Effect of PEEP and inhaled nitric oxide on pulmonary gas exchange during gaseous and partial liquid ventilation with small volumes of perfluorocarbon.
BACKGROUND
Partial liquid ventilation, positive end-expiratory pressure (PEEP) and inhaled nitric oxide (NO) can improve ventilation/perfusion mismatch in acute lung injury (ALI). The aim of the present study was to compare gas exchange and hemodynamics in experimental ALI during gaseous and partial liquid ventilation at two different levels of PEEP, with and without the inhalation of nitric oxide.


METHODS
Seven pigs (24+/-2 kg BW) were surfactant-depleted by repeated lung lavage with saline. Gas exchange and hemodynamic parameters were assessed in all animals during gaseous and subsequent partial liquid ventilation at two levels of PEEP (5 and 15 cmH2O) and intermittent inhalation of 10 ppm NO.


RESULTS
Arterial oxygenation increased significantly with a simultaneous decrease in cardiac output when PEEP 15 cmH2O was applied during gaseous and partial liquid ventilation. All other hemodynamic parameters revealed no relevant changes. Inhalation of NO and instillation of perfluorocarbon had no additive effects on pulmonary gas exchange when compared to PEEP 15 cmH2O alone.


CONCLUSIONS
In experimental lung injury, improvements in gas exchange are most distinct during mechanical ventilation with PEEP 15 cmH2O without significantly impairing hemodynamics. Partial liquid ventilation and inhaled NO did not cause an additive increase of PaO2.
Max
M
M
Klinik für Anästhesie, Medizinische Einrichtungen der RWTH Aachen, Germany. Martin.Max2@post.rwth-aachen.de
Kuhlen
R
R
Falter
F
F
Reyle-Hahn
M
M
Dembinski
R
R
Rossaint
R
R
D000280:Administration, Inhalation; D000818:Animals; D001794:Blood Pressure; D002302:Cardiac Output; D005260:Female; D005466:Fluorocarbons; D006842:Hydrocarbons, Brominated; D009569:Nitric Oxide / Q000008:administration & dosage*; D011175:Positive-Pressure Respiration / Q000379:methods; D011659:Pulmonary Gas Exchange; D012121:Respiration, Artificial; D012128:Respiratory Distress Syndrome / Q000503:physiopathology / Q000628:therapy; D015656:Respiratory Mechanics; D013552:Swine
D005466:Fluorocarbons; D006842:Hydrocarbons, Brominated; D009569:Nitric Oxide; C003072:perflubron