Loss of Resistance, w/wo Stimulation, For Epidural Placement

All subjects will receive a thoracic epidural catheter placement at the level appropriate for
their surgery and will be randomized to either have the epidural placed with a loss of
resistance technique alone or loss of resistance technique with confirmation by nerve
stimulation. In the traditional loss of resistance technique group, the epidural catheter
will be placed after achieving loss of resistance to air. In the electrical stimulation
group, following the location of the epidural space with a loss of resistance technique
(using air), nerve stimulation will be utilized to elicit a myotomal contraction of the
abdominal or thoracic wall. Nerve stimulation will be started at a pulse width of 0.3 ms and
a frequency of 1 Hz and a current of 0.2mA.

Inclusion Criteria:

- Adults undergoing intra-thoracic or intra-abdominal procedures that normally would
receive thoracic epidurals for post-operative analgesia will be eligible.

Exclusion Criteria:

- Subjects with contraindications to regional anesthesia:

- history of allergy to amide local anesthetics

- presence of a progressive neurological deficit

- patients that are on anticoagulant medications that prohibit placement of an epidural

- Systemic infection

- Infection at the site of placement