Comparação dos efeitos da posição prona associada à ventilação oscilatória de alta frequência e à mecânica convencional protetora em lesão pulmonar aguda induzida experimentalmente
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Data
2013-01-28
Autores
Klefens, Susiane de Oliveira [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
A Síndrome do Desconforto Respiratório Agudo (SDRA) caracteriza-se por processo inflamatório com desenvolvimento de edema intersticial e alveolar, diminuição da complacência pulmonar e hipoxemia refratária à administração de oxigênio. Estudos tomográficos de pulmões em pacientes com SDRA demonstraram que o comprometimento pulmonar é heterogêneo e que a lesão varia de acordo com o posicionamento, sendo maior o comprometimento nas áreas dependentes da gravidade. Dessa forma, a colocação do paciente em posição prona passou a integrar o arsenal de terapias adjuvantes na SDRA. A ventilação pulmonar mecânica (VM) constitui um dos pilares do tratamento da SDRA, sendo capaz de modificar a evolução da doença. Existem dois métodos ventilatórios de proteção pulmonar utilizados na síndrome, um baseado na VM convencional (VMC) e outro na ventilação oscilatória de alta frequência (VOAF). O objetivo do estudo foi comparar os efeitos da VOAF e da VMC protetora associadas à posição prona sobre oxigenação, inflamação, histologia e dano oxidativo pulmonar, em modelo experimental de lesão pulmonar aguda (LPA) induzida em coelhos. Quarenta e cinco coelhos foram instrumentados com traqueostomia, acessos vasculares e ventilados mecanicamente. A LPA foi induzida por infusão traqueal de salina aquecida (30mL/Kg, 38°C). Foram formados três grupos experimentais: a) Animais sadios + VMC Protetora [grupo controle (GC) em posição supina; n=15]; b) Animais com LPA + VMC Protetora (posição prona, GVMC; n=15); c) Animais com LPA + VOAF (posição prona, GVAF; n=15). Após 10 minutos do início da ventilação específica de cada grupo, foi colhida gasometria arterial, sendo este momento denominado tempo zero (T0), após o qual o animal foi posicionado em posição prona assim permanecendo por 4 horas. A oxigenação foi avaliada pela relação PaO2/FiO2, a inflamação pulmonar pelo nível...
Acute Respiratory Distress Syndrome (ARDS) is characterized by inflammation with development of interstitial and alveolar edema, decreased lung compliance and hypoxemia refractory to oxygen. Tomographic studies in the lungs of patients with ARDS have shown that impaired lung is heterogeneous and that injury varies with the position being higher in the areas commitment dependent on gravity. Thus, placing the patient in the prone position became part of the arsenal of adjuvant therapies for ARDS. Mechanical ventilation (MV) is the most important ARDS treatment, being able to modify the course of disease. There are two protective ventilatory methods, one based on conventional MV (CMV) and the other in high-frequency oscillatory ventilation (HFOV). The aim of this study was to compare the effects of HFOV and CMV protective associated with prone position on oxygenation, inflammation, histology and oxidative lung damage in an experimental model of acute lung injury (ALI) induced in rabbits. Forty-five rabbits were instrumented with tracheostomy, vascular access and mechanically ventilated. ALI was induced by infusion of warm saline tracheal (30ml/kg, 38° C). The study involved three groups: a) Healthy animals + Protective CMV [control group (CG) in the supine position, n = 15], b) animals with ALI + Protective CMV (prone position, GVMC, n = 15); c) Animals with ALI + HFOV (prone position, GVAF, n = 15). After 10 minutes of the beginning of each group of specific ventilation an arterial blood gases was collected, being designated time zero point (T0). After that the animal was placed in prone position and remained so for 4 hours. Oxygenation was measured by PaO2/FiO2 ratio, lung inflammation by TNF-alpha and counting of the number of polymorphonuclear cells (PMN) recovered from bronchoalveolar lavage fluid (BAL), pulmonary oxidative stress was determined by Total Antioxidant Performance Assay (TAP) and ...
Acute Respiratory Distress Syndrome (ARDS) is characterized by inflammation with development of interstitial and alveolar edema, decreased lung compliance and hypoxemia refractory to oxygen. Tomographic studies in the lungs of patients with ARDS have shown that impaired lung is heterogeneous and that injury varies with the position being higher in the areas commitment dependent on gravity. Thus, placing the patient in the prone position became part of the arsenal of adjuvant therapies for ARDS. Mechanical ventilation (MV) is the most important ARDS treatment, being able to modify the course of disease. There are two protective ventilatory methods, one based on conventional MV (CMV) and the other in high-frequency oscillatory ventilation (HFOV). The aim of this study was to compare the effects of HFOV and CMV protective associated with prone position on oxygenation, inflammation, histology and oxidative lung damage in an experimental model of acute lung injury (ALI) induced in rabbits. Forty-five rabbits were instrumented with tracheostomy, vascular access and mechanically ventilated. ALI was induced by infusion of warm saline tracheal (30ml/kg, 38° C). The study involved three groups: a) Healthy animals + Protective CMV [control group (CG) in the supine position, n = 15], b) animals with ALI + Protective CMV (prone position, GVMC, n = 15); c) Animals with ALI + HFOV (prone position, GVAF, n = 15). After 10 minutes of the beginning of each group of specific ventilation an arterial blood gases was collected, being designated time zero point (T0). After that the animal was placed in prone position and remained so for 4 hours. Oxygenation was measured by PaO2/FiO2 ratio, lung inflammation by TNF-alpha and counting of the number of polymorphonuclear cells (PMN) recovered from bronchoalveolar lavage fluid (BAL), pulmonary oxidative stress was determined by Total Antioxidant Performance Assay (TAP) and ...
Descrição
Palavras-chave
Sindrome do desconforto respiratorio, Decúbito ventral, Pulmões - Doenças, Respiracao artificial, Ventilação de alta frequência, Respiratory Distress Syndrome
Como citar
KLEFENS, Susiane de Oliveira. Comparação dos efeitos da posição prona associada à ventilação oscilatória de alta frequência e à mecânica convencional protetora em lesão pulmonar aguda induzida experimentalmente. 2013. 42 f. Dissertação (mestrado) - Universidade Estadual Paulista Julio de Mesquita Filho, Faculdade de Medicina de Botucatu, 2013.