A retrospective study of multivariable analysis of predictive values of lactate-related ratios on 28-day mortality in intensive care units

In this retrospective research, it was aimed to evaluate predictive values of lactate-related ratios on mortality in intensive care units (ICUs) at multivariable level. A total of 4985 patients who were hospitalized in the Anesthesia Intensive Care Unit of Istanbul Gaziosmanpaşa SUAM between January 2015 and January 2025 were included in the study. Patients' age, gender, body mass index, hospitalization diagnoses and chronic diseases, lactate, albumin, hemoglobin, potential of hydrogen (pH), HCO₃⁻, base excess, platelets, APACHE II score, and 28-day mortality values were obtained. Lactate albumin ratio (LAR), lactate hemoglobin ratio, lactate pH ratio, and lactate bicarbonate ratio of the patients were analyzed. Age, pH, and LAR parameter means were significantly higher in the non-survival group, whereas blood extracellular fluid mean was significantly higher in the survival group (P < .05). Acute renal failure and ketoacidosis were more common in the non-survival group (P < .05). Twenty-eight-day mortality was significantly correlated with age (R = 0.077; P < .01), acute renal failure (R = 0.030; P < .05), ketoacidosis (R = 0.028; P < .05), albumin (r = -0.117; P < .01), base excess in the extracellular fluid (R = 0.032; P < .05), pH (R = 0.036; P < .05), LAR (0.057; P < .01), and hospitalization duration (R = 0.044; P < .01). Effects of age (B = 0.020; P < .01), acute renal failure (B = -0.648; P < .05), base excess in the extracellular fluid (B = 0.024; P < .05), pH (B = 1.753; P < .05), and LAR (B = 4.893; P < .01) were statistically significant. Although the LAR parameter has a predictive value on 28-day mortality in ICU patients, this is not the case in acute renal failure patients. The LAR variable in acute renal failure patients may have different mechanism than in other ICU patients, and this mechanism may be misleading for LAR. Therefore, further predictive parameters are needed for ICU 28-day mortality in acute renal failure patients.