Critically ill patients with spontaneously prolonged pro-thrombin time, where administration of intravenous administration of phytomenadione (vitamin K) has been ordered by the treating physician will be identified. After signed informed consent baseline samples will be collected. Phytomenadione will be given and 24 hours after administration new blood samples will be collected. Several different advanced coagulation and vitamin K-assays will be performed before and 24 hours after vitamin K administration.

Vitamin K-deficiency is common in the peri-operative and intensive care setting. It is often seen in patients with prolonged prothrombin complex (PK-INR). A prolonged (PK-INR) is sometimes treated with intravenous vitamin K, even in non-warfarin treated or non-liver failure patients. Despite the development of this practice the knowledge about how intravenously given vitamin K affects routine coagulation status and other advanced laboratory coagulations assays is rare.

The aim of this study is to investigate the effects of intravenously administered vitamin K on routine coagulation status and on advanced coagulation and vitamin K-assays in post-operative- and critically ill patients with prolonged PK-INR.

Patients with spontaneously prolonged PK-INR are routinely given intravenous vitamin K but it is largely unknown how this procedure affects the included coagulation assays. This research project may contribute to increased knowledge concerning effects of intravenously given vitamin K in critical ill patients with spontaneous coagulopathies. Since spontaneous coagulopathy is frequently occurring in critically ill and postoperative patients due to various underlying conditions and current evidence for vitamin K administration is based on scarce evidence more research in this area is motivated.

Inclusion Criteria:

• Critically ill patients at the postoperative care unit or at the intensive care unit with a prothrombin complex (PK-INR) > 1.2 during office hours who are ordered parenteral phytomenadione 10 mg will be eligible for inclusion

Exclusion Criteria:

• Warfarin treatment
• Treatment with novel oral anticoagulants
• Hepatocellular carcinoma
• Liver resection within 6 months
• Known pre-existing coagulopathy

Critically ill patients at the postoperative care unit or at the intensive care unit with a prothrombin complex (PK-INR) > 1.2 during office hours who are ordered parenteral phytomenadione 10 mg will be eligible for inclusion