The utility of abnormal initial arterial blood gas values in determining clinical futility of trauma cases with severe hemorrhage.

BACKGROUND

Patients who experience trauma with severe hemorrhage requiring immediate surgery and massive blood transfusion often present with markedly abnormal laboratory values. These cases require valuable resources; however, little is known regarding prognostic factors that correlate with mortality. The purpose of this study was to determine whether abnormal initial arterial blood gas (ABG) pH, a marker for severe blood loss, could serve as a prognostic indicator for these patients.

METHODS

An IRB approved retrospective study was performed at LAC+USC Medical Center Level I Trauma Center. Data was collected from trauma patients with severe hemorrhage admitted between June 2015 and April 2016 who were immediately admitted to the OR following entry into the ER. Baseline variables of age, sex and mechanism of trauma were collected. The pH readings from the initial three ABG data were obtained, and mortality was determined for each patient.

RESULTS

We identified 247 patients, 84.2% of which were male. Ages ranged from 1 to 91years (average=38.4). Overall mortality was 13.8%. The average initial pH value for non-survivors (7.10±0.13) was significantly lower than for survivors (7.34±0.07) [p<0.001]. Among patients whose initial three ABG pH values averaged ≤7.15, the survival rate was 8.7%. Ten patients had any single recorded pH value≤6.91. The mortality rate among these patients was 90%.

CONCLUSIONS

Consideration should be given to initial pH values when resuscitating "red blanket" patients. However, the pH values alone cannot reliably be used to determine clinical futility in individual patients in the early period after injury.