title: Transcutaneous oxygen pressure measurement in diabetic foot ulcers: mean values and cut-point for wound healing.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  Prospective, descriptive study.
  
  
  METHODS
  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 TxPO2 were 88.6%, 82.4%, 90.7%, and 72.2%, respectively.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Chuan Yang, PhD, MD, Endocrinology Department, Sun Yat-sen Memorial Hospital of SunYat-sen University, Guangzhou, China. Huan Weng, MD, Endocrinology Department, Sun Yat-sen Memorial Hospital of SunYat-sen University, Guangzhou, China. Lihong Chen, PhD, MD, Endocrinology Department, Sun Yat-sen Memorial Hospital of SunYat-sen University, Guangzhou, China. Haiyun Yang, MD, Ultrasonic Department, Sun Yat-sen Memorial Hospital of SunYat-sen University, Guangzhou, China. Guangming Luo, MD, Ultrasonic Department, Sun Yat-sen Memorial Hospital of SunYat-sen University, Guangzhou, China. Lifang Mai, RN, Endocrinology Department, Sun Yat-sen Memorial Hospital of SunYat-sen University, Guangzhou, China. Guoshu Jin, MD, Endocrinology Department, Sun Yat-sen Memorial Hospital of SunYat-sen University, Guangzhou, China. Li Yan, MD, Endocrinology Department, Sun Yat-sen Memorial Hospital of SunYat-sen University, Guangzhou, China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Yang
authors.forename: Huan
authors.initials: H
authors.lastname: Weng
authors.forename: Lihong
authors.initials: L
authors.lastname: Chen
authors.forename: Haiyun
authors.initials: H
authors.lastname: Yang
authors.forename: Guangming
authors.initials: G
authors.lastname: Luo
authors.forename: Lifang
authors.initials: L
authors.lastname: Mai
authors.forename: Guoshu
authors.initials: G
authors.lastname: Jin
authors.forename: Li
authors.initials: L
authors.lastname: Yan
mesh_terms: D000368:Aged; D001785:Blood Gas Monitoring, Transcutaneous; D017719:Diabetic Foot / Q000097:blood* / Q000503:physiopathology; D005260:Female; D005528:Foot / Q000098:blood supply; D006801:Humans; D008297:Male; D011312:Pressure; D011446:Prospective Studies; D014945:Wound Healing / Q000502:physiology