Fibrinogène dès que l'Hb baisse ?

Estimation of plasma fibrinogen levels based on hemoglobin, base excess and Injury Severity Score upon emergency room admission

Schlimp CJ et Al. Crit Care. 2013 Jul 12;17(4):R137. doi: 10.1186/cc12816.

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Il existe un grand débat sur la manière de prendre en charge la coagulopathie traumatique des traumatisés ballistiques en contexte d'isolement (1,2).Un des sujets porte sur la manière de corriger l'hypofibrinogénémie soit par apport de Plasma soit par apport de concentrés de fibrinogène (3, 4). Le consensus européen valide les deux approches (5). Mais dans notre contexte d'intervention quels critères d'administration appliquer ? L'hémoglobinémie à la prise en charge permettrait d'indiquer l'apport de fibrinogène, en gros dès qu'elle est abaissée et surtout <10g/dl. C'est ce que peut laisser penser cette étude. Des moyens simples utilisables en contexte d'isolement permettent donc de stratifier les indications de fibrinogène apporté soit sous forme concentré soit sous forme de plasma (6).

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INTRODUCTION:

Fibrinogen plays a key role in hemostasis and is the first coagulation factor to reach critical levels in massively bleeding trauma patients. Consequently, rapid estimation of plasma fibrinogen (FIB) is essential upon emergency room (ER) admission, but is not part of routine coagulation monitoring in many centers. We investigated the predictive ability of the laboratory parameters hemoglobin (Hb) and base excess (BE) upon admission, as well as the Injury Severity Score (ISS), to estimate FIB in major trauma patients.

METHODS:

In this retrospective study, major trauma patients (ISS ≥16) with documented FIB analysis upon ER admission were eligible for inclusion. FIB was correlated with Hb, BE and ISS, alone and in combination, using regression analysis.

RESULTS:

A total of 675 patients were enrolled (median ISS 27). FIB upon admission correlated strongly with Hb, BE and ISS.

 

Multiple regression analysis showed that Hb and BE together predicted FIB (adjusted R2 = 0.46; loge(FIB) = 3.567 + 0.223.Hb - 0.007.Hb2 + 0.044.BE), and predictive strength increased when ISS was included (adjusted R2 = 0.51; loge(FIB) = 4.188 + 0.243.Hb - 0.008.Hb2 + 0.036.BE - 0.031.ISS + 0.0003.ISS2). Of all major trauma patients admitted with Hb <12 g/dL, 74% had low (<200 mg/dL) FIB and 54% had critical (<150 mg/dL) FIB. Of patients admitted with Hb <10 g/dL, 89% had low FIB and 73% had critical FIB. These values increased to 93% and 89%, respectively, among patients with an admission Hb <8 g/dL. Sixty-six percent of patients with only a weakly negative BE (<-2 mmol/L) showed low FIB. Of patients with BE <-6 mmol/L upon admission, 81% had low FIB and 63% had critical FIB. The corresponding values for BE <-10 mmol/L were 89% and 78%, respectively.

CONCLUSIONS:

Upon ER admission, FIB of major trauma patients shows strong correlation with rapidly obtainable, routine laboratory parameters such as Hb and BE. These two parameters might provide an insightful and rapid tool to identify major trauma patients at risk of acquired hypofibrinogenemia. Early calculation of ISS could further increase the ability to predict FIB in these patients. We propose that FIB can be estimated during the initial phase of trauma care based on bedside tests.