Cardiac dysrhythmias adrenaline

Small quantities of adrenaline, such as are present as an additive in local anesthetic formulations, can be dangerously potentiated by beta-adrenoceptor blockers propranolol should be discontinued at least 3 days in advance of administering such products for local anesthesia. A combined infusion of adrenaline and propranolol has been used for diagnosing insulin resistance, but it can evoke cardiac dysrhythmias, even in patients without signs of coronary disease (17). 

Cardiac dysrhythmias are generally considered to be less frequent, or at least less severe, with enflurane than with halothane (5,6). However, caution in the use of adrenaline is advisable, especially in patients with cardiac disease or hjrperthyroidism. Isorhythmic atrioventricular dissociation was seen in 16 of 105 patients after the use of 1.0-1.5% enflurane (7). 

For acute anaphylaxis, immediate treatment is essential, with adrenaline followed by intravenous histamine Hi receptor antagonists, glucocorticoids, fluids, and electrolytes. In view of the frequency of cardiac dysrhythmias and conduction disturbances in patients with anaphylactic shock, they should immediately be monitored (198,199). 

Sevoflurane has a similar effect on regional blood flow to other halogenated anesthetics, although it is perhaps slightly less of a coronary artery vasodilator than isoflurane. It reduces myocardial contractility and does not potentiate adrenaline-induced cardiac dysrhythmias (5). 

Bupivacaine can cause ventricular extra beats (8). Ventricular dysrhythmias and seizures were reported in a patient who received 0.5% bupivacaine 30 ml with adrenaline 5 micrograms/ml for lumbar plexus block, after a negative aspiration test (9). The patient developed ventricular fibrillation and required advanced cardiac life support for 1 hour, including 15 defibrillations, and adrenaline 40 mg before sinus rhythm could be restored. There were no neurological sequelae. 

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