[Anxiety: an independent factor of axillary brachial plexus block failure?]

To evaluate the impact of the anxiety level using Spielberger test on axillary block success.

Prospective double-blind study.

An axillary brachial plexus block was performed with a nerve stimulator for all patients undergoing elective or emergency upper limb surgery. Spielberger test result was blinded for both patient and anaesthesiologist performing the block. Time to perform the block (minutes) was measured. Anxiety and pain scores were assessed, using a numeric scale (NS), at different time. Successful block was defined as complete sensory blockade combined with painless during surgical incision. Data were compared using Spearman test and multivariate logistical regression analysis.

Patients (184) were included (elective surgery=62%; emergency=38%). Failure rate was 10%. On multivariate logistical regression analysis, time to perform the block and NS anxiety score before starting the block were associated with block failure. Spielberger score correlated with NS anxiety score before puncture (Rho = 0,586, p<10(-4)). Anxiety level was increased in emergency context.

Patient's anxiety level before axillary brachial plexus block is a risk factor of failure, especially in emergency condition. We suggest anesthesiologists to evaluate patient anxiety prior to block performance. A specific anxiolytic treatment may be recommend in some cases.