Patients that had regional anesthesia using dorsal penile nerve block

Patients that had regional anesthesia using caudal epidural block

Patients were positioned laterally for the procedure. The ultrasound transducer was first positioned transversely at the midline to visualize the sacral cornua, sacrococcygeal ligament, sacral bone, and sacral hiatus in a transverse view. It was then rotated 90° to obtain a longitudinal view of the sacrococcygeal ligament and sacral hiatus. A 22G, 50 mm needle was inserted caudal to cranial into the sacral canal under direct real-time longitudinal ultrasound guidance

The time interval (measured in hours) from a specific starting point until the patient requires their first dose of additional pain medication (the "rescue" dose).