Lactate-to-Albumin Ratio Predicts Development of ARDS, Mortality Risk From Flu

Investigators found that lactate-to-albumin ratio (LAR) strongly predicted the development of acute respiratory distress syndrome (ARDS) for patients with influenza A virus pneumonia. There was a significant correlation with disease severity and predictive efficiency for extrapulmonary complications and 28-day mortality, according to the investigators.

Flu, ARDS, Mortality, Hospitalization, Influenza A | Image Credit: terovesalainen | stock.adobe.com

ARDS is known to be a common complication of influenza A, associated with hypoxemia, respiratory distress, severe noncardiogenic pulmonary edema, and high mortality. According to the study authors, there have been limited studies that verified the efficacy of LAR to predict mortality for patients with sepsis and sepsis-induced organ injury, but data have not shown any clinical significance for LAR for influenza A. In the current study, they aim to determine the predictive value of LAR in ARDS and ARDS-related complications as well as the 28-day mortality.

Between January 1, 2011, and October 31, 2023, investigators included patients who were hospitalized with influenza A viral pneumonia at the First Affiliated Hospital of Soochow University. The APACHE II and SOFA scores for risk factor prediction were collected within the first 24 hours of admission, and if they were repeatedly measured during the first 24 hours, the worst value was selected. Individuals included had flu-like symptoms, were positive for influenza A virus nucleic acid, and measured lactate and albumin levels. Patients were divided into 2 groups: those with ARDS (n = 74) and those without ARDS (n = 31).

A total of 105 patients were included in the final analysis, with the baseline demographics and clinical symptoms being comparable. However, the ARDS group had significantly higher APACHE II scores, SOFA scores, and lower PaO₂/FiO₂ ratios compared with those in the non-ARDS group. Investigators found that there were laboratory differences between the 2 groups, with the ARDs group having higher levels of neutrophils, lactate, aspartate aminotransferase, lactate dehydrogenase, and creatine kinase (CK). Further, the LAR level was significantly higher in the ARDS group compared with the non-ARDS group at admission, according to the study authors.

In the analysis, the investigators found that LAR had better predictions of ARDS development through the ROC curve AUC than lactate or albumin alone. Therefore, the investigators selected that for the analysis, and CK, APACHE II score, and LAR at admission were all independently associated with the development of ARDS in individuals with influenzas A virus pneumonia.

They also found that the AUC for LAR was stronger than the AUC for CK and was comparable to APACHE II and SOFA scores. For disease severity, the study authors reported that invasive ventilation, septic shock, hepatic injury, and 28-day mortality during hospitalization was significantly higher for the high LAR group (LAR ≥ 44.81 × 10^− 3, n = 53) compared with the low LAR group (LAR < 44.81 × 10^− 3, n = 21). They also found that the cardiac injury and acute kidney injury were similar across both groups. LAR was positively correlated with duration of invasive ventilation, APACHE II score, and SOFA score, but negatively correlated with PaO₂/FiO₂ ratio for patients with ARDS. The analysis was also refined to further validate the findings. The AUC of LAR predicted the complications and 28-day mortality greater than either lactate or albumin alone, according to the study investigators. The AUC was also comparable to, and even superior, to APACHE II and SOFA scores, the study authors said. They concluded that LAR could be used as a predictor of disease severity and 28-day mortality risk.

REFERENCE

Gao J, Yang X, Fang X, Zhang Z, Wang D, Wang J. Clinical significance of lactate-to-albumin ratio in patients with influenza A virus-induced acute respiratory distress syndrome: a single-center retrospective study. BMC Anesthesiol. 2024;24(1):459. Published 2024 Dec 19. doi:10.1186/s12871-024-02843-9