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.

Anti-osteosarcoma effect of antiserum against cross antigen TPD52 between osteosarcoma and Trichinella spiralis

“…The heart, liver, spleen, lung, and kidneys of each group of nude mice were harvested for haematoxylin and eosin (HE) staining, and the histopathological damage was observed under a microscope. The heart, liver, spleen, lung, and kidneys were scored using the histopathological scoring scale used by Wu [ 31 ], Camargo [ 32 ], Schwab [ 33 ], Kredel [ 34 ], and Jha [ 35 ]. The score was positively correlated with pathological changes.…”