The problem of infusing air into IV tubing and into a patient from a IV fluid bag inside a pressure infusion cuff is solved by collar embodiments that inhibit the air from being forced into the IV tubing. A collar can include one or more curved arms that create a channel in which that part of the fluid bag is protected against being squeezed by a pressure infusion cuff. A collar allows the fluid bag to be squeezed by the pressure infusion cuff until such time that the fluid level is sufficiently reduced that the collar can inhibit further pressure on the fluid bag by the pressure infusion cuff. Also disclosed is a fluid bag and a pressure infusion cuff that are modified to have a collar incorporated therewith.