Scientific paper The efficacy of B-type natriuretic peptide for early identification of blood loss in traumatic injury Michael Kia, D.O. a , Andrea Cooley, D.O. a, *, Greg Rimmer, D.O. b , Taylor MacDonald, M.S. c , Kimberly Barber, Ph.D. c , Patricia Manion, R.N., M.S. d , Brian Shapiro, M.D., F.A.C.S. d , John Socey, D.O., F.A.C.S. a , Douglas Iddings, D.O. a a Department of General Surgery, Genesys Regional Medical Center, 1 Genesys Pkwy., Grand Blanc, MI 48439, USA b Department of Emergency Medicine, Genesys Regional Medical Center, 1 Genesys Pkwy., Grand Blanc, MI 48439, USA c Department of Research, Genesys Regional Medical Center, 1 Genesys Pkwy., Grand Blanc, MI 48439, USA d Department of Trauma Surgery, Genesys Regional Medical Center, 1 Genesys Pkwy., Grand Blanc, MI 48439, USA Manuscript received August 17, 2005; revised manuscript October 28, 2005 Presented at the 48th Annual Meeting of the Midwest Surgical Association, Ontario, Canada, August 14 –17, 2005 Abstract Background: Because B-type natriuretic peptide (BNP) secretion has a direct linear correlation with intravascular volume status, it was assessed as an initial marker for blood loss (BL) in polytrauma patients. Methods: Hemodynamically unstable trauma patients between 18 and 45 years had serial BNP levels and hemoglobin (Hgb) levels obtained on admission, at 8 and 24 hours, and every morning during resuscitation. Results: The 14 patients were categorized into 2 groups based on the 24-hour trend in Hgb levels: clinically significant blood loss (Hgb decrease 3 g/dL) or no clinical blood loss (Hgb decrease 3 g/dL). On admission, the 5 patients in the no blood loss group had normal BNP levels, whereas the 9 patients in the BL group had below-normal BNP levels. Because patients in the BL category were resuscitated, their BNP levels normalized. Conclusions: BNP levels below normal are indicative of intravascular volume loss in traumatically injured patients. © 2006 Excerpta Medica Inc. All rights reserved. Keywords: Blood loss; B-type natriuretic peptide; Trauma B-type natriuretic peptide (BNP) currently serves a major role in the evaluation of congestive heart failure and left ventricular function [1–3]. BNP is a cardiac neurohormone secreted from membrane granules in the cardiac ventricles in response to increased end-diastolic pressure and volume expansion [4,5]. BNP has therefore been likened to a “chemical Swan-Ganz monitor” for identifying intravascu- lar volume status. Although the clinical significance of increased BNP has been well established, studies to evaluate decreased BNP levels in the body are limited. For a trauma patient, the identification of blood loss (BL) is an essential aspect of the initial survey. In the acute setting, current techniques include clinical measurements such as heart rate (HR) and mean arterial pressure (MAP); laboratory measures such as hemoglobin (Hgb), arterial base excess, and pH; and more invasive measures such as SvO 2 monitoring and the use of pulmonary artery pressure measurements [6]. With each individual method of mea- surement there are known inherent qualities that make each inaccurate or overly invasive for the young trauma patient [6,7]. Currently there is no inexpensive minimally invasive objective measure available to quantify hemorrhage. Because BNP has a direct correlation with intravascular volume status, it was assessed in traumatically injured patients to determine its utility in identifying clinically significant BL. Methods Between August and December 2004, a series of 14 consecutive traumatically injured patients between the ages * Corresponding author. Tel.: 1-810-606-5000. E-mail address: craburn@hotmail.com The American Journal of Surgery 191 (2006) 353–357 0002-9610/06/$ – see front matter © 2006 Excerpta Medica Inc. All rights reserved. doi:10.1016/j.amjsurg.2005.10.033