No correlation between minimal electrical charge at the tip of the stimulating catheter and the efficacy of the peripheral nerve block catheter for brachial plexus block: a prospective blinded cohort study

Table 1 Protocol violations

Event	MEC* (nC)
Toxic reaction after 14 mL loading dose ropivacaine 0.75%	1425
Loading dose of 30 instead of 20 mL ropivacaine 0.75%	46
Catheter discomfort and postoperative pain (catheter removed, single shot interscalene block with ropivacaine 0.2%)	72
Postop pain requiring extra ropivacaine (20 mL ropi 0.2%),	46
Postop pain requiring extra ropivacaine (10 mL ropi 0.75%)	68
Postop pain requiring extra ropivacaine (20 mL ropi 0.2%)	120

*MEC = Minimal electrical charge necessary to elicit an appropriate motor response.

ISSN: 1471-2253