noradrenaline / norepinephrine
- noradrenaline is the preferred 1st line vasopressor in Mx of sepsis / septicaemia not responding to iv fluid therapy
- an endogenous sympathomimetic agent, its main action is as a alpha-1 agonist with beta-1 agonist actions and little beta-2 agonist actions (thus no skeletal muscle vasodilation nor the glucose metabolism effects as with adrenaline)
- variable effect on HR and cardiac output:
- low doses often result in vagal reflex bradycardia accompanying the rise in MAP, and thus cardiac output may even fall.
- it's alpha-1 vasocontrictive actions (vasopressor) may result in reduced peripheral, pulmonary, renal and splanchnic perfusion.
- allergy and hypersensitivity reactions in those sensitive to sulphites, take care in patients with PH asthma
- reflex bradycardia
- may occur at low doses, and may actually reduce cardiac output
- prolonged administration of any potent vasopressor may result in plasma volume depletion and hypotension
- theoretical risk of increased myocardial ischaemia in patients with acute myocardial infarction (AMI/STEMI/NSTEMI)
- use with care in those with heart disease, thyroid disease, hypertension, or diabetes
- may cause local ischaemia and abscesses if used im or there is tissue extravasation at iv site
- the antidote for extravasation ischaemia is local infiltration with phentolamine
- prolonged vasoconstriction may prevent adequate volume expansion of circulation and lead to persistent shock
- vials are usually 1mg/ml (1:1000) and in 4ml volumes (ie. 4mg)
- dilute with 5% dextrose
- note there are many drug incompatibilities - see P.I.
usual central line administration:
Victorian Safer care formulation 2019
- add 4mL (4mg) of 1:1000 to 66mL 5% dextrose OR 6mL to 100mL 5% dextrose
- concentration = 60mcg/mL
- 1mL/hr = 1 microgram/min titrate as needed
- usual starting dose 2-12 microgram/min
- Usual dose range: 0.5 to 30microg/min
- Maximum dose: up to 100 microg/min in extreme cases
- should not be ceased abruptly.
noradrenaline.txt · Last modified: 2019/07/25 07:10 by 127.0.0.1