Wound pH and temperature as predictors of healing: an observational study

Objective: The aim of this study was to measure wound pH, wound temperature and wound size together to gain further understanding of their impact as predictors of wound healing outcomes. Method: This study employed a quantitative non-comparative, prospective, descriptive observational design. Participants with both acute and hard-to-heal (chronic) wounds were observed weekly for four weeks. Wound pH was measured using pH indicator strips, wound temperature was measured using an infrared camera and wound size was measured using the ruler method. Results: Most of the 97 participants (65%, n=63) were male; participant's ages ranged between 18 and 77 years (mean: 42 +/- 17.10. Most of the wounds observed were surgical 60%, (n=58) and 72% (n=70) of the wounds were classified as acute, with 28% (n=27) classified as hard-to-heal wounds. At baseline, there was no significant difference in pH between acute and hard-to-heal wounds; overall the mean pH was 8.34 +/- 0.32, mean temperature was 32.86 +/- 1.78 degrees C) and mean wound area was 910.50 +/- 1132.30mm(2). In week 4, mean pH was 7.71 +/- 1.11, mean temperature was 31.90 +/- 1.76 degrees C and mean wound area was 339.90 +/- 511.70mm(2). Over the study follow-up period, wound pH ranged from 5-9, from week 1 to week 4, mean pH reduced by 0.63 units from 8.34 to 7.71. Furthermore, there was a mean 3% reduction in wound temperature and a mean 62% reduction in wound size. Conclusion: The study demonstrated that a reduction in pH and temperature was associated with increased wound healing as evidenced by a corresponding reduction in wound size. Thus, measuring pH and temperature in clinical practice may provide clinically meaningful data pertaining to wound status.