Serum Lactate as a Screening Tool and Predictor of Outcome in Pediatric Patients Presenting to the Emergency Department With Suspected Infection

Objectives: No single reliable sepsis biomarker exists for risk stratification and prognostication in pediatric patients presenting to the emergency department (ED). Serum lactate (LA) predicts mortality in septic adults. We sought to determine if serum LA correlated with the diagnosis of sepsis, admission rates, and outcomes in pediatric patients presenting to the ED with suspected infection. Methods: This retrospective study was performed in an ED with a sepsis protocol that included serum LA with every blood culture. Of 735 pediatric patients with blood cultures drawn, 289 had serum LA obtained concomitantly. Appropriate statistical analyses determined the relationship between serum LA and variables of interest. Results: A significant positive correlation was found between serum LA and pulse, respiratory rate, white blood cell count, platelets, and length of stay, whereas a significant negative correlation was seen with temperature, HCO3-, and blood urea nitrogen. Admitted patients had higher serum LA (2.36 mM) than did those not admitted (1.70 mM), P = 0.0001. Of patients discharged, there was no difference in serum LA between those who returned within 3 days (1.80 mM) and those who did not (1.72 mM), P = 0.6654. Mean serum LA for those with sepsis (2.03 mM) did not differ from those without sepsis (1.91 mM), P = 0.3364. Conclusions: Higher serum LA in pediatric patients presenting to the ED with suspected infection correlated with increased pulse, respiratory rate, white blood cell count, and platelets and decreased blood urea nitrogen, HCO3-, and age. Serum LA may be predictive of hospitalization and length of stay and thus suggestive of disease severity, but not of return rates or pediatric sepsis screening in the ED.