Arginine vasopressin, copeptin, and the development of relative AVP deficiency in hemorrhagic shock

BackgroundArginine vasopressin (AVP) is critical for maintaining vasomotor tone and low levels have been associated with the development of irreversible shock. We investigated the clinical relationship between AVP, copeptin (the C-terminal fragment of the AVP precursor), and the development of relative AVP deficiency following hemorrhagic shock.MethodsA prospective, observational study of 21 hypotensive (SBP<90 mmHg X 2) or presumptively bleeding trauma patients was conducted. Demographics, mechanism of injury, vital signs, laboratory values, transfusions, crystalloid volume, and blood samples were collected on arrival and serially for 48 h. AVP and copeptin were measured post hoc.ResultsAVP and copeptin levels were markedly elevated on admission, but decreased rapidly over time (p < 0.001). AVP and copeptin levels were positively correlated on admission (r = 0.769, p < 0.001), in the ICU (r = 0.768, p < 0.001), and at 48 h (r = 0.537, p = 0.02). Initial AVP and copeptin levels predicted the need for ≥10 unit blood product transfusion (AUC = 81% and 87%, respectively). The development of a relative AVP deficiency occurred frequently and was associated with an increased need for blood product transfusion.ConclusionCopeptin correlates well with AVP and initial values predict the need for massive transfusion in trauma patients. Copeptin demonstrates promise as a clinical biomarker in hemorrhagic shock.