What are the emergency indications for dialysis in patients with chronic kidney disease (CKD) and what are the potential complications during hemodialysis and their management?

Emergency Indications for Dialysis in CKD

Dialysis should be initiated emergently when life-threatening complications of kidney failure are present, specifically: refractory hyperkalemia, severe metabolic acidosis, uremic pericarditis, uremic encephalopathy, severe volume overload unresponsive to diuretics, or intractable uremic symptoms causing significant clinical deterioration. 1

Absolute Emergency Indications (Initiate Dialysis Immediately)

Life-Threatening Metabolic Derangements

• Hyperkalemia with ECG changes (peaked T waves, widened QRS, sine wave pattern) or serum potassium >6.5-7.0 mEq/L refractory to medical management (calcium gluconate, insulin/glucose, salbutamol, sodium bicarbonate, and ion exchange resins) 2
• Severe metabolic acidosis with pH <7.1 or bicarbonate <10 mEq/L causing hemodynamic instability or altered mental status 2

Uremic Complications

• Uremic pericarditis with or without pericardial effusion—this is an absolute indication regardless of GFR level 1
• Uremic encephalopathy manifesting as confusion, asterixis, seizures, or altered consciousness 1
• Uremic bleeding (platelet dysfunction) causing clinically significant hemorrhage 1

Volume Overload

• Refractory pulmonary edema with respiratory distress despite maximal diuretic therapy (combination loop diuretics at high doses with thiazides) 1, 3
• Severe hypertension with end-organ damage (hypertensive encephalopathy, acute heart failure) uncontrolled by medical therapy 1

Urgent Indications (Initiate Within 24-48 Hours)

• Progressive deterioration in nutritional status with protein-energy wasting despite dietary intervention, manifested by >6% involuntary weight loss in <6 months or serum albumin drop ≥0.3 g/dL to <4.0 g/dL 1
• Intractable nausea/vomiting preventing adequate oral intake and causing dehydration 1
• Severe pruritus refractory to medical management 1
• Cognitive impairment attributable to uremia 1

GFR Considerations

While symptoms drive the decision, these complications typically occur when GFR falls to 5-10 mL/min/1.73 m² 1. However, never delay dialysis based solely on GFR if emergency indications are present 1.

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Hemodialysis Complications and Management

Intradialytic Complications

Hypotension (Most Common Complication)

Occurs in 20-30% of treatments; caused by excessive ultrafiltration rate, reduced plasma refill, autonomic dysfunction, or cardiac dysfunction 1

Prevention strategies:

• Lower dialysate temperature to 35-36°C to promote peripheral vasoconstriction 1
• Limit ultrafiltration rate to <10-13 mL/kg/hour to avoid exceeding plasma refill capacity 1
• Increase treatment time to allow slower, gentler fluid removal—prescribe minimum 3 hours per session for patients with residual kidney function <2 mL/min 1
• Avoid eating during dialysis as splanchnic blood pooling exacerbates hypotension 1
• Assess and optimize dry weight through gradual probing rather than aggressive volume removal 4, 3

Acute management:

• Place patient in Trendelenburg position
• Reduce or stop ultrafiltration temporarily
• Administer 100-250 mL normal saline boluses (use cautiously to avoid volume overload)
• Consider midodrine 5-10 mg administered 30-60 minutes pre-dialysis for recurrent episodes 1

Muscle Cramps

Occur in 5-20% of treatments; related to rapid fluid/electrolyte shifts and hypovolemia 1

Management:

• Reduce ultrafiltration rate
• Administer hypertonic saline (23.4% NaCl, 10-20 mL) or 50% dextrose (50 mL)
• Passive stretching of affected muscle groups
• Prevention: Reassess dry weight upward if cramps are recurrent; consider increasing dialysate sodium concentration 1

Nausea and Vomiting

Caused by hypotension, dialysis disequilibrium syndrome (rapid solute shifts), or uremia itself 1

Management:

• Treat underlying hypotension as above
• Administer antiemetics (ondansetron 4-8 mg IV)
• For first few treatments in severely uremic patients (BUN >150 mg/dL), use shorter treatment times (2-2.5 hours) with lower blood flow rates (200-250 mL/min) to prevent disequilibrium syndrome 1

Dialysis Disequilibrium Syndrome

Rare but serious; occurs with rapid urea reduction causing cerebral edema—presents with headache, confusion, seizures 1

Prevention in high-risk patients (first dialysis, severe uremia):

• Limit initial treatment to 2 hours
• Target Kt/V of 0.9-1.0 for first session
• Use lower blood flow rates (200 mL/min)
• Consider prophylactic mannitol (12.5-25 g IV) 1

Vascular Access Complications

Catheter-Related Bloodstream Infections

Occur at 1.1-5.5 episodes per 1000 catheter-days; affect ~50% of patients within 6 months 5

Management:

