Correlation of End Tidal CO 2 (ETCO 2 ) Level with Hyperlactatemia in Patient with Hemodynamic Disturbance

Abstract Background: Critically ill and hemodynamically unstable patients usually have perfusion disturbance that causes anerobic metabolism, causing increased lactate production. Hyperlactatemia induces metabolic acidosis, which then compensated by hyperventilation. Decreased PaCO 2 as the consequence of hyperventilation can be measured as end-tidal CO 2 (ETCO 2 ). High ETCO 2 was hypothesized as related to hyperlactatemia, thus monitoring of ETCO 2 could be a non-invasive monitoring in hemodynamically unstable patients. Objective: This study aimed to search the correlation between ETCO 2 level and hyperlactatemia in patients with hemodynamic disturbance. Method: This was observational, cross sectional study conducted on January to February 2017 in Sanglah General Hospital, Bali, Indonesia. Subjects were hemodinamicaly unstable patients aged 13-90 years old without primary pulmonary diseases recruited by consecutive sampling. ETCO 2 measurement by capnograph, lactate level measurement, and blood good analysis were done to all eligible patients. We did an association test to determine ther relation between ETCO 2 level and lactate level in such patients. Results: There were 70 subjects analyzed with median age 55 years old. Subjects’ case was 35.7% called for resuscitation, 32.9% was septic shock with surgery, 17.1% was septic shock without surgery, and 14.3% was hypovolemic shock with surgery. Most of most of the patients had compensated metabolic acidosis (82.9%). Correlation analysis between ETCO 2 and lactate level showed significantly strong negative correlation (correlation coefficient [r]=-0.852, p=0.001). Linear regression analysis of correlation showed that an increase of 1 mmol/L lactate was associated with decrease of 3.42 mmol/L ETCO 2 (p<0.001). Conclusion: ETCO 2 was related to serum lactate level in patients with hemodynamic disturbance. ETCO 2 measurement by capnograph was a non-invasive and fast method to detect hyperlactatemia.