ASSESSMENT OF PH, HEMOGLOBIN, AND BILE ACID IN GASTRIC FLUID FROM MAJOR TORSO TRAUMA PATIENTS

Abstract

In an ongoing epidemiology study of major torso trauma patients, serial gastric fluid samples were examined for factors that may be related to Multiple Organ Failure (MOF). This one year (2005) study comprised samples from 50 consecutive patients including 10 MOF patients (Denver score), that met criteria for shock resuscitation and had no direct gastric injury. When present, gastric fluid was collected during the first 12 hr after admission to the Shock Trauma ICU, and then at 16-24 hr, and daily thereafter for up to 4 days. Samples were analyzed for pH to determine acidity/alkalinity, hemoglobin [Hb] as a measure of GI injury, and bile acid [BA] as an indication of duodenogastric reflux. No acid-blocking drugs were administered. Results from non-MOF patients showed that the mean gastric pH was elevated initially (pH 5.9 ± 0.3) and it declined significantly (? pH 4.5) by day 3 and 4, whereas in MOF patients, the mean gastric pH was elevated (? pH 4.9) over the 4 day observation period. Gastric [Hb] was elevated initially in both MOF and non-MOF groups (? 2000 μg/ml), declined in non-MOF patients, and remained elevated in MOF patients at day 4 (MOF=1571 ± 631 and non-MOF=182 ± 49 μg/ml, p < 0.05). Gastric [BA] was elevated in both groups with no clear patterns evident over time. These data suggest that in most major torso trauma patients, an alkaline gastric condition and gastric injury occur early and could be related, in part, to reflux of intestinal/biliary contents. The return of gastric pH to a more normal acidic range in non-MOF patients was paralleled by a reduction in gastric bleeding, consistent with improved outcome. In contrast, MOF patients had more persistent gastric alkalinity and presence of [Hb] in gastric fluid, which were harbingers of a poor outcome. We propose that monitoring of gastric fluid for pH, [Hb], and potentially other variables may result in improved assessments of patient status. (Funded by NIGMS P50GM38529.)