Analysis of the Relationship Between Early Serum Phosphate Levels and Short-Term Mortality in Septic Patients: A Retrospective Study Based on Mimic-Iv

Abstract

The aim of the study is to explore the impact of early serum phosphate levels on the prognosis of critically ill patients with sepsis. Methods: In this retrospective large cohort study, data of patients with sepsis were obtained from the Medical Information Mart for Intensive Care IV database. Patients were retrospectively divided into a control group and three study groups according to their daily serum phosphate levels within 2 days of intensive care unit (ICU) admission. A Cox regression model was used to evaluate the association between serum phosphate levels and 28-day morbidity. Results: This study included 9,691 patients diagnosed with sepsis. During the first 2 days of ICU admission, patients with hyperphosphatemia in either of the 2 days had higher 28-day mortality, while patients in the hypophosphatemia group had lower 28-day mortality (first day, 32.9% vs. 16.3%; second day, 36.3% vs. 14.7%). After adjusting for potential confounders, hyperphosphatemia was significantly associated with 28-day mortality; however, only hypophosphatemia on the second day was independently associated with reduced 28-day mortality. After stratification in the hypophosphatemia group, subgroup analysis showed that only the association between the mild hypophosphatemia group and 28-day mortality reached statistical significance (hazard ratio = 0.76, 95% CI = 0.65-0.89, P = 0.001). Conclusions: Mild hypophosphatemia might improve the short-term prognosis of patients with sepsis, and hyperphosphatemia is an independent risk factor for the outcomes of septic patients. After ICU admission, the serum phosphate levels on the second day had a better independent correlation with 28-day mortality, which prompted us to reconsider the optimal timing of phosphate evaluation.

Exploring the association between serum phosphate levels and mortality in patients hospitalized with infectious diseases: a nationwide study

“…Among 24,289 patients, elevated phosphate levels were independently associated with an increased risk of ICU mortality, hazard ratio 1.06 (95% confidence interval (CI): 1.02–1.09, p < 0.001). Two other studies ( 5 , 6 ), both published in 2023, indicated similar results, but focused specifically on patients with sepsis. Among 1,855 patients with sepsis, Black et al ( 5 ) reported higher mortality among those with phosphate levels in the highest quartile (>4.0 mg/dL) than in the three lower quartiles.…”

“…Among 1,855 patients with sepsis, Black et al ( 5 ) reported higher mortality among those with phosphate levels in the highest quartile (>4.0 mg/dL) than in the three lower quartiles. Among 9,691 patients with sepsis, Xu et al ( 6 ), observed higher 28-day mortality among those with hyperphosphatemia within 2 days of ICU admission. Importantly, the above studies included only patients with sepsis who were hospitalized in critical care units.…”

Prognostic value of serum phosphate levels in sepsis: a systematic review and meta-analysis

“…After a full-text review of the 151 studies, 141 were excluded. Finally, 10 studies ( Jung et al, 2016 ; Al Meshari et al, 2019 ; Jang et al, 2020 ; Miller et al, 2020 ; Wang et al, 2020 , 2021 ; Cao et al, 2021 ; Guo et al, 2022 ; Li, Shen & Han, 2022 ; Xu et al, 2023 ) were included in the meta-analysis ( Fig. 1 ).…”

“…Seven studies ( Jung et al, 2016 ; Al Meshari et al, 2019 ; Jang et al, 2020 ; Miller et al, 2020 ; Wang et al, 2021 ; Li, Shen & Han, 2022 ; Xu et al, 2023 ) reported mortality in patients with high serum phosphate levels compared to those with normal serum phosphate levels ( Fig. 2 ).…”

Effect of early serum phosphate disorder on in-hospital and 28-day mortality in sepsis patients: a retrospective study based on MIMIC-IV database

“…Current studies mainly focus on baseline phosphate levels, but emerging evidence suggests that even subtle fluctuations within the normal range can increase the risk of mortality in patients with sepsis [ 10 ]. Xu X et al detected higher mortality in patients with fluctuating serum phosphate levels by comparing patients with fluctuating serum phosphate levels with those with stable serum phosphate levels [ 22 ]. In addition, Kim et al [ 23 ] showed that higher serum phosphate fluctuations are associated with higher hospital mortality.…”