A proposed algorithm for initiation of renal replacement therapy in adult critically ill patients

Abstract

Critically ill patients whose course is complicated by acute kidney injury often receive renal replacement therapy (RRT). For these patients, initiation of RRT results in a considerable escalation in both the complexity and associated cost of care. While RRT is extensively used in clinical practice, there remains uncertainty about the ideal circumstances of when to initiate RRT and for what indications. The process of deciding when to initiate RRT in critically ill patients is complex and is influenced by numerous factors, including patient-specific and clinician-specific factors and those related to local organizational/logistical issues. Studies have shown marked variation between clinicians, and across institutions and countries. As a consequence, analysis of ideal circumstances under which to initiate RRT is challenging. Recognizing this limitation, we review the available data and propose a clinical algorithm to aid in the decision for RRT initiation in critically ill adult patients. The algorithm incorporates several patient-specific factors, based on evidence when available, that may decisively influence when to initiate RRT. The objective of this algorithm is to provide a starting point to guide clinicians on when to initiate RRT in critically ill adult patients. In addition, the proposed algorithm is intended to provide a foundation for prospective evaluation and the development of a broad consensus on when to initiate RRT in critically ill patients.

Timing of RRT Based on the Presence of Conventional Indications

“…Clinical practice has traditionally been predicated on starting RRT only when a life-threatening complication of AKI arises (1,8). These indications include severe metabolic acidosis, refractory hyperkalemia, and fluid overload with pulmonary edema unresponsive to other forms of treatment (1,8,9).…”

The Outcomes of Critically Ill Patients with Combined Severe Acute Liver and Kidney Injury Secondary to Paracetamol Toxicity Requiring Renal Replacement Therapy

“…The optimum time to commence RRT in critically ill patients is yet to be clearly defined. 13 Our findings may simply represent a type II statistical error owing to the sample size as there was a lower mortality in those patients receiving RRT earlier although it did not reach statistical significance. An alternative explanation may be that worse kidney function prompts earlier critical care involvement with timely resuscitation and specialist input thus improving the outlook for these patients.…”

Sepsis and cardiorenal syndrome: Etiopathogenesis, diagnosis and treatment

“…Prior to making a decision to initiate RRT treatment in patients with mild or moderate renal injury, the treatment objectives, primary diagnosis, severity of the patient's clinical condition, renal functional reserve and the need to prevent development of complications should be taken into account. In patients with sepsis (high catabolism), there is a potential benefit of early initiation of dialysis treatment [40]. When making the decision to start dialysis treatment with supportive therapy, clinical conditions that adversely affect renal function in ICU patients, such as increased intra-abdominal pressure, mechanical positive pressure ventilation and use of nephrotoxins and radiocontrast agents, should be considered [40].…”

“…In patients with sepsis (high catabolism), there is a potential benefit of early initiation of dialysis treatment [40]. When making the decision to start dialysis treatment with supportive therapy, clinical conditions that adversely affect renal function in ICU patients, such as increased intra-abdominal pressure, mechanical positive pressure ventilation and use of nephrotoxins and radiocontrast agents, should be considered [40].…”

“…Absolute indications for initiation of dialysis treatment include: serum urea concentration ≥ 36 mmol/L, complications of uraemia (uremic encephalopathy, uremic pericarditis), resistant hyperkalaemia (K + > 6.5 mmol/L with or without electrocardiographic changes), hypermagnesaemia (Mg 2+ ≥ 4.0 mmol/L and absence of deep tendon reflexes), severe metabolic acidosis (arterial blood pH ≤ 7.15) and volume overload (pulmonary oedema) resistant to diuretics in the presence of oligoanuric AKI [40]. In patients with severe AKI (RIFLE-F or AKIN III), initiation of dialysis supportive therapy is to be considered, and increased monitoring and treatment is recommended in those with mild/moderate AKI (RIFLE-R or I, AKIN I or II).…”