Wiki Sacral ulcer debridement calculation (x-post from derm)

[NM36]

I need clarification on how to calculate the debridement of a sacral ulcer. The surgeon did not specify the total amount of debrided tissue, but he did give the before and after wound sizes;

"Pre debridement measurements of this full-thickness stage IV ulcer were 9cm long by 8 cm wide by 4 cm deep. There was foul-smelling necrotic tissue at the superior margin and in the depth of the wound. The inferior margin was actually somewhat clean and with evidence of granulation tissue. That caudal or inferior margin was also only about 15 mm away from the anal verge. This also was then sharply debided with the Bovie such that the ultimate wound measurements were 9 cm long by now 10 cm wide by 7 cm deep. The debridement was into subcutaneous fat as well as musculature of the buttock, as well as exposed periosteum of the sacrum in several areas, but no bony debridement was done nor thought to be required as that periosteum appeared to be healthy..."

Surface area of wound before debridement: 9x8 = 72 sq cm
Surface area after debridement: 9x10 = 90 sq cm
Depth of debridement: (7-4) = 3 cm
So (90x3)-72 = 198 sq cm debrided

Am I calculating this right??

If so, I'm suing codes 11044, and 11047x9

Any insight welcome.
Thanks

 

[NM36]

To answer my own question...
I was thinking too hard
Subtract beginning measurement from ending measurement.
Beginning wound measurement: 9x8x4= 288
Ending wound measurement: 9x10x7 = 630
630-288= 342 sq cm. tissue debrided.

 

[thomas7331]

If the entire wound was debrided, you would use the only final measurement of the wound size after the procedure (the physician is debriding the original wound area in addition to the area into which the wound is being expanded, so you do not subtract out the original wound size). The surface area is calculated by multiplying length by width for sq cm (do not use depth as that would calculate cubic cm, not sq). The debridement area in the example here would be 90 sq cm.