The impact of severe traumatic brain injury on a novel base deficit- based classification of hypovolemic shock

Abstract

BackgroundRecently, our group has proposed a new classification of hypovolemic shock based on the physiological shock marker base deficit (BD). The classification consists of four groups of worsening BD and correlates with the extent of hypovolemic shock in severely injured patients. The aim of this study was to test the applicability of our recently proposed classification of hypovolemic shock in the context of severe traumatic brain injury (TBI).MethodsBetween 2002 and 2011, patients ≥16 years in age with an AIShead ≥ 3 have been retrieved from the German TraumaRegister DGU® database. Patients were classified into four strata of worsening BD [(class I (BD ≤ 2 mmol/l), class II (BD > 2.0 to 6.0 mmol/l), class III (BD > 6.0 to 10 mmol/l) and class IV (BD > 10 mmol/l)] and assessed for demographic and injury characteristics as well as blood product transfusions and outcomes. The cohort of severely injured patients with TBI was compared to a population of all trauma patients to assess possible differences in the applicability of the BD based classification of hypovolemic shock.ResultsFrom a total of 23,496 patients, 10,201 multiply injured patients with TBI (AIShead ≥ 3) could be identified. With worsening of BD, a consecutive increase of mortality rate from 15.9% in class I to 61.4% in class IV patients was observed. Simultaneously, injury severity scores increased from 20.8 (±11.9) to 41.6 (±17). Increments in BD paralleled decreasing hemoglobin, platelet counts and Quick’s values. The number of blood units transfused correlated with worsening of BD. Massive transfusion rates increased from 5% in class I to 47% in class IV. Between multiply injured patients with TBI and all trauma patients, no clinically relevant differences in transfusion requirement or massive transfusion rates were observed.ConclusionThe presence of TBI has no relevant impact on the applicability of the recently proposed BD-based classification of hypovolemic shock. This study underlines the role of BD as a relevant clinical indicator of hypovolaemic shock during the initial assessment in respect to haemostatic resuscitation and transfusion requirements.

Red Blood Cell Transfusion in Patients With Traumatic Brain Injury: A Systematic Review and Meta-Analysis

“…Four studies [7,26,27,38] had selected a sample of patients reflecting a valid estimate (external validity in regard to our question). Twelve studies [7,17,26,32,33,37,39,[41][42][43][44][45] reported information on the way they collected transfusion data that were concordant with a low risk of measurement error. Fifteen studies [7,[26][27][28]32,33,[36][37][38][41][42][43]45,47,48] collected data on RBC transfusion during ICU stay or full hospitalization.…”

“…Fifteen studies [7,[26][27][28]32,33,[36][37][38][41][42][43]45,47,48] collected data on RBC transfusion during ICU stay or full hospitalization. Eighteen studies [7,17,[28][29][30][31][32][33][34][35][36][37][38][39]41,45,47,49] reported a proportion of missing data less than 10%.…”

“…Cumulative incidences (23 studies, n = 7524) were highly heterogeneous (I 2 = 98%), ranging from 9% to 82%, with a pooled frequency of 36% (95% CI, 28%-44%) (Fig 3). One study [39] having reported data on number of units of RBC transfused and frequency of transfusion of any blood product could not be included in the analyses.…”

“…One study did not report a specific timeframe [43]. Seventeen studies [7,17,26,27,29,30,[32][33][34][37][38][39][43][44][45]47,48] had RBC transfusion as an exposure or outcome of interest. Other studies reported data on RBC transfusion for descriptive purposes or as a covariate.…”

“…Three were conducted in Canada; 2, in Taiwan; and others, in China, Columbia, Germany, Switzerland, Tunisia, or United Kingdom. Two studies [35,37] were completed before 1999, year of the publication of the TRICC trial [12]; 19 were conducted after its publication [7,17,[26][27][28][29][30][31]33,34,36,38,39,41,42,45,[47][48][49]; and 2 started before and ended after its publication [32,44]. One study did not report a specific timeframe [43].…”