A study comparing two objective methods of quantifying the production of wound exudate.

Objective: The objective assessment of chronic wound therapies for exudate management (WRAP study) tested a variety of methods that could be used to improve understanding of dressing performance in the presence of wound exudate, including measurement of the levels of exudate production. The aim of this study was to identify a valid and reliable method of measuring wound exudate production per unit area of wound surface.

Method: Two methods were tested. Method A measured the weight of exudate collected in dressings by 'before and after' weighing of all dressing materials that came into contact with wound exudate. Method B measured wound exudate collected as part of topical negative pressure (TNP) therapy.

Results: Method A: Complete data were collected on three patients (at which point the study was halted), but it was only possible to obtain accurate measurements for two of these. Exudate production was 0.10g/cm2/24 hours and 0.21g/cm2/24 hours. It was time-consuming and required special equipment. Method B: Fifteen measurements from five patients were analysed and showed a mean exudate production of 1.3g/cm2/24 hours.

Conclusion: There are problems with both methods of exudate measurement, but measuring wound fluid collected inTNP canisters seems simpler than weighing dressings and deserves further investigation.