Elevated wound fluid pH correlates with increased risk of wound infection

Introduction
There is no definitive method to determine infection status in non-healing wounds. Measurement of wound pH might be a promising indicator of infection as it is relatively easy to perform, provides objective results within a few seconds, and is inexpensive. The aim of this investigation was to determine if wound pH could be a potential indicator of early or established infection in non-healing wounds.

Methods
We explored the relationship between wound pH and two indicators of wound infection: expert clinical judgement and elevated neutrophil-derived enzyme activity. Data was used from 120 wound samples previously collected at Medisch Spectrum Twente hospital.

Results
With increasing wound pH, there was also an increase in the proportion of infected wounds as determined by expert clinical judgement. In addition, increases in the activities of myeloperoxidase, elastase and lysozyme were also associated with elevated pH.

Conclusions
The strength of the relationship between wound pH and clinical judgement or enzyme activities observed in this study is not sufficient to promote the use of elevated pH alone as an indicator for wound infection. However, the use of pH in combination with other indicators for wound infection, such as elevated neutrophil enzyme activity, warrants further research.