Sistema FMUSP-HC: Faculdade de Medicina da Universidade de São Paulo (FMUSP) e Hospital das Clínicas da FMUSPSANTOS, Raquel S.MAIA, Ligia de A.OLIVEIRA, Milena V.SANTOS, Cintia L.MORAES, LillianPINTO, Eliete F.SAMARY, Cynthia dos S.MACHADO, Joana A.CARVALHO, Anna CarolinnaFERNANDES, Marcos Vinicius de S.MARTINS, VanessaCAPELOZZI, Vera L.MORALES, Marcelo M.KOCH, TheaABREU, Marcelo Gama dePELOSI, PaoloSILVA, Pedro L.ROCCO, Patricia R. M.2018-09-132018-09-132018ANESTHESIOLOGY, v.128, n.6, p.1193-1206, 20180003-3022https://observatorio.fm.usp.br/handle/OPI/28248Background: The authors hypothesized that low tidal volume (V-T) would minimize ventilator-induced lung injury regardless of the degree of mechanical power. The authors investigated the impact of power, obtained by different combinations of V-T and respiratory rate (RR), on ventilator-induced lung injury in experimental mild acute respiratory distress syndrome (ARDS). Methods: Forty Wistar rats received Escherichia coli lipopolysaccharide intratracheally. After 24h, 32 rats were randomly assigned to be mechanically ventilated (2 h) with a combination of different V-T (6 ml/kg and 11 ml/kg) and RR that resulted in low and high power. Power was calculated as energy (Delta P,(2)(L)/E,(L)) x RR (Delta P,(L) = transpulmonary driving pressure; E,(L) = lung elastance), and was three-fold higher in high than in low power groups. Eight rats were not mechanically ventilated and used for molecular biology analysis. Results: Diffuse alveolar damage score, which represents the severity of edema, atelectasis, and overdistension, was increased in high V-T compared to low V-T, in both low (low V-T: 11 [9 to 14], high V-T: 18 [15 to 20]) and high (low V-T: 19 [16 to 25], high V-T: 29 [27 to 30]) power groups. At high V-T, interleukin-6 and amphiregulin expressions were higher in high-power than in low-power groups. At high power, amphiregulin and club cell protein 16 expressions were higher in high V-T than in low V-T. Mechanical energy and power correlated well with diffuse alveolar damage score and interleukin-6, amphiregulin, and club cell protein 16 expression. Conclusions: In experimental mild ARDS, even at low V-T, high mechanical power promoted ventilator-induced lung injury. To minimize ventilator-induced lung injury, low V-T should be combined with low power.engrestrictedAccessinduced lung injuryend-expiratory pressuredriving pressureventilationpulmonaryflowinflammationmetaanalysishypercapniastrategiesarticleCopyright LIPPINCOTT WILLIAMS & WILKINS10.1097/ALN.0000000000002143Anesthesiology1528-1175