Salbutamol
Salbutamol and aminophylline have a place at this point, the choice of which depends on whether or not the patient takes regular aminophylline, and also the personal preference of the anaesthetist.
| Salbutamol | |
|---|---|
| Presentation | 1 ml ampoules containing 500 μg/ml; there is also a 5 ml ampoule containing 5 mg salbutamol. The recommended dilution is 50 μg/ml. |
| Dose | The recommended dose is 250 μg by slow IV injection. In theatre this should be given over at least 20 minutes, taking care to avoid tachycardia. The intensive care unit (ICU) recommended rate of infusion is 5 μg/min. |
| Mechanism of action | Salbutamol is a beta agonist mainly at beta-2 receptors. At high doses it acts on beta-1 receptors. |
| Side-effects | It may cause tachycardia and arrhythmias and it may exacerbate hypokalaemia. |
Salbutamol is commonly given by:
Inhaler
Administration technique is crucial for inhalers.
The patient is required to produce a high inspiratory flow rate in order to get the drug into the lungs.
It is not possible to achieve this in an anaesthetized patient.
Nebulizer
Nebulizers can be successfully attached to ICU ventilators, but for the most part this is not possible in theatres. The most effective way to administer salbutamol to an anaesthetized patient is intravenously.