[Test dose for epidural anesthesia in patients treated with beta-blockaders]

Two cases are reported, demonstrating the difficulty to verify the lack of inadvertent intravascular injection of local anaesthetic during epidural anaesthesia in patients under beta-blockers. The tachycardia usually elicited by intravascular injection of a local anaesthetic-adrenaline mixture does not occur in these patients. The alternative consists in measuring blood pressure at the second minute after a test injection.