Assisted ventilation modes reduce the expression of lung inflammatory and fibrogenic mediators in a model of mild acute lung injury
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The goal of the study was to compare the effects of different assisted ventilation modes with pressure controlled ventilation (PCV) on lung histology, arterial blood gases, inflammatory and fibrogenic mediators in experimental acute lung injury (ALI).
Paraquat-induced ALI rats were studied. At 24 h, animals were anaesthetised and further randomized as follows (n = 6/group): (1) pressure controlled ventilation mode (PCV) with tidal volume (V T) = 6 ml/kg and inspiratory to expiratory ratio (I:E) = 1:2; (2) three assisted ventilation modes: (a) assist-pressure controlled ventilation (APCV1:2) with I:E = 1:2, (b) APCV1:1 with I:E = 1:1; and (c) biphasic positive airway pressure and pressure support ventilation (BiVent + PSV), and (3) spontaneous breathing without PEEP in air. PCV, APCV1:1, and APCV1:2 were set with P insp = 10 cmH2O and PEEP = 5 cmH2O. BiVent + PSV was set with two levels of CPAP [inspiratory pressure (P High = 10 cmH2O) and positive end-expiratory pressure (P Low = 5 cmH2O)] and inspiratory/expiratory times: T High = 0.3 s and T Low = 0.3 s. PSV was set as follows: 2 cmH2O above P High and 7 cmH2O above P Low. All rats were mechanically ventilated in air and PEEP = 5 cmH2O for 1 h.
Assisted ventilation modes led to better functional improvement and less lung injury compared to PCV. APCV1:1 and BiVent + PSV presented similar oxygenation levels, which were higher than in APCV1:2. Bivent + PSV led to less alveolar epithelium injury and lower expression of tumour necrosis factor-α, interleukin-6, and type III procollagen.
In this experimental ALI model, assisted ventilation modes presented greater beneficial effects on respiratory function and a reduction in lung injury compared to PCV. Among assisted ventilation modes, Bi-Vent + PSV demonstrated better functional results with less lung damage and expression of inflammatory mediators.
KeywordsAcute lung injury Ventilator-associated lung injury Cytokines Type III procollagen
We would like to express our gratitude to Mr. Andre Benedito da Silva for animal care, Mrs. Miriam Regina Taborda Simone and Ana Lucia Neves da Silva for their help with microscopy, Ms. Jaqueline Lima do Nascimento for her skillful technical assistance during the experiments, Mrs. Moira Elizabeth Schöttler for assistance in editing the manuscript, and Maquet for borrowing us Servo-I ventilator. Supported by Centres of Excellence Program (PRONEX-FAPERJ), Brazilian Council for Scientific and Technological Development (CNPq), Carlos Chagas Filho, Rio de Janeiro State Research Supporting Foundation (FAPERJ), São Paulo State Research Supporting Foundation (FAPESP).
- 1.Esteban A, Alía I, Tobin MJ, Gil A, Gordo F, Vallverdú I, Blanch L, Bonet A, Vázquez A, de Pablo R, Torres A, de La Cal MA, Macías S, Spanish Lung Failure Collaborative Group (1999) Effect of spontaneous breathing trial duration on outcome of attempts to discontinue mechanical ventilation. Am J Respir Crit Care Med 159:512–518PubMedGoogle Scholar
- 9.Kallet RH, Daniel BM, Gropper M, Matthay MA (1998) Acute pulmonary edema following upper airway obstruction: case reports and brief review. Respir Care 43:476–480Google Scholar
- 19.Weibel ER (1990) Morphometry: stereological theory and practical methods. In: Gil J (ed) Models of lung disease-microscopy and structural methods. Marcel Dekker, New York, pp 199–247Google Scholar
- 21.Pássaro CP, Silva PL, Rzezinski AF, Abrantes S, Santiago VR, Nardelli L, Santos RS, Barbosa CM, Morales MM, Zin WA, Amato MB, Capelozzi VL, Pelosi P, Rocco PR (2009) Pulmonary lesion induced by low and high positive end-expiratory pressure levels during protective ventilation in experimental acute lung injury. Crit Care Med 37:1011–1017. doi: 10.1097/CCM.0b013e3181962d85 CrossRefPubMedGoogle Scholar
- 22.Steimback PW, Oliveira GP, Rzezinski AF, Silva PL, Garcia CS, Rangel G, Morales MM, Lapa E, Silva JR, Capelozzi VL, Pelosi P, Rocco PR (2009) Effects of frequency and inspiratory plateau pressure during recruitment manoeuvres on lung and distal organs in acute lung injury. Intensive Care Med 35:1120–1128. doi: 10.1007/s00134-009-1439-y CrossRefPubMedGoogle Scholar
- 23.Leite-Junior JH, Garcia CS, Souza-Fernandes AB, Silva PL, Ornellas DS, Larangeira AP, Castro-Faria-Neto HC, Morales MM, Negri EM, Capelozzi VL, Zin WA, Pelosi P, Bozza PT, Rocco PR (2008) Methylprednisolone improves lung mechanics and reduces the inflammatory response in pulmonary but not in extrapulmonary mild acute lung injury in mice. Crit Care Med 36:2621–2628. doi: 10.1097/CCM.0b013e3181847b43 CrossRefPubMedGoogle Scholar
- 25.[No authors listed] (2000) Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. The Acute Respiratory Distress Syndrome Network. N Engl J Med 342:1301–1308Google Scholar
- 26.Farias LL, Faffe DS, Xisto DG, Santana MC, Lassance R, Prota LF, Amato MB, Morales MM, Zin WA, Rocco PR (2005) Positive end-expiratory pressure prevents lung mechanical stress caused by recruitment/derecruitment. J Appl Physiol 98:53–61. doi: 10.1152/japplphysiol.00118.2004 CrossRefPubMedGoogle Scholar
- 34.Wrigge H, Zinserling J, Neumann P, Muders T, Magnusson A, Putensen C, Hedenstierna G (2005) Spontaneous breathing with airway pressure release ventilation favors ventilation in dependent lung regions and counters cyclic alveolar collapse in oleic-acid-induced lung injury: a randomized controlled computed tomography trial. Crit Care 9:R780–R789. doi: 10.1186/cc3908 CrossRefPubMedGoogle Scholar
- 38.Fanelli V, Mascia L, Puntorieri V, Assenzio B, Elia V, Fornaro G, Martin EL, Bosco M, Delsedime L, Fiore T, Grasso S, Ranieri VM (2009) Pulmonary atelectasis during low stretch ventilation: “open lung” versus “lung rest” strategy. Crit Care Med 37:1046–1053. doi: 10.1097/CCM.0b013e3181968e7e CrossRefPubMedGoogle Scholar
- 41.Spieth PM, Carvalho AR, Pelosi P, Hoehn C, Meissner C, Kasper M, Hübler M, von Neindorff M, Dassow C, Barrenschee M, Uhlig S, Koch T, de Abreu MG (2009) Variable tidal volumes improve lung protective ventilation strategies in experimental lung injury. Am J Respir Crit Care Med 179:684–693. doi: 10.1164/rccm.200806-975OC CrossRefPubMedGoogle Scholar
- 42.Gama de Abreu M, Spieth PM, Pelosi P, Carvalho AR, Walter C, Schreiber-Ferstl A, Aikele P, Neykova B, Hübler M, Koch T (2008) Noisy pressure support ventilation: a pilot study on a new assisted ventilation mode in experimental lung injury. Crit Care Med 36:818–827. doi: 10.1097/01.CCM.0000299736.55039.3A CrossRefPubMedGoogle Scholar