Lactate clearance: the earlier the better?
© BioMed Central Ltd 2008
Published: 13 March 2008
In cardiorespiratory failure there is an oxygen-metabolism imbalance mirrored in a timely fashion by a rise in blood lactate associated with a lowering of blood pH. If the therapeutic approach were able to repay this oxygen debt and to restore an adequate blood flow to the lactate-remover organs, effective lactate clearance (LC) should be observed. The study aim was to evaluate whether a short-term (2 hour) LC could be used as a prognostic marker to tailor the therapy in cardiorespiratory insufficiencies.
Ninety-seven consecutive admissions to our emergency department for acute cardiorespiratory insufficiency were included. Exclusion criteria were sepsis, GCS < 8 and need for immediate intubation. Arterial blood gas analysis (BGA) and lactatemia were assessed at emergency department arrival and 2, 6, and 24 hours later. LC was calculated as: [lactate start - lactate 2 hours] × 100/lactate start. The 7-day mortality or orotracheal intubation (negative outcome) versus discharge or downward transfer (positive outcome) was evaluated. A logistic regression model was performed taking into account different risk factors.
Negative outcome (n = 29)
Positive outcome (n = 68)
OR (95% CI)
LC at 2 hours < 25%
29 (8.6 - 99), P < 0.0001
Lactate at 2 hours > 2 mmol/l
7.7 (2 - 28), P = 0.0006
The systematic monitoring of 2-hour LC could be used in cases of acute cardiorespiratory insufficiencies to identify high-risk patients who require more aggressive therapy/monitoring. On the other hand, 2-hour LC > 25% is highly predictive of positive outcome and may confirm the therapeutic approach.
This article is published under license to BioMed Central Ltd.