Characterization of Acidosis in Trauma Patient

Recent data suggest that acidosis alone is not a good predictor of mortality in trauma patients. Little data are currently available regarding factors associated with survival in trauma patients presenting with acidosis.

The aims were to characterize the outcomes of trauma patients presenting with acidosis and to identify modifiable risk factors associated with mortality in these patients.

This is a retrospective observational study of University of Arkansas for Medical Sciences (UAMS) trauma patients between November 23, 2013, and May 21, 2017.

Data were collected from the UAMS trauma registry. The primary outcome was hospital mortality. Analyses were performed using t-test and Pearson's Chi-squared test. Simple and multiple logistic regressions were performed to determine crude and adjusted odds ratios.

There were 532 patients identified and 64.7% were acidotic (pH < 7.35) on presentation: 75.9% pH 7.2-7.35; 18.5% pH 7.0-7.2; and 5.6% pH ≤ 7.0. The total hospital mortality was 23.7%. Nonsurvivors were older and more acidotic, with a base deficit >-8, Glasgow Coma Scale (GCS) ≤ 8, systolic blood pressure ≤ 90, International Normalized Ratio (INR) >1.6, and Injury Severity Score (ISS) >15. Mortality was significantly higher with a pH ≤ 7.2 but mortality with a pH 7.2-7.35 was comparable to pH > 7.35. In the adjusted model, pH ≤ 7.0, pH 7.0-7.2, INR > 1.6, GCS ≤ 8, and ISS > 15 were associated with increased mortality. For patients with a pH ≤ 7.2, only INR was associated with increase in mortality.

A pH ≤ 7.2 is associated with increased mortality. For patients in this range, only the presence of coagulopathy is associated with increased mortality. A pH > 7.2 may be an appropriate treatment goal for acidosis. Further work is needed to identify and target potentially modifiable factors in patients with acidosis such as coagulopathy.