Transcutaneous Oxygen Pressure Measurement in Diabetic Foot Ulcers Mean Values and Cut-Point for Wound Healing

作者：Yang Chuan; Weng Huan; Chen Lihong; Yang Haiyun; Luo Guangming; Mai Lifang; Jin Guoshu; Yan Li^*

来源：Journal of Wound, Ostomy and Continence Nursing, 2013, 40(6): 585-589.

DOI：10.1097/WON.0b013e3182a9a7bf

• foot ulcers
• transcutaneous oxygen pressure measurement
• type 2 diabetes mellitus

PURPOSE: The purpose of this study was to investigate mean values and cut-point of transcutaneous oxygen pressure (TcPo2) measurement in patients with diabetic foot ulcers.
DESIGN: Prospective, descriptive study.
SUBJECTS AND SETTING: Sixty-one patients with diabetes mellitus and foot ulcers comprised the sample. The research setting was Sun Yat-sen Memorial Hospital of SunYat-sen University, Guangzhou, China.
METHODS: Participants underwent transcutaneous oxygen (TcPo2) measurement at the dorsum of foot. Patients were classified into 3 groups according to clinical outcomes: (1) ulcers healed with intact skin group, (2) ulcer improved, and (3) ulcer failed to improve. TcPo2 was assessed and cut-points for predicting diabetic foot ulcer healing were calculated.
RESULTS: Thirty-six patients healed with intact skin, 8 experienced improvement, and 17 showed no improvement. Mean TcPo2 levels were significantly higher (P < .001) in healed ulcers with intact skin (32 +/- 10 mmHg) when compared to the improvement group (30 +/- 7 mmHg) and the nonhealing group (15 +/- 12 mmHg). All patients with TcPo2 = 10 mmHg failed to heal or experienced deterioration in their foot ulcers. In contrast, all patients with TcPo2 = 40 mmHg achieved wound closure. Measurement of TcPo2 in the supine position revealed a cut-point value of 25 mmHg as the best threshold for predicting diabetic foot ulcer healing; the area under the curve using this cut-point was 0.838 (95% confidence interval = 0.700-0.976). The sensitivity, specificity, positive predictive value, and negative predictive value for TxPo(2) were 88.6%, 82.4%, 90.7%, and 72.2%, respectively.
CONCLUSION: TcPo2 = 40 mmHg was associated with diabetic foot ulcer healing, but a TcPo2 = 10 mmHg was associated with failure of wound healing. We found that a cut-point of 25 mmHg was most predictive of diabetic foot ulcer healing.