Noradrenaline

Noradrenaline - The a1 effect predominates over its B1 effect, raising the BP by increasing the SVR. It increases the myocardial oxygen requirement without increasing coronary blood flow. Noradrenaline (norepinephrine) reduces renal, hepatic and muscle blood flow, but in septic shock, noradrenaline may increase renal blood flow and enhance urine production by increasing perfusion pressure.Acute renal failure secondary to inadequate renal perfusion is a common form of kidney failure seen in the ICU. Once intravascular volume has been restored, the MAP should be restored to a level that optimally preserves renal perfusion pressure i.e. above 65 mmHg (or higher in previously hypertensive patients).

Uses
Septic shock, with low SVR

Contraindications
Hypovolaemic shock
Acute myocardial ischaemia or MI

Administration
• Usual dose range: 0.01–0.4 μg/kg/min IV infusion via a central vein
Initially start at a higher rate than intended, to increase the BP more rapidly, and then reduce rate 4 mg made up to 50 ml glucose 5% (80 μg/ml)

Dosage chart (ml/h):

Weight (kg)	Dose (ug/kg/min)
	0.02	0.05	0.1	0.15		0.2
50	0.8	1.9	3.8		5.6	7.5
60	0.9	2.3	4.5		6.8	9
70	1.1	2.6	5.3		7.9	10.5
80	1.2	3	6		9	12
90	1.4	3.4	6.8		10.1	13.5
100	1.5	3.8	7.5		11.3	15
110	1.7	4.1	8.3		12.4	16.5
120	1.8	4.5	9		13.5	18

How not to use noradrenaline
In the absence of haemodynamic monitoring
Do not use a peripheral vein (risk of extravasation)
Do not connect to CVP lumen used for monitoring pressure (surge of drug during flushing of line)

Adverse effects
Bradycardia
Hypertension
Arrhythmias
Myocardial ischaemia

Cautions
Hypertension
Heart disease
If extravasation of noradrenaline occurs – phentolamine 10 mg in 15 ml sodium chloride 0.9% should be infiltrated into the ischaemic area with a 23-G needle