Vol. 89, Issue 4, 1513-1521, October 2000
Unilateral lung edema: effects on pulmonary gas
exchange, hemodynamics, and pulmonary perfusion distribution
Klaus
Slama1,
Mareike
Gesch2,
Johannes C.
Böck3,
Sylvia M.
Pietschmann2,
Walter
Schaffartzik4, and
Ulrich
Pison2
1 Department of Anesthesiology, Krankenhaus Spandau,
D-13578; Departments of 2 Anesthesiology and Intensive Care
Medicine and 3 Radiology, Charité, Campus
Virchow-Klinikum, Humboldt-University, D-13353; and 4 Department
of Anesthesiology, Critical Care Medicine, and Pain Therapy,
Unfallkrankenhaus Marzahn, D-12683 Berlin, Germany
Two types of unilateral
lung edema in sheep were characterized regarding their effects on
pulmonary gas exchange, hemodynamics, and distribution of pulmonary
perfusion. One edema type was induced with aerosolized HCl (0.15 M, pH
1.0) and the other with NaCl (0.15 M, pH 7.4). Both aerosols were
nebulized continuously for 4 h into left lungs. In HCl-treated
animals, pulmonary gas exchange deteriorated [from a partial arterial
O2 pressure-to-inspired O2 fraction ratio
(PaO2/FIO2)
of 254 at baseline to 187 after 4 h HCl]. In addition,
pulmonary artery pressure and total pulmonary vascular resistance
increased (from 16 to 19 mmHg and from 133 to 154 dyn · s · cm
5, respectively). In
NaCl-treated animals, only the central venous pressure significantly
increased (from 7 to 9 mmHg). Distribution of pulmonary perfusion
(measured with fluorescent microspheres) changed differently in both
groups. After HCl application, 6% more blood flow was directed to the
treated lung, whereas, after NaCl, 5% more blood flow was directed to
the untreated lung. HCl and NaCl treatment both induce an equivalent
lung edema, but only HCl treatment is associated with gas exchange
alteration and tissue damage. Redistribution of pulmonary perfusion
maintains gas exchange during NaCl treatment and decreases it during
HCl inhalation.
respiratory distress syndrome; heart-lung interactions; hydrostatic
and permeability lung edema; lung injury
