Interventional Agents
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Anaesthetic agents have a number of side effects and it is often necessary to treat these issues using some of the following drugs -
[[Dobutamine
Dobutamine is a synthetic catecholamine which acts as a β1 selective adrenoceptor agonist. Dobutamine is a sympathomimetic and postive inotrope. It exerts this effect by stimulating β1 adrenergic receptors. This causes a rise in cAMP though the activation of adenylate cyclase. This increase causes an increase in slow inward calcium currents. It also increases calcium storage in the sarcoplasmic reticulum making more calcium available to contractile muscle fibres, thereby increasing myocardial contractility. It also acts at β1 and β2 receptors in the peripheral vasculature.
Dobutamine has a low half life and so is given via a continuous rate intravenous infusion. Due to its potential side effects however, it can only be administered for a maximum of 48 hours.
Contraindications and Side Effects
- Hypertension
- Cardiac arrhythmias
Indications
Used in patients with heart failure. It can be used as emergency treatment in patients with cardiogenic shock. It can be used in anaesthesia when there is hypotension or bradycardia due to poor myocardial contractility.
Vasopressin
Vasopressin is a non-catecholamine vasopressor. It is a hypothalamic hormone found in the posterior pituitary. It promotes the renal reabsorption fo water as well as smooth muscle contraction particularly of capillaries and small arterioles. This smooth muscle contraction may lead to decreased blood flow to systems but increased hepatic blood flow. Vasporessin is indicated in patients with vasodilatory shock or ventricular fibrillation. However, possible side effects include vasconstriction and arrhythmias. It should be avoided in patients with vascular disease, history of seizures, heart failure, asthma or pregnant patients.