Can dialysis be used in an adult patient with acute kidney injury?

Can Dialysis Be Used in AKI Patients?

Yes, dialysis (renal replacement therapy/RRT) is absolutely indicated and should be used in patients with acute kidney injury when specific clinical criteria are met, particularly life-threatening complications or when metabolic and fluid demands exceed kidney capacity.

When to Initiate Dialysis in AKI

Emergency/Absolute Indications

The 2020 KDIGO guidelines recommend initiating RRT emergently in the presence of life-threatening changes 1:

• Severe hyperkalemia with cardiac manifestations
• Refractory fluid overload causing pulmonary edema or hemodynamic compromise
• Severe metabolic acidosis unresponsive to medical management
• Life-threatening electrolyte disturbances
• Uremic complications (pericarditis, encephalopathy, bleeding)

Clinical Decision Framework

Rather than relying on arbitrary numerical cutoffs (like BUN >75 mg/dL), initiate RRT when metabolic and fluid demands exceed the kidney's capacity to meet them 1. This requires:

• Regular reassessment of the patient's evolving clinical status
• Evaluation of the trajectory of kidney injury (worsening vs. stabilizing)
• Assessment of volume status, electrolytes, and acid-base balance
• Consideration of the patient's overall prognosis and clinical context

Important caveat: Existing evidence does not support using biomarkers alone when deciding whether to initiate RRT 1. The decision remains primarily clinical.

Choosing the Dialysis Modality

Hemodynamically Unstable Patients

In hemodynamically unstable patients, continuous RRT is more physiologically appropriate than intermittent hemodialysis 1. Key considerations:

• Continuous RRT provides better hemodynamic stability
• Lower risk of intracranial pressure changes (important in neurocritical patients)
• However, RCTs have not demonstrated mortality benefit over intermittent hemodialysis
• Both modalities can lead to intracranial pressure changes, but risk is higher with intermittent RRT

Hemodynamically Stable Patients

Either intermittent hemodialysis or continuous RRT can be used based on:

• Local expertise and resources
• Patient-specific factors
• Availability of equipment and trained personnel

Peritoneal Dialysis Option

Peritoneal dialysis should be considered a suitable modality for AKI treatment in all settings 2. Recent evidence shows:

• Comparable mortality to extracorporeal dialysis (OR 1.05,95% CI 0.62-1.76) 3
• Similar kidney function recovery rates 3
• Faster time to kidney recovery (3.34 days shorter) 3
• Equivalent infection rates 3
• Particularly advantageous in cardiorenal syndrome, hepatorenal syndrome, and patients on vasopressors 4

Dialysis Prescription Specifics

For Intermittent/Extended RRT

• Deliver Kt/V of at least 1.2 per treatment, 3 times weekly 1

For Continuous RRT

• Deliver effluent volume of 20-25 ml/kg/h 1
• May require higher prescription to achieve target dose

For Peritoneal Dialysis

• Target weekly Kt/Vurea of 2.2 (equivalent to higher doses) 2
• Use short cycle times (1-2 hours) initially for rapid correction of uremia, hyperkalemia, or fluid overload
• Increase to 4-6 hourly cycles once stabilized 2

Vascular Access

Use an uncuffed non-tunneled dialysis catheter of appropriate length and gauge to initiate RRT 1:

Preferred insertion sites (in order):

1. Right internal jugular vein (first choice)
2. Femoral vein (first choice, but inferior in obese patients)
3. Left internal jugular vein
4. Subclavian vein (last choice due to stenosis risk)

For patients with expected prolonged RRT need, consider a cuffed catheter 1.

Anticoagulation

Use regional citrate anticoagulation for continuous RRT in patients without contraindications 1. This recommendation from 2012 KDIGO remains supported by current evidence.

When to Discontinue Dialysis

Discontinue RRT when 1:

• Kidney function has recovered sufficiently
• RRT becomes inconsistent with shared care goals
• Patient is passing >1 L urine/24 hours with spontaneous creatinine reduction 2

For ICU patients on continuous RRT, consider transitioning to intermittent hemodialysis when 1:

• Vasopressor support has been stopped
• Intracranial hypertension has resolved
• Positive fluid balance can be controlled by intermittent hemodialysis

Common Pitfalls to Avoid

1. Don't delay dialysis waiting for arbitrary BUN thresholds—use clinical judgment based on the patient's trajectory 5
2. Don't use diuretics to prevent or treat AKI except for volume overload management 6
3. Don't use low-dose dopamine, fenoldopam, or ANP to prevent or treat AKI 6
4. Don't rely solely on biomarkers for timing decisions 1
5. Don't assume dialysis dependency is permanent—up to 31% of patients requiring dialysis at discharge may recover kidney function, with average recovery time of 93 days 7

Prognosis and Recovery

Patients with AKI requiring dialysis should be closely monitored after discharge, as renal recovery can occur even in patients with advanced CKD at baseline or those requiring dialysis for >3 months 7. Vasopressor use during hospitalization is an independent predictor of renal recovery (OR 16.2) 7.