Instructed patient abour the V.A.C. therapy System is an Advanced Wound Therapy System consisting of a V.A.C. Therapy unit that delivers negative pressure and a sterile plastic tubing with SensaT.R.A.C, pressure sensing lumens that connect the therapy unit to the dressing Special foam dressings. KCI recommends the V.A.C. Dressings be changed every 48 to 72 hours, but no less than 3 times per week. Patient has the ability to move around depending on the condition, the wound location and type of therapy unit prescribed. The V.A.C. Therapy System may be disconnected so you can take a shower. Therapy may not be off any longer than two hours per day.