Open Access Open Badges Study protocol

Does point of care prothrombin time measurement reduce the transfusion of fresh frozen plasma in patients undergoing major surgery? The POC-OP randomized-controlled trial

Natalie Urwyler1, Sven Trelle2, Lorenz Theiler1*, Peter Jüni2, Lukas P Staub3, Cedric Luyet1, Lorenzo Alberio4, Kay Stricker1 and Robert Greif1

Author Affiliations

1 University Department of Anesthesiology and Pain Therapy, University Hospital of Bern, Inselspital, 3010 Bern, Switzerland

2 CTU Bern, Bern University Hospital and Institute of Social and Preventive Medicine, University of Bern, Niesenweg 6, 3012 Bern, Switzerland

3 NHMRC Clinical Trials Centre, University of Sydney, Locked Bag 77, Camperdown NSW 1450, Australia

4 University Department of Hematology, University Hospital of Bern, Inselspital, 3010 Bern, Switzerland

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Trials 2009, 10:107  doi:10.1186/1745-6215-10-107

Published: 23 November 2009



Bleeding is a frequent complication during surgery. The intraoperative administration of blood products, including packed red blood cells, platelets and fresh frozen plasma (FFP), is often live saving. Complications of blood transfusions contribute considerably to perioperative costs and blood product resources are limited. Consequently, strategies to optimize the decision to transfuse are needed.

Bleeding during surgery is a dynamic process and may result in major blood loss and coagulopathy due to dilution and consumption. The indication for transfusion should be based on reliable coagulation studies. While hemoglobin levels and platelet counts are available within 15 minutes, standard coagulation studies require one hour. Therefore, the decision to administer FFP has to be made in the absence of any data. Point of care testing of prothrombin time ensures that one major parameter of coagulation is available in the operation theatre within minutes. It is fast, easy to perform, inexpensive and may enable physicians to rationally determine the need for FFP.


The objective of the POC-OP trial is to determine the effectiveness of point of care prothrombin time testing to reduce the administration of FFP. It is a patient and assessor blind, single center randomized controlled parallel group trial in 220 patients aged between 18 and 90 years undergoing major surgery (any type, except cardiac surgery and liver transplantation) with an estimated blood loss during surgery exceeding 20% of the calculated total blood volume or a requirement of FFP according to the judgment of the physicians in charge. Patients are randomized to usual care plus point of care prothrombin time testing or usual care alone without point of care testing. The primary outcome is the relative risk to receive any FFP perioperatively. The inclusion of 110 patients per group will yield more than 80% power to detect a clinically relevant relative risk of 0.60 to receive FFP of the experimental as compared with the control group.


Point of care prothrombin time testing in the operation theatre may reduce the administration of FFP considerably, which in turn may decrease costs and complications usually associated with the administration of blood products.

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