ABSTRACT
BACKGROUND: Conventional mechanical ventilation (CMV) is fundamental in acute respiratory distress syndrome (ARDS) treatment. Inhaled nitric oxide (INO), an adjunctive therapy, has been used with ventilation in an attempt to improve oxygenation and reduce lung injury. OBJECTIVE: To analyze the early effects of low INO dose on oxygenation, oxidative stress, inflammatory, and histopathological lung injury in a rabbit model of acute lung injury (ALI). METHODS: This was a prospective, controlled, in vivo animal laboratory study. Forty rabbits were instrumented and ventilated at F(IO(2)) 1.0. ALI was induced by tracheal infusion of warm saline (30 mL/kg, 38°C) and lung oxidative stress was assessed by total antioxidant performance (TAP) assay. Animals were assigned to groups: control group (no. = 10, low tidal volume [V(T)] = 6 mL/kg, PEEP = 5 cm H(2)O), ALI without INO (no-INO group, no. = 10, low V(T) = 6 mL/kg, PEEP = 10 cm H(2)O), ALI plus INO (INO group, no. = 10, low V(T) = 6 mL/kg, PEEP = 10 cm H(2)O, INO = 5 ppm). Plateau pressure was limited to 30 cm H(2)O in all groups. Ten non-instrumented animals (healthy group) were studied for TAP assay. Ventilatory and hemodynamic parameters were recorded every 30 min for 4 hours. RESULTS: After lung injury, the instrumented groups were worse than the control group for P(aO(2)) (control group 438 ± 87 mm Hg, no-INO group 80 ± 13 mm Hg, INO group 81 ± 24 mm Hg, P < .001). The INO group showed decreased lung inflammation by leukocyte count in lung lavage fluid (no-INO group 4.8 ± 1.64, control group 0.16 ± 0.15, INO group 0.96 ± 0.35 polymorphonuclear cells × 10(6)/bronchoalveolar lavage fluid/lung, P < .001), decreased histopathological injury score (no-INO group 5 [range 1-16], INO group 2 [range 0-5], control group 0 [range 0-3], P < .001), and better lung protection against oxidative injury than the no-INO group (healthy group 68 ± 8.7, control group 66.4 ± 6.8, INO group 56.3 ± 5.1, no-INO group 45.9 ± 3.4 percent protection/g protein, P < .001). CONCLUSIONS: INO attenuates oxidative stress and histopathological and inflammatory lung injury in a saline-lavaged rabbit ALI model.
Subject(s)
Acute Lung Injury , Nitric Oxide , Oxidative Stress/drug effects , Oxygen/metabolism , Respiratory Distress Syndrome , Acute Lung Injury/metabolism , Acute Lung Injury/therapy , Administration, Inhalation , Animals , Antioxidants , Biological Availability , Bronchodilator Agents/administration & dosage , Bronchodilator Agents/pharmacokinetics , Chemotherapy, Adjuvant , Dose-Response Relationship, Drug , Humans , Inflammation/drug therapy , Inflammation/metabolism , Models, Animal , Monitoring, Physiologic , Nitric Oxide/administration & dosage , Nitric Oxide/pharmacokinetics , Prospective Studies , Rabbits , Respiration, Artificial/methods , Respiratory Distress Syndrome/metabolism , Respiratory Distress Syndrome/therapyABSTRACT
Introdução: A droga antineoplásica doxorrubicina apresenta a cardiotoxicidade como o efeito colateral mais grave. A forma aguda é pouco estudada e pode ser mais bem entendida por meio de avaliações funcionais repetidas. O objetivo deste estudo foi avaliar a utilidade do ecocardiograma no estudo da cardiotoxicidade aguda induzida pela doxorrubicina em ratos. Métodos: Foram utilizados ratos machos Wistar, submetidos à injeção intraperitoneal única de doxorrubicina na dose de 20mg/Kg(n=15) e grupo controle (n=15), com injeção de salina. Foram avaliados por Doppler-ecocardiografia antes e 48h após a infusão. As comparações entre os momentos foram efetuadas pelo teste t pareado, com nível de significância p<0,05. Resultados: Após 48 horas, houve diminuição do peso corporal...
