The Influence of Alcohol on the Base Excess Parameter in Trauma Patients

The base excess (BE) parameter can be used as an indicator of mortality. However, study results on the influence of alcohol on the validity of BE as a prognostic parameter in alcohol-intoxicated patients are controversial. Thus, this study examined the hypothesis: An increasing blood alcohol level reduces the prognostic value of the BE parameter on mortality.

In a retrospective analysis of the multicenter database of the TraumaRegister DGU, patients from 2015 to 2017 were grouped depending on their blood alcohol level (BAL) into a BAL+ and BAL- group. The hypothesis was verified using logistic regression with an assumed significance level of 1% (P < 0.01).

Eleven thousand eight hundred eighty-nine patients were included; 9,472 patients in the BAL- group and 2,417 patients in the BAL+ group. Analysis of the BE showed lower values in the BAL+ group (BAL-: -1.8 ± 4.4 mmol/L vs. BAL+: -3.4 ± 4.6 mmol/L). There is a trend toward lower BE levels when BAL increases. Assuming a linear relationship, then BE decreases by 0.6 points per mille alcohol (95% CI: 0.5-0.7; P < 0.001). The mortality rate was significantly lower in the BAL+ group (BAL-: 11.1% vs. BAL+: 7.9%). The logistic regression analysis showed a significant beneficial influence of BAL+ on the mortality rate (OR 0.706, 95% CI 0.530-0.941, P = 0.018). To analyze whether a low BE (≤-6 mmol/L) has different prognostic effects in patients with and without alcohol, logistic regression models were calculated. However, the effect of BE ≤ -6 mmol/L was similar in both models (regression coefficients in BAL-/+ patients: 0.379/0.393).

The data demonstrate an existing influence of alcohol on the BE parameter; however, this does not negatively affect the BE as a prognostic parameter at a threshold of ≤ -6 mmol/L.