Decreased Risk of Mortality in Patients With Septic Shock Complicated by Acute Respiratory Distress Syndrome Who Had Early Lactate Clearance in a Single Institution

Abstract

SESSION TITLE: Sepsis I SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, October 26, 2016 at 01:30 PM - 02:30 PM PURPOSE: Recent research has revealed that early lactate clearance is associated with a reduction in inflammatory markers and improved clinical outcomes in septic shock. Acute respiratory distress syndrome (ARDS) is a well-established complication of septic shock, yet little is known about the relationship between ARDS and lactate clearance. The aim here was to evaluate whether improved lactate clearance is associated with improved outcomes in patients with septic shock complicated by ARDS. METHODS: A retrospective cohort of all patients diagnosed with septic shock in an ICU at a community hospital during a three-month period of time was compiled. Patients were excluded if they did not meet criteria for septic shock on manual review, or if they had heart disease that would preclude the diagnosis of ARDS such as severe valvular heart disease or heart failure with reduced ejection fraction measured by echocardiogram. ARDS was defined based on the Berlin Criteria using review of arterial blood gas, x-ray and/or CT chest imaging and radiologist interpretation. Lactate clearance was calculated as a repeat lactate level (4-24 hours after initial) divided by lactate level at the time of septic shock diagnosis. Additional variables were collected including demographics, source of infection, and possible confounders (medications, cirrhosis, and transfusion). A multivariate logistic regression analysis was employed where in-hospital mortality was the dependent variable, and lactate level as well as lactate clearance (along with other covariates of interest) were the independent variables, to identify whether any relationship was present. RESULTS: Of the 268 patients reviewed, 135 were excluded (47 did not meet criteria for septic shock, 88 had significant heart disease, and 15 had missing data). Of the included patients, 61% were female, 29% were non-white, mean age was 67 years. Ultimately, 117 septic shock patients were included in this analysis and 57 died in hospital. Mean lactate level was 4.24 mmol/L (SD 3.63), and lactate clearance of at least 10% from baseline was observed in 45/63 cases (71%). As expected, baseline lactate levels were a strong predictor of mortality - an increase of 1 mmol/L was associated with a 15% increased risk of death (HR 1.15, 95% CI 1.07-1.23, p<0.001). Additionally, in patients with septic shock complicated by ARDS, lactate clearance of at least 10% from baseline was associated with a reduced mortality risk of 97% (HR=0.03, 95% CI 0.002-0.44, p=0.01). CONCLUSIONS: Lactate clearance is associated with decreased mortality in patients with septic shock complicated by ARDS. CLINICAL IMPLICATIONS: Lactate clearance in addition to lactate levels should be futher examined to risk stratify patients with septic shock complicated by ARDS. DISCLOSURE: The following authors have nothing to disclose: Mohammad Elballat, Martin Aldana-Campos, Brian Garnet, Varun Shah, Atif Shah, Elie Donath, Samer Fahmy No Product/Research Disclosure Information