Effect of chronic β-blockade on the utility of an epinephrine-containing test dose to detect intravascular injection in nonsedated patients.

Background And Objectives: A test dose containing epinephrine is routinely used during epidural blockade to detect accidental intravenous needle or catheter placement before the administration of local anesthetics to avert local anesthetic systemic toxicity. β-Blocker therapy may interfere with the expected hemodynamic response from an intravascular injection. This study describes a cohort of 24 patients and their response to an epinephrine test dose (ie, if expected increased heart rates during test-dose administration are valid in this population.