ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Vasopressor (Alpha-1 Adrenoceptor Agonist) Pregnancy: Intraoperative use in obstetric spinal hypotension — phenylephrine preferred for fetal acidosis prevention, but norepinephrine emerging as equivalent

Norepinephrine (Noradrenaline — Perioperative Vasopressor)

Brand names: Noradrenaline (generic), Levophed

Adult dose

Dose: 0.01–3 mcg/kg/min IV continuous infusion. Titrate to MAP ≥65 mmHg. Usual starting dose: 0.05–0.1 mcg/kg/min
Route: IV continuous infusion via central venous access (CVC) preferred; short-term peripheral acceptable
Frequency: Continuous infusion — titrate to haemodynamic response
Max: 3 mcg/kg/min (doses above this may be used in refractory shock under specialist supervision)
Dilute in 5% glucose or normal saline. Standard concentration: 4 mg in 50 mL (80 mcg/mL) or 8 mg in 50 mL (160 mcg/mL). Central venous access strongly preferred for infusions >30 min. Short-term peripheral IV at low doses (<0.1 mcg/kg/min) acceptable in emergency while CVC placed.

Paediatric dose

Dose: 0.05 mcg/min/kg
Route: IV central line
Frequency: Continuous infusion — titrate to MAP target
Max: 2 mcg/kg/min
Concentration: 0.4 mg/mL for infusion (age/weight-appropriate dilution) mcg/min/ml
Children: 0.05–2 mcg/kg/min IV; titrate to BP response. Neonatal septic shock: 0.01–2 mcg/kg/min. Central access essential in neonates and small children.

Dose adjustments

Renal

No dose adjustment required — titrate to effect

Hepatic

No dose adjustment required — titrate to effect

Paediatric weight-based calculator

Children: 0.05–2 mcg/kg/min IV; titrate to BP response. Neonatal septic shock: 0.01–2 mcg/kg/min. Central access essential in neonates and small children.

Clinical pearls

  • Surviving Sepsis Campaign and ESA guidelines: norepinephrine is the first-line vasopressor for septic shock and distributive perioperative hypotension
  • Extravasation emergency: if norepinephrine extravasates peripherally → tissue necrosis; treat urgently with phentolamine 5 mg in 10 mL saline locally infiltrated
  • Vasopressin adjunct: in refractory septic shock, adding vasopressin 0.03 units/min IV allows norepinephrine dose reduction (Vasopressin and Septic Shock Trial)
  • MAP target: ≥65 mmHg is standard target for most ICU patients; higher targets (≥80 mmHg) in patients with chronic hypertension or known cerebrovascular disease
  • Volume first: vasopressors do NOT replace volume resuscitation — ensure adequate IV fluid before or concurrently with norepinephrine in hypovolaemia

Contraindications

  • Hypovolaemia — must correct volume deficit before/alongside vasopressor
  • Peripheral vascular disease (relative — use with caution)

Side effects

  • Hypertension (if over-dosed — titrate carefully)
  • Reflex bradycardia
  • Tissue necrosis (extravasation — use CVC; if peripheral extravasation: phentolamine 5–10 mg in 10 mL saline infiltrated locally)
  • Digital/limb ischaemia (high doses/prolonged use)
  • Metabolic acidosis (tissue hypoperfusion)

Interactions

  • MAOIs — severe hypertensive crisis (avoid, or extreme caution)
  • Volatile anaesthetics — increased arrhythmia risk
  • Beta-blockers — enhanced vasopressor response (reflex bradycardia may worsen)

Monitoring

  • MAP (arterial line essential for high doses or prolonged use)
  • Cardiac output/SVR (if available — LIDCO, PiCCO)
  • Urine output (>0.5 mL/kg/hr target)
  • Peripheral perfusion (skin temperature, capillary refill)
  • Lactate (resolution of tissue hypoperfusion)

Reference: BNFc; BNF; Surviving Sepsis Campaign Guidelines 2021; ESA/ESICM Perioperative Haemodynamics Guidelines; VASST Trial (2008). Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Pathways