Objective: This study aimed to investigate acute and chronic effects of varenicline on lung tissue in an experimental study. Methods: A total of 34 rats were randomly allocated into study (varenicline) and control groups. The rats were divided into two groups (i) control group, (ii) varenicline group. Then, the rats in the each group were sub‑divided equally in turn as acute (C1; V1) and chronic (C2; V2) ; all rats of acute and chronic groups were sacrificed under the anesthesia on the 45th day for acute group [C1 (n=5) and V1 (n=12)] and the 90th day for chronic group [C2 (n=5) and V2 (n=12)], respectively. Thus, biochemical and histopathological analysis were carried out. Results: Thirty four rats completed the study, 24 were in varenicline group and 10 were in control group. In chronic exposure to varenicline, oxidant levels comprising of malondialdehyde (MDA), and myeloperoxidase (MPO) increased and superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and glutathione peroxidase (GPx) levels, named as antioxidants, decreased significantly when compared to the control group. MDA and MPO levels were also significantly higher and SOD, CAT, GPx, GSH levels were also significantly lower in chronic varenicline group when compared to acute varenicline group. These findings were also supported by histopathological observations. Conclusion: This is the first study, which evaluated pulmonary effects of varenicline experimentally on an animal model. It was observed that chronic varenicline treatments cause inflammation and lung cell injury.

Keywords: Varenicline; Lung tissue; Oxidative stress; Pulmonary toxicity.

Objective: To evaluate the stability of hemodynamic, respiratory and gas exchange variables in an animal model of oleic acid-induced acute lung injury. Methods: This was an experimental study involving 10 mongrel dogs. The variables were measured at baseline, as well as at 30, 60, 90 and 120 min after the administration of oleic acid. In order to analyze repeated measurements, linear and quadratic effects were tested. Mixed linear models with diversified variance and covariance structures were used, depending on the variable studied. Results: We found that mean arterial blood pressure stabilized at 30 min, as did heart rate, pulmonary arterial pressure and pulmonary capillary pressure at 60 min. Respiratory rate, tidal volume, minute volume and respiratory work stabilized at 30 min. Regarding gas exchange variables, PaO2, PaO2/FiO2 ratio and pulmonary shunt fraction stabilized at 30 min. The remaining variables maintained a continuous rise or fall. Conclusions: This oleic acid-induced acute lung injury model is stable for some of the variables tested, although stabilization occurs at different times. The respiratory and gas exchange variables stabilized at 30 min, whereas the hemodynamic variables stabilized at 60 min.

Keywords: Respiratory distress syndrome, adult; Models, animal; Statistical analysis.

Background: The search for an ideal procedure to accomplish aerostasis, after partial surgical resection of the lung parenchyma, remains a practical challenge for the thoracic surgeon. Objective: The objective of this study was to compare the ability of four types of parenchymal pulmonary sutures in preventing air leaks, using a porcine model with incremental endobronchial pressures. Method: Ex vivo experimental study in porcine lungs (n = 5) at the Laboratory of Experimental Surgery of the Universidade de Caxias do Sul. Four different parenchymal pulmonary types of suture were analyzed: type 1 (absorbable suture), type 2: (stapled suture), type 3 (stapled suture with bovine pericardium) and type 4 (stapled suture with biologic glue). The surgical sutures (n = 40) were exposed to different intrabronchial pressure levels, varying from 10 cmH2O to 60 cmH2O. The presence of air leaks along the suture line was verified through the water seal maneuver. Results: The mean intrabronchial pressure level needed to cause suture line air leaks for each type were: type 1 (n = 10): 29 cmH2O; type 2 (n = 10): 38.5 cmH2O; type 3 (n = 10): 44 cmH2O; and type 4 (n = 10): 51.4 cmH2O. The comparison between the mean intrabronchial pressure level of type 1 and of types 2 and 3 sutures was statistically significant, respectively: p = 0.04 and p = 0.01. However, the comparison between types 2, 3 and 4 did not show statistic significance (p > 0.05). Conclusions: The pulmonary suture covered by biologic glue demonstrated more resistance to incremental levels of intrabronchial pressure. Parenchymal pulmonary sutures using stapled suture exclusively or stapled with bovine pericardium or biologic glue demonstrated an increased ability to avoid air leaks if compared to absorbable sutures in a model of porcine lung with incremental levels of intrabronchial pressure. There were no differences between stapler exclusively or stapler and bovine pericardium or biologic glue.

Keywords: Experimental study. Thoracic surgery. Biologic glue. Staplers.