Transfmion Medicine, f992, 2, 97-98
EDITORIAL
Fresh frozen plasma-opinion
and evidence patient) and in this subgroup there was no difference in blood loss. The study sample was large enough to detect a threefold increase in blood loss with a P-value of 0-05 for a PT or PTT of up to twice the mid-normal range. In fact the data showed no trend towards increased blood loss with increasingly abnormal coagulation results. One could argue that a prospective controlled clinical trial of FFP is still needed to determine if its use could reduce blood loss in this group of patients. However, in the absence of what would have to be a very large trial, this thorough retrospective analysis, based on useful intermediate outcomes (bleeding and transfusion requirement), provides the basis for a firm recommendation that prophylactic FFP is not required before paracentesis or thoracocentesis when the PT or PTT are below twice the control values. How well is our current practice likely to measure up to the new guidelines; will we be able to find out from the clinical records we keep, or will prospective surveys be required? We may take some slight reassurance from an examination of the overall use of FFP nationally: at least the UK does not appear to be in the major league of FFP consumption. We use 1 unit for every 8-14 red cell units transfused (SNBTS, NBTS statistics, 1988).This compares with a ratio of 1 F F P to 2.5 red cell units in the USA (Menitove, 1986) and similar figures in several European countries. Even so, a restrospective audit of the use of FFP in the U.K. (Thompson el al., 1991) suggests that 60-85% of FFP use fell outside the indications of the NIH consensus guidelines, a figure similar to that found in the United States (Barnette et af.,1990) and in Israel (Mozes ef af., 1989). Perhaps even more disturbing is the fact that in many such studies, it is evident that the clinical records of the majority of recipients gave no indication whatsoever of the reasons for administering FFP. These new guidelines should play an important role in focusing attention of the use of F F P in the U.K. Backed up by well designed simple audit measures which can be widely applied they should be used to help us answer three basic audit questions enunciated by Simpson (1982).
The guidelines for use of Fresh Frozen Plasma (FFP) published in the March issue are a welcome addition to the rack of charts we require to help navigate through the patchy fog of transfusion practice. They provide sensible answers to a number of questions that arise in daily practice and will doubtless be used as the starting point for the development of a variety of audit measures designed to move practice closer to conformity with the guideline. The authors, like those who have written guidelines for the use of other blood components, have of course had to struggle with the remarkable lack of adequate clinical trial data on the efficacy of FFP for many clinical indications. In particular, studies which establish the effect of FFP therapy on major clinical outcomes are few and far between. There is always therefore the nagging concern that guidelines and the ensuing audit process may occasionally be an effective means of enshrining a practice, which although supported by consensus is either ineffective or may even be harmful. Looking, for example, at the use of FFP and coagulation factor concentrates in patients with impaired coagulation associated with chronic liver disease, it is interesting to compare the paper of Mannucci et al. (1976) with a recent report by McVay & Toy (1991). The Italian study demonstrated elegantly that correction of coagulation tests was best achieved by a combination of FFP and prothrombin complex concentrates, and provided a basis for guidelines on the use of FFP, while emphasizing reservations about the balance of risks and benefits of prothrombin complex concentrates in these patients. The question raised by McVay & Toy (1991) is whether any replacement therapy is needed prior to invasive procedures in such patients if coagulation disturbances are moderate. They carried out a detailed retrospective study of 600 patients, the largest group of whom had alcoholic liver disease, undergoing paracentesis or thoracocentesis. Bleeding was assessed by determining the pre- and post-procedure haemoglobin level, correcting for any transfusion given. The authors found that in patients with mild to moderate coagulation abnormalities (PT or PTT up to twice the midpoint normal range) there was no increase in blood loss. Only 10% of patients with abnormal prothrombin times received FFP transfusions (4.2 & 2.0 units per
What was transfused? Why was it transfused? What was the result of the transfusion? 97
98 Editorial
If this apparently simple information was available in 100% of case records of patients receiving FFP, we would have made a great leap forward. The answers t o more basic questions about when FFP is actually efficacious remain as a challenge t o transfusion medicine, a challenge which will become even more important as the availability of virally inactivated plasma removes what is for many clinicians one of the major constraints o n using this product.
