The PVB was performed under ultrasonographic guidance in the sitting position. Surgical disinfection of thoracoabdominal paravertebral area was done. A linear high-frequency transducer (10-12 MHz, Sonosite, Bothell, WA, USA) was used. The scanning process (Longitudinal out-of-plane technique) was started at 5-10 cm lateral to the spinous process of thoracic vertebrae to identify the rounded ribs and parietal pleura underneath. The transducer is then moved progressively more medially until the transverse processes are identified as more squared structure deeper to the ribs. A 100 mm needle was inserted out-of-plane to contact the transverse process of thoracic vertebra and then, walked off above the transverse process 1-1.5 cm deeper searching for loss of resistance injecting 10 ml of 0.25% bupivacaine + 3 mg morphine for group PVB morphine in incremental doses of 3 ml.

the quantity of analgesic (morphine) consumed by the patient in the first postoperative 24 hour

a scle in which 0 = no pain and 10 = maximum tolerable pain