Overview
The objective of this article is to characterize changes in vital signs of trauma victims from pre-hospital to hospital settings, their associations with injury severity, and the need for an emergency operation. Methods: a prospective cohort included 601 patients admitted to a level one trauma centre from 1 July to 30 September 2007. All pre-hospital and hospital admission values of Glasgow coma score (GCS), systolic blood pressure (SBP), heart rate (HR), respiratory rate (Resp) and oxygen saturation (SpO2) were recorded. All urgent major surgical procedures were graded in real-time as: emergency, urgent, or not urgent. Injury severity score (ISS) was calculated following completion of all the diagnostic work-up. Patients were classified as major trauma victims if their calculated ISS was 16 or greater, and those who needed an urgent intervention or intensive care. Vital signs trends were analyzed using the students' T–test. Associations with injury severity and the need for an emergency operation were analyzed using chi-squared test. The statistical significance level was set at 5% (P £ 0.05). Results: 243(40%) patients were classified as major trauma. 39(6.5%) patients required an emergency operative intervention—29 for active bleeding and 10 for imminent cerebral herniation. The time from injury to hospital arrival was 44.8 ± 17.63 minutes (mean±standard deviation), the time did not differ for those needing an emergency operation. Pre-hospital GCS £12 and SBP £90 were associated with a severe injury (a relative risk(RR) of 4.95, 95 % confidence interval(CI) 3.25–7.58 for low GCS and 4.60, 2.67–7.94 for low SBP) and emergency surgical procedures (RR, 95 % CI 4.43, 2.28–8.58 for low GCS and 11.69, 5.85–23.36 for low SBP). These values changed significantly from the field to the hospital with the mean GCS increasing 1.65 points and the mean SBP decreasing 7.23 mmHg (P<0.001). One patient out of 473 with a GCS ³14 in the field and no one out of 483 patients with a GCS ³14 on admission needed a neurosurgical procedure. 15/533(2.8%) patients with a pre-hospital SBP >90, and only 2/542(0.4%) patients with a SBP >90 on admission required emergency bleeding control (P<0.005). HR ³120 and changes in HR of 20 beats per minute (bpm) or more were not associated with injury severity. The respiratory rate and the SpO2 did not change significantly, and were not associated with injury severity. Conclusion: pre-hospital vital signs values are expected to change significantly over time. Pre-hospital GCS £12 and SBP £90 predict major trauma, while the HR is not a good indicator of haemodynamic status. When these parameters normalize on admission, an
