A patient has a nephrostomy tube that has been inserted because of an obstruction in the ureter. What special precautions in the care of the nephrostomy tube should the nurse implement?

Instilling no more than 50 mL of sterile water if sterile irrigations are ordered.

Being certain the tube is connected, not kinked, or not clamped to ensure that it continually drains.

Clamping every 2 hours to allow expansion of the kidney pelvis.

Leaving the nephrostomy site open to air.