Blood lactate concentration is a strong predictor of mortality, more so than other measures of acidity in the blood, according to Australian researchers.
Their study aimed to find out whether markers of blood acidity would be most useful in alerting clinicians to which critical care patients were likely to deteriorate subsequently leading to death.
“Lactate should always be considered in managing critically ill patients”
The researchers, from the Royal Perth Hospital and the University of Western Australia, noted that changes in the acidity of blood and other body fluid were common in patients after major surgery or trauma and those with infection.
They highlighted that such changes could take many forms and it was previously uncertain whether changes in any one form of acidity was more important in reflecting how sick a patient was.
Using data obtained within the first hour of intensive care unit admission from 6,878 patients, the researchers assessed the ability of different markers of blood acidity to predict subsequent hospital mortality.
Of the 6,878 patients included in the study, 924 patients (13.4%) subsequently died, despite intensive care treatment.
Almost all initial blood acidity markers were significantly different between those who subsequently died and those who survived, confirming that an early change in blood acidity was very common before a patient’s subsequent deterioration.
Of the 12 different markers of blood acidity assessed, blood lactate concentrations had the best ability – with over 70% accuracy – to predict a critically ill patient’s subsequent survival outcome.
Lead study author Dr Kwok Ho said: “Arterial lactate concentration had a better ability than all other blood acidity markers to predict mortality of the critically ill.
“Lactate should always be considered in managing critically ill patients and a high blood lactate can be used as an early warning test to alert doctors which patients are at most risk of subsequent deterioration requiring urgent evaluation and treatment,” he added.