage of precious blood components. STUDY DESIGN AND METHODS: Twenty units of FFP, five units of each blood group A, B, AB, and O, were thawed, and aliquots were taken for measurement of coagulation factors. The plasma units were then kept for 24 hours at 4 degrees C, at which point a second aliquot was taken, The remaining FFP units were refrozen and kept at -80 degrees C for 1 week. The above procedure was then repeated. Coagulation-factor activity and fibrinogen level were measured by the coagulation analyzer. RESULTS: The mean levels of prothrombin, FVII, F IX, FX, and fibrinogen of each blood group (A, B, AB, and O) were calculated for each of four time points and found not statistically different (p > 0.05). Therefore, the rest of the analysis was done for all 20 FFP units as one group. The mean +/- SD levels of each coagulation factor at each time point demonstrated that all levels were within normal limits of all factors measured and that for none of the factors was there a significant decay of activity. CONCLUSIONS: The levels of prothrombin, FVII, F IX, FX, and fibrinogen remain stable and adequate for transfusion in twice-thawed-and-refrozen FFP. This component can be safely used for transfusion as a source of vitamin K-dependent clotting factors and fibrinogen.     

Increased transforming growth factor β contributes to deterioration of refrigerated fresh frozen plasma's effects in vitro on endothelial cells

Resuscitation with fresh frozen plasma (FFP) is associated with improved outcomes after hemorrhagic shock. Many trauma centers are using thawed plasma that has been stored for up to 5 days at 4°C (refrigeration), yet the effect of refrigeration on FFP is relatively unknown. Previously, our group showed that refrigeration of FFP changed its coagulation factors and diminished its beneficial effects on endothelial cell (EC) function and resuscitation in an animal model of hemorrhagic shock. We hypothesize that growth factor composition of FFP is altered during refrigeration, leading to a diminished beneficial effect on EC. Transforming growth factor (TGF-β) is a potent inhibitor of EC migration and is released during refrigeration of platelets. We found increased TGF-β1 protein levels and greater activation of downstream mediators Smad2/3 during refrigeration of FFP. Both day 0 FFP (used on the same day after being thawed) and day 5 FFP (used after being thawed and refrigerated for 5 days) stimulated EC migration in vitro; however, the EC migration in day 5 FFP was significantly reduced. Inhibition of TGF-β type I receptor blocked FFP-induced Smad3 signaling in EC cells and restored the effectiveness of day 5 FFP on EC migration to a comparable level seen in day 0 FFP. These data suggest that the increased TGF-β levels during FFP refrigeration contribute to the deterioration of refrigerated FFP's effects on EC migration. This study identifies a novel molecular mechanism contributing to the reduced efficacy of refrigerated FFP.     

Coagulation parameters in apheresis and leukodepleted whole-blood plasma during storage

BACKGROUND: Thawing fresh-frozen plasma (FFP) may cause delay in delivery, and one approach to circumvent this is to store plasma at +4 degrees C. Thawed plasma is commonly discarded after a few days of storage, owing to the assumption that coagulation factor activity decreases to clinically unacceptable levels. STUDY DESIGN AND METHODS: Eighteen apheresis plasma (AP) units were collected from blood donors. The collected plasma was divided into two equal parts: one part frozen at -74 degrees C as FFP and one part stored at +4 degrees C as fresh liquid plasma (FLP). Thirty-nine units of whole blood (WB) were collected from blood donors and leukodepleted by inline filtration, followed by plasma separation. Twenty plasma units were frozen at -74 degrees C as FFP and 19 plasma units were stored at +4 degrees C as FLP for 28 days. Plasma aliquots were collected before freezing and immediately after thawing FFP and before and during storage of FLP at Days 14 and 28. Factor (F)V, FVIII, D-dimers, and C1-esterase inhibitor levels were assessed. RESULTS: No significant differences in coagulation factor levels were assessed between FLP prepared from AP and FLP prepared from WB. FV and FVIII levels decreased on average 25 and 50 percent, respectively, at Day 14 of storage. C1-esterase inhibitor and D-dimers levels were not affected. CONCLUSION: Leukodepleted apheresis and WB plasma stored for 14 days retain sufficient levels of FV and FVIII activity for maintenance of normal hemostasis and could therefore be considered useful in selected clinical situations.     

