What is the appropriate medication dose for a patient with a 25% ejection fraction?

Norepinephrine Dosing for Heart Failure with Reduced Ejection Fraction (25%)

For a patient with 25% ejection fraction requiring norepinephrine (noradrenaline), start at 0.1 mcg/kg/min IV and titrate upward to achieve adequate perfusion, with doses typically ranging from 0.1-1.0 mcg/kg/min, though doses as high as 5 mcg/kg/min may be necessary in refractory shock. 1

Initial Dosing Strategy

• Starting dose: Begin at the lowest effective dose of 0.1 mcg/kg/min via continuous IV infusion 1
• Titration: Increase gradually based on clinical response, targeting adequate blood pressure and end-organ perfusion 1
• Typical therapeutic range: 0.1-1.0 mcg/kg/min for most patients 1
• Maximum doses: Up to 5 mcg/kg/min may be required in severe, refractory shock states 1

Critical Administration Considerations

Route of Administration

• Preferred route: Central venous access is strongly preferred to minimize risk of extravasation injury 1
• Peripheral access: If central access is unavailable, peripheral IV or intraosseous routes can be used temporarily (typically safe for 2-4 hours) while establishing central access 2
• Extravasation management: If tissue infiltration occurs, inject phentolamine 0.1-0.2 mg/kg (maximum 10 mg) diluted in 10 mL of 0.9% sodium chloride intradermally at the extravasation site 1

Monitoring Requirements

• Hemodynamic monitoring: Continuous arterial blood pressure monitoring is essential, preferably via arterial line 1
• Separate IV line: Administer through a dedicated IV line separate from other medications and fluids 1
• Clinical endpoints: Monitor for adequate perfusion (mental status, urine output, lactate clearance, capillary refill) rather than targeting a specific blood pressure number alone 1

Special Considerations for Heart Failure Patients

Volume Status Assessment

• Pre-vasopressor resuscitation: Ensure adequate volume resuscitation before initiating norepinephrine, though the exact volume varies by clinical context 2
• Avoid excessive fluid: In patients with severely reduced ejection fraction (25%), balance the need for preload optimization against the risk of pulmonary edema 1

Concurrent Medications

• Beta-blockers: Exercise caution when norepinephrine is used in patients already on beta-blockers for heart failure management, as the combination may affect hemodynamic response 1
• ACE inhibitors/ARBs: These guideline-directed medical therapies for heart failure should typically be held during acute shock states but can be cautiously reintroduced once hemodynamically stable 1

Pediatric Dosing (if applicable)

• Starting dose: 0.1 mcg/kg/min 1
• Typical range: 0.1-1.0 mcg/kg/min 1
• Maximum reported: Doses up to 2.5 mcg/kg/min (mean maximum) have been used safely in pediatric septic shock, with some cases requiring higher doses 2
• Peripheral access safety: Peripheral or intraosseous administration for median duration of 3 hours has been shown safe without adverse effects in pediatric populations 2

Common Pitfalls to Avoid

• Inadequate initial resuscitation: Do not start vasopressors before addressing hypovolemia, as this can worsen tissue perfusion 2
• Delayed central access: While peripheral administration is temporarily acceptable, prolonged use significantly increases extravasation risk 1
• Fixed dosing: Norepinephrine must be titrated to clinical effect, not administered at a standard dose 1
• Ignoring underlying cause: Norepinephrine supports hemodynamics but does not treat the underlying cause of shock; identify and address precipitating factors (infection, ischemia, arrhythmia) 1