Wound Care

140 Nurse to Nurse
Tunica initima
Endothelium
Internal elastic membrane
Tunica media
Tunica adventitia
Smooth muscle
External elastic membrane
Adventitia
Figure 5–2A Anatomy of a Blood Vessel. (Reproduced with permission
from Wound Care Made Incredibly Easy. 2nd ed. Philadelphia,
PA: Lippincott Williams and Wilkins; 2007.)
Conditions that contribute to the increase in viscosity
are dehydration and polycythemia. Mild dehydration
in an older individual may result in a decrease of
extremity perfusion. Rehydrating an elderly person
may therefore reduce the red cell mass and allow
improved perfusion
In the case of abnormal concentrations of proteins such
as multiple myeloma, which increases viscosity, the
treatment of choice may be plasmapheresis.
— Another determinant of perfusion is red blood cell (RBC)
deformity or how readily the individual RBCs change cell
shape. If the individual has a condition that causes the
RBCs to maintain rigid cell membranes, tissue perfusion
decreases from the precapillary to postcapillary level.