• Obtain blood cultures from catheter and peripheral vein
• Initiate empiric antibiotics covering gram-positive organisms (vancomycin) and gram-negative organisms (ceftazidime or cefepime)
• Catheter lock therapy with high-concentration antibiotics (vancomycin 5 mg/mL + gentamicin 5 mg/mL) for uncomplicated infections
• Remove catheter if: tunnel infection, septic emboli, endocarditis, persistent bacteremia >72 hours despite antibiotics, or S. aureus bacteremia 5

Arteriovenous Access Thrombosis

Fistula/graft thrombosis prevents dialysis delivery

Immediate management:

• Arrange urgent thrombectomy (surgical or interventional radiology) within 24-48 hours
• Place temporary dialysis catheter if thrombectomy cannot be performed immediately
• Do not attempt to use thrombosed access 1

Cardiovascular Complications

Arrhythmias and Sudden Cardiac Death

CKD patients have 20-fold increased risk; exacerbated by rapid electrolyte shifts during dialysis 6, 5

Prevention:

• Avoid low potassium dialysate (<2 mEq/L) in patients on digoxin or with baseline hypokalemia
• Use bicarbonate-based dialysate rather than acetate to reduce myocardial stunning 1
• Monitor for prolonged QTc interval
• Gradual potassium removal with longer treatment times 6

Intradialytic Hypertension

Paradoxical blood pressure rise during or after dialysis; occurs in 5-15% of patients 4

Management:

• Strict dietary sodium restriction (<2 g/day) to reduce interdialytic weight gain 1, 4
• Reassess dry weight—may indicate volume overload despite weight loss
• Continue antihypertensive medications on dialysis days (contrary to older practice of holding them) 4, 7
• Consider longer or more frequent dialysis sessions 1

Hematologic Complications

Anemia

Target hemoglobin 11-12 g/dL; levels <7 g/dL require urgent intervention 4

Management:

• Iron supplementation: Maintain transferrin saturation ≥20% and ferritin ≥100 ng/mL; administer IV iron (iron sucrose 100 mg or ferric gluconate 125 mg per dialysis session) 4
• Erythropoiesis-stimulating agents (ESAs): Epoetin alfa or darbepoetin; avoid targeting hemoglobin >11.5 g/dL due to increased cardiovascular risk 4
• Transfuse packed RBCs if hemoglobin <7 g/dL with symptoms or active bleeding 4

Bleeding Diathesis

Uremic platelet dysfunction causes prolonged bleeding time despite normal platelet count

Management:

• Desmopressin (DDAVP) 0.3 mcg/kg IV for acute bleeding—effect lasts 4-8 hours
• Conjugated estrogens 0.6 mg/kg/day IV for 5 days for sustained effect (lasts weeks)
• Cryoprecipitate 10 units IV for severe bleeding
• Optimize dialysis adequacy—improved uremic control reduces bleeding risk 1

Metabolic Complications

Hyperphosphatemia and Mineral Bone Disease

Phosphate accumulation leads to secondary hyperparathyroidism, vascular calcification, and bone disease 1, 8

Management:

• Dietary phosphate restriction to 800-1000 mg/day
• Phosphate binders: Calcium-based (calcium acetate 667 mg with meals) or non-calcium-based (sevelamer 800-1600 mg TID with meals, lanthanum carbonate)
• Monitor serum calcium, phosphate, PTH, and vitamin D levels every 1-3 months in stage 5 CKD 1
• Avoid sevelamer if metabolic acidosis present as it worsens acidosis 2

Residual Kidney Function Preservation

Critical priority: RKF provides continuous clearance and strongly correlates with survival 1, 3

Strategies to preserve RKF:

• Avoid intradialytic hypotension through measures listed above—hypotensive episodes accelerate RKF loss 1, 3
• Use biocompatible membranes and ultrapure dialysate 1
• Continue loop diuretics (furosemide 80-240 mg daily) if urine output >100 mL/day to maintain diuresis between sessions 1, 3
• Maintain ACE inhibitors/ARBs when tolerated—may help preserve RKF despite causing up to 30% creatinine increase 1, 7, 3
• Avoid nephrotoxins: NSAIDs, aminoglycosides, IV contrast 1

Critical Pitfalls to Avoid

• Never restart all antihypertensive medications simultaneously post-dialysis—this causes severe hypotension; restart sequentially over days while monitoring blood pressure 7
• Do not use thiazide diuretics when eGFR <30 mL/min—they are ineffective and should be replaced with loop diuretics 7, 2
• Avoid aggressive ultrafiltration rates >13 mL/kg/hour—this exceeds plasma refill capacity and causes hypotension, myocardial stunning, and RKF loss 1
• Never delay emergency dialysis to achieve "optimal" vascular access—place temporary catheter and initiate dialysis immediately for life-threatening indications 1
• Do not hold ACE inhibitors/ARBs for creatinine increases <30% from baseline—this represents acceptable hemodynamic effect, not true AKI 1, 7