Volume replacement in trauma patients within the first 24 h and its impacton the interpretation of biochemical data

Background and aims: Patients of the same and particularly of different tra uma studies are primarily incomparable due to different volume replacements . The aim of this prospective study was to analyze the amount of initially administered fluids in trauma patients during the first 24 h and to estimat e the impact of dilution on plasma protein concentrations (PPCs) of prostan oids. These substances are vascular endothelium-derived and are thus influe nced by blood pressure. Patients/methods: Sixty-nine casualties suffering f rom multiple injuries were enrolled in the study. The amount of any fluid a dministered was scrutinized during the first 24 h. Patients were divided in to subsets according to trauma severity by Injury Severity Score (ISS) (gro up=G-I: less than or equal to9; G-II: 10-18; G-III: 19-32; G-IV: > 32) and between survivors and non-survivors. At corresponding time points, hemoglob in, hematocrit (Hct) and PPC as well as prostaglandins (PGI, TxA, PGF(2a)) were evaluated at the site of accident, at hospital admission, and every ho ur thereafter for the first 24 h. Results: During this period, the total am ount of infused fluids ranged between 0.5 1 (G-I) and >48 1 (G-IV). The hig her the trauma severity, the greater the volume infused (G-III/IV P=0.0003 vs G-I/II). Simultaneously, PPC dropped markedly (P<0.01). Patients who die d within 35 h required higher volumes (P<0.003) than survivors. PPC was lin early related (r(2)=.6685, P<0.001) to Hct. During the first 24 h, the time course of prostanoid concentration was altered when dilution is not taken into account. Conclusion: PPC proved a suitable parameter to estimate dilut ion effects and to adjust plasma concentrations of prostanoids. We recommen d that consideration be given to possible dilution effects during the first 24 h when interpreting biochemical data in trauma patients.