Coagulopathy, a common complication of traumatic brain injury (TBI), is characterized by a hypercoagulable state developing immediately after injury, with hyperfibrinolysis and bleeding tendency peaking 3 h after injury, followed by fibrinolysis shutdown. Reflecting this timeframe, the coagulation factor fibrinogen is first consumed and then degraded after TBI, its concentration rapidly decreasing by 3 h post-TBI. The fibrinolytic marker D-dimer reaches its maximum concentration at the same time. Hyperfibrinolysis in the acute phase of TBI is associated with poor prognosis via hematoma expansion. In the acute phase, the coagulation and fibrinolysis parameters must be monitored to determine the treatment strategy. The combination of D-dimer plasma level at admission and the level of consciousness upon arrival at the hospital can be used to predict the patients who will "talk and deteriorate." Fibrinogen and D-dimer levels should determine case selection and the amount of fresh frozen plasma required for transfusion. Surgery around 3 h after injury, when fibrinolysis and bleeding diathesis peak, should be avoided if possible. In recent years, attempts have been made to estimate the time of injury from the time course of coagulation and fibrinolysis parameter levels, which has been particularly useful in some cases of pediatric abusive head trauma patients.

BackgroundDiabetic ketoacidosis (DKA) is associated with a high mortality rate, especially if cerebral edema develops during the disease course. It is rarer and more severe in adults than in children. We present cases of two patients with cerebral edema‐related DKA.Case presentationThe first patient was a 38‐year‐old man with diabetes mellitus who presented with DKA‐related disturbed consciousness. Although glycemic correction was performed slowly, he showed pupil dilation 11 h later. He underwent emergency ventricular drainage, but died of cerebral herniation. The second patient was a 25‐year‐old woman who presented with impaired consciousness secondary to DKA. Head computed tomography showed subarachnoid hemorrhage and cerebral edema. No related intraoperative findings were observed; it was concluded that the first computed tomography scan revealed pseudo‐subarachnoid hemorrhage.ConclusionDiabetic ketoacidosis‐related cerebral edema develops despite treatment according to guidelines and is difficult to predict. Therefore, adult patients should be treated cautiously during DKA management.