A Clinical Review of Continuous Renal Replacement Therapy: Modalities, Indications, and Management in Critical Care

Elmukhtar Habas¹, Ala Habas², Amnna Rayani³, Khaled Alarabi⁴

Author Affiliation

1 Professor, Senior Consultant, Hamad Medical Corporation, Hamad General Hospital, Doha, Qatar
2 Medicine Resident, TCH, University of Tripoli, Tripoli, Libya
3 Professor, Senior Consultant, University of Tripoli, Tripoli, Libya
4 Associate Consultant, Hamad Medical Corporation, Hamad General Hospital, Doha, Qatar

Abstract

Continuous renal replacement therapy (CRRT) is a cornerstone of contemporary intensive care for patients experiencing severe acute kidney injury (AKI), especially in cases involving hemodynamic instability or multiorgan dysfunction. In contrast to intermittent modalities, CRRT facilitates gradual and continuous removal of solutes and fluids, thereby enhancing hemodynamic stability and enabling precise metabolic regulation. This review synthesizes existing evidence and practice, outlining the pathophysiology of AKI in critical illness and the technical specifications of core CRRT modalities: Continuous Venovenous Hemofiltration (CVVH), Continuous Venovenous Hemodialysis (CVVHD), and Continuous Venovenous Hemodiafiltration (CVVHDF). It analyzes the evidence-based indications and optimal timing for initiation, highlighting the shift from early empirical use to a strategy guided by specific clinical criteria. The review delineates fundamental operational principles, encompassing dosing (20–25 mL/kg/h effluent), fluid management, and the pivotal function of regional citrate anticoagulation. The prevention and management of complications, particularly electrolyte disturbances such as hypophosphatemia, nutrient depletion, and altered drug pharmacokinetics, is a primary focus. The analysis focuses on key controversies surrounding the application of CRRT for blood purification in sepsis. This discussion situates CRRT within the wider framework of organ support, emphasizing future advancements in personalized medicine, integrated sorbent technologies, and wearable devices. This review outlines a framework for clinicians to enhance CRRT delivery and improve outcomes for critically ill patients, while recognizing the limitations in the evidence base and global accessibility.

DOI: 10.63475/yjm.v4i3.0259

Keywords: Continuous renal replacement therapy (CRRT), acute kidney injury (AKI), critical care, hemodiafiltration, regional citrate anticoagulation, drug dosing, metabolic complications

Pages: 492-506

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DOI URL: https://doi.org/10.63475/yjm.v4i3.0259

Publish Date: 31-12-2025

Full Text

Continuous renal replacement therapy (CRRT) represents a cornerstone of modern intensive care for patients with severe acute kidney injury (AKI). Unlike intermittent modalities, CRRT provides gradual, continuous, and physiologically gentle clearance of solutes and fluids. Its capacity for precise volume control while maintaining hemodynamic stability makes it the preferred modality for critically ill patients with hemodynamic instability, multiorgan dysfunction, or refractory circulatory shock. [1] The clinical necessity for this therapy is underscored by the immense global burden of AKI, a syndrome affecting approximately 13.3 million individuals annually and directly contributing to an estimated 1.7 million deaths. [2] This burden exhibits stark regional disparities shaped by variations in healthcare infrastructure and prevalent etiologies.

In Europe, AKI incidence ranges from 10% to 20% in general hospital admissions to over 50% in intensive care unit (ICU) populations, with associated mortality rates of 20% to 50%. [3,4] In the Middle East and North Africa (MENA) region, AKI is often community-acquired, linked to volume depletion, sepsis, and nephrotoxin exposure, with reported ICU mortality ranging from 35% to 60%. [3,4] Research from Asia reveals a comparable burden, with studies from China and India showing AKI occurs in 20% to 30% of ICU patients and is a significant independent predictor of mortality. [3,4] In Africa, epidemiology is characterized by infectious diseases (e.g., malaria, diarrheal illnesses), obstetric complications, and untreated chronic kidney disease, with hospital mortality rates often exceeding 50% due to late presentation and restricted access to renal replacement therapy (RRT).

Within this context of a high global burden and stark inequities in access, CRRT has emerged as a crucial tool for managing severe AKI. However, its utilization mirrors global health inequities. In well-resourced healthcare systems, CRRT may constitute over 70% of all RRT initiated in the ICU for hemodynamically unstable patients. [5] were on chronic dialysis, or had kidney transplant or if their length of hospital stay was <24 hrs. Interventions: None. Measurements and main results: We included 20,126 patients. Mean age was 64 yrs, 14.7% of patients required intensive care unit admission, and hospital mortality was 8.0%. According to the RIFLE criteria, 9.1% of all patients were in the Risk category for acute renal failure, 5.2% were in the Injury category, and 3.7% were in the Failure category. There was an almost linear increase in hospital mortality from Normal to Failure (Normal, 4.4%; Risk, 15.1%; Injury, 29.2%; and Failure, 41.1% Its application remains constrained across much of Asia, Africa, and the MENA region by substantial barriers, including cost, technical complexity, and a scarcity of trained personnel. [2–4]

This review synthesizes evidence identified through a targeted literature search conducted in December 2025. The highest priority was assigned to evidence from large, multicenter randomized controlled trials (RCTs) and individual patient data meta-analyses (e.g., STARRT-AKI, RENAL, and ATN trials). Where high-level RCT evidence was absent or inconclusive, findings from well-designed prospective observational cohorts, registry studies, and international consensus guidelines from expert societies (e.g., Kidney Disease: Improving Global Outcomes [KDIGO], Acute Disease Quality Initiative [ADQI], and European Society for Clinical Nutrition and Metabolism [ESPEN]) were incorporated. For technical and mechanistic details, pivotal physiological studies and manufacturer data were also considered.

To capture developments following pivotal trials (e.g., 2018–2025), the search focused primarily on publications from January 1, 2020, to December 30, 2025. Searches were performed in the biomedical databases PubMed/MEDLINE, Scopus, and the Cochrane Central Register of Controlled Trials (CENTRAL). A structured search strategy employed a combination of Medical Subject Headings (MeSH) and relevant keywords, including: “Renal Replacement Therapy” [MeSH] OR “Continuous Renal Replacement Therapy” OR CRRT OR CVVH OR CVVHD OR CVVHDF AND (“Acute Kidney Injury” [Mesh] OR “Acute Renal Failure”) AND (modalities OR indication OR prescription OR anticoagulation OR citrate OR heparin OR dosing OR complication OR outcome).

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