gms | German Medical Science

Objective: ATC has been well described in iTBI. However, there is no consensus on ATC within iTBI in terms of its clinical definition, incidence (7-86%) and mortality (17-86%). The first aim of this study was to develop a clinically relevant definition of ATC within iTBI. The second aim was to investigate whether the presence of ATC reduces time from injury to death from iTBI and therefore add to the evidence base that ATC directly contributes to poorer outcomes.

Methods: Single centre retrospective cohort study of patients admitted with iTBI (head AIS ≥ 3, extracranial AIS < 3) to a major trauma centre from 2012 to 2016. Patients with incomplete data sets were excluded. Data extracted from the trauma registry included demographic data and admission data (ISS, GCS and coagulation bloods). The main outcome measures were in-hospital mortality and time to death

Results: During the study period 2445 patients were admitted with TBI. 675 were excluded due to extracranial AIS >2. 1322 patients had data complete for admission INR (overall mortality 13.9%). INR 0.9-1.1 (n=1065) had a mortality of 9.5%, INR 1.2 (n=127) had a mortality of 22.2% (p<0.01), INR 1.3 (n=56) had a mortality of 41.2 % (p<0.01) and INR ≥1.4 had a mortality of 43.2% (p<0.01). 1267 patients had data complete for admission APTT (overall mortality 13.7%). APTT 18-32 (n=1206) had a mortality of 11.2%, APTT 33-36 (n=27) had a mortality of 55.6% (p<0.01) and APTT >36 (n=34) had a mortality of 70.6% (p<0.01). 265 patients had data complete for admission fibrinogen (overall mortality 25.7%). Fib ≥1.5 (n=195) had a mortality of 15.9%, Fib 1-1.49 (n=52) had a mortality of 42.3% (p<0.01) and Fib <1 (n=18) had a mortality of 83.3% (p<0.01). 1497 patients had data complete for admission platelet count (overall mortality 13.4%). Plt ≥150 (n=1248) had a mortality of 11.1%, Plt 100-149 (n=179) had a mortality of 23.5% (p<0.01) and Plt <100 (n=70) had a mortality of 30% (p<0.01). For the second part of the study 1331 patients were included for having coagulation bloods on admission along with complete demographic and outcome data. Overall mortality was 14.1% (188/1331). ATC was present in 32.7% (435/1331). As expected, the ATC group had significantly higher rates of mortality (27.8% v 7.5%, p<0.01), transfusion requirements, ISS/AIS, older age and lower GCS. However, when deaths in the ATC group (n=121) were compared to deaths in the no ATC group (n=67) they were similar for age, gender, mechanism of injury, GCS, ISS and head AIS. The ‘ATC died’ group had significantly shorter time to death (4.8d v 9.3d, p=0.04) and more deaths within 24h of admission (28.9% v 14.9%, p=0.03)

Conclusion: These results suggest that the clinical definition of ATC within iTBI should be broadened to INR ≥1.2, APTT >32, Fib <1.5 and Plt <150 to reflect the consistent findings that intermediate values are associated with higher mortality. iTBI patients with ATC appear to die faster when compared to a group, similar for age and injury severity, without ATC.