Elderly trauma patients have high circulating noradrenaline levels but attenuated release of adrenaline, platelets, and leukocytes in response to increasing injury severity

Abstract

Objective: High patient age is a strong predictor of poor outcome in trauma patients. The present study investigated the effect of age on mortality and biomarkers of sympathoadrenal activation, tissue, endothelial, and glycocalyx damage, coagulation activation/inhibition, fibrinolysis, and inflammation in trauma patients at admission.

Design: Prospective observational study.

Setting: Single level I trauma center.

Patients: Eighty adult trauma patients (≥18 yrs) who met criteria for full trauma team activation and had an arterial cannula.

Intervention: Blood sampling a median of 68 min (interquartile range 48-88) post injury.

Measurements: Data on demography, biochemistry, Injury Severity Score, and 30-day mortality were recorded and plasma/serum was analyzed for biomarkers reflecting sympathoadrenal activation (adrenaline, noradrenaline), tissue/endothelial cell/glycocalyx damage (histone-complexed DNA fragments, annexin V, thrombomodulin, syndecan-1), platelet activation (soluble CD40 ligand), coagulation activation/inhibition (prothrombin fragment 1.2, thrombin/antithrombin complex, antithrombin, protein C, activated protein C, protein S, soluble endothelial protein C receptor, tissue factor pathway inhibitor, von Willebrand factor, fibrinogen, factor XIII), fibrinolysis (D-dimer, tissue-type plasminogen activator, plasminogen activator inhibitor-1), and inflammation (interleukin-6, terminal complement complex). Patients were stratified according to the median age (46 yrs) of the full cohort.

Results: Older trauma patients had markedly higher noradrenaline (p < .001) but an attenuated increase in adrenaline with increasing Injury Severity Score and lower platelets and leukocytes (both p < .05) compared to the younger patients. Older patients displayed a biomarker profile suggestive of enhanced release, activation, and consumption of the natural anticoagulants (low antithrombin, high activated protein C, protein S, and tissue factor pathway inhibitor) and hyperfibrinolysis (high tissue-type plasminogen activator) (all p < .05 vs. younger patients). Age was an independent predictor of mortality (hazard ratio 1.04 [95% confidence interval 1.01-1.07], p = .005) after adjusting for Injury Severity Score, prehospital Glasgow Coma Scale, and plasma catecholamines.

Conclusions: In trauma patients, the association between age and mortality was confirmed. Older patients had high plasma noradrenaline but attenuated adrenaline release with higher Injury Severity Score, impaired platelet and leukocyte mobilization, enhanced consumption of anticoagulants, and hyperfibrinolysis, which may all contribute to the poor outcome in these patients.