Abstract: An IV container spike and drip chamber assembly is provided that includes an automatic shut off mechanism which allows nurses to change the fluid container without removing the catheter from the patient. The automatic shut off mechanism comprises a floating ball capable of being supported by or floating in the fluid due to the buoyancy of the fluid. The IV container spike also includes an air vent which allows the air in the drip chamber to vent out directly when the nurses want to change the container of medicinal fluid. The air vent is closed for the initial use and during the infusion process. As the medicinal fluid is gradually reduced in level in the drip chamber, the floating ball is lowered thereby and when the floating ball reaches the bottom of the drip chamber, the floating ball blocks the outlet so as to stop the injection.