Additive effects of thermal injury and infection on gut permeability
C. M. Ryan, S. H. Bailey, E. A. Carter, D. A. Schoenfeld and R. G. Tompkins
Surgical Service, Massachusetts General Hospital, Boston.
OBJECTIVE: To determine the effects of burn size and burn wound infection
on gut permeability to the macromolecule polyethylene glycol 3350 (PEG
3350; molecular weight, 3350 d). DESIGN: Randomized, controlled study using
36 male Sprague-Dawley rats. SETTING: Hospital research laboratory.
INTERVENTIONS: Animals received scald burns to 0%, 20%, or 35% of their
total body surface area. Half of the animals in each group were infected
with Pseudomonas aeruginosa. MAIN OUTCOME MEASURES: Gut permeability was
measured using the intestinal absorption and renal excretion of enterally
administered PEG 3350 and mannitol (molecular weight, 182 d). RESULTS:
There were dramatic increases in PEG 3350 excretion and in the PEG
3350/mannitol ratios (P = .0001 in both instances) that were seen in
relation to burn size. Significant increases in PEG 3350 excretion and in
the PEG 3350/mannitol ratios (P = .017 and P = .045, respectively) were
also seen in animals in which infection was present. This was in addition
to the effects of burn size already noted. CONCLUSIONS: A direct
relationship between gut permeability and the extent of burn injury was
found, which is consistent with the results from a previous study in
humans. In addition, this study found that further separate increases in
gut permeability occur in the presence of P aeruginosa in burn wound
infections.
