Dialysis indication
Reading File
Finding Sources
Searching PubMed
"dialysis" AND "indications" AND "acute kidney injury"
Reading File
Reading File
Reading File
Here is a comprehensive overview of dialysis indications, organized by clinical context:
Indications for Dialysis
The "AEIOU" Mnemonic (Emergency/Urgent Indications)
The classic emergency indications are remembered as AEIOU:
| Letter | Indication |
|---|---|
| A | Acidosis — Severe metabolic acidosis (pH < 7.2) refractory to treatment, especially with AKI |
| E | Electrolytes — Uncontrolled hyperkalemia (K⁺ > 6.5 mEq/L or rapidly rising); also severe hypo/hypernatremia (Na⁺ < 115 or > 165 mEq/L), hypermagnesemia, hypercalcemia |
| I | Intoxication — Life-threatening poisoning with a dialyzable substance |
| O | Overload (fluid) — Refractory pulmonary edema/fluid overload unresponsive to diuretics |
| U | Uremia — Symptomatic uremia (pericarditis, encephalopathy, bleeding, nausea/vomiting) |
1. Acute Dialysis Indications (AKI Setting)
These are urgent or emergent indications regardless of absolute BUN/creatinine values:
- Uremic pericarditis — urgent indication even without cardiac tamponade
- Uremic encephalopathy — progressive encephalopathy, asterixis, seizures
- Uremic bleeding dyscrasia — bleeding attributable to uremia
- Refractory hyperkalemia — K⁺ > 6.5 mEq/L or rising despite medical management; hemodialysis preferred over peritoneal dialysis for speed
- Refractory pulmonary edema / fluid overload — with hypoxia, unresponsive to diuretics
- Severe metabolic acidosis — especially if volume overload or hypocalcemia precludes bicarbonate administration
- Severe electrolyte disturbances — symptomatic hypermagnesemia, severe hypo/hypernatremia
- Dialyzable toxin/drug ingestion — methanol, ethylene glycol, salicylates, lithium, isopropanol (particularly urgent if kidneys cannot excrete the agent)
- Uncontrolled hypertension — refractory to antihypertensive medication
2. Chronic Dialysis Indications (ESRD/CKD Stage 5)
Initiation of maintenance dialysis is based on symptoms and complications, not absolute lab values alone:
- Uremic encephalopathy or neuropathy
- Pericarditis or pleuritis attributable to uremia
- Uremic bleeding
- Fluid overload refractory to diuretics
- Hypertension poorly controlled on medications
- Persistent electrolyte/acid-base disturbances — hyperkalemia, metabolic acidosis, hyperphosphatemia, hypocalcemia refractory to medical therapy
- Malnutrition or weight loss attributable to uremia
- Persistent nausea and vomiting
Note on GFR thresholds: Dialysis is typically initiated when GFR falls to approximately 5–10 mL/min/1.73 m² in symptomatic patients. Serum creatinine (~10 mg/dL) and BUN (~100 mg/dL) are used as rough guidelines only — neither level alone is a definitive indication, as neither correlates reliably with uremic symptoms.
3. Dialyzable Toxins/Overdoses
| Agent | Notes |
|---|---|
| Methanol | Urgent — toxic metabolites cause blindness |
| Ethylene glycol | Urgent — causes oxalate nephropathy |
| Salicylates (aspirin) | When severe toxicity present |
| Lithium | Especially with neurological toxicity |
| Isopropanol |
4. Dialysis Adequacy (Maintenance Hemodialysis)
Once on dialysis, adequacy is monitored by:
- Kt/V ≥ 1.2 (single-pool urea clearance, thrice-weekly schedule) — minimum target
- URR (urea reduction ratio) ≥ 65%
- Increasing to 6×/week (nocturnal home HD) improves BP, LVH regression, and phosphorus but not short-term mortality
Key Clinical Pearls
- BUN/creatinine alone do not mandate dialysis — uremic symptoms and complications drive the decision
- Pericarditis in a previously undialyzed progressive CKD patient = time to initiate dialysis (not necessarily emergency, but urgent)
- For hemodynamically unstable patients, continuous venovenous hemofiltration (CVVH) is preferred over intermittent HD, though no survival advantage has been demonstrated in RCTs
- Early vs. late initiation in AKI: current evidence does not support early initiation of RRT to improve survival or renal recovery; ultrafiltration for fluid overload should be reserved for those refractory to diuretics
Sources: Goldman-Cecil Medicine, 26e (Table 117-1); Rosen's Emergency Medicine, 9e (Box 83.9); Tintinalli's Emergency Medicine, 9e (Table 88-7)
This is a shared conversation. Sign in to Orris to start your own chat.