Predictive Value of Point-of-care Lactate Measurement in Patients Meeting Level II and III Trauma Team Activation Criteria that Present to the Emergency Department: A Prospective Study

The predictive value of serum lactate to forecast injury severity in trauma-patients increases taking age into account

BACKGROUND

Two-tier trauma team activation (TTA)-protocols often fail to safely identify severely injured patients. A possible amendment to existing triage scores could be the measurement of serum lactate. The aim of this study was to determine the ability of the combination of serum lactate and age to predict severe injuries (ISS > 15).

METHODS

We conducted a retrospective cohort study in a single level one trauma center in a 20 months study-period and analyzed every trauma team activation (TTA) due to the mechanism of injury (MOI). Primary endpoint was the correlation between serum lactate (and age) and ISS and mortality. The validity of lactate (LAC) and lactate contingent on age (LAC + AGE) were assessed using the area under the curve (AUC) of the receiver operating characteristics (ROC) curve. We used a logistic regression model to predict the probability of an ISS > 15.

RESULTS

During the study period we included 325 patients, 75 met exclusion criteria. Mean age was 43 years (Min.: 11, Max.: 90, SD: 18.7) with a mean ISS of 8.4 (SD: 8.99). LAC showed a sensitivity of 0.82 with a specificity of 0.62 with an optimal cutoff at 1.72 mmol/l to predict an ISS > 15. The AUC of the ROC for LAC was 0.764 (95% CI: 0.67-0.85). The LAC + AGE model provided a significantly improved predictive value compared to LAC (0.765 vs. 0.828, p < 0.001).

CONCLUSIONS

The serum lactate concentration is able to predict injury severity. The prognostic value improves significantly taking the patients age into consideration. The combination of serum lactate and age could be a suitable Ad-on to existing two-tier triage protocols to minimize undertriage.

LEVEL OF EVIDENCE

Level IV, retrospective cohort study.

Elevated serum lactate levels and age are associated with an increased risk for severe injury in trauma team activation due to trauma mechanism

BACKGROUND

The identification of risk factors for severe injury is crucial in trauma triage and trauma team activation (TTA) depends on a sufficient triage. The aim of this study was to determine whether or not elevated serum lactate levels and age are risk factors for severe injury in TTA due to trauma mechanism.

METHODS

We conducted a retrospective cohort study in a single level one trauma center between September 2019 and May 2021 and analysed every TTA due to trauma mechanism. Primary endpoint of interest was the association of serum lactate as well as age with injury severity assessed by the injury severity score (ISS).

RESULTS

During the study period, we included 250 patients. Mean age was 43.3 years (Min.: 11, Max.: 90, SD: 18.7) and the initial lactate level was 1.7 mmol/L (SD: 0.95) with a mean ISS of 8.4 (SD: 8.99). The adjusted odds ratio (OR) for age > 65 being associated with an ISS > 16 is 9.7 (p < 0.001; 95% CI 4.01-25.58) and for lactate > 2.2 mmol/L being associated with an ISS > 16 is 6.29 (p < 0.001; 95% CI 2.93-13.48). A lactate level of > 4 mmol/L results in a 36-fold higher risk of severe injury with an ISS > 16 (OR 36.06; 95% CI 4-324.29).

CONCLUSION

This study identifies age (> 65) and lactate (> 2.2 mmol/L) as independent risk factors for severe injury in a TTA due to trauma mechanism. Existing triage protocols might benefit from congruous amendments.

Point-of-Care Testing for the Emergency Department Patient: Quantity and Quality of the Available Evidence

CONTEXT.—

Point-of-care test (POCT) instruments produce lab results with rapid turnaround times. Based on that fact, emergency department (ED) POCT requests are predicated on the belief that rapid test turnaround times lead to improved care, typically a decreased ED length of stay (LOS).

OBJECTIVE.—

To compile the available peer-reviewed data regarding use of POCT in the ED with an emphasis on ED-LOS.

DATA SOURCES.—

An English-language PubMed search using the following free text terms: ("EMERGENCY" AND "POINT OF CARE") NOT ULTRASOUND as well as "RAPID INFECTIOUS DISEASE TESTING." In addition, the PubMed "similar articles" functionality was used to identify related articles that were not identified on the initial search.

CONCLUSIONS.—

Seventy-four references were identified that studied POCT ED use to determine if they resulted in significant changes in ED processes, especially ED-LOS. They were divided into 3 groups: viral-influenza (n = 24), viral-respiratory not otherwise specified (n = 8), and nonviral (n = 42). The nonviral group was further divided into the following groups: chemistry, cardiac, bacterial/strep, C-reactive protein, D-dimer, drugs of abuse, lactate, and pregnancy. Across all groups there was a trend toward a significantly decreased ED-LOS; however, a number of studies showed no change, and a third group was not assessed for ED-LOS. For POCT to improve ED-LOS it has to be integrated into existing ED processes such that a rapid test result will allow the patient to have a shorter LOS, whether it is to discharge or admission.