Stellate ganglion block is a selective sympathetic block that affects the ipsilateral head, neck, upper extremity and upper part of the thorax. Convulsions are a recognized complication of intra-arterial injection during stellate ganglion block. As central nervous system toxicity depends ultimately on the concentration of the local anaesthetics presented to the brain, the likely causative factors are discussed as well as the types of toxic symptoms and their onset times. The paper considers the aetiological factors of such convulsions resulting from stellate ganglion block in two patients.

In anaesthetized dogs, stellate ganglion blockade led to a moderate disturbance in left ventricular diastolic function. We investigated the effect of a left-sided block, following injection of 10 mL bupivacaine 0.5%, on echocardiographic variables of ventricular function in eight otherwise healthy patients with sympathetically mediated pain syndromes. After the blockade, heart rate (control: 66±3 (mean± SEM), block: 64± 3 min−1) and mean arterial blood pressure (88.5±6.0 vs. 84.0±8.1 mmHg) were unchanged, but afterload decreased (end-systolic meridional wall stress; 69.6±9.9 vs. 59.8±7.1, P<0.05). Stroke volume increased from 71.2±8.1 to 79.6±7.4 mL, P <0.05. Variables of systolic function were unchanged, but relaxation was prolonged (isovolumic relaxation time; 71±5 vs. 81±4 ms, P<0.05). In patients who were ASA I, there was a small impairment in echocardiographic variables during ventricular relaxation after a left stellate ganglion blockade. This small effect did not compromise ventricular function, and the heart responded with a small stroke volume increase to the simultaneous afterload reduction.