Objective: To document the effect of administering artificial surfacta
nt into the trachea, either by instillation or aerosolization, on acut
e lung injury experimentally induced with kerosene in sheep. Design: R
andomized, prospective, controlled study, Setting: Research laboratory
, Subjects: Sheep (n = 24), weighing 8.5 to 25.2 kg (average 16.6). In
terventions: In anesthetized, tracheally intubated sheep with pulmonar
y and femoral artery catheters inserted, lung injury was induced by in
stilling kerosene (0.3 mL/kg) into the trachea. After 15 mins of spont
aneous breathing, mechanical ventilation was instituted with a uniform
Fro, and a tidal volume of 10 mL/kg, Sheep were then assigned randoml
y to one of four regimens as follows: exogenous surfactant or saline (
5 mL/kg each) was administered as a bolus intratracheally or by aeroso
lization for 6 hrs, Measurements and Main Results: Arterial and mixed
venous blood gases, pH, airway pressure, and static respiratory system
compliance were measured and compared between aerosol saline and aero
sol surfactant and between bolus saline and bolus surfactant. For all
variables except static respiratory system compliance, the hourly rate
of change from 15 mins, 1 hr, and 6 hrs after kerosene instillation w
as determined for each animal, and group rank sums of hourly rates of
change were compared. For static respiratory system compliance, the sl
ope of the pressure-volume curve with volumes of 100, 200, 300, 400, a
nd 500 mt was computed for each animal at baseline and at 3 and 6 hrs
after kerosene instillation, Group rank sums for static respiratory sy
stem compliance at 3 and 6 hrs were compared, Also, the 3- and 6-hr st
atic respiratory system compliance values at each of the volumes were
compared. With saline, six of eight sheep died; with surfactant, no sh
eep died (p=.001), When compared with saline at 15 mins, 1 hr, and 6 h
rs after kerosene instillation, surfactant, regardless of whether admi
nistered by aerosol or bolus, significantly increased rate of change o
f arterial oxygen saturation, mixed venous oxygen saturation, and Po-2
. Conclusions: In the present animal study, artificial surfactant was
an effective treatment for hydrocarbon aspiration, Aerosolized surfact
ant achieved results similar to instilled surfactant but at a lower to
tal dose.