What is the recommended use and dosage of noradrenaline (norepinephrine) in treating severe hypotension?

Recommended Use and Dosage of Noradrenaline in Severe Hypotension

Noradrenaline should be administered at an initial dose of 0.05-0.1 μg/kg/min, titrated by 0.05-0.1 μg/kg/min every 5-15 minutes to achieve a target mean arterial pressure (MAP) ≥65 mmHg, and should only be used after fluid resuscitation fails to achieve target blood pressure. 1

Indications and Clinical Context

Noradrenaline (norepinephrine) is indicated for:

• Restoration of blood pressure in adult patients with acute hypotensive states 2
• Management of severe hypotension when fluid resuscitation alone is insufficient 3, 1
• First-line vasopressor for managing shock, particularly septic shock 1

Dosing Protocol

Initial Administration:

• Start with 0.05-0.1 μg/kg/min 1
• Alternative starting dose: 0.25 mL to 0.375 mL (8-12 μg of base) per minute 2

Titration:

• Increase by 0.05-0.1 μg/kg/min every 5-15 minutes 1
• Titrate to maintain MAP ≥65 mmHg 1
• For trauma patients, target systolic BP of 80-90 mmHg 3

Maintenance:

• Average maintenance dose: 0.0625-0.125 mL/min (2-4 μg of base) 2
• Higher doses may be required in refractory shock (>4 μg/kg/min) 4

Administration Guidelines

Route of Administration:

• Must be administered intravenously 2
• Infuse into a large vein to prevent tissue ischemia 2
• Arterial line monitoring should be established when using vasopressors 1

Important Considerations:

1. Fluid First Approach: Initiate fluid therapy with 0.9% sodium chloride or balanced crystalloid solution before starting noradrenaline 3
2. Timing: Consider early administration of noradrenaline in profound hypotension (diastolic BP ≤40 mmHg) to prevent prolonged hypotension 5
3. Weaning: Reduce the infusion rate gradually to prevent marked hypotension 2

Monitoring Parameters

• Blood pressure (target MAP ≥65 mmHg) 1
• Heart rate
• Urine output (target ≥0.5 ml/kg/h)
• Skin perfusion
• Mental status
• Lactate clearance
• Renal and liver function tests 1

Potential Complications

• Tissue ischemia and necrosis from extravasation 2
• Cardiac arrhythmias, especially in patients with underlying heart disease 2
• Allergic reactions (contains sodium metabisulfite) 2
• Bradycardia, anxiety, transient headache, respiratory difficulty 2
• Hypertension (resolve with dose reduction) 6

Adjunctive Therapies

• Vasopressin: Can be added to reduce noradrenaline requirements (maximum dose 0.03 U/min) 1
• Dobutamine: Recommended for myocardial dysfunction (2.5-20 μg/kg/min) 1
• Hydrocortisone: Consider up to 300 mg/day if escalating vasopressor doses are required 1

Special Considerations

• In trauma patients, noradrenaline should only be used if systolic BP <80 mmHg despite restricted volume replacement 3
• Higher target MAP may be appropriate in patients with chronic hypertension 7
• Peripheral venous access or intraosseous route can be used safely in emergency situations when central access is not immediately available 6

Management of Extravasation

If extravasation occurs:

• Infiltrate the area as soon as possible with 10-15 mL of saline solution containing 5-10 mg of an adrenergic blocking agent 2

Noradrenaline remains the first-choice vasopressor for severe hypotension with strong evidence supporting its use, but proper administration techniques and close monitoring are essential to minimize complications.