Early Lactate Dynamics in Critically Ill Non-Traumatic Patients in a Resuscitation Room of a German Emergency Department (OBSERvE-Lactate-Study).

BACKGROUND: Management of critically ill non-trauma patients in the resuscitation room of an emergency department (ED) is very challenging, and it is difficult to identify patients with a higher risk of death. Previous studies have shown that lactate indices can predict survival for selected diseases and syndromes.

OBJECTIVE: As reported for other patient populations, we set out to determine whether admission lactate or lactate dynamics (LD) within 24 h can predict 30-day mortality in unselected critically ill non-traumatic patients.

METHODS: In this retrospective study over a 1-year period, admission lactate, time weighted average lactate (LacTW ) and LD of all critically ill adult patients admitted from ED to intensive care unit were analyzed. A linear regression model was implemented to estimate lactate data 1 h after admission.

RESULTS: The admission lactate, LacTW , and LD within 24 h were analyzed from 392 critically ill patients. The overall 30-day mortality rate was around 29%. Admission lactate (4.1 ± 4.0 mmol/L vs. 6.6 ± 6.1 mmol/L; p < 0.01) and LacTW (1.8 ± 1.7 mmol/L vs. 4.1 ± 4.8 mmol/L; p < 0.01) were different between survivors and non-survivors. LD between survivors and non-survivors did not differ at 1 h, 6 h, 12 h, or 24 h. After excluding patients with out-of-hospital or in-hospital cardiac arrest during resuscitation room management, admission lactate and LD between survivors and non-survivors did not differ at 1 h, 12 h, and 24 h. LD at 6 h (44% ± 42% vs. 33% ± 58%; p = 0.042) and LacTW (1.7 ± 1.6 mmol/L vs. 2.6 ± 3.0 mmol/L; p < 0.01) did differ.

CONCLUSIONS: In critically ill ED patients initially requiring treatment in a resuscitation room setting, LD at 6 h and LacTW may predict their survival beyond 30 days. These findings need to be confirmed in a prospective study design.