My mother in law of 86 years (dementia) has developed some sort of blister on the inside of her left leg and she burt it and it bleeds. I have covered it with waterproof plasters but it's not healing. I do clean the would with disinfectant before dressing it. What can I do?
If by "disinfectant" you mean something like hydrogen peroxide, you need to stop using that. It actually prevents wounds from healing.
" If the wound is minor enough to be treated at home, antiseptics such as hydrogen peroxide, rubbing alcohol, Purell, iodine, salt, or baking powder should never be applied to the wound. While antiseptics effectively kill bacteria with little harm when applied to the outside of healthy skin, they do more harm than good when applied to wounds."
Source:
https://wtamu.edu/~cbaird/sq/2013/04/04/how-often-should-hydrogen-peroxide-be-used-to-treat-wounds/#:~:text=Hydrogen%20peroxide%20should%20never%20be,does%20more%20harm%20than%20good.
https://my.clevelandclinic.org/health/diseases/17169-leg-and-foot-ulcers