What can be given to a patient on dialysis (renal replacement therapy) with bradycardia (abnormally slow heart rate)?

Management of Bradycardia in Dialysis Patients

Atropine 0.5-1 mg IV is the first-line treatment for symptomatic bradycardia in dialysis patients, repeated every 3-5 minutes up to a maximum total dose of 3 mg, followed by dopamine infusion (5-20 mcg/kg/min) or epinephrine (2-10 mcg/min) if atropine fails, with transcutaneous pacing as a critical backup for refractory cases. 1, 2

Initial Assessment and Treatment Algorithm

First-Line: Atropine

• Administer atropine 0.5-1 mg IV immediately for symptomatic bradycardia, avoiding doses <0.5 mg as they may paradoxically worsen bradycardia 1, 2, 3
• Repeat every 3-5 minutes as needed up to a maximum total dose of 3 mg 1, 2
• Atropine works by blocking muscarinic acetylcholine receptors, increasing sinus node automaticity and facilitating sinoatrial conduction with onset of action within 3 minutes 1, 3
• Monitor for response by assessing heart rate, blood pressure, and symptom resolution 2

Second-Line: Vasopressor/Chronotropic Support

If bradycardia persists despite maximum atropine dosing:

Dopamine is the preferred second-line agent for dialysis patients with bradycardia:

• Start at 5 mcg/kg/min IV, increasing by 5 mcg/kg/min every 2 minutes 1, 2, 4
• Titrate up to 20 mcg/kg/min based on heart rate and blood pressure response 1, 4
• At doses of 5-20 mcg/kg/min, dopamine provides both chronotropic (heart rate) and inotropic (contractility) effects through beta-adrenergic stimulation 1, 2
• Critical warning: Doses >20 mcg/kg/min cause excessive vasoconstriction and arrhythmias and should be avoided 1, 2, 4

Alternative agents if dopamine is unavailable or ineffective:

• Epinephrine: 2-10 mcg/min IV or 0.1-0.5 mcg/kg/min IV, titrated to effect 1, 2
• Isoproterenol: 20-60 mcg IV bolus or 1-20 mcg/min infusion, particularly useful as it provides chronotropy without vasoconstriction 1, 2

Third-Line: Transcutaneous Pacing

• Initiate transcutaneous pacing immediately for unstable patients who remain hemodynamically compromised despite atropine (Class IIa recommendation) 2
• TCP serves as a temporizing measure while preparing for definitive therapy 2
• May require sedation/analgesia due to discomfort in conscious patients 2

Critical Considerations Specific to Dialysis Patients

BRASH Syndrome Recognition

Dialysis patients are at particular risk for BRASH syndrome (Bradycardia, Renal failure, AV nodal blockers, Shock, Hyperkalemia), which requires management beyond standard ACLS protocols 5, 6, 7:

• Check potassium levels immediately in any dialysis patient presenting with bradycardia 5, 6, 7

• If hyperkalemia is present (typically >6.5 mEq/L in this context):

  • Administer calcium gluconate 1-3 g IV immediately for cardiac membrane stabilization 1
  • Give insulin-dextrose infusion (1 unit/kg bolus followed by 0.5 units/kg/h) 1
  • Consider albuterol nebulization and sodium zirconium cyclosilicate 5
  • Arrange urgent hemodialysis for refractory hyperkalemia 5, 6

• Review and hold all AV nodal blocking medications (beta-blockers, non-dihydropyridine calcium channel blockers, digoxin) 1, 5, 6

• The synergy between hyperkalemia and AV nodal blockers creates a vicious cycle that standard atropine doses may not break 5, 6, 7

Dialysis-Related Hemodynamic Considerations

• Bradycardic hypotension during dialysis may represent severe hypovolemia rather than primary cardiac pathology 8
• Tachycardia is actually the more common heart rate response to dialysis-associated hypotension; bradycardia suggests more severe cardiovascular underfilling 8
• If bradycardia occurs during active dialysis, consider temporarily reducing or stopping ultrafiltration while treating the bradycardia 8

Common Pitfalls and How to Avoid Them

Atropine Ineffectiveness

• Atropine is likely ineffective for type II second-degree AV block or third-degree AV block with wide QRS complex, where the block is infranodal 2
• In these cases, proceed directly to transcutaneous pacing or chronotropic infusions rather than giving repeated atropine doses 2

Drug Dosing Errors

• Never give atropine doses <0.5 mg, as this may cause paradoxical bradycardia 1, 2
• Do not exceed dopamine 20 mcg/kg/min due to risk of severe vasoconstriction and arrhythmias 1, 2, 4
• Avoid bolus administration of any vasopressor; use controlled infusion pumps 4

Ischemia Risk

• Use beta-agonists (isoproterenol, dopamine, epinephrine) with extreme caution if coronary ischemia is suspected, as increasing heart rate may worsen ischemia or increase infarct size 1, 2
• Monitor continuously for chest pain or ECG changes during chronotropic therapy 1

Medication Interactions

• Check for recent fomepizole administration in dialysis patients, as it can cause severe bradycardia and hypotension during hemodialysis 9
• Review all home medications for AV nodal blockers that may be contributing to the clinical picture 1, 5, 6

Practical Implementation Summary

1. Immediate actions: Ensure adequate oxygenation, establish IV access, obtain ECG, check potassium level 2
2. Give atropine 0.5-1 mg IV, repeat every 3-5 minutes up to 3 mg total 1, 2
3. If no response after maximum atropine: Start dopamine 5 mcg/kg/min, titrate up to 20 mcg/kg/min 1, 2
4. If hyperkalemia present: Calcium gluconate, insulin-dextrose, arrange urgent dialysis 5, 6
5. If refractory to medications: Initiate transcutaneous pacing 2
6. Hold all AV nodal blocking agents and reassess after stabilization 5, 6