Past studies are limited in which proposing SpO2 as mortality predictor of trauma patients. The aim of our study was to investigate the correlation between pulse oxygen saturation (SpO2) and prognosis in emergency trauma patients.
We collected 1720 trauma patients admitted to the Emergency Department of the First Affiliated Hospital of Soochow University from November 1, 2016 to November 30, 2019 to retrospective analysis. The mortality of trauma patients in the emergency department was defined as end-point of outcome. The patients were divided into six subgroups with 75%, 80%, 85%, 90% and 95% SpO2 as the bound values. SpO2>=95% subgroup was defined as basis reference, we calculated the crude HR of other subgroups and adjusted HR after the adjustment for confounders including age and sex by Cox regression model. The ROC curve was performed and the area under the curve (AUC) was calculated to evaluate the predictive value of SpO2 in emergency mortality.
Compared to basis reference, the mortality of other subgroups was gradually increased with the decrease of SpO2. The crude HR and 95% CI of each subgroup calculated by univariate Cox regression were: SpO2 90%-95%, 7.62(2.65-21.95), p<0.001; SpO2 85%-90%, 12.25(2.90-51.66), p=0.001; SpO2 80%-85%,35.81(9.53-134.50), p<0.001; SpO2 75%-80%, 32.88(7.53-143.54), p<0.001; SpO2<75%, 155.07(56.41-426.29), p<0.001. The adjusted HR and 95%CI after adjustment for age and sex were respectively 6.75(2.30-19.81), p=0.001; 11.34(2.69-47.84), p=0.001; 33.26(8.83-125.38), p<0.001; 48.27(9.02-258.48), p<0.001; 162.64(57.62-459.03), p<0.001. ROC curve analysis showed that the AUC was 0.898, 95%CI (0.845-0.951), the optimal cut-off value was 94%, and the corresponding sensitivity and specificity were 79.07% and 85.84%, respectively.
Our study revealed that SpO2 was closely related to the prognosis of emergency trauma patients and had a good predictive value for emergency room death. The lower the SpO2, the higher the mortality.
This study was retrospectively registered in the First Affiliated Hospital of Soochow University.