Tracking the National Early Warning Score 2 from Prehospital Care to the Emergency Department: A Prospective, Ambulance-Based, Observational Study.

Aim of the study: To assess the prognostic ability of the National Early Warning Score 2 (NEWS2) at three time points of care -at the emergency scene (NEWS2-1), just before starting the transfer by ambulance to the hospital (NEWS2- 2), and at the hospital triage box (NEWS2-3)- to estimate in-hospital mortality after two days since the index event.Methods: Prospective, multicenter, ambulance-based, cohort ongoing study in adults (>18 years) consecutively attended by advanced life support (ALS) and evacuated with high-priority to the emergency departments (ED) between October 2018 and May 2021. Vital sign measures were used to calculate the NEWS2 score at each time point, then this score was entered in a logistic regression model as the single predictor. Two outcomes were considered: first, all-cause mortality of the patients within 2 days of presentation to EMS, and second, unplanned ICU admission. The calibration and scores comparison was performed by representing the predicted vs the observed risk curves according to NEWS score value.Results: 4943 patients were enrolled. Median age was 69 years (interquartile range 53- 81). The NEWS2-3 presented the better performance for all-cause two-day in-hospital mortality with an AUC of 0.941 (95% CI: 0.917-0.964), showing statistical differences with both the NEWS2-1 (0.872 (95% CI: 0.833-0.911); p < 0.003) and with the NEWS2- 2 (0.895 (95% CI: 0.866-0.925; p < 0.05). The calibration and scores comparison results showed that the NEWS2-3 was the best predictive score followed by the NEWS2-2 and the NEWS2-1, respectively.Conclusions: The NEWS2 has an excellent predictive performance. The score showed a very consistent response over time with the difference between "at the emergency scene" and "pre-evacuation" presenting the sharpest change with decreased threshold values, thus displaying a drop in the risk of acute clinical impairment.

Prehospital Lactate Levels Obtained in the Ambulance and Prediction of 2-Day In-Hospital Mortality in Patients With Traumatic Brain Injury.

BACKGROUND AND OBJECTIVES: To analyze the ability of prehospital lactate levels to predict 2-day in-hospital mortality in patients with traumatic brain injury (TBI), severe TBI (Glasgow Coma Scale (GCS) ≤ 8 points), and mild or moderate TBI (GCS ≥ 9 points). Second, 90-day mortality was also explored. METHODS: This was a prospective, multicenter, emergency medical services (EMSs) delivery, ambulance-based, derivation-validation cohort study developed in 5 tertiary hospitals (Spain), from November 1, 2019, to July 31, 2022. Patients were recruited from among all phone requests for emergency assistance among adults who were later evacuated to referral hospitals with acute TBI. The exclusion criteria were minors, pregnancy, trauma patients without TBI, delayed presentations, patients were discharged in situ, participants with cardiac arrest, and unavailability to obtain a blood sample. The primary outcome was all-cause 2-day in-hospital mortality and 90-day mortality in patients with moderate or mild TBI compared with patients with severe TBI. Clinical and analytical parameters (lactate and glucose) were collected. The discriminative power (area under the receiver operating characteristic curve [AUC]) and calibration curve were calculated for 2 geographically separated cohorts. RESULTS: A total of 509 patients were ultimately included. The median age was 58 years (interquartile range: 43-75), and 167 patients were female (32.8%). The primary outcome occurred in 9 (2.2%) of 415 patients with moderate or mild TBI and in 42 (44.7%) of 94 patients with severe TBI. The predictive capacity of the lactate concentration was globally validated in our cohort, for which the AUC was 0.874 (95% CI 0.805-0.942) for the validation cohort. The ability of the GCS score to predict lactate concentration was greater in patients with a GCS score ≥9 points, with an AUC of 0.925 (95% CI 0.808-1.000) and a negative predictive value of 99.09 (95% CI 98.55-99.64) in the validation cohort. CONCLUSION: Our results show the benefit of using lactate in all patients with TBI, particularly in those with a GCS ≥9 points. Routine incorporation of lactate in the screening of patients with TBI could presumably reduce mortality and deterioration rates because of quicker and better identification of patients at risk.