Prognostic Value Of Lactate Clearance In The First 6 Hours Of Intensive Medicine Course

Lactic acid was discovered back in 1780 in putrid milk by the Swiss chemist Karl Wilhelm Scheele. Its use as a biomarker is of great interest to scientists and clinicians of the most diverse specialties. It is generally called hyperlactacidemia when the lactate values are 2-5 mEq/ l; lactic acidosis refers to values higher than these.

The aim of this study, carried out by Cardinal Fernández et al., was to analyse the use of lactate clearance at the sixth hour of admission (CL6) in the evaluation of the prognosis of patients entering the Intensive Care Unit.

This prospective, observational and analytical study was carried out between 2004 and 2006 in the surgical ICU of the Medical Assistance Center of Uruguay, with patients older than 18 years whose initial lactate level was greater than 2 mEq/l .

Lactate clearance was calculated at the sixth hour of admission and the sensitivity, specificity, positive predictive value and negative predictive value for different lactate clearance values were calculated at the sixth hour. The optimal value of lactate clearance in the first 6 hours after admission was considered as the one which added greater sensitivity and specificity.

108 patients participated in this study, of which 64 died (ICU mortality of 59.3%).

ICU mortality related variables, identified by Cox regression analysis, were CL6 (HR = 0.458; CI 95%, 0.239-0.876), L0 (HR = 1.16; CI 95%, 1.033-1.303) and SAPSII (HR = 1.019; CI 95%, 1.006-1.034). A CL6 equal to or lower than 0.4 was considered as optimal cutoff with a pos­itive prognostic value of 74% and negative prog­nostic value of 61%. It was also associated with lower survival adjusted by the SAPSII value and L0.

After analyzing the results of this study, the authors concluded that in critical surgical patients the lactate clearance at the sixth hour can be of aid to discern the prognosis in the ICU.

This is a summary of the article written in Spanish under the title “Valor pronóstico del aclaramiento de lactato en las primeras 6 h de evolución en medicina intensiva”, by Pablo Alejandro Cardinal Fernández, Estela Olano, Clotilde Acosta, Hugo Bertullo, Henry Albornoz and Homero Bagnulo, and which was published in Medicina Intensiva, Med Intensiva.2009;33:166-70 – Vol. 33 Núm.4

Click here to download the original article, written in Spanish:
Valor pronóstico del aclaramiento de lactato en las primeras 6 h de evolución en medicina intensiva