Early Venous Thromboembolic Event Prophylaxis in Traumatic Brain Injury with Low-Molecular-Weight Heparin: Risks and Benefits

Abstract

Traumatic brain injury (TBI) patients are known to be at high risk for venous thromboembolic events (VTEs). The Brain Trauma Foundation Guidelines (2007) state that low-molecular-weight heparin or unfractionated heparin should be used to prevent VTE complications, but suggest that there is an increased risk of expansion of intracranial hemorrhages (ICH) with VTE prophylaxis. In addition, it is unclear which treatment regimen (i.e., medication, dose, and timing) provides the best risk:benefit ratio in TBI patients. We reviewed all moderate-to-severe TBI patients admitted over a 5-year period to: (1) examine the occurrence of VTEs and their timing; (2) examine the symptomatic expansion of ICH while on VTE prophylaxis; and (3) compare the efficacy of two prophylactic agents: enoxaparin and dalteparin. Two-hundred eighty-seven patients were included. VTE prophylaxis was started 48-72 h post-trauma in all individuals who had no confounding coagulopathy, when two consecutive computed tomography (CT) scans revealed hemorrhage stability. VTEs occurred in 7.3% of treated patients, mostly within 2 weeks after trauma. Proximal VTEs occurred in 3.1% of treated patients. No significant difference in VTE rates was seen between enoxaparin (7.0%) and dalteparin (7.5%; p = 0.868). Moreover, the group treated with dalteparin was more severely injured (higher Injury Severity Score [p = 0.002]), had lower Glasgow Coma Scale (GCS) scores (p = 0.003), and had more inferior vena cava (IVC) filters placed (p = 0.007). The two groups did not show significant differences in the development of VTE when controlled for ISS and IVC filters (p = 0.819). Importantly, only one patient suffered a symptomatic expansion of ICH while on VTE prophylaxis, at 15 days post-trauma. These results suggest that current regimens of VTE prophylaxis used in our TBI population provide a relatively high level of protection against VTEs, and an extremely low risk of expanding ICH. They also suggest that there was no difference in VTE between dalteparin- and enoxaparin-treated patients.

Which traumatic brain injury patients should be treated with anticoagulants and when?

“…Of note, in our study, all patients had head Abbreviated Injury score >3, all patients had a follow-up head CT 48-72 h after initiation of chemoprophylaxis and chemoprophylaxis was intended to be initiated after a stable head CT 24 h after injury [4]. These results are consistent with those of Cothren et al [11], Dudley et al [12], Saadeh et al [13] and Thorson et al [14]. Chemoprophylactic anticoagulation is safe after TBI, with a stable head CT 24 h after injury.…”

Safety and efficacy of early thromboembolism chemoprophylaxis after intracranial hemorrhage from traumatic brain injury

“…These results are consistent with other recent reports, which demonstrate safety and efficacy of chemoprophylaxis. 1,3,[5][6][7]10,12,[21][22][23] These studies vary in severity of head injury, time to initiation of chemoprophylaxis, chemoprophylaxis agent, and indications for postinitiation follow-up head CT to assess for hemorrhage progression. Most of these other studies focus on head AIS scores of 2 or 3 1,5,7,13,21,22 and range in initiation of chemoprophylaxis from 24 hours post injury up to 3 days after admission.…”

“…Compliance rates in other studies range from 10% to 85%. 5,7,14,15,21 Minshall et al 13 intended chemoprophylaxis to begin at 24 hours after injury as well but had mean times to initiation of 47 hours for low-molecular-weight heparin and 54.8 hours for unfractionated heparin. Fifty percent of patients were started on chemoprophylaxis later than the 24 hours intended by Saadeh et al 21 In addition, Kim et al 10 and Depew et al 6 had 23% and 43% of patients, respectively, in whom chemoprophylaxis was initiated after their 72-hour protocol.…”

Traumatic Brain Injury - Acute Care

“…Evidence in a neurosurgical population indicates that pharmacological prophylaxis used in conjunction with mechanical devices is more effective than mechanical measures alone (Nurmohamed et al 1996;Agnelli et al 1998). Recent observational evidence suggests that initiation of prophylactic treatment w i t h L M W H w i t h i n 4 8 h o u r s o f i n j u r y o r n e urosurgical intervention is effective and associated with an acceptably low risk of complications (Norwood et al 2008;Dudley et al 2010). Unfortunately, the most effective agent and dosing strategy is yet to be determined.…”