A wound alkalinity measurement to predict non-healing wound outcomes

Objective: As wound pH could influence wound healing rates, this study examined the alkalinity of the entire wound during patients' follow-up visits to predict the final non-healing outcome. Method: Wound alkalinity of patients with diabetic foot ulcers (DFUs), venous leg ulcers, and other wounds during three follow-up visits within a four week period was recorded. All wounds were followed until 12 weeks to confirm that healed wounds did not relapse. The alkalinity of various wounds over multiple visits with varying durations was compared with final wound status to assess whether one-time wound alkalinity measurement could predict non-healing wounds. The effect of wound types, infection, age and sex on such determinations was also studied. Results: A total of 96 patients were included in this study. Based on probability variations of pre- and post-test non-healing outcomes from multiple visits over 12 weeks, second visit assessment gave the highest increase in risk of non-healing for an alkaline test result (+8.0%) and decrease in risk of non-healing for a non-alkaline test result (-19.7%). Moreover, a second visit (7-21 days from first visit) showed a greater change in risk for non-healing based on alkaline and non-alkaline test results (+15.7% and -38.1% respectively), compared with a visit within seven days (+6.3% and -12.5%, respectively). Wound type, infection, age and sex did not affect the prognostic ability of wound alkalinity. Conclusion: The results of this study support that a single wound alkalinity measurement during the second visit (7-21 days from first visit) can be used to predict non-healing wounds. Wound alkalinity may be routinely assessed to predict non-healing wounds and to determine whether the wounds are healing as expected following initial treatment.