Is pre-hospital haemoglobin an efficient marker of the need for transfusion and haemorrhagic shock in severe trauma patients? A retrospective observational study.

Background: Haemorrhagic shock is the leading cause of preventable death among trauma patients. Early detection of severe haemorrhage is essential for initiating timely resuscitation and mobilizing resources for massive transfusion (MT) protocols and damage control procedures. This study aimed to assess the predictive value of prehospital haemoglobin (Hb) levels for the need for transfusion at admission, the presence of haemorrhagic shock (HS), and the necessity for MT or haemostatic surgery. Additionally, the study sought to compare the diagnostic accuracy of Hb with established multiparametric scores such as TASH, ABC, Red Flag, and Shock Index (SI).

Methods: This retrospective, single-centre study was conducted at the Military Teaching Hospital (HIA) Sainte Anne, Toulon, France, a Level 1 trauma centre, from January 1, 2015, to December 31, 2022. Trauma patients older than 16 years, with an Injury Severity Score (ISS) ≥ 15, and at least one prehospital Hb measurement were included. The primary outcome was the predictive ability of Hb for the need for transfusion at admission. Secondary outcomes included the prediction of HS, MT, and haemostatic surgery, compared to TASH, ABC, Red Flag, and SI scores.

Results: Among 2731 trauma patients, 1040 had an ISS ≥ 15 and at least one prehospital Hb measurement. Of these, 227 (21.8%) exhibited HS. Hb levels predicted the need for transfusion at admission with an AUC of 0.82. Hb, along with TASH, ABC, Red Flag, and SI, significantly predicted HS, MT, and haemostatic surgery. Using a cut-off value of 11.45 g/dL, Hb predicted the need for transfusion in 79% of cases.

Conclusion: Prehospital Hb levels are as effective as established multiparametric scores in predicting the need for transfusion, HS, MT, and haemostatic surgery. Due to its simplicity and practicality, Hb can serve as an alternative to complex scoring systems in prehospital settings, potentially improving triage and treatment outcomes in civilian and military trauma care.