How to manage hypotension during dialysis?

Managing Hypotension During Dialysis to Complete Treatment

For acute hypotension during dialysis, immediately reduce or stop ultrafiltration, place the patient in Trendelenburg position, and administer a normal saline bolus—these interventions allow most patients to complete their dialysis session. 1

Immediate Interventions for Active Hypotension

When blood pressure drops during dialysis, implement these steps sequentially:

• Reduce or temporarily stop ultrafiltration to prevent further blood pressure decline while maintaining the patient on dialysis 1
• Place the patient in Trendelenburg position (head down, legs elevated) to improve venous return and cardiac output 1
• Administer intravenous normal saline bolus (typically 100-250 mL) to rapidly expand plasma volume 1, 2
• Provide supplemental oxygen to improve tissue oxygenation and reduce hypotensive symptoms 1

Normal saline is the fluid of choice for treating intradialytic hypotension—a randomized controlled trial in 72 patients demonstrated that 5% albumin offers no advantage over normal saline for restoring blood pressure, achieving target ultrafiltration, or reducing treatment failures. 2, 3 Given albumin's significantly higher cost and equivalent efficacy, saline should be first-line therapy. 3

Dialysate Modifications to Prevent Hypotension

Adjust the dialysate composition to maintain vascular stability:

• Increase dialysate sodium concentration to 148 mEq/L, particularly early in the session, to prevent rapid osmotic shifts 1
• Implement sodium profiling by starting with higher sodium concentration and gradually decreasing it throughout treatment to maintain plasma refill 1
• Switch to bicarbonate-containing dialysate instead of acetate-based solutions, as acetate causes inappropriate decreases in total vascular resistance 1
• Reduce dialysate temperature from 37°C to 34-35°C to increase peripheral vasoconstriction and cardiac output through enhanced sympathetic tone 4, 1

The cooler dialysate reduces symptomatic hypotension from 44% to 34% of sessions, with greatest benefit in patients experiencing frequent hypotensive episodes. 4 However, monitor for uncomfortable hypothermia in some patients. 1

Pharmacological Prevention with Midodrine

Administer midodrine 30 minutes before dialysis initiation for patients with recurrent intradialytic hypotension. 4, 1, 5

• Midodrine is a selective α1-adrenergic agonist that increases peripheral vascular resistance through arteriolar vasoconstriction and enhances venous return through venular constriction 4
• Typical dosing ranges from 2.5-25 mg (mean 8 mg), titrated to effect 5
• In a study of 21 patients with severe hemodialysis hypotension, midodrine significantly increased mean minimal systolic pressure from 93 to 107 mmHg during dialysis 5
• The drug is well-tolerated with few side effects and provides hemodynamic benefits comparable to hypothermic dialysis 4

Ultrafiltration Rate Adjustments

Modify the ultrafiltration strategy to allow treatment completion:

• Slow the ultrafiltration rate by extending treatment time when possible—longer dialysis sessions (5 hours versus 4 hours) cause significantly less intradialytic and postdialysis hypotension 4, 1
• Reevaluate the estimated dry weight, as recurrent hypotension may indicate it is set too low 1
• Consider adding isolated ultrafiltration periods to the standard treatment regimen for patients with excessive interdialytic weight gain 4

Prevention Strategies for Recurrent Episodes

Address underlying factors contributing to hypotension:

• Limit dietary sodium to 100 mmol/day and restrict fluid intake between sessions to reduce interdialytic weight gain and ultrafiltration requirements 4, 1
• Avoid food intake immediately before or during dialysis, as eating causes decreased peripheral vascular resistance that precipitates hypotension 4, 1
• Raise hemoglobin to 11 g/dL through appropriate anemia management to improve oxygen-carrying capacity 4, 1
• Review antihypertensive medications and adjust timing or dosing, as these may contribute to intradialytic hypotension—though evidence on this relationship is contradictory 4, 1

Critical Caveats

Higher dialysate sodium concentrations increase thirst and interdialytic weight gain, potentially creating a cycle of larger ultrafiltration requirements and worsening hypotension. 1 Monitor weight gains closely when implementing this strategy.

Reduced dialysate temperature may cause intolerable symptomatic hypothermia in some patients, limiting its use despite hemodynamic benefits. 4, 1

Engage patients in understanding their role—the hemodialysis care team must educate patients about adhering to fluid restrictions and the complete prescribed dialysis session, as patient behavior significantly influences hypotension frequency. 4