D. B. L. MCCLELLAND Edinburgh and S.E. Scotland Blood Transfusion Service Department of Transfusion Medicine Royal Infirmary of Edinburgh Lauriston Place. Edinburgh EH3 9HB Scotland REFERENCES Barnette, R.E., Fish, D.J. & Eisenstaedt, R.S.(1990) Modification of fresh frozen plasma transfusion practices through educational intervention. Transfusion, 30, 253257.
Mannucci, P.M., Franchi, F. & Dioguardi, N. (1976) Correction of abnormal coagulation in chronic liver
disease by combined use of fresh frozen plasma and prothrombin complex concentrates. Lancet, ii, 542-545. Menitove, J . (1986) Blood utilisation. In: New Frontiers in Blood Banking, (eds Wallas C.H. & McCartgt, L.J.) pp. 117. American Association of Blood Banks, Arlington, VA. Mozes, B., Epstein, M., Ben Bassat, I., Modan, B. & Halken, H. (1989) Evaluation of the appropriateness of blood and blood product transfusion using present criteria. Transfusion, 29, 473-476. McVay, P.A. & Toy, P.T.C.Y. (1991) Lack of increased bleeding after paracentesis and thoracocentesis in patients with mild coagulation abnormalities. Transfusion, 31, 164-171. Scottish National Blood Transfusion Service and National Blood Transfusion Service Annual Statistics 1988. SNBTS, Edinburgh. Simpson, M.B. (1982) Audit criteria for transfusion practices. In: The Hospital Transfusion Committee, (eds Wallas, C.H. & Muller, V.H.) pp. 21-58. American Association of Blood Banks, Arlington, VA. Thomson, A., Contreras, M. & Knowles, S. (1991) Blood component treatment: a retrospective audit in five major London hospitals. Journal of Clinical Pathology 44, 734737.
EDITORIAL
Fresh frozen plasma-opinion
and evidence patient) and in this subgroup there was no difference in blood loss. The study sample was large enough to detect a threefold increase in blood loss with a P-value of 0-05 for a PT or PTT of up to twice the mid-normal range. In fact the data showed no trend towards increased blood loss with increasingly abnormal coagulation results. One could argue that a prospective controlled clinical trial of FFP is still needed to determine if its use could reduce blood loss in this group of patients. However, in the absence of what would have to be a very large trial, this thorough retrospective analysis, based on useful intermediate outcomes (bleeding and transfusion requirement), provides the basis for a firm recommendation that prophylactic FFP is not required before paracentesis or thoracocentesis when the PT or PTT are below twice the control values. How well is our current practice likely to measure up to the new guidelines; will we be able to find out from the clinical records we keep, or will prospective surveys be required? We may take some slight reassurance from an examination of the overall use of FFP nationally: at least the UK does not appear to be in the major league of FFP consumption. We use 1 unit for every 8-14 red cell units transfused (SNBTS, NBTS statistics, 1988).This compares with a ratio of 1 F F P to 2.5 red cell units in the USA (Menitove, 1986) and similar figures in several European countries. Even so, a restrospective audit of the use of FFP in the U.K. (Thompson el al., 1991) suggests that 60-85% of FFP use fell outside the indications of the NIH consensus guidelines, a figure similar to that found in the United States (Barnette et af.,1990) and in Israel (Mozes ef af., 1989). Perhaps even more disturbing is the fact that in many such studies, it is evident that the clinical records of the majority of recipients gave no indication whatsoever of the reasons for administering FFP. These new guidelines should play an important role in focusing attention of the use of F F P in the U.K. Backed up by well designed simple audit measures which can be widely applied they should be used to help us answer three basic audit questions enunciated by Simpson (1982).
