Continuous renal replacement therapy for patients with sepsis in a low – resource medical intensive care unit ( MICU ) : incidence, risk factors, and outcomes

Introduction Sepsis is one of the leading causes of ICU admissions, with a substantial proportion of patients developing sepsis-associated acute kidney injury (S-AKI). In such cases, continuous renal replacement therapy (CRRT) is a cornerstone of renal supportive care; however, evidence from low-resource settings (LRS) remains limited. This study aimed to describe the demographic and clinical characteristics of patients with S-AKI treated with CRRT in an LRS medical ICU (MICU), as well as to identify predictors of mortality. Subjects and methods This retrospective, observational, consecutive, single-center study included adult patients admitted to the MICU between June 1, 2023, and June 1, 2024, with a diagnosis of sepsis complicated by S-AKI, and managed with CRRT. Statistical analyses were conducted using the Mann-Whitney U and Pearson χ² tests, and multinomial logistic regression was used to identify independent predictors of mortality. ORs were reported for key predictors, and Kaplan-Meier survival analysis was performed to assess time to event. Results A total of 96 patients with S-AKI were treated with CRRT (65 male patients, median age 64.5 years). The 28- day all-cause mortality rate was 69.8%, with a high rate of septic shock at admission among nonsurvivors (n=49, p= 0.019). Kaplan-Meier analysis demonstrated a median survival of 12 days (95%CI: 8.95-15.05). The majority of patients were admitted from hospital wards (n=59), and the most common comorbidities were hypertension (n=63), diabetes (n=38), and cardiomyopathy (n=27). Survivors had a longer MICU length of stay (p= 0.003). Nonsurvivors had a higher initial Sequential Organ Failure Assessment and Simplified Acute Physiology Score II (SAPS II) scores at MICU admission (p< 0.000), and prominent abnormalities at CRRT initiation for albumin (p= 0.004), troponine I (p= 0.032), and lactate (p= 0.004). Invasive mechanical ventilation and vasopressor therapy were predominantly used among nonsurvivors (p< 0.001). Continuous Venovenous Hemodiafiltration (CVVHDF) was the CRRT modality used for all patients (three patients used a combination of continuous and intermittent techniques), and hemoadsorption filters were used in 38 patients. The preferential indications for CVVHDF included anuria and profound metabolic acidosis, either in combination (n=51) or alone (n=17 and n=22). The most common sources of sepsis were pneumonia (n=42), urinary tract infection (n=13), multiple site infection (n=11), and abdomen (n=11). At MICU admission, blood cultures were positive in 34 patients (21 with gram-positive bacteria), urine cultures in 21 patients (12 with gram-negative bacteria), and tracheal aspirate/bronchoalveolar lavage in 39 patients (26 with gram-negative bacteria). Among the patients, 10 had a concurrent viral infection, six had candidiasis, and three had aspergillosis. Logistic regression identified an association between poor outcome and SAPS II at MICU admission (OR=1.07; 95%CI: 1.03-1.12), albumin (OR=0.89; 95%CI: 0.81-5.63), and vasopressor therapy (OR= 8.36; 95%CI: 1.51-46.33) at CRRT initiation. Conclusion Patients with S-AKI requiring CRRT represent a particularly vulnerable subgroup with a high risk of poor outcomes, especially when presenting with septic shock. In this single-center, low-resource MICU study, independent predictors of mortality were a high SAPS II score at MICU admission, as well as vasopressor requirement and hypoalbuminemia at CRRT initiation.