Influência da estratégia ventilatória no desempenho funcional de enxertos pulmonares em um modelo experimental de transplante pulmonar unilateral de doadores após parada cardiocirculatória

Abstract

Objective: To compare the influence of two different ventilation strategies-volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV)-on the functional performance of lung grafts in a canine model of unilateral left lung transplantation using donor lungs harvested after three hours of normothermic cardiocirculatory arrest under mechanical ventilation. Methods: The study comprised 40 mongrel dogs, randomized into two groups: VCV and PCV. Of the 20 recipients, 5 did not survive the transplant, and 5 died before the end of the post-transplant assessment period. The remaining 10 survivors (5 in each group) were evaluated for 360 min after lung transplantation. The functional performance of the grafts was evaluated regarding respiratory mechanics, gas exchange, and lung graft histology. Results: There were no significant differences between the groups regarding respiratory mechanics (peak inspiratory pressure, plateau pressure, mean airway pressure, dynamic compliance, and static compliance) or gas exchange variables (PaO 2 , venous oxygen tension, PaCO 2 , venous carbon dioxide tension, and the arterial-venous oxygen content difference). The histopathological findings were consistent with nonspecific acute lung injury and did not differ between the groups. Conclusions: This model of lung transplantation showed that the functional performance of lung grafts was not influenced by the ventilation strategy employed during the first six hours after reperfusion.Keywords: Pulmonary ventilation; Respiration, artificial; Lung transplantation; Dogs; Organ preservation. ResumoObjetivo: Comparar a influência de duas estratégias ventilatórias -ventilação controlada a volume (VCV) e ventilação controlada a pressão (VCP) -no desempenho funcional de enxertos pulmonares em um modelo canino de transplante pulmonar unilateral esquerdo, utilizando-se doadores cujos pulmões foram captados após três horas de parada cardiocirculatória em temperatura ambiente e sob ventilação mecânica. Métodos: O estudo incluiu 40 cães mestiços randomizados nos grupos VCV e VCP. Dos 20 receptores, 5 não sobreviveram ao transplante, e 5 não sobreviveram ao período de avaliação pós-transplante. Os 10 receptores sobreviventes (5 em cada grupo) foram avaliados durante 360 min após o término do transplante pulmonar. O desempenho funcional dos enxertos foi estudado através da avaliação da mecânica respiratória, trocas gasosas e histologia do enxerto. Resultados: Não houve diferenças significativas entre os grupos quanto às variáveis de mecânica respiratória (pressão de pico inspiratória, pressão de platô, pressão média de vias aéreas, complacência dinâmica e complacência estática) e de trocas gasosas (PaO 2 , pressão venosa mista de oxigênio, PaCO 2 , pressão venosa mista de CO 2 e diferença arteriovenosa de oxigênio). As alterações histopatológicas foram compatíveis com o padrão de lesão pulmonar aguda não específica e não diferiram entre os grupos. Conclusões: Este modelo de transplante pulmonar mostrou que o desempenho funcional do...

A survey of recently published cardiovascular, hematological and pneumological original articles in the Brazilian scientific press

“…Silveira et al77 endeavored to determine whether inspiratory muscle training can increase strength and endurance of these muscles in quadriplegic patients and found that quadriplegic patients can benefit from training at low loads (30% of MIP), which can improve inspiratory muscle strength, FVC and expiratory muscle performance. Felix et al78 compared the influence of two different ventilation strategies-volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV)-on the functional performance of lung grafts in a canine model of unilateral left lung transplantation using donor lungs harvested after three hours of normothermic cardiocirculatory arrest under mechanical ventilation. Their data indicate that in this model of lung transplantation showed that the functional performance of lung grafts was not influenced by the ventilation strategy employed during the first six hours after reperfusion.…”

RC-3095, a Selective Gastrin-Releasing Peptide Receptor Antagonist, Does Not Protect the Lungs in an Experimental Model of Lung Ischemia-Reperfusion Injury

“…Several methods and substances have been used as an attempt to protect the lungs during the early phase of posttransplantation and to improve short- and long-term graft performance; however, these efforts have generated limited results [ 6 , 7 ]. The techniques include lung protective ventilation [ 8 , 9 ], appropriate fluid management, the optimization of organ preservation in lung transplantation, and the minimization of ventilation and anoxic ischemic time [ 10 ].…”