The guidelines for use of Fresh Frozen Plasma (FFP) published in the March issue are a welcome addition to the rack of charts we require to help navigate through the patchy fog of transfusion practice. They provide sensible answers to a number of questions that arise in daily practice and will doubtless be used as the starting point for the development of a variety of audit measures designed to move practice closer to conformity with the guideline. The authors, like those who have written guidelines for the use of other blood components, have of course had to struggle with the remarkable lack of adequate clinical trial data on the efficacy of FFP for many clinical indications. In particular, studies which establish the effect of FFP therapy on major clinical outcomes are few and far between. There is always therefore the nagging concern that guidelines and the ensuing audit process may occasionally be an effective means of enshrining a practice, which although supported by consensus is either ineffective or may even be harmful. Looking, for example, at the use of FFP and coagulation factor concentrates in patients with impaired coagulation associated with chronic liver disease, it is interesting to compare the paper of Mannucci et al. (1976) with a recent report by McVay & Toy (1991). The Italian study demonstrated elegantly that correction of coagulation tests was best achieved by a combination of FFP and prothrombin complex concentrates, and provided a basis for guidelines on the use of FFP, while emphasizing reservations about the balance of risks and benefits of prothrombin complex concentrates in these patients. The question raised by McVay & Toy (1991) is whether any replacement therapy is needed prior to invasive procedures in such patients if coagulation disturbances are moderate. They carried out a detailed retrospective study of 600 patients, the largest group of whom had alcoholic liver disease, undergoing paracentesis or thoracocentesis. Bleeding was assessed by determining the pre- and post-procedure haemoglobin level, correcting for any transfusion given. The authors found that in patients with mild to moderate coagulation abnormalities (PT or PTT up to twice the midpoint normal range) there was no increase in blood loss. Only 10% of patients with abnormal prothrombin times received FFP transfusions (4.2 & 2.0 units per
What was transfused? Why was it transfused? What was the result of the transfusion? 97
98 Editorial
If this apparently simple information was available in 100% of case records of patients receiving FFP, we would have made a great leap forward. The answers t o more basic questions about when FFP is actually efficacious remain as a challenge t o transfusion medicine, a challenge which will become even more important as the availability of virally inactivated plasma removes what is for many clinicians one of the major constraints o n using this product.
D. B. L. MCCLELLAND Edinburgh and S.E. Scotland Blood Transfusion Service Department of Transfusion Medicine Royal Infirmary of Edinburgh Lauriston Place. Edinburgh EH3 9HB Scotland REFERENCES Barnette, R.E., Fish, D.J. & Eisenstaedt, R.S.(1990) Modification of fresh frozen plasma transfusion practices through educational intervention. Transfusion, 30, 253257.
Mannucci, P.M., Franchi, F. & Dioguardi, N. (1976) Correction of abnormal coagulation in chronic liver
disease by combined use of fresh frozen plasma and prothrombin complex concentrates. Lancet, ii, 542-545. Menitove, J . (1986) Blood utilisation. In: New Frontiers in Blood Banking, (eds Wallas C.H. & McCartgt, L.J.) pp. 117. American Association of Blood Banks, Arlington, VA. Mozes, B., Epstein, M., Ben Bassat, I., Modan, B. & Halken, H. (1989) Evaluation of the appropriateness of blood and blood product transfusion using present criteria. Transfusion, 29, 473-476. McVay, P.A. & Toy, P.T.C.Y. (1991) Lack of increased bleeding after paracentesis and thoracocentesis in patients with mild coagulation abnormalities. Transfusion, 31, 164-171. Scottish National Blood Transfusion Service and National Blood Transfusion Service Annual Statistics 1988. SNBTS, Edinburgh. Simpson, M.B. (1982) Audit criteria for transfusion practices. In: The Hospital Transfusion Committee, (eds Wallas, C.H. & Muller, V.H.) pp. 21-58. American Association of Blood Banks, Arlington, VA. Thomson, A., Contreras, M. & Knowles, S. (1991) Blood component treatment: a retrospective audit in five major London hospitals. Journal of Clinical Pathology 44, 734737.
