There may be a loss of bowel and bladder function as the nervous system shuts down. The caregiver - usually a nurse or hospice caretaker - may suggest a catheter to collect urine; you can also place absorbent pads on the bed in case of accidents.
Fibroblasts begin entering the wound site two to five days after wounding as the inflammatory phase is ending, and their numbers peak at one to two weeks post-wounding. By the end of the first week, fibroblasts are the main cells in the wound. Fibroplasia ends two to four weeks after wounding.
With scrapes like these, the scab tends to stay in place for a few weeks, after which it will fall off to reveal the new skin, which tends to be initially bright pink in color but may change to a brownish color as you have noticed as well.