Objective  

Physiological variables are important in the assessment of trauma patients. The role of respiratory rate (RR) and peripheral oxygen saturation (SpO₂) remains a matter of debate. We therefore assessed the role of RR and SpO₂ in predicting death in trauma patients.

Design  

Prospective analysis of a multicentric cohort of trauma patients in 2002.

Patients  

A cohort of 1,481 trauma patients cared for by a prehospital mobile intensive care unit (mean age 38 ± 17 years, 91% blunt and 9% penetrating trauma).

Intervention  

None.

Results  

Systolic arterial blood pressure, heart rate, Glasgow coma scale, RR and SpO₂ were recorded and the Injury Severity Score (ISS) and Trauma Related Injury Severity Score (TRISS) calculated. TRISSn was obtained by neutralizing RR. Systolic arterial blood pressure (99.9%), heart rate (99.9%), and Glasgow coma scale (99.3%) were recorded in most patients, but not RR (63%) and SpO₂ (67%). In patients with both RR and SpO₂ recording (n = 675), the discrimination and calibration of TRISS was not significantly modified when RR was neutralized. Whatever the manner of expressing RR and SpO₂ (continuous, five classes, dichotomous), none was significant in predicting mortality with TRISSn. Initial SpO₂ was abnormal (< 90%) and recorded again at the hospital in 97 patients, and the proportion of patients with a non-measurable SpO₂ significantly decreased (8 vs. 42%, p < 0.001) and measurable SpO₂ markedly increased (median 99 vs. 85%, p < 0.001).

Conclusion  

Respiratory rate and SpO₂ do not add significant value to other variables when predicting mortality in severe trauma patients.