Comparison between values of central venous and arterial lactate and standard base excess in shocked patients

Introduction

Hemodynamic optimization based on tissue perfusion markers is a strategy considered adequate for the management of patients in shock in ICUs.

Objectives

To evaluate the variability and correlation between venous and arterial standard base excess (SBE) and lactate samples.

Materials and methods

The analysis of lactate levels was performed and the SBE obtained from the same blood of central venous and arterial samples of 115 patients. We compared these measurements (Wilcoxon signed rank test), and determined the correlation between these variables (Spearman rank order correlation).

Results

There was a statistically significant difference between the value of venous SBE: -4.3 mEq/l (-7.4 to -0.9) as compared with the arterial value: -3.2 (-6.9 to 0), P < 0.001; but there was no difference between the venous lactate: 1.67 mmol/l (1.22–2.22) as compared with the arterial lactate: 1.56 (1.22–2.22), P = 0.792. The correlation coefficients were 0.929 to venous and arterial SBE (bias: 0.09) and 0.826 to lactate (bias: -0.024).

Discussion

The agreement between venous and arterial samples permits one to use the central venous lactate level similar to the arterial level and their variations. For SBE, the module value was different between the measurements, otherwise their variation has good correlation. As these variations guide the clinical decision, we can use it as a goal of hemodynamic monitoring.

Conclusion

It is possible to guide hemodynamic monitoring in shock patients using values of central venous lactate and variations of SBE.