What are the steps to manage hypotension with a blood pressure reading of 99/57 mmHg during dialysis?

Management of Intradialytic Hypotension (BP 99/57 on Norepinephrine 1 mcg/kg/min)

Immediately reduce the ultrafiltration rate or temporarily stop ultrafiltration, place the patient in Trendelenburg position, and administer a 100-250 mL normal saline bolus while reassessing the target dry weight, as this patient is likely below their true dry weight given they require vasopressor support during dialysis. 1, 2

Immediate Interventions During This Dialysis Session

First-Line Actions

• Stop or reduce ultrafiltration immediately to prevent further intravascular volume depletion, as ultrafiltration is the primary driver of intradialytic hypotension 1, 3
• Place the patient in Trendelenburg position to improve venous return and cerebral perfusion 3
• Administer 100-250 mL normal saline bolus to restore intravascular volume 1, 3
• Maintain MAP ≥65 mmHg during the dialysis session to ensure adequate tissue perfusion and prevent end-organ ischemia (heart, brain, gut, kidneys) 4, 5

Critical Assessment

• The fact that this patient requires norepinephrine 1 mcg/kg/min AND still has low blood pressure (99/57) during dialysis strongly suggests the target dry weight is set too low 2, 5
• Review for signs that estimated dry weight is inappropriately low: improving nutritional status with rising albumin/creatinine, recurrent symptomatic hypotension, or paradoxically increased interdialytic weight gains 2, 1

Modifications for Subsequent Dialysis Sessions

Target Weight Reassessment (Most Critical)

• Increase the target dry weight by 0.5-1.0 kg as the primary intervention, since this patient cannot tolerate current ultrafiltration goals even with vasopressor support 5, 2
• Target weight should vary treatment-to-treatment based on clinical status; maintaining slightly above estimated dry weight may be appropriate in acute illness 5
• A target weight that is too low leads to hypotension and faster loss of residual kidney function 5

Ultrafiltration Rate Modifications

• Limit ultrafiltration rate to <6 mL/h/kg to reduce mortality risk and prevent end-organ ischemia 1, 5
• Extend dialysis treatment time to >4 hours to allow slower ultrafiltration rates and better hemodynamic stability 1, 2
• Consider increasing treatment frequency to >3 times per week to reduce per-session ultrafiltration requirements 2

Dialysate Modifications

• Reduce dialysate temperature to 35-36°C (instead of standard 37°C) to increase peripheral vasoconstriction and reduce hypotensive episodes 1, 2
• Consider sodium profiling by increasing dialysate sodium concentration early in the session (around 145 mmol/L), followed by stepwise decrease later in treatment 1
  • Caveat: Sodium profiling may increase interdialytic weight gain and thirst, creating a vicious cycle 1
• Use bicarbonate-containing dialysate instead of acetate-containing dialysate to minimize hypotension 1

Medication Management

Antihypertensive Medication Review

• Immediately review and likely discontinue or reduce all antihypertensive medications, as this patient is hypotensive and requiring vasopressor support 2, 1
• If the patient is taking antihypertensives before dialysis, these are likely contributing significantly to intradialytic hypotension 2
• Consider dialyzability of current medications (e.g., metoprolol is highly dialyzable and may cause rebound effects) 2

Midodrine for Intradialytic Hypotension

• Administer midodrine 5-10 mg orally 30 minutes before hemodialysis to increase peripheral vascular resistance and enhance venous return 1, 6, 7
• Midodrine increases standing systolic blood pressure by approximately 15-30 mmHg at 1 hour after dosing, with effects persisting 2-3 hours 6
• In a study of 21 patients with severe hemodialysis hypotension, midodrine (mean dose 8 mg) significantly increased minimal systolic pressure from 93.1 to 107.1 mmHg during hemodialysis 7
• Important: Midodrine is removed by dialysis, so timing 30 minutes pre-dialysis is critical 6

Additional Strategies

Dietary and Fluid Management

• Counsel patient to avoid eating during or immediately before dialysis, as food intake causes splanchnic vasodilation and worsens hypotension 1, 2
• Maintain sodium intake at 2-3 g/day with regular dietitian counseling 2
• Limit interdialytic weight gain to <3 kg between sessions 2

Monitoring Considerations

• The current norepinephrine requirement of 1 mcg/kg/min during dialysis is highly unusual and suggests either severe volume depletion from inappropriate dry weight OR an unexpected cause of hypotension that needs investigation 8
• Consider whether this is chronic hypotension (systolic <100 mmHg interdialytically), which affects 5-10% of hemodialysis patients and is characterized by reduced peripheral vascular resistance 9

Common Pitfalls to Avoid

• Do not continue aggressive ultrafiltration in a hypotensive patient requiring vasopressors - this will cause end-organ ischemia and increase mortality risk 5, 1
• Do not rely solely on predialysis blood pressure measurements - home blood pressure monitoring provides more accurate assessment 4, 2
• Recognize that both very low (<110 mmHg systolic) and very high blood pressure are associated with increased mortality in dialysis patients; target predialysis systolic BP of 110-140 mmHg for most patients 2
• Avoid the assumption that all hypotension requires more aggressive ultrafiltration - paradoxically, excessive ultrafiltration may be causing the hypotension 5, 2