title: Pulmonary effects of positive end-expiratory pressure and fluid therapy in experimental lung injury.
abstract: The separate effects of positive end-expiratory pressure (PEEP) and intravascular volume administration on the histopathologic lung injury were not investigated in experimental lung injury previously. The authors hypothesized that high PEEP and a restrictive volume therapy would yield the best oxygenation and the least degree of lung injury. Pigs (52.8 ± 3.4 kg) underwent saline lavage-induced lung injury. The animals were ventilated either with low PEEP (mean PEEP 9 to 12 cm H₂O) and liberal volume therapy using hydroxyethyl starch (LowP/Vol+) or high PEEP (mean PEEP 21 cm H₂O) combined with recruitment maneuvers and liberal (HighP/Vol+) or restrictive volume therapy (HighP/Vol-). After 6.5 hours, lung injury was determined by using a histopathologic score evaluating overdistension, edema, exsudation, and inflammation. When volume therapy was liberal, high PEEP (HighP/Vol+) improved the Pao₂/Fio₂ index (416 ± 80 mm Hg) compared to low PEEP (LowP/Vol+, 189 ± 55 mm Hg; P < .05) but there was no difference in the median (interquartile range) lung injury score: 1.6 (1.2-1.9) and 1.9 (1.4-2.0). High PEEP with restrictive volume therapy (HighP/Vol-) did not further improve oxygenation (400 ± 55 mm Hg) but ameliorated the degree of lung injury: 0.9 (0.8-1.4) (P < .05). In lavage-induced lung injury, high PEEP improved oxygenation, but restrictive volume administration markedly reduced the lung injury score, mainly by reduced edema.
authors.affiliation: Department of Anaesthesia and Critical Care, University of Würzburg, Würzburg, Germany. Kredel_M@klinik.uni-wuerzburg.de
authors.forename: Markus
authors.initials: M
authors.lastname: Kredel
authors.forename: Ralf M
authors.initials: RM
authors.lastname: Muellenbach
authors.forename: Nicolas
authors.initials: N
authors.lastname: Schlegel
authors.forename: Christian
authors.initials: C
authors.lastname: Wunder
authors.forename: Michael
authors.initials: M
authors.lastname: Klingelhöfer
authors.forename: Markus
authors.initials: M
authors.lastname: Lange
authors.forename: Norbert
authors.initials: N
authors.lastname: Roewer
authors.forename: Jens
authors.initials: J
authors.lastname: Waschke
authors.forename: Jörg
authors.initials: J
authors.lastname: Brederlau
mesh_terms: D000818:Animals; D003131:Combined Modality Therapy; D004195:Disease Models, Animal; D005260:Female; D005440:Fluid Therapy; D006439:Hemodynamics; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology*; D008168:Lung / Q000473:pathology / Q000503:physiopathology*; D008170:Lung Compliance; D055370:Lung Injury / Q000209:etiology / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D010952:Plasma Substitutes / Q000494:pharmacology*; D011014:Pneumonia / Q000503:physiopathology / Q000628:therapy; D011175:Positive-Pressure Respiration; D011312:Pressure; D011654:Pulmonary Edema / Q000503:physiopathology / Q000628:therapy; D015656:Respiratory Mechanics; D056152:Respiratory Rate; D012720:Severity of Illness Index; D012965:Sodium Chloride; D013552:Swine; D013997:Time Factors
chemical_list: D006895:Hydroxyethyl Starch Derivatives; D010952:Plasma Substitutes; D012965:Sodium Chloride