Chapter 6. Wound Healing
Which phase of acute wound healing is prolonged during progression to a chronic wound?
The correct answer is B. Inflammation. An acute wound is defined by its ability to normally progress, in a predictable and timely manner, through all of the phases of wound healing; coagulation, inflammation, fibroplasia, angiogenesis, and remodeling. A protracted inflammatory phase is the usual mechanism for the formation of a chronic wound. All clinical efforts should be made to reduce chronic wound inflammation in an effort to support healing.
Which cell is most important for signaling wound healing?
The correct answer is C. Macrophage. The macrophage is the most important source of growth factor signals for wound healing. Experimental studies show that wound healing is most impaired in the absence of macrophages. Although fibroblasts are the main source of collagen synthesis and endothelial cells are required for revascularization, they are dependent on macrophage signaling to stimulate and direct tissue repair. A platelet is not a cell.
Which is the most predictive direct measure of impaired or delayed wound healing?
The correct answer is E. Tco2 < 30 mm Hg. Wounds will not heal when the tissue concentration of oxygen falls below 30 mm Hg. It is the most powerful predictive measure of delayed or impaired wound healing. Vitamin C deficiency may result in impaired collagen cross linking (scurvy) and weak scars. Low serum albumin predicts increased wound complications, like wound infection. The microangiopathy of radiated tissue indirectly reduces perfusion and therefore, Tco2 levels. Finally, smoking impairs wound healing through the vasoconstrictive effects of chronic nicotine and relative hypoxia as well.
Which of the following is not a clinical impediment to wound healing?