SESSION TITLE: Critical Care Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: Serum lactate levels are commonly used as markers of perfusion in the management of shock. However, several studies have shown that hyperlactatemia may not just be the result of hypoperfusion but also increased adrenergic stimulation. Based on these findings, some have postulated that persistently normal lactate levels in shock may represent a relative adrenergic deficiency. To our knowledge, no studies to date have evaluated outcomes in shock patients with persistently normal lactate levels. The purpose of this study is to compare all-cause mortality and severity of shock in patients with persistently normal serum lactate levels (lactate level <2.0 mmol/L for the first 6 hours during the treatment of shock) to those with elevated lactate levels (lactate level >2.0 mmol/L). METHODS: This is an IRB-approved, retrospective chart review of critically ill adult patients admitted to the intensive care unit (ICU) from December 2018 to November 2019 at NYU Langone Brooklyn. The inclusion criterion was the confirmed administration of catecholamine-based vasopressor therapy for at least 1 hour. Exclusion criteria included critical limb or mesenteric ischemia, documented chronic liver disease, epinephrine administration, metformin toxicity, confirmed seizure within 24 hours of vasopressor initiation, elevated alcohol level, or transition to comfort care. The primary endpoints were in-hospital and ICU mortality. Secondary endpoints included duration of therapy and the number of vasopressors required. Length of stay (LOS) and the need for organ support therapies were also evaluated. RESULTS: A total of 137 patients were analyzed (55 in normal lactate group and 82 in elevated lactate group). Overall, rates of ICU (36.6% vs 18.2%, p = 0.02) and in-hospital mortality (47.6% vs 30.1%, p=0.05) were higher in the elevated lactate group. This was despite there being no difference the duration of vasopressor therapy (29 vs 30 hours, p = 0.81) or the number of vasopressors required (1 vs 1, p = 0.211). In addition, there were no differences in the need for mechanical ventilation (37.8% vs 36.6%, p = 0.864), renal replacement therapy (7.3% vs 7.3%, p = 0.992), or hospital length of stay (10 vs 8 days, p = 0.142). CONCLUSIONS: Based on our findings, persistently normal lactate levels in shock appear to be associated with reduced all-cause mortality compared to those with elevated lactate levels. However, this does not appear to correlate with decreases in the duration of vasopressor therapy or the need for organ replacement therapies. CLINICAL IMPLICATIONS: Persistently normal lactate levels may represent good prognostic value as they appear to be associated with reduced mortality in critically ill patients with shock. However, without differences in vasopressor therapy duration or organ replacement therapy needs, it is unclear if elevated serum lactate levels are not simply the result of worsening end-organ perfusion. DISCLOSURES: No relevant relationships by Bhaskara Garimella, source=Web Response No relevant relationships by Vickie Kassapidis, source=Web Response No relevant relationships by John Kileci, source=Web Response No relevant relationships by Guillermo Munoz-Jurado, source=Web Response