Objective—To evaluate the effect of a phospholipid
emulsion (PLE) on the initial response of horses to
administration of endotoxin.
Animals—12 healthy adult horses.
Procedures—Horses were assigned to 2 treatment
groups (6 horses/group). The control group was
administered 1 L of saline (0.9% NaCl) solution, and
the treated group was administered PLE (200 mg/kg,
IV); treatments were administered during a period of
120 minutes. An infusion of endotoxin was initiated in
both groups starting 1 hour after initiation of the
saline or PLE solutions. Physical examination and
hemodynamic variables were recorded, and blood
samples were analyzed for concentrations of tumor
necrosis factor (TNF)-α, interleukin-6, thromboxane B2
(TxB2), 6 keto-prostaglandin F (PGF)1α, total leukocyte
count, and PLE concentrations. An ANOVA was used
to detect significant differences.
Results—Administration of PLE resulted in significantly
lower rectal temperature, heart rate, cardiac
output, right atrial pressure, and pulmonary artery
pressure and higher total leukocyte counts in treated
horses, compared with values for control horses. The
TNF-α concentration was significantly less in treated
horses than in control horses. The TxB2 and 6 keto-
PGF1α concentrations were significantly different
between treated and control horses at 30 minutes
(TxB2) and at 30 and 60 minutes (6 keto-PGF1α).
Conclusions and Clinical Relevance—Prior infusion
of PLE in horses administered a low dose of endotoxin
decreased rectal temperature, heart rate, pulmonary
artery pressure, and TNF-α concentrations.
Results of this study support further evaluation of PLE
for use in the treatment of horses with endotoxemia.
(Am J Vet Res 2002;63:1370–1378)