Browsing by Author "Lillo, Felipe"

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Liquid extracorporeal carbon dioxide removal: use of THAM (tris-hydroxymethyl aminomethane) coupled to hemofiltration to control hypercapnic acidosis in a porcine model of protective mechanical ventilation
    (2016) Tapia, Pablo; Lillo, Felipe; Soto, Dagoberto; Escobar, Leslie; Simon, Felipe; Hernandez, Karina; Alegria, Leyla; Bruhn, Alejandro
    A promising approach to facilitate protective mechanical ventilation is the use of extracorporeal CO2 removal techniques. Several strategies based on membrane gas exchangers have been developed. However, these techniques are still poorly available. The goal of this study was to assess the efficacy and safety of THAM infusion coupled to hemofiltration for the management of hypercapnic acidosis. A severe respiratory acidosis was induced in seven anesthetized pigs. Five of them were treated with THAM 8-mmol . kg(-1) . h(-1) coupled to hemofiltration (THAM+HF group) at 100 mL . kg(-1) . h(-1). After 18-hours of treatment the THAM infusion was stopped but hemofiltration was kept on until 24-hours. The 2 other animals were treated with THAM but without hemofiltration. After 1-hour of treatment in THAM+HF, PaCO2 rapidly decreased from a median of 89.0 (IQR) (80.0, 98.0) to 71.3 (65.8, 82.0) mmHg (P<0.05), while pH increased from 7.12 (7.01, 7.15) to 7.29 (7.27, 7.30) (P<0.05). Thereafter PaCO2 remained stable between 60-70 mmHg, while pH increased above 7.4. After stopping THAM at 18 hours of treatment a profound rebound effect was observed with severe hypercapnic acidosis. The most important side effect we observed was hyperosmolality, which reached a maximum of 330 (328, 332) mOsm . kg H2O-1 at T18. The animals treated only with THAM developed severe hypercapnia, despite the fact that pH returned to normal values, and died after 12 hours. Control-group had an uneven evolution until the end of the experiment. A combined treatment with THAM coupled to hemofiltration may be an effective treatment to control severe hypercapnic acidosis.
  • Thumbnail Image
    Item
    Progression of regional lung strain and heterogeneity in lung injury: assessing the evolution under spontaneous breathing and mechanical ventilation
    (2020) Hurtado Sepúlveda, Daniel; Sarabia Vallejos, Mauricio; Iturrieta, Pablo; Erranz, Benjamín; Lillo, Felipe; Morales, Felipe; Blaha, Katherine; Medina, Tania; Diaz, Franco; Cruces, Pablo
    Abstract Background Protective mechanical ventilation (MV) aims at limiting global lung deformation and has been associated with better clinical outcomes in acute respiratory distress syndrome (ARDS) patients. In ARDS lungs without MV support, the mechanisms and evolution of lung tissue deformation remain understudied. In this work, we quantify the progression and heterogeneity of regional strain in injured lungs under spontaneous breathing and under MV. Methods Lung injury was induced by lung lavage in murine subjects, followed by 3 h of spontaneous breathing (SB-group) or 3 h of low Vt mechanical ventilation (MV-group). Micro-CT images were acquired in all subjects at the beginning and at the end of the ventilation stage following induction of lung injury. Regional strain, strain progression and strain heterogeneity were computed from image-based biomechanical analysis. Three-dimensional regional strain maps were constructed, from which a region-of-interest (ROI) analysis was performed for the regional strain, the strain progression, and the strain heterogeneity. Results After 3 h of ventilation, regional strain levels were significantly higher in 43.7% of the ROIs in the SB-group. Significant increase in regional strain was found in 1.2% of the ROIs in the MV-group. Progression of regional strain was found in 100% of the ROIs in the SB-group, whereas the MV-group displayed strain progression in 1.2% of the ROIs. Progression in regional strain heterogeneity was found in 23.4% of the ROIs in the SB-group, while the MV-group resulted in 4.7% of the ROIs showing significant changes. Deformation progression is concurrent with an increase of non-aerated compartment in SB-group (from 13.3% ± 1.6% to 37.5% ± 3.1%), being higher in ventral regions of the lung. Conclusions Spontaneous breathing in lung injury promotes regional strain and strain heterogeneity progression. In contrast, low Vt MV prevents regional strain and heterogeneity progression in injured lungs.
  • Thumbnail Image
    Item
    Renal decapsulation prevents intrinsic renal compartment syndrome in ischemia-reperfusion - Induced acute kidney injury : a physiologic approach
    (2018) Cruces, Pablo; Lillo, Pablo; Salas, Camila; Salomon, Tatiana; Lillo, Felipe; González, Carlos; Pacheco, Alejandro; Hurtado Sepúlveda, Daniel