Association of hypochloremia with mortality among patients requiring continuous renal replacement therapy

Association of serum chloride levels with all-cause mortality among patients in surgical intensive care units: a retrospective analysis of the MIMIC-IV database

This study explores the association between serum chloride concentrations and all-cause mortality among patients in the Surgical Intensive Care Unit (SICU). Employing a retrospective cohort design, the study utilized data extracted from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database, specifically focusing on individuals admitted to the surgical/trauma ICUs. This dataset encompassed demographic profiles, laboratory findings, historical medical data, vital statistics, and variables pertinent to prognosis. Participants were divided into four groups based on their serum chloride concentrations. The primary outcomes assessed were mortality rates at 30, 90, and 180 days post-admission to the ICU. Analytical methods included Kaplan-Meier survival curves, Cox proportional hazards regression models, and Restricted Cubic Spline (RCS) analyses to delineate the relationship between serum chloride concentrations and patient outcomes. The study cohort comprised 10,996 patients, with observed mortality rates of 12.78% at 30 days, 17.14% at 90 days, and 20.32% at 180 days. Kaplan-Meier analyses revealed significant disparities in survival rates across the quartiles of serum chloride during the follow-up intervals (p < 0.001). The results from the multivariable Cox regression suggested a substantial inverse association between high serum chloride levels and decreased mortality at 30 days (hazard ratio [HR]: 0.96; 95%confidence interval [CI]: 0.95-0.97; P < 0.001), 90 days (HR: 0.97; 95% CI: 0.96-0.98; P < 0.001), and 180 days (HR: 0.97; 95% CI: 0.96-0.98; P < 0.001). Particularly, patients in the highest quartile of serum chloride faced significantly lower mortality risks compared to those in the lowest quartile (30 days HR = 0.65, 90 days HR = 0.71, 180 days HR = 0.69, P < 0.001). RCS analysis depicted an L-shaped curve demonstrating the dynamics between serum chloride concentrations and the risk of all-cause mortality across the 30-day, 90-day, and 180-day periods.Starting at a concentration of 104 mmol/L, a decrease in serum chloride levels was associated with an increased risk of mortality.These findings elucidate a marked nonlinear association between serum chloride levels and all-cause mortality in SICU patients, enhancing our comprehension of serum chloride's impact on clinical outcomes in this setting.

Association of Serum Phosphate Derangement With Mortality in Patients on Continuous Renal Replacement Therapy

Background:

There is limited evidence on the association of serum phosphate with mortality in patients receiving continuous renal replacement therapy (CRRT).

Objective:

To assess the association of serum phosphate with mortality in critically ill patients requiring CRRT for acute kidney injury (AKI).

Design:

A cohort study.

Setting:

A tertiary referral hospital in the United States.

Patients:

Acute kidney injury patients receiving CRRT from 2006 through 2015 in intensive care units.

Measurements:

(1) Serum phosphate before CRRT and (2) mean serum phosphate during CRRT were categorized into 3 groups; ≤2.4 (hypophosphatemia), 2.5 to 4.5 (normal serum phosphate group), and ≥4.6 (hyperphosphatemia) mg/dL.

Methods:

Multivariable logistic regression was used to assess the association between serum phosphate and 90-day mortality.

Results:

A total of 1108 patients were included in this study. Of these, 55% died within 90 days after CRRT initiation. Before CRRT, 3%, 30%, and 66% had hypophosphatemia, normophosphatemia, and hyperphosphatemia, respectively. Before CRRT, both hypophosphatemia and hyperphosphatemia were significantly associated with higher 90-day mortality with the adjusted odds ratio (OR) of 2.22 (95% confidence interval [CI]: [1.03, 4.78]) and 1.62 (95% CI: [1.21, 2.18]), respectively. During CRRT, 3%, 85%, and 12% had mean serum phosphate in hypophosphatemia, normophosphatemia, and hyperphosphatemia range. During CRRT, hyperphosphatemia was significantly associated with higher 90-day mortality with adjusted OR of 2.22 (95% CI: [1.45, 3.38]).

Limitations:

Single center, observational design, lack of information regarding causes of serum phosphate derangement.

Conclusion:

Most CRRT patients had hyperphosphatemia before CRRT initiation but maintain normal serum phosphate during CRRT. Before CRRT, hypo- and hyperphosphatemia, and during CRRT, hyperphosphatemia predicted higher mortality.

Trial registration:

Not registered.