CORRELATION OF METABOLIC-ACIDOSIS WITH OUTCOME FOLLOWING INJURY AND ITS VALUE AS A SCORING TOOL

This study looked at preresuscitation arterial pH as a predictor of ou tcome in injury. Seriously injured patients admitted to the Trauma Ser vice over a 5-month period were evaluated prospectively. Data collecte d included basic patient demographics, initial arterial blood gas dete rminations (ABGs) including pH, bicarbonate (HCO3), base deficit or ex cess (BASE), admitting trauma score (TS), discharge injury severity sc ore (ISS), total blood products used for initial resuscitation (TBP), and outcome. There were 191 patients averaging 34.7 years old with ave rage TS 13.6, ISS 19.5, initial pH 7.38 +/- 0.09, HCO3 20.9 +/- 4.0, a nd BASE -3.3 +/- 4.7. The average TBP was 1309 cc, and overall mortali ty was 13/191 (6.8%). Comparing survivors to nonsurvivors, the ISS (18 .2 vs. 38.3), TS (14.1 vs. 7.8), TBP (976 vs. 5881 cc), HCO3 (21.1 vs. 17.6), and BASE (-3.1 vs. -5.8) data were significantly different; pH (7.38 vs. 7.36) and age (34.4 vs. 38.5) were not. Using multiple regr ession with TBP as the dependent variable, BASE, age, TS, and to a les ser extent pH and HCO3 correlated (r = 0.536; p < 0.001); using outcom e as the dependent variable, only TS and age correlated (r = 0.465; p < 0.0001). Although metabolic acidosis (pH, HCO3, BASE) predicts the T BP used, it does not improve on TS and age for predicting outcome.