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In trauma patients, elevated initial serum lactate may not independently predict mortality, traumatic ICU admissions, or the need for mechanical ventilation.

Elevated initial serum lactate (iSL) levels are often used to assess trauma severity; however, their predictive value in mortality and morbidity is inconsistent.

Findings published in the International Journal of Emergency Medicine that assess the association of iSL with mortality and morbidity demonstrated that elevated levels may not independently predict mortality, traumatic ICU admissions, or the need for mechanical ventilation.

Pablo Rodríguez-Ortiz, MD, and colleagues conducted a retrospective study of trauma patients aged 18 and older with iSL measured within the first 48 hours of admission. The study team classified patients into two groups based on iSL levels: normal (4.5-19.8 mg/dL) and elevated (≥19.9 mg/dL). The primary endpoint was in-hospital mortality. Secondary endpoints included morbidity indicators (eg, trauma ICU admission and need for mechanical ventilation).

Impact of iSL Does Not Persist

Among 536 patients, more than half (54.3%) had elevated iSL levels. Both patient cohorts were predominately men, with 8% more men in the high iSL group versus the normal group (82.8% vs 74.3%, respectively; P=0.02).

Motor vehicle collision was the most prevalent injury in both groups, with a lower proportion seen in the elevated iSL group compared with the normal group (38.8% vs 42.9%, respectively; P<0.01). Regarding gunshot wounds, the proportion of patients with this trauma doubled in the elevated group compared with the normal group (26.5% vs 13%, respectively; P<0.01), making it the second most common mechanism among patients in the elevated iSL cohort.

Initially, the researchers found elevated iSL was linked with in-hospital mortality (OR, 2.18; 95% CI, 1.36-3.51; P<0.001), traumatic ICU admission (OR, 2.06; 95% CI, 1.46-2.92; P<0.001), and need for mechanical ventilation (OR, 2.80; 95% CI, 1.97-3.98; P<0.001).

However, after adjusting for confounding factors, adjusted analyses indicated no significant associations with mortality (adjusted OR [aOR], 1.72; 95% CI, 0.97-3.04; P=0.06), traumatic ICU admission (aOR, 1.11; 95% CI, 0.71-1.75; P=0.65), or the need for mechanical ventilation (aOR, 1.49; 96% CI: 0.89-2.49; P=0.13).

Furthermore, both iSL (area under the curve [AUC]; 0.59; 95% CI, 0.54-0.64) and injury severity scores (AUC, 0.50; 95% CI, 0.54-0.64) showed limited availability to predict mortality, with no statistically significant differences between them.

“Future research should explore the combined predictive power of iSL levels with established scoring systems to improve the accuracy of mortality and morbidity predictions in trauma patients,” Dr. Rodríguez-Ortiz and colleagues wrote.