Understanding critically ill sepsis patients with normal serum lactate levels: results from U.S. and European ICU cohorts

Abstract

While serum lactate level is a predictor of poor clinical outcomes among critically ill patients with sepsis, many have normal serum lactate. A better understanding of this discordance may help differentiate sepsis phenotypes and offer clues to sepsis pathophysiology. Three intensive care unit datasets were utilized. Adult sepsis patients in the highest quartile of illness severity scores were identified. Logistic regression, random forests, and partial least square models were built for each data set. Features differentiating patients with normal/high serum lactate on day 1 were reported. To exclude that differences between the groups were due to potential confounding by pre-resuscitation hyperlactatemia, the analyses were repeated for day 2. Of 4861 patients included, 47% had normal lactate levels. Patients with normal serum lactate levels had lower 28-day mortality rates than those with high lactate levels (17% versus 40%) despite comparable physiologic phenotypes. While performance varied between datasets, logistic regression consistently performed best (area under the receiver operator curve 87–99%). The variables most strongly associated with normal serum lactate were serum bicarbonate, chloride, and pulmonary disease, while serum sodium, AST and liver disease were associated with high serum lactate. Future studies should confirm these findings and establish the underlying pathophysiological mechanisms, thus disentangling association and causation.

What Is Left for Real-Life Lactate Monitoring? Current Advances in Electrochemical Lactate (Bio)Sensors for Agrifood and Biomedical Applications

“…In the same vein, lactate assessment is highly appreciated in intensive care units (ICUs), where an abnormal level is a beacon of meaningful information of the current and future status of the patient. In this sense, it is possible to relate it with situations such as haemorrhagic shock, pulmonary embolism, cardiogenic shock, respiratory poisoning and renal failure, among others [ 8 , 9 , 10 , 11 , 12 , 13 ]. Moreover, alternative studies pointed out the existence of abnormal lactate concentration in cancer cells during metastases [ 14 ].…”

Association Between Lactate and 28-Day Mortality in Elderly Patients with Sepsis: Results from MIMIC-IV Database

“…Lactate level is associated with mortality in sepsis, which should be evaluated within 1 h after admission [ 18 ]. Much evidence was accumulated clarifying that there is a significant prognostic value of lactate in sepsis [ 19 – 21 ]. One study in adult sepsis showed that for predicting mortality, the cutoff value of lactate was 1.6 mmol/l with a sensitivity of 79.59% and a specificity of 32.10% [ 22 ].…”

28-day sepsis mortality prediction model from combined serial interleukin-6, lactate, and procalcitonin measurements: a retrospective cohort study

“…Our study showed that LACcD3 was a valuable predictor of 28-day mortality in septic patients. Although several previous studies have shown that increased LAC levels are a valuable prognostic marker of high mortality in sepsis [16,17,37,38], another study showed that critically ill patients with sepsis had normal serum LAC levels [39]. Therefore, it is better to collect serial LAC measurements and combine LAC levels with other markers to evaluate sepsis prognosis more accurately.…”