[libribook.com] Traumatic Scar Tissue Management 1st Edition

from the tissues and taken up by the lymphatic system. The rate of lymph flow
from burn-injured tissue directly correlates with the amount of fluid crossing the
capillary membrane into the interstitial space during the edema process. The
fluid is protein-rich, as evidenced by the high content of lymph albumin and
globulin relative to the plasma protein value. The continued increase in lymph
flow for more than 36 hours after burn injury indicates that the increased
capillary permeability to protein persists for several days (Shankar et al. 2007).
Lymph flow rate and lymph protein content have been used frequently to
monitor microvascular fluid filtration rate and protein permeability
characteristics. Lymph flow rate reflects the degree of either fluid fluctuation or
transport across the capillary at any given moment, as the lymph channels open
very close to the capillary interstitium.
Several researchers have used various lymph preparations for the study of burn
edema. The concentration of large molecules in lymph, such as protein or
dextrans, has been used to determine the permeability characteristics of the
microcirculation. Because lymph is derived from interstitial fluid, various
vasoactive substances released from the burn may appear in high concentration
in the regional lymph areas that are injured (Demling 2005).
Lymph flow appears to be a valid means of accurately monitoring partialthickness
burns, or non-burned tissue, where capillaries and lymphatics remain
intact.
With deeper burns, capillary or microvascular occlusion decreases the perfusion
(delivery of blood) to the burn tissue. Therefore, less fluid is likely to enter the
interstitium and local lymphatics. In addition, subsequent lymphatic damage
decreases the efficiency of the lymphatic network.
The concentration of larger molecules in the lymph fluid, such as proteins, has
been used to study the permeability of microcirculation. The microcirculation is
highly responsive to, and a vital participant in, the inflammatory response.
Because a burn patient receives high volumes of fluid in the early stages of
injury, the measured lymph flow rate in deep burns is likely to underestimate the
actual degree of injury and the actual edema formation in deeper burns (Demling
2005).
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