How to manage hypotension in a patient during hemodialysis?

Management of Hypotension During Hemodialysis

The most effective approach to managing intradialytic hypotension involves immediate interventions to stabilize the patient, followed by systematic modification of the dialysis prescription to prevent recurrence, with ultrafiltration rate control being the single most critical factor. 1

Acute Management During Hypotensive Episode

When hypotension occurs during dialysis, implement these immediate interventions:

• Stop or reduce ultrafiltration immediately to prevent further blood pressure decline and allow vascular refilling 2, 1
• Place the patient in Trendelenburg position (head down, legs elevated) to improve venous return and increase blood pressure 2, 1, 3
• Administer supplemental oxygen to improve tissue oxygenation and reduce symptoms 2, 1, 3
• Give intravenous normal saline bolus (typically 100-250 mL) to rapidly expand plasma volume, though avoid routine saline administration for every episode as this perpetuates volume overload 2, 1

Dialysis Prescription Modifications to Prevent Recurrence

The following modifications address the underlying causes of recurrent hypotension:

Ultrafiltration Rate Management

• Keep ultrafiltration rates below 6 mL/h/kg as rates exceeding this threshold are associated with higher mortality risk and increased hypotension 1
• Extend treatment time to minimum 4 hours per session to slow the ultrafiltration rate and allow adequate vascular refilling 2, 1
• Increase dialysis frequency from twice to three times weekly when patients have excessive interdialytic weight gain requiring aggressive ultrafiltration that exceeds vascular refilling capacity 2, 1

Dry Weight Reassessment

• Reassess the estimated dry weight if hypotension is recurrent, as the target may be set too low—a common pitfall is underestimating true dry weight in patients with residual urine output 2, 1

Dialysate Modifications

These adjustments improve hemodynamic stability during dialysis:

• Increase dialysate sodium concentration to 148 mEq/L, especially early in the dialysis session, or implement sodium profiling (starting higher and gradually decreasing) to maintain vascular stability 2, 1, 3
• Reduce dialysate temperature from 37°C to 34-35°C to increase peripheral vasoconstriction and cardiac output through increased sympathetic tone, which decreases symptomatic hypotension from 44% to 34% 2, 1, 3
• Switch from acetate-containing to bicarbonate-containing dialysate to prevent inappropriate decreases in total vascular resistance and venous pooling 2, 1, 3

Important caveat: Increased dialysate sodium may lead to increased thirst, interdialytic weight gain, and hypertension 2, 1, while reduced dialysate temperature may cause uncomfortable hypothermia in some patients 2

Pharmacological Management

Midodrine (Primary Agent)

• Administer midodrine (oral α1-adrenergic agonist) 30 minutes before dialysis initiation at a mean dose of 8 mg (range 2.5-25 mg) to increase peripheral vascular resistance and enhance venous return 2, 1, 3, 4
• Midodrine significantly increases mean minimal systolic pressure from 93.1 to 107.1 mmHg during hemodialysis 4

Medication Review

• Review and reduce antihypertensive medications, particularly when patients are on four or more concurrent agents, as these prevent compensatory vasoconstriction during ultrafiltration 1
• Consider adjusting beta-blockers like carvedilol, which blunt compensatory tachycardia and cardiac output increases needed during volume removal 1
• Administer antihypertensive drugs preferentially at night to reduce the nocturnal surge of blood pressure and minimize intradialytic hypotension when drugs are taken the morning before a dialysis session 5

Long-Term Prevention Strategies

Fluid and Sodium Management

• Limit sodium intake to <5.8 g/day (2-3 g/day sodium) to reduce thirst and interdialytic weight gain, as water intake adjusts to match salt intake 5, 1
• Restrict interdialytic weight gain to <3% of body weight between sessions to prevent excessive ultrafiltration requirements 1
• Provide education and regular counseling by dietitians every 3 months 5

Dietary Modifications

• Avoid food intake immediately before or during hemodialysis, as this causes decreased peripheral vascular resistance and may precipitate hypotension 2, 1, 3

Anemia Management

• Maintain hemoglobin at 11 g/dL per NKF-K/DOQI guidelines to improve oxygen-carrying capacity and cardiovascular compensation during ultrafiltration 2, 1, 3

Critical Pitfalls to Avoid

• Do not continue twice-weekly dialysis in patients with recurrent hypotension, as this forces dangerously high ultrafiltration rates and inadequate solute clearance 1
• Do not routinely administer saline for every hypotensive episode, as this perpetuates volume overload and fails to address the underlying problem 1
• Do not assume hypotension defines intravascular volume status—reevaluate the estimated dry weight if patients show signs of improving nutrition (increasing serum albumin, creatinine, or normalized protein catabolic rate) alongside hypotension 1

Special Considerations

Pathophysiology

Hypotension during dialysis results from an impairment of arteriolar tone and left ventricular function, not simply from an inability to maintain blood volume or decreased cardiac filling 6. The dialysis procedure itself appears to impair both vascular tone and left ventricular function 6.

Rare Causes

Consider secondary adrenal insufficiency in patients with persistent hypotension despite standard interventions, particularly if accompanied by hypoglycemia 7