Panel calls for curbing use of fresh frozen plasma.
Medical and blood banking specialists attending a recent three-day consensus conference offered those conclusions in a draft report and press briefing immediately following the meeting. The National Institutes of Health and the Food and Drug Administration convened the gathering expressly to examine issues surrounding the growing professional concerns about FFP indications, effectiveness, and safety.
The 11-member panel that authored the post-conference statement and conclusions was emphatic. FFP administration, it said, has increased dramatically in recent years "despite the paucity of definitive indications for its use" and "in the presence of mounting evidence of its potential risks," including viral hepatitis and possibly AIDS.
Many patients who receive FFP can be managed "more effectively and safely with alternative modalities," the panel said, noting that FFP use "must be justified on clinical grounds until better evidence is available."
The panel also pointedly criticized one practice. "There is no justification for the use of FFP as a volume expander. Safer alternative therapy exists."
The most appropriate indications for FFP, the panel said, are:
* some documented protein deficiencies;
* selected patients who require massive transfusions;
* patients with multiple coagulation defects as in liver disease;
* in conjunction with therapeutic plasma exchange for thrombotic thrombocytopenic purpura;
* infants with protein-losing enteropathy; and
* selected patients with other immune deficiencies.
"Its use in most other cases should be discouraged," the report concluded.
Translated to percentages, the picture is more graphic. Harvard medical school professor emeritus Dr. James Tullis, the panel chairman, estimated that 90 per cent of current FFP use is inappropriate. Figures supplied by researchers at the conference indicate that some 700,000 patients a year are receiving 1.8 million units of FFP--a tenfold increase over the last five years.
During the same period, while little apparently was done to define specifications for therapeutic applications, blood product specialists came to realize that risk of disease transmission through FFP had become "significant." Panel members referred to one estimate that perhaps 20,000 to 70,000 cases of viral hepatitis are transmitted each year through FFP. They also cited studies indicating that the incidence of non-icteric and icteric hepatitis following multiple transfusions of whole blood or red blood cells is between 3 and 10 per cent. They believe the range for transfusions with FFP is likely the same.
The panelists said most of the misuse probably occurs in replacing blood lost during cardiac surgery, while a second troublesome practice is combining plasma with red blood cells when other combining fluids could be used with less risk.
Dr. Scott Swisher, a Michigan State University medical professor who addressed the conference, reported that American Red Cross records showed that FFP went largely to tertiary care, high-technology hospitals.
University medical centers, university-affiliated hospitals, and VA facilities represent 4.31 per cent of the hospitals served by the Red Cross, yet received 25.8 per cent of the FFP distributed, he said. In contrast, general and speciality hospitals ordered FFP in "direct proportion" to their representation: 69.4 per cent of FFP to 72.8 per cent of facilities served. And investor-owned, military, and Public Health Service hospitals received less FFP than their representation on the roster.
What accounts for this blood product's popularity if, as the report noted, little in the literature supports its increased use in clinical medicine?
"The trend may be attributable, in part, to a decreased availability of whole blood due to widespread acceptance of the concept of component therapy," the panel's statement said.
Other contributing factors mentioned during the conference but not included in the summary document included the high cost of some alternatives, limited knowledge among clinicians about scientifically sound transfusion practices, and inadequate instruction of medical school students and residents.
Some questioned whether clinical laboratory directors, hospital transfusion service chiefs, and blood bank directors always have access to or comply with the latest scientific opinion, or whether they at times promote FFP use because the product is a revenue generator. Also cited: the accepted medical practice of administering component-loaded plasma rather than determining and ordering the specific components a patient needs.
As for alternatives, the panel said the most important is a comprehensive program of blood conservation. This includes measures such as autologous donations before elective surgery, the use of cell savers, reinfusion of shed blood, "and the realization that in many patients normovolemic anemia is not life-threatening."
Added the panel: "Single-donor plasma is efficacious in treating mild deficiencies of stable clotting factors" and "of value for multiple deficiencies, as in reversal of warfarin effects or in liver disease .... Cryoprecipitate should be used when fibrinogen or von Willebrand factor is needed. For treatment of hemophilia A, cryoprecipitate of factor VIII concentrates, heated or unheated, are available. For hemophilia B, factor IX complex is preferable .... Albumin, plasma protein fraction, crystalloid solutions, hydroxyethyl starch, or dextran are preferable to FFP for volume replacement. Whole blood or blood modified by removal of the platelets and cryoprecipitate should be used if available, rather than the combined administration of plasma and red blood cells."
The panel noted that FFP use is controlled locally and determined largely by existing practice. "Attempts to alter FFP use frequencly have been ineffective," it pointed out. But where successful, a "strong local proponent of modern transfusion practices" is usually found.
"Ongoing collaborative efforts, including component therapy workshops involving clinicians and blood bank directors, can do much to alter existing practices," it advised. "Increased attention to the risks and benefits of component therapy in the medical schools and teaching hospitals also may change FFP use."
When appropriate, information regarding FFP's potential risks and benefits, as well as those for other blood products, should be made available to patients who receive them, the panel said.
The report also provided a lengthy list of recommended future research goals, including:
* A national prospective epidemiologic study to identify the current usage patterns of FFP and related products.
* Defining the etiology of uncontrollable hemorrhage in the massively transfused patient.
* Clinical investigations to identify the factor(s) in fresh frozen plasma that appears to cause beneficial effects in patients who are undergoing apheresis for treatment of syndromes such as thrombotic thrombocytopenic purpura.
* Blood salvage during operative procedures to allow a more judicious use of FFP and other blood products.
* Production of the safest possible FFP or substitutes.
* Technology involving membrane-separation techniques to separate cellular products more effectively.
* Development of an efficient system by which a larger volume of FFP can be collected from a single donation, thus lessening the number of donor exposures.
At this writing, panel participants were reviewing the draft document, and a final version was to have been published late last month. Some close to the working group expected only minor wording changes, while others anticipated considerable rewriting. No one, however, predicted major substantive changes since no major rifts emerged among the specialists during the conference.
Meanwhile, a Red Cross spokesman said the ARC fully supported the draft. Officials at the American Association of Blood Banks elected to withhold comment until the final version was available.
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|Publication:||Medical Laboratory Observer|
|Date:||Nov 1, 1984|
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