What vasopressor should be used to maintain blood pressure in an ARDS patient on Cytosorb (cytokine adsorber) with snake bite-induced AKI and ongoing dialysis?

Vasopressor Management in ARDS Patient with Snake Bite-Induced AKI on Cytosorb

Norepinephrine should be used as the first-line vasopressor to maintain blood pressure in an ARDS patient on Cytosorb with snake bite-induced AKI and ongoing dialysis. 1, 2

Rationale for Norepinephrine as First Choice

Norepinephrine is the recommended first-line vasopressor for several important reasons:

• It provides reliable vasoconstriction with minimal impact on heart rate and mild inotropic effects 3
• It has been shown to significantly improve right ventricular function by restoring mean arterial pressure 4
• It is specifically recommended by the Surviving Sepsis Campaign as the first-choice vasopressor for shock states 1
• In patients with AKI, norepinephrine helps restore renal perfusion pressure, which is critical in this snake bite patient with compromised kidney function 5

Dosing and Administration

• Initial dose: 0.05-0.1 μg/kg/min 1
• Titrate by 0.05-0.1 μg/kg/min every 5-15 minutes 1
• Target mean arterial pressure (MAP) ≥65 mmHg 1
• Administer through a large vein, preferably via central venous access 2
• Dilute in dextrose-containing solutions (5% dextrose or 5% dextrose with sodium chloride) to prevent oxidation and loss of potency 2

Second-Line Options

If norepinephrine alone is insufficient to maintain adequate blood pressure:

1. Add vasopressin (up to 0.03 U/min) as a second-line agent 1, 6

   • Particularly beneficial in this case as vasopressin has shown benefit in improving renal function in patients with acute kidney injury 1
   • Does not require metabolism by the kidneys, making it suitable for patients with AKI 6
   • The combination of norepinephrine and vasopressin has shown synergistic effects in restoring hemodynamics 7

2. Consider hydrocortisone (up to 300 mg/day) if escalating vasopressor doses are required 1

   • Particularly if there is suspicion of relative adrenal insufficiency, which is common in critically ill patients 4

Special Considerations for This Patient

• Fluid management: Given the patient has ARDS and is on dialysis, a conservative fluid strategy is recommended to prevent worsening pulmonary edema 4
• Cytosorb therapy: Monitor for potential drug adsorption by the Cytosorb filter, which may necessitate higher doses of vasopressors 8
• Renal monitoring: Despite having some urine output (100 ml/hr), continue close monitoring of renal function as snake venom can cause ongoing kidney damage 9
• Anticoagulation management: Be vigilant for premature circuit clotting in the Cytosorb system despite anticoagulation, which is frequently observed 8

Monitoring Parameters

• Blood pressure (target MAP ≥65 mmHg)
• Heart rate and cardiac output
• Urine output (currently 100 ml/hr - maintain or improve)
• Skin perfusion and capillary refill
• Mental status
• Lactate clearance
• Renal and liver function tests
• Oxygenation parameters

Pitfalls to Avoid

• Excessive fluid administration: Can worsen ARDS and pulmonary edema 4
• Delayed initiation of vasopressors: Waiting for central access before starting vasopressors can lead to prolonged hypoperfusion; peripheral administration is acceptable initially 1
• Inadequate MAP targets: Maintaining MAP below 65 mmHg may lead to inadequate organ perfusion, particularly in a patient with AKI 1
• Ignoring right ventricular function: ARDS patients often have right ventricular dysfunction, which norepinephrine can help improve 4

By following this approach, you can optimize hemodynamic management in this complex patient with ARDS, snake bite-induced AKI on dialysis, and Cytosorb therapy.