Thoracic Spinal Versus Thoracic Epidural Anesthesia for Patients with Chronic Obstructive Pulmonary Disease Undergoing Supine Percutaneous Nephrolithotomy for Management of Renal Stones.

The epidural needle was inserted At T6-8 space, After verification of the epidural space by resistance loss technique, a test dose of 2 ml of 0.5% bupivacaine was injected. In the Cephalad direction, the epidural catheter was threaded 3 cm into the epidural space. A total dose of 8-12 ml 0.5 percent plain bupivacaine was administered .

Thoracic spinal anesthesia: At T5-T6 or T6-T7, a 27G needle was inserted. The needle's stylet will be removed and the hub observed for free flow of CSF; once flow of clear CSF, 4 ml of isobaric bupivacaine 0.5% plus 0.5 ml of 250 ug morphine was injected