dxy

6.1.3. Water baths. 
It is essential to place the primary FFP pack in a vacuum-sealed over-wrap to protect it from bacterial contamination. Once thawed, the primary pack should be removed from the over-wrap bag and examined for leaks or damage. Damaged packs should not be used. Water baths used for thawing FFP must only be used for this purpose. They should be cleaned regularly (at least once a day) and filled with clean, laboratory grade water. Water bath use and maintenance schedules should be described by a specific standard operating procedure. All maintenance should be logged. The average time for 2 units to thaw is 20 min.

6.2. Storage after thawing

Thawed plasma and cryosupernatant should be kept at 4 C if there is any delay in transfusion. Current UK guidelines (United Kingdom Blood Transfusion Services/National Institute for Biological Standards and Control, 2002), require transfusion within 4 h; whereas the American Association of Blood Banks (2002) allow a delay of up to 24 h. The FVIII activity in FFP will decline after 24 h at 4 C by up to 28%, but all other factors remain stable for 5 d (see Table IV). Shehata et al (2001) showed that storing FFP for up to 72 h after thawing caused about 40% of the FVIII activity to be lost, although the FVIII activity and fibrinogen content were still substantially higher than in cryosupernatant. The activities of FII and FV in FFP were maintained up to 72 h after thawing. These authors recommended that FFP stored for up to 72 h after thawing can, like cryosupernatant plasma, be used when FVIII replacement is not required. Another concern is safety from contamination with microorganisms that may be introduced during thawing, particularly if a water bath is used. Proper protocols and documentation, and a method of thawing which does not rely on immersion in water, will reduce this risk. Therefore, further study is needed before post-thaw storage beyond 24 h could be recommended. 

Recommendation
After thawing, and when FVIII replacement is not required, FFP and cryosupernatant may be stored at 4 C in an approved blood storage refrigerator before administration to the patient so long as the infusion is completed within 24 h of thawing (grade B recommendation, level III evidence).

7. Control of issue and transfusion

The recommendations of the BCSH guidelines for the administration of blood and blood components and management of transfused patients should be followed (BCSH, 1990b, 1994, 1999). As for all blood components, FFP should be administered to adults and children only after being passed through a 170–200 lm filter, as provided in standard giving sets.
Fresh-frozen plasma and cryoprecipitate should be issued from hospital blood banks using the same criteria as for red cells and platelets. The same standard of care should be taken to ensure that blood samples are collected from the correct patient when completing the request form or prescription, and when administering and documenting the transfusion. Hospitals should have a policy for handling FFP that is in accordance with these guidelines.

8. Response to FFP transfusion

Responses should be monitored, as they will serve as a guide to further supportive care. If FFP is given because the patient is bleeding, the clinical response may well be the best indication of effectiveness of transfusion. If FFP is given to correct abnormal coagulation parameters, the degree of correction should be recorded. Monitoring may be through measuring coagulation activities by traditional laboratory techniques, or through various ‘near-patient’ testing devices; the chosen methods should be timely and suit the clinical situation.

9. Adverse effects

9.1. Allergy

Allergy resulting in urticaria has been reported in 1–3% of transfusions, whilst anaphylaxis is rare (Bjerrum & Jersild, 1971; Sandler et al, 1995). In the first 6 years of the SHOT scheme, 23 allergic and 25 anaphylactic reactions were reported to FFP, and one acute reaction in which IgA antibodies were implicated. For patients who have proven sensitivity to IgA, IgA deficient plasma is available on request. Patients suffering severe adverse effects of transfusion should be managed according to McClelland (2001).

9.2. TRALI

Transfusion-related acute lung injury is manifest clinically as severe respiratory distress, with hypoxia, pulmonary oedema, infiltrates or ‘white-out’ on chest X-ray, and sometimes fever and hypotension, which usually develops within 4 h of transfusion (Kopto & Holland, 1999). It cannot be distinguished clinically from adult respiratory distress syndrome or other forms of acute lung injury (Popovsky et al, 1992; Murphy, 2001; Palfi et al, 2001). Symptoms usually improve after a few days, although morbid signs can persist for at least 7 d.

Since 1996, the SHOT scheme has received reports of TRALI in 109 transfusion recipients of whom 30% died – usually of compound reasons. In the 15-month period 2001–2002, FFP was the implicated component in 12 of 22 cases of TRALI. Of these cases, one (who received only FFP) died.

According to some authors, TRALI develops in two steps (Silliman et al, 2003). First, a predisposing condition, such as surgery or active infection, releases cytokines and encourages neutrophils to attach to the vascular endothelium particularly in the pulmonary capillaries. The second step is that lipid and other cytokines, or human leucocyte antigen or granulocyte alloantibodies (found in 80% of the donors in some series, most of whom are women who have been pregnant) cause further neutrophil priming, activation and pulmonary damage.

If alloantibodies to leucocytes are important in TRALI, the incidence associated with plasma might be reduced by using FFP from male donors. Plans for expediting such availability in parts of the UK may provide further support for this as yet unproved hypothesis. No substantiated case of TRALI has been reported after SDFFP. This may be because the pooling process dilutes any unit with high titre alloantibodies.