Rapid thawing of fresh frozen plasma in two-liter bags

The authors hypothesized that plasma could be rapidly thawed in two-liter Transfer Pack Units, because of their greater surface area (993 cm2) compared to standard satellite bags (348 cm2) of Blood Pack Units (both from Fenwal, Baxter Healthcare Corp, Deerfield, IL). Five units of FFP were prepared in each bag. The Sterile Connection Device (DuPont, Wilmington, DE) was used to transfer plasma from the satellite to transfer pack units, and these were put in metal canisters before all units were frozen at -65 degrees C. Thawing time was 4.8 +/- 1.3 (SD) minutes and 15 +/- 3.2 (SD) min. for units prepared in modified and standard methods respectively (t = 6.33, P less than .01). The thermal rate constants were calculated as 0.0034 and 0.0033 for the two methods. The finding of similar values substantiate the theory that thawing time is related to the volume to surface area ratio.     

Evaluation and comparison of coagulation factor activity in fresh-frozen plasma and 24-hour plasma at thaw and after 120 hours of 1 to 6°C storage

BACKGROUND: Current transfusion-related acute lung injury reduction strategies include avoiding transfusion of plasma products collected from female donors or female donors that have been pregnant to reduce transfusion of plasma-containing HLA antibodies. Such a policy considerably decreases the number of donors available for generation of fresh-frozen plasma (FFP). To increase the supply of FFP, substitution of 24-hour plasma (FP24) and thawed plasma (TP) derived from either FFP or FP24 may be viable substitutes. To justify such a policy the coagulation factor content of FFP, FP24, and TP derived from both product types was assessed.
STUDY DESIGN AND METHODS: Coagulation factor (F)II, FV, FVII, FVIII, F IX, and FX; protein C (PC) and protein S (PS); von Willebrand factor antigen and ristocetin cofactor; fibrinogen; and antithrombin activities were analyzed in nonpaired FFP and FP24 at the time of product thaw and again after 120 hours of 1 to 6°C storage.
RESULTS: At thaw, mean FVIII and PC activities were lower in FP24 than FFP. Mean PC and PS activities were lower in FP24- than FFP-derived 120-hour-old TP. No other differences in mean activity reached significance. Activity levels were generally lower in TP; FVIII, FV, and FVII showed the largest changes. However, prestorage leukoreduction appears to improve the stability of FV.
CONCLUSION: FFP, FP24, and the derived TP all contain adequate coagulation factor activities to maintain hemostatic activity. As FFP becomes less available, increased use of FP24 and TP are viable alternatives for most clinical situations.     

Effect of freezing, long-term storage, and microwave thawing on the stability of ketorolac tromethamine

BACKGROUND: Ketorolac tromethamine is a nonsteroidal agent with potent analgesic and moderate antiinflammatory activity. Advance preparation of intravenous solution could be useful to improve quality assurance, time management, and cost-savings of drug delivery. OBJECTIVE: To investigate the effect of freezing, long-term storage, and microwave thawing on the stability of ketorolac tromethamine in dextrose 5% infusion. METHODS: Five polyolefin bags of solution containing ketorolac tromethamine 20 mg per 100 mL of dextrose 5% were frozen for 3 months at -20 degrees C, thawed in a microwave oven with a validated cycle, and stored at 4 degrees C. The concentration of ketorolac was measured by HPLC. Visual inspection and pH measurement were also carried out. RESULTS: No color change or precipitation was observed. Ketorolac was stable for at least 60 days under refrigeration after freeze-thaw. Throughout this period, the lower confidence limit of the estimated regression line of the concentration-time profile remained >90% of the initial concentration, and the pH value decreased slightly without affecting chromatographic parameters. CONCLUSIONS: Within these limits, ketorolac tromethamine in dextrose 5% infusion may be prepared and frozen in advance by a centralized intravenous admixture service, then thawed before use in clinical units.     

Preanalytical handling of stored urine samples, and measurement of beta 2-microglobulin, orosomucoid, albumin, transferrin and immunoglobulin G in urine by enzyme-linked immunosorbent assays (ELISA)

Urinary beta 2-microglobulin, orosomucoid, albumin, transferrin and IgG were measured by enzyme-linked immunosorbent assays (ELISA). In urine samples stored at -20 degrees C three of these proteins decreased during the period of freezing. After 1 week at -20 degrees C urinary transferrin decreased by 81%, IgG by 39% and albumin by 26% of the pre-freezing values; however, addition of Tween-20 restored these values. In previously stored urine samples with bovine albumin, the decreased value after freezing at -20 degrees C could be increased by changing the thawing procedure and including addition of Tween-20. Urine samples thawed at room temperature just before analysis decreased by 80% for transferrin, 57% for IgG, 30% for albumin and 26% for beta 2-microglobulin compared with samples thawed at 37 degrees C, had Tween-20 added and then were kept for a few days at room temperature before analysis. Furthermore, previously frozen urine samples that were thawed at 37 degrees C, had Tween-20 added and then were stored at room temperature did not show significant changes in any of the protein results measured the day after thawing and 35 days later. Orosomucoid seemed to be less variable as regards the effect of freezing and thawing procedure.