firmly Have a gloved assistant occlude the penile urethra in a male infant to prevent urination while preparations are made or have an open sterile urine cup available to catch the urine stream Select a puncture site in the midline of the abdomen, approximately to cm cephalad to the superior edge of the pubic bone ( Fig 130.32B,C ) Prepare the skin by cleansing with antiseptic solution Anesthetize the skin and soft tissue with lidocaine if desired Position a 1.5-in 22-gauge needle with a 5-mL syringe attached at the planned puncture site perpendicular to the plane of the abdominal wall ( Fig 130.32B ) Slowly advance the needle while aspirating with the syringe If urine is not obtained, withdraw the needle maintaining negative pressure on the plunger, but not remove the needle tip from below the surface of the skin Instead, change the angle of the needle, and reinsert it as previously described Attempt the procedure at two different angles; first, about 20 degrees caudad to the perpendicular, and second, about 20 degrees cephalad to the perpendicular If urine is not obtained after the third attempt, further trials are unlikely to be successful Wait to hours before attempting again or use ultrasound to assess for the presence of urine in the bladder INCISION AND DRAINAGE OF AN ABSCESS Indications Diagnostic and therapeutic drainage of fluctuant adenitis or superficial soft tissue abscess