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.

A Comparison of the Clinical Characteristics of Short-, Mid-, and Long-Term Mortality in Patients Attended by the Emergency Medical Services: An Observational Study.

AIM: The development of predictive models for patients treated by emergency medical services (EMS) is on the rise in the emergency field. However, how these models evolve over time has not been studied. The objective of the present work is to compare the characteristics of patients who present mortality in the short, medium and long term, and to derive and validate a predictive model for each mortality time. METHODS: A prospective multicenter study was conducted, which included adult patients with unselected acute illness who were treated by EMS. The primary outcome was noncumulative mortality from all causes by time windows including 30-day mortality, 31- to 180-day mortality, and 181- to 365-day mortality. Prehospital predictors included demographic variables, standard vital signs, prehospital laboratory tests, and comorbidities. RESULTS: A total of 4830 patients were enrolled. The noncumulative mortalities at 30, 180, and 365 days were 10.8%, 6.6%, and 3.5%, respectively. The best predictive value was shown for 30-day mortality (AUC = 0.930; 95% CI: 0.919-0.940), followed by 180-day (AUC = 0.852; 95% CI: 0.832-0.871) and 365-day (AUC = 0.806; 95% CI: 0.778-0.833) mortality. DISCUSSION: Rapid characterization of patients at risk of short-, medium-, or long-term mortality could help EMS to improve the treatment of patients suffering from acute illnesses.

Comparison of eight prehospital early warning scores in life-threatening acute respiratory distress: a prospective, observational, multicentre, ambulance-based, external validation study.

BACKGROUND: A myriad of early warning scores (EWSs) exist, yet there is a need to identify the most clinically valid score to be used in prehospital respiratory assessments to estimate short-term and midterm mortality, intensive-care unit admission, and airway management in life-threatening acute respiratory distress. METHODS: This is a prospective, observational, multicentre, ambulance-based, external validation study performed in 44 ambulance services and four hospitals across three Spanish provinces (ie, Salamanca, Segovia, and Valladolid). We identified adults (ie, those aged 18 years and older) discharged to the emergency department with suspected acute respiratory distress. The primary outcome was 2-day all-cause in-hospital mortality, for all the patients or according to prehospital respiratory conditions, including dyspnoea, chronic obstructive pulmonary disease (COPD), COVID-19, other infections, and other conditions (asthma exacerbation, haemoptysis, and bronchoaspirations). 30-day mortality, intensive-care unit admission, and invasive and non-invasive mechanical ventilation were secondary outcomes. Eight EWSs, namely, the National Early Warning Score 2, the Modified Rapid Emergency Medicine Score, the Rapid Acute Physiology Score, the Quick Sequential Organ Failure Assessment Score, the CURB-65 Severity Score for Community-Acquired Pneumonia, the BAP-65 Score for Acute Exacerbation of COPD, the Quick COVID-19 Severity Index, and the Modified Sequential Organ Failure Assessment (mSOFA), were explored to determine their predictive validity through calibration, clinical net benefit as determined through decision curve analysis, and discrimination analysis (area under the curve of the receiver operating characteristic [AUROC], compared with Delong's test). FINDINGS: Between Jan 1, 2020, and Nov 31, 2022, 902 patients were enrolled. The global 2-day mortality rate was 87 (10%); in proportion to various respiratory conditions, the rates were 35 (40%) for dyspnoea, nine (10%) for COPD, 13 (15%) for COVID-19, 28 (32%) for other infections, and two (2%) for others conditions. mSOFA showed the best calibration, a higher net benefit, and the best discrimination (AUROC 0·911, 95% CI 0·86-0·95) for predicting 2-day mortality, and its discrimination was statistically significantly more accurate (p<0·0001) compared with the other scores. The performance of mSOFA for predicting 2-day mortality was higher than the other scores when considering the prehospital respiratory conditions, and was also higher for the secondary outcomes, except for non-invasive mechanical ventilation. INTERPRETATION: Our results showed that mSOFA outperformed other EWSs. The inclusion of mSOFA in prehospital decision making will entail a quick identification of patients in acute respiratory distress at high risk of deterioration, allowing prioritisation of resources and patient care. FUNDING: Gerencia Regional de Salud, Public Health System of Castilla y León (GRS Spain). TRANSLATION: For the Spanish translation of the abstract see Supplementary Materials section.