Clinical Characteristics and In-Hospital Outcomes of Critically Ill Patients Receiving Hemodialysis or Continuous Venovenous Hemodiafiltration in the Emergency Department

Emergency renal replacement therapy may be required in critically ill patients with life-threatening conditions such as severe hyperkalemia, refractory metabolic acidosis, fluid overload or pulmonary edema, uremic complications, acute kidney injury, acute deterioration in patients with chronic kidney disease, sepsis-associated renal dysfunction, cardiorenal syndrome, or selected intoxications. In routine clinical practice, these patients are generally managed in intensive care settings. However, when intensive care capacity is limited or transfer to the hospital dialysis unit is not clinically feasible, renal replacement therapy may need to be initiated and continued in an emergency department critical care area.

This single-center, retrospective, observational, descriptive-analytical study will review the medical records of critically ill adult patients who received hemodialysis (HD) or continuous venovenous hemodiafiltration (CVVHDF) in the Emergency Department of Antalya Training and Research Hospital between January 1, 2023, and August 1, 2026. Data will be obtained from the hospital information management system, electronic medical records, laboratory records, clinical follow-up notes, renal replacement therapy records, and discharge summaries.

The study will characterize the clinical profile of patients requiring emergency renal replacement therapy and examine treatment indications, treatment modality, treatment course, pre- and post-treatment laboratory findings, treatment-related complications, and in-hospital clinical outcomes. Renal replacement therapy indications will be evaluated under predefined clinical categories, and patients with more than one indication may be classified in more than one category. Laboratory changes, particularly in potassium, pH, bicarbonate, urea, creatinine, and lactate, will be assessed using available routine clinical measurements before and after treatment.

The study is intended to provide descriptive and exploratory evidence regarding the use of HD and CVVHDF in critically ill patients managed in the emergency department and to contribute to the evaluation of emergency critical care processes in settings where intensive care capacity may be limited. No study-specific intervention will be performed, and all analyses will be based exclusively on routinely collected retrospective clinical data.

Inclusion criteria

• Age 18 years or older.
• Followed in the critical care area of the Emergency Department of Antalya
• Training and Research Hospital between January 1, 2023, and August 1, 2026.
• Presence of an indication for emergency renal replacement therapy.
• Underwent hemodialysis (HD) or continuous venovenous hemodiafiltration (CVVHDF) in the emergency department.
• Required critical care-level monitoring or management.
• Availability of sufficient demographic, clinical, laboratory, and in-hospital outcome data in the hospital information system, electronic medical records, laboratory records, or clinical follow-up notes.

Exclusion criteria

• Age younger than 18 years.
• Renal replacement therapy initiated outside the emergency department.
• Presentation only for routine chronic hemodialysis at the hospital dialysis unit without receiving renal replacement therapy in the emergency department.
• Renal replacement therapy planned in the emergency department but HD or CVVHDF could not be performed.
• Missing essential clinical, laboratory, or in-hospital outcome data. In patients with repeated emergency department admissions, only the first emergency renal replacement therapy episode will be included to reduce statistical dependency.