Superiority of water application to water sealing in burn wound healing

Recently there have appeared on the market many external dressings for wound management. They all use water-sealing materials to maintain wounds in a moist state. However, in our daily clinical observations, a water-sealing material sometimes results in poor wound healing. Although a water-sealing material does in fact keep the wound moist, the quality of the water is far from that of the optimum extracellular fluid.

A second-degree burn wound was made in the rat by contact with a metal stick. Experiment 1 was to evaluate the influence of delayed primary wound treatment on burn-wound depth progression. We used a time lag procedure. Each group was treated with a water-sealing application (hydrocolloid sheet). Experiment 2 was to investigate the progression-preventing effect of normal saline on a burn allowed to dry for 3 hours, we compared a group that received a water sealing (non-moistening and incomplete moisture) dressing with one that received a water-supplying (moistening) dressing with using chi-square test.

In the Experiment 1 (time lag and water sealing test), the early group showed quite normal wound healing at 7 days after onset. The slough was thin (about 10-20% of full dermal thickness). The delayed groups showed the poor healing characteristic. The slough was relatively thick (about 30-60% of full dermal thickness). Three hours' delay seemed to bring about poor healing. In the Experiment 2 (water application test), the moistening (water application) group showed relatively good healing after seven days. The slough was as thin as in the early group in the Experiment 1. The non-moistening group showed a poor healing process like the delayed group in the Experiment 1. For the moistening group, the healing percentage of 77.8% was significantly greater than the 41.3% observed in the non-moistening group (chi-square test, p < 0.05).

All the materials in wound dressing are water-sealing. When the component water under the sheet is far from the extracellular fluid, these applications bring about poor healing. Delayed application and incomplete moisture should be corrected by external water-application.