In a randomised, double-blind, controlled trial, a comparison was made of the relative efficacy of using streptokinase/streptodornase (Varidase) in a hydrogel (KY Jelly) or the hydrogel alone in the debridement of Grade IV pressure sores. Seventeen subjects aged 57-94 years (mean age 81) took part; 21 sores were studied, 11 of which were randomised to the enzyme treatment regime. Both treatments led to eschar removal; fewer days were needed in the hydrogel-only group (mean 8.1 days, sd 1.8) compared to the enzyme/hydrogel group (mean 11.8 days, sd 2.9), but this was not statistically significant. The results suggest that the use of hydrogel alone may be a cost-effective alternative to the use of streptokinase/streptodornase and hydrogel in the treatment of these wounds.