Plasma catecholamine response to cataract surgery: a comparison between general and local anaesthesia.

We studied the plasma catecholamine, plasma glucose and cardiovascular responses to cataract surgery in 20 elderly patients allocated randomly to receive either general anaesthesia or local anaesthesia by retrobulbar block. Local anaesthesia prevented the increase in plasma noradrenaline, adrenaline and glucose concentrations found in those patients who received general anaesthesia and also improved cardiovascular stability. The results show the beneficial effects of local anaesthesia in preventing the hormonal, metabolic and cardiovascular changes found when cataract surgery is conducted under general anaesthesia.