Age-related differences in fibrinolytic parameters in patients with acute traumatic brain injury

Abstract

Background: Coagulopathy and old age have been associated with poor outcomes in traumatic brain injury (TBI) patients; however, the relationships of coagulopathy and age with the acute phase of TBI remain unclear. We hypothesized that coagulation/fibrinolytic abnormalities are more severe in older patients in the acute phase of TBI and may explain, in part, their poor outcome.

Methods: We analyzed the relationship between coagulation/fibrinolytic parameters and age in the acute phase of TBI by retrospectively evaluating 274 patients with initial blood samples obtained no more than 1 hour after injury. Measurement of platelet count, prothrombin time, activated partial thromboplastin time, plasma levels of fibrinogen, and D-dimer was done in the emergency department on arrival as well as 3, 6, and 12 hours following injury. Values were compared between patients aged 16-55 years (group 1) and those aged older than 55 years (group 2) with an Abbreviated Injury Score (AIS)-head of 3-5 to identify any relationship between these parameters and age.

Results: When groups 1 and 2 were matched for AIS-head, plasma levels of D-dimer in group 2 were significantly higher than those in group 1 from hospital admission to 12 hours after injury. The Glasgow Outcome Scale scores at 3 months post-injury of group 2 with AIS 4 and 5 were significantly lower than those of group 1 (both P < 0.0001).

Conclusions: Fibrinolytic abnormalities are more severe in older acute-phase TBI patients, which may be a factor associated with their poor prognosis.

Keywords: Age; D-dimer; coagulopathy; fibrinolysis; traumatic brain injury.

Figure 1

Platelet count, PT, aPTT, and plasma levels of fibrinogen and D-dimer of patients aged 16–55 years (Group 1) or aged older than 55 years (Group 2) with AIS-head 3 on admission and at 3, 6, and 12 hours after TBI. The gray zones represent the normal ranges for each parameter. *P < 0.05, **P < 0.01

Figure 2

Platelet count, PT, aPTT, and plasma levels of fibrinogen and D-dimer of patients aged 16–55 years (Group 1) or aged older than 55 years (Group 2) with AIS-head 4 on admission and at 3, 6, and 12 hours after TBI. The gray zones represent the normal ranges for each parameter. *P < 0.05, **P < 0.01

Figure 3

Platelet count, PT, aPTT, and plasma levels of fibrinogen and D-dimer of patients aged 16–55 years (Group 1) or aged older than 55 years (Group 2) with AIS-head 5 on admission and at 3, 6, and 12 hours after TBI. The gray zones represent the normal ranges for each parameter. *P < 0.05, **P < 0.01, ***P < 0.001