In virtually every hospital, admitted patients receive injections of blood thinners to prevent blood clots (thrombosis) and pulmonary embolisms. This preventive treatment, known as thromboprophylaxis, has been standard care for decades, including in the intensive care unit. Yet, despite this, thrombosis still occurs regularly.
This raises the question of what the optimal dosage is. That is precisely what ICU physician Eric Keus, internist Ruben Eck, and hematologist Karina Meijer are investigating. The reason for their research is a unique one. “We discovered that hospitals use different dosages,” explains Ruben Eck. “In an ICU in Groningen, a patient might receive a different amount of blood thinners than in Maastricht or Rotterdam.”
An international survey of hundreds of ICU units confirmed this picture. Eck and Keus sent a questionnaire to more than 700 intensive care physicians, extending far beyond Europe. The responses showed significant variation in dosages. Keus: “There are no clear guidelines for what the best dosage is. There is a great deal of evidence that preventive treatment against thrombosis works well, regardless of the dose of blood thinners. That is not up for debate. But the fascinating thing is that the very best dose has never been properly investigated. As a result, local practices have emerged.”
With funding from the Thrombosis Foundation, Keus and Eck are now launching a large-scale study to finally answer the question of the optimal dose. In their research, they are comparing three different dosages: a low dose, a medium dose, and a dose adjusted to the patient’s body weight.
The differences between these strategies are significant. Eck: “Patients in the medium-dose group receive double the dose compared to the low-dose group. In the weight-dependent group, the dose can even be three to four times higher than in the low-dose group, depending on body weight. We suspect that a weight-based dosage offers the best balance between effectiveness and safety. But that still needs to be proven.”
Together with patients, we determined in advance the best way to interpret the study’s outcomes. Keus: “In the study, we therefore focus primarily on how long patients survive and remain outside the hospital, and what their quality of life is after an ICU admission. We also look at the incidence of thrombosis and bleeding.”
The ultimate goal is clear: to determine which dosage of blood thinners works best for critically ill patients. Keus: “If the study yields convincing results, it could influence medical guidelines worldwide. There are no other studies in this field that are this large. If we can demonstrate what the optimal dose is, it could make a difference for thousands of patients each year.”
Eck expects between 2,500 and 4,500 ICU patients to participate in the study. “The study will take about three years, and we are conducting it together with colleagues from Copenhagen within a network of European hospitals.”
The study is part of a so-called platform study, a relatively new approach to clinical research. This involves establishing a fixed research structure in which multiple treatments or questions can be investigated simultaneously. New studies like this one can be added more easily.
Throughout the study, the researchers continuously monitor the interim results. If a treatment clearly isn’t working as well, it can be discontinued sooner. Conversely, patients gradually receive the treatment that appears most promising.
