Transversus abdominis plane (TAP) block has gained popularity for the control of
postoperative pain in various surgeries. Three studies showed inconsistent result on pain
control after TAP block in laparoscopic cholecystectomy. The TAP technique used in these
studies was classic ultrasound guided TAP block. Besides periumbilical incision, sub-xiphoid
incision is usually made during laparoscopic cholecystectomy. As typical posterior TAP rarely
extend above T8, the investigators undergo subcostal TAP block for this type of surgery. The
investigators are going to investigate the effect of subcostal TAP on early postoperative
pain after laparoscopic cholecystectomy.