Traumatic Brain Injury and Acute Kidney Injury-Outcomes and Associated Risk Factors

Association between Serum Magnesium Levels and Risk of Acute Kidney Injury in Patients with Traumatic Brain Injury: A Retrospective Cohort Study from the MIMIC-IV Database

INTRODUCTION

The occurrence of acute kidney injury (AKI) is associated with a higher risk of mortality in patients with traumatic brain injury (TBI). This study aimed to explore the relationship between serum magnesium levels and the risk of AKI in patients with TBI.

METHODS

Patients with TBI were identified from the Medical Information Mart Intensive Care IV (MIMIC-IV) 2008-2019. The relationship between serum magnesium levels at admission and magnesium coefficient of variation (CV) during hospitalization and the risk of AKI was analyzed using multivariable logistic regression analysis and expressed as odds ratio (OR) and 95% confidence interval (CI). Subgroup analyses were performed according to Glasgow Coma Scale (GCS) score (<14, ≥14), sepsis (no, yes), and estimated glomerular filtration rate (eGFR; <60, ≥60).

RESULTS

Of the 991 patients included, 140 (14.13%) developed AKI during hospitalization. Patients with magnesium levels ≤1.7 mg/dL (tertile 1) (OR = 1.68, 95% CI: 1.01-2.81) were associated with a higher risk of AKI compared to those with magnesium levels of 1.7-2.0 mg/dL (tertile 2), but no association was found in those with magnesium levels >2.0 mg/dL (tertile 3) (p = 0.479). For magnesium CV, patients with magnesium CV >10% (tertile 3) (OR = 2.26, 95% CI: 1.16-4.41) were linked to an increased risk of AKI compared to those with magnesium CV ≤4% (tertile 1), but there may be a slight association between magnesium CV of 4%-10% (tertile 2) and AKI risk (OR = 1.86, 95% CI: 0.99-3.48; p = 0.053). Subgroup analyses showed that lower magnesium levels (≤1.7 mg/dL) or greater magnesium CV (>10%) were associated with a higher risk of AKI only in patients with a GCS score ≥14, non-sepsis, or eGFR ≥60 mL/min/1.73 m2 (p < 0.05).

CONCLUSION

Lower serum magnesium levels at admission or greater magnesium CV during hospitalization were associated with a higher risk of AKI in patients with TBI.

Racial/Ethnic and Geographic Disparities in Comorbid Traumatic Brain Injury-Renal Failure in US Veterans and Associated Veterans Affairs Resource Costs, 2000-2020

Studies have identified disparities by race/ethnicity and geographic status among veterans with traumatic brain injury (TBI) and renal failure (RF). We examined the association of race/ethnicity and geographic status with RF onset in veterans with and without TBI, and the impact of disparities on Veterans Health Administration resource costs.

METHODS

Demographics by TBI and RF status were assessed. We estimated Cox proportional hazards models for progression to RF and generalized estimating equations for inpatient, outpatient, and pharmacy cost annually and time since TBI + RF diagnosis, stratified by age.

RESULTS

Among 596,189 veterans, veterans with TBI progressed faster to RF than those without TBI (HR 1.96). Non-Hispanic Black veterans (HR 1.41) and those in US territories (HR 1.71) progressed faster to RF relative to non-Hispanic Whites and those in urban mainland areas. Non-Hispanic Blacks (-$5,180), Hispanic/Latinos ($-4,984), and veterans in US territories (-$3,740) received fewer annual total VA resources. This was true for all Hispanic/Latinos, while only significant for non-Hispanic Black and US territory veterans < 65 years. For veterans with TBI + RF, higher total resource costs only occurred ≥ 10 years after TBI + RF diagnosis ($32,361), independent of age. Hispanic/Latino veterans ≥ 65 years received $8,248 less than non-Hispanic Whites and veterans living in US territories < 65 years received $37,514 less relative to urban veterans.

CONCLUSION

Concerted efforts to address RF progression in veterans with TBI, especially in non-Hispanic Blacks and those in US territories, are needed. Importantly, culturally appropriate interventions to improve access to care for these groups should be a priority of the Department of Veterans Affairs priority for these groups.

Chronic kidney disease as a predictive factor for poor prognosis in traumatic brain injury among older adults: a case-control study

Objective

Traumatic brain injury (TBI) is a highly prevalent neurological disorder that affects a gradually increasing proportion of older adults. Chronic kidney disease (CKD) significantly contributes to global years of life lost, with an estimated one-tenth of the global population affected by CKD. However, it remains unclear whether CKD impacts TBI prognosis. We conducted a case-control study to investigate the clinical outcomes of TBI patients with or without CKD comorbidity and identified the risk factors associated with a poor prognosis.

Methods

From January 2017 through April 2023, 11 patients with TBI and CKD were included, and 27 control TBI cases with normal kidney function were matched by age, gender, and admission Glasgow Coma Scale (GCS) score as the control group.

Results

The CKD TBI group had a significantly lower GCS score upon discharge (7.1 ± 5.9) compared to the non-CKD TBI group (13.1 ± 2.6) (p < 0.01). ICU stay time and hospitalization expenses were higher in the CKD group than the non-CKD group, though there were no statistical differences. Additionally, patients in the CKD TBI group had a higher frequency of hospital-acquired infections (54.4%) compared with those in the non-CKD TBI group (7.4%) (p < 0.01). The two groups exhibited no differences in hemoglobin levels, albumin levels, or coagulation function. Logistic regression analysis showed that advanced age, low admission GCS score, elevated blood urea, and creatinine levels were associated with a poor neurological prognosis.

Conclusion

TBI patients comorbid with CKD have a poorer prognosis than those with normal kidney function.

Acute kidney injury in neurocritical care

Approximately 20% of patients with acute brain injury (ABI) also experience acute kidney injury (AKI), which worsens their outcomes. The metabolic and inflammatory changes associated with AKI likely contribute to prolonged brain injury and edema. As a result, recognizing its presence is important for effectively managing ABI and its sequelae. This review discusses the occurrence and effects of AKI in critically ill adults with neurological conditions, outlines potential mechanisms connecting AKI and ABI progression, and highlights AKI management principles. Tailored approaches include optimizing blood pressure, managing intracranial pressure, adjusting medication dosages, and assessing the type of administered fluids. Preventive measures include avoiding nephrotoxic drugs, improving hemodynamic and fluid balance, and addressing coexisting AKI syndromes. ABI patients undergoing renal replacement therapy (RRT) are more susceptible to neurological complications. RRT can negatively impact cerebral blood flow, intracranial pressure, and brain tissue oxygenation, with effects tied to specific RRT methods. Continuous RRT is favored for better hemodynamic stability and lower risk of dialysis disequilibrium syndrome. Potential RRT modifications for ABI patients include adjusted dialysate and blood flow rates, osmotherapy, and alternate anticoagulation methods. Future research should explore whether these strategies enhance outcomes and if using novel AKI biomarkers can mitigate AKI-related complications in ABI patients.