Today I had to write a letter to a NPWT company in order to prevent that therapy from being discontinued. The patient is a quadriplegic with an ischial pressure ulcer. I’ve been seeing him for the past 4 months and have managed to keep him out of the hospital, debriding a pretty big ulcer down to the bone in the clinic and bringing about a substantial reduction in size with NPWT. The problem is that there is a lot of undermining and it’s easy to get different depths depending on how the tissue is held as he is measured. So, one day the depth appears to be different from another. It’s really hard to accurately measure the volume of an undermined wound.
I’ve been part of many research projects in the past 25+ years trying to find an accurate way to do volume measurements. We have tried water displacement, dental mold, and  3-D laser cameras. But, today, I spent half an hour writing a letter to Medicare to explain why a 0.3 cm difference in-depth (which of course caused the wound volume to be MUCH larger that day) did not mean that the patient was worse.