Am. J. Respir. Crit. Care Med.,
Volume 164, Number 4, August 2001, 642-647
Application of Tracheal Gas Insufflation to Acute
Unilateral Lung Injury in an Experimental Model
LLUIS
BLANCH,
THOMAS E.
VAN der KLOOT,
A. MELYNNE
YOUNGBLOOD,
GASTON
MURIAS,
ALBERTO
NAVEIRA,
ALEX B.
ADAMS,
PABLO V.
ROMERO,
and
AVI
NAHUM
Department of Pulmonary and Critical Care Medicine, University of Minnesota, Regions Hospital, St. Paul, Minnesota; Servei de Medicina Intensiva,
Hospital de Sabadell, Corporació Parc Tauli, Sabadell, Spain; and Servei de Pneumologia i Unitat de Recerca Experimental, Hospital Universitari de
Bellvitge, Hospitalet de Llobregat, Barcelona, Spain
In unilateral lung injury, application of global positive end-expiratory pressure (PEEP) may cause overdistension of normal alveoli
and redistribution of blood flow to diseased lung areas, thereby
worsening oxygenation. We hypothesized that selective application of tracheal gas insufflation (TGI) will recruit the injured lung
without causing overdistension of the normal lung. In eight anesthetized dogs, left lung saline lavage was performed until PaO2/FIO2
fell below 100 mm Hg. Then, the dogs were reintubated with a
Univent single lumen endotracheal tube that incorporates an internal catheter to provide TGI. After injury, increasing PEEP from 3 to 10 cm H2O did not change gas exchange, hemodynamics, or
lung compliance. Selective TGI, while keeping end-expiratory lung
volume (EELV) constant, improved PaO2/FIO2 from 212 ± 43 to 301 ± 38 mm Hg (p < 0.01) while PaCO2 and airway pressures decreased
(p < 0.01). During selective TGI, reducing tidal volume to 5.2 ml/kg
while keeping EELV constant, normalized PaCO2, did not affect
PaO2/FIO2, and decreased end-inspiratory plateau pressure from
16.6 ± 1.0 to 11.9 ± 0.5 cm H2O (p < 0.01). In unilateral lung injury, we conclude that selective TGI (1) improves oxygenation at a
lower pressure cost as compared with conventional mechanical ventilation, (2) allows reduction in tidal volume without a change in alveolar ventilation, and (3) may be a useful adjunct to limit ventilator-associated lung injury.
