Isoprenaline Hydrochloride for paediatric complete heart block (1117)

Objectives

To provide a guideline for the use of Isoprenaline Hydrochloride in paediatric complete heart block.

Scope

This guideline is intended for all healthcare professionals involved in the care of paediatric patients with complete heart block who require treatment with Isoprenaline Hydrochloride.

For neonatal guidance refer to the West of Scotland NEONATAL Parenteral Drug Monographs

Background:

• Isoprenaline is a non-selective β-adrenoceptor agonist. 
• At cardiac β1 receptors, Isoprenaline has positive inotropic and chronotropic effects.  This increases cardiac output and heart rate.
• At β2 receptors, Isoprenaline causes systemic and pulmonary arterial vasodilation.  This leads to a reduction in systemic vascular resistance and bronchodilation.¹

Preparations:

Isoprenaline Hydrochloride Injection 1mg/5ml

Dose:

IV Infusion Dose for Complete Heart Block²:

IV Infusion: 0.1-1micrograms/Kg/minute
Infusion rate to be titrated according to clinical response.  Dose may be increased every 2-3 minutes until appropriate response obtained as directed by Consultant Cardiologist.

Route of administration³:

Continuous intravenous infusion, preferably via a central line. 
Isoprenaline has a low PH and may cause venous irritation and tissue damage in cases of extravasation. 
If a central line is not available, administer via a large peripheral vein.

Dilution³:

Diluent : Glucose 5% (preferred) or Nacl 0.9%

Peripheral line: Add 1mg (5mls) Isoprenaline hydrochloride to 45mls of diluent to make a final concentration of 1mg/50ml (20micrograms/ml)

If requiring doses greater than 25mls/hour:

Prepare an infusion of 10mg Isoprenaline hydrochloride in 500mls diluent

• Withdraw 50mls from the 500ml bag of diluent.
• Add 10mg (50mls) of Isoprenaline hydrochloride to make a final concentration of 10mg/500mls (20micrograms/ml).

Central line: Add 3mg (15ml) Isoprenaline to 35mls of diluent to make a final concentration of 3mg/50ml (60micrograms/ml)

If requiring doses greater than 25mls/hour:

Prepare an infusion of 30mg (150mls) Isoprenaline hydrochloride in 350mls diluent

• Withdraw 150mls from the 500ml bag of diluent.
• Add 30mg (150mls) of Isoprenaline hydrochloride to make a final concentration of 30mg/500mls (60micrograms/ml).

To calculate infusion rate: