We measured pre- and postoperative ankle:brachial index (ABI), regiona
l perfusion index (RPI = foot/chest transcutaneous oxygen tension [T(c
)PO2]), and variation in RPI with limb elevation in 22 ischemic lower
extremities of 20 patients to compare ABI and RPI measurements for qua
ntifying limb perfusion and analyze perioperative positional changes i
n RPI. Measurements were compared, using t tests, with all limbs group
ed according to severity of clinical ischemia and, again, according to
presence or absence of diabetes. Preoperative mean and mean post-reva
scularization increases in ABI values ranged from 0.27 to 0.48 and 0.4
0 to 0.54, respectively; corresponding RPI values ranged from 0.18 to
0.45 and 0.48 to 0.60, respectively. Pre- and postoperative decreases
in RPI with elevation ranged from 0.07 to 0.11 and 0.11 to 0.23, respe
ctively. ABI and RPI values were equally effective in assessing clinic
al ischemia preoperatively and increased perfusion postoperatively, re
gardless of degree of ischemia or diabetes. Upon elevation, all limbs
exhibited larger decrements in blood flow to the skin postoperatively
compared to preoperatively, as estimated by RPI. However, postoperativ
e positional decrease in RPI was greater in diabetics compared with no
ndiabetics (0.23 +/- 0.12 vs 0.12 +/- 0.06; P < 0.05), suggesting post
operative elevation of diabetic limbs with ischemic skin lesions may b
e unadvisable.