Day-to-day variability of transcutaneous oxygen tension in patients with diabetes mellitus and peripheral arterial occlusive disease.

PURPOSE We evaluated the day-to-day variability of transcutaneous oxygen tension (tcPO2) in patients with diabetes mellitus and peripheral arterial occlusive disease who were at risk for chronic foot ulceration. METHODS The tcPO2 was measured in the morning once daily for 3 consecutive days in 10 male patients with diabetes mellitus who were hospitalized. The mean age of the patients was 65 +/- 13 years, and they had a mean duration of diabetes mellitus of 33 +/- 6 years. The tcPO2 was measured at a reference point at the chest (I2 dx), the dorsum of the foot, and in the first intermetatarsal space. Measurements of tcPO2 in the first intermetatarsal space were performed before and during inhalation of 100% oxygen. RESULTS The mean tcPO2 was higher (P <.001) at I2 dx (56 +/- 10 mm Hg) than at the dorsum of the foot (25 +/- 19 mm Hg) and first intermetatarsal space (27 +/- 20 mm Hg). tcPO2 increased (P <.001) during inhalation of 100% oxygen, whereas the increase was severely reduced in three patients with tcPO2 less than 10 mm Hg at baseline. A reasonably good day-to-day variability of tcPO2 was seen; the linear relations between tcPO2 investigated on days 1, 2, and 3 were highly significant (P =.0001) at each measuring site, and no systematic differences were seen between the repeated measurements (analysis of variance; P =.13 to.85). CONCLUSION The results show an acceptable day-to-day variability of tcPO2, both at baseline and during oxygen inhalation, in patients with diabetes mellitus and peripheral arterial occlusive disease.