Research Article: Association of serum bicarbonate with 28-day and 90-day mortality in patients with epilepsy and concurrent sepsis: a retrospective cohort study
Abstract:
Serum bicarbonate concentration is a predictor of adverse outcomes in various diseases. However, its role in forecasting outcomes specifically for patients with epilepsy and concurrent sepsis remains unclear. This study examines the relationship between serum bicarbonate levels and 28-day and 90-day mortality in patients with epilepsy and sepsis who were admitted to the intensive care unit (ICU).
Clinical data from 1,271 patients with epilepsy and concurrent sepsis were retrieved from the Medical Information Mart for Intensive Care (MIMIC)-IV database (2008–2022) for retrospective analysis. The primary outcomes measured were mortality rates at 28 and 90?days. We used multivariate Cox regression analysis, restricted cubic splines, threshold effect analysis, and survival curves to assess the impact of serum bicarbonate levels on 28-day and 90-day mortality.
Mortality rates for patients with epilepsy and sepsis were 21.4% at 28?days and 28.6% at 90?days. Two distinct non-linear relationships were observed between serum bicarbonate levels and mortality rates at 28 and 90?days. Below their respective threshold points, each unit increase in serum bicarbonate was associated with a decrease in mortality [hazard ratio (HR) 0.941, 95% confidence interval (CI) 0.9–0.985, p =?0.0084 at 28?days, and HR 0.952, 95% CI 0.915–0.99, p =?0.0144 at 90?days]. Above the thresholds, increases in bicarbonate levels were linked with elevated mortality risk (HR 1.1, 95% CI 0.979–1.236, p =?0.109 at 28?days, and HR 1.112, 95% CI 1.002–1.235, p =?0.0464 at 90?days). Kaplan–Meier survival analysis showed statistically significant survival differences at 28 and 90?days across serum bicarbonate levels ( p =?0.00015), with normal levels correlating with higher survival rates.
Two unique non-liner U-shaped relationships were identified between serum bicarbonate levels and mortality at 28 and 90?days in patients with epilepsy and concurrent sepsis. The lowest mortality rates were observed at approximately 25.0 and 25.9?mEq/L, respectively.
Introduction:
Sepsis is characterized by an excessive systemic inflammatory response to infection, leading to physiological, pathological, and biochemical dysregulation that can cause multi-system and multi-organ dysfunction or failure ( 1 ). Despite significant advancements in diagnosis and treatment, sepsis remains highly prevalent, especially in high-income countries, with an incidence of approximately 270 cases per 100,000 people per year and an in-hospital mortality rate of 26% ( 2 , 3 ). Globally, the incidence is…
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