Elevated adipose tissue lactate to pyruvate (L/P) ratio predicts poor outcome in critically ill patients with septic shock: a microdialysis study.
Minerva Anestesiol. 2013 Nov;79(11):1229-37
Authors: Nikitas N, Kopterides P, Ilias I, Theodorakopoulou M, Vassiliadi DA, Armaganidis A, Dimopoulou I
BACKGROUND: Sepsis is a disease affecting tissue metabolism; in vivo microdialysis (MD) is a bedside technique enabling researchers to monitor tissue metabolic changes. We conducted this study aiming to evaluate the relationship between lactate to pyruvate (L/P) ratio, a sensitive marker of tissue oxygenation and perfusion, and mortality in critically ill septic patients.
METHODS: We enrolled 105 patients with septic shock hospitalized in the mixed intensive care unit of a tertiary hospital. A MD catheter was inserted in the subcutaneous adipose tissue of the upper thigh and interstitial fluid samples were collected and analyzed for glucose, lactate, pyruvate, and glycerol.
RESULTS: Multivariate regression analysis showed that among variables registered on day 1, APACHE II and SOFA scores, blood lactate and microdialysis-assessed tissue L/P ratio were independently associated with 28-day mortality. Even in patients with normal (<2 mmol/L) blood lactate, adipose tissue L/P ratio showed a strong trend to statistical significance. During the 6-day study period, non-survivors had significantly higher L/P ratios compared to survivors (P=0.001) and mixed model analysis revealed a different pattern of evolution in time with non-survivors experiencing an increase while survivors had a late decline in their L/P ratio. The AUC for L/P ratio was similar to that of APACHE II (P=0.67) and SOFA score (P=0.73). Comparison of the Kaplan-Meier 28-day survival curves of patients with normal (≤ 25) versus elevated (>25) L/P ratios showed that the latter survived significantly less (P=0.02; log-rank test).
CONCLUSION: Elevated adipose tissue L/P ratio is associated with poor outcome in critically ill patients with septic shock. Microdialysis deserves to be further studied as a research tool in the multi-modal monitoring of septic critically ill patients.
PMID: 23857439 [PubMed - indexed for MEDLINE]