Browsing by Author "Retamal, J."

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    Atenolol versus propranolol for the treatment of infantile hemangiomas : a randomized controlled study
    (2014) Abarzúa, Alvaro; Navarrete Dechent, Cristián Patricio; Heusser Risopatron, Felipe; Retamal, J.; Zegpi Trueba, María Soledad
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    Decreasing tidal volume from 6 to 4 ml/kg: feasibility and effects on repeated opening and closing
    (2010) Retamal, J.; Libuy Mena, Javiera Camila; Jimenez, M.; Delgado, M.; Besa, C.; Bugedo, G.; Bruhn, A.
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    Evaluation of ZAR1 and SFRP4 methylation status as potentials biomarkers for diagnosis in cervical cancer : exploratory study phase I
    (2014) Brebi, P.; Hoffstetter, R.; Andana, A.; Ili, C.G.; Saavedra, K.; Viscarra, T.; Retamal, J.; Sanchez, R.; Roa Strauch, Juan Carlos Enrique
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    Frecuencia de Virus Papiloma Humano en Tumores no Ginecológicos de la Región de la Araucanía, Chile
    (2014) Hoffstetter, R.; Andana, A.; Guzman, P.; Ili, C.; Retamal, J.; Mora, B.; Roa Strauch, Juan Carlos Enrique; Sanchez, R.
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    Loss of ZNF516 protein expression is related with HR-HPV infection and cervical preneoplastic lesions
    (2019) Ili, C.; Lopez, J.; Buchegger, K.; Riquelme, I.; Retamal, J.; Zanella, L.; Mora-Lagos, B.; Vivallo, C.; Roa Strauch, Juan Carlos Enrique; Brebi, P.
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    Natamycin versus voriconazole for fungal keratitis
    (2018) Retamal, J.; Ordenes-Cavieres, G.; Grau Diez, Arturo Eduardo
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    Physiologic Effects of High Flow Nasal Cannula Compared to Conventional Oxygen Therapy Postextubation: A Randomized Crossover Study
    (2022) Basoalto Escobar, Roque Ignacio; Damiani Rebolledo, Luis Felipe; Jalil Contreras, Yorschua Frederick; Garcia, P.; Carpio Cordero, David Bernardo; Bachmann Barron, María Consuelo; Alegria Aguirre, Luz Katiushka; Oviedo Álvarez, Vanessa Andrea; Bugedo Tarraza, Guillermo Jaime; Retamal, J.; Bruhn Cruz, Alejandro Rodrigo
    Rationale: High flow nasal cannula (HFNC) has been shown to generate several physiological which would be responsible forreducing weaning failure rates. However, there are not many physiological studies focused on the post-extubationstage.Objective: To determine the physiological effects of HFNC in the post-extubation period.Methods:Prospective randomizedcrossover study in the post-extubation period of patients with acute respiratory failure (ARF), which was approved by the HealthSciences Scientific Ethics Committee of Pontificia Universidad Católica de Chile. Critically ill patients connected to mechanicalventilation (MV) more than 48 hours, with PaO2/FiO2 <300 mmHg, and in whom the physician planned to perform a spontaneousventilation test (SBT) were included. After obtaining consent informed a catheter with an esophageal and gastric balloon andelectrodes to record the electrical activity of the diaphragm (EAdi) were installed. Moreover, an electrical impedance tomography(EIT) around the chest was connected, arterial and venous blood gases were recorded, in addition to the usual clinical signs.After extubation, the patients were connected to HFNC set at 50 L/min for one hour and conventional oxygen therapy (venturimask) for one hour in a random sequence.Results:Nine patients (6 men) aged 60.7 ± 10.0 years were included. Patients wereconnected to MV for 6.6 ± 3.2 days. Compared with conventional oxygen therapy, HFNC significantly reduces the respiratoryeffort observed by a reduction of esophageal pressure swings (ΔPes)(p= 0.006) and pressure-time product (PTPes) (p= 0.047)of 30% and 27%, respectively. In the HFNC period, the end-expiratory lung impedance (p< 0.001) and dynamic lung compliance(VT/ΔPes) (p= 0.041) was significantly higher. However, no differences were observed in tidal volume (p= 0.255), electricalactivity of the diaphragm (ΔEAdi) (p= 0.104), Neuro-ventilatory efficiency (p= 0.262), and respiratory rate (RR) (p= 0.299)compared to the period of conventional oxygen therapy. Finally, the PaO2 / FiO2 ratio was also higher in the HFNC period (p =0.029).Conclusion:The use of HFNC in the post-extubation period in patients with acute respiratory failure reduces work ofbreathing and is capable of increasing end-expiratory lung volume, dynamic compliance, and gas exchange.
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    Physiological and inflammatory consequences of high and low respiratory rate in acute respiratory distress syndrome
    (John Wiley and Sons Inc, 2021) Retamal, J.; Damiani, L.F.; Basoalto, R.; Bruhn, A.; Bugedo, G.; Benites, M.H.; Larsson, A.
    © 2021 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons LtdUsing protective mechanical ventilation strategies with low tidal volume is usually accompanied by an increment of respiratory rate to maintain adequate alveolar ventilation. However, there is no robust data that support the safety of a high respiratory rate concerning ventilator-induced lung injury. Several experimental animal studies have explored the effects of respiratory rate over lung physiology, using a wide range of frequencies and different models. Clinical evidence is scarce and restricted to the physiological impact of increased respiratory rate. Undoubtedly, the respiratory rate can influence respiratory mechanics in various ways as a factor of multiplication of the power of ventilation, and gas exchange, and also on alveolar dynamics. In this narrative review, we present our point of view over the main experimental and clinical evidence available regarding the effect of respiratory rate on ventilator-induced lung injury development.
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    Positive end-expiratory pressure increases strain in patients with ALI/ARDS
    (2011) Bugedo Tarraza, Guillermo; Bruhn, Alejandro; Regueira Heskia, Tomás; Romero, C.; Retamal, J.; Hernández P., Glenn
    The study aimed to evaluate a methodology to quantify the porosity of the soil using computed tomography in areas under no-tillage, conventional tillage and native forest. Three soil management systems were selected for the study: forest, conventional tillage and no-tillage. In each soil management system, undisturbed soil samples were collected in the surface layer (0.0 to 0.10 m). The tomographic images were obtained using a X-ray microtomography. After obtaining the images, they were processed, and a methodology was evaluated for image conversion into numerical values. The statistical method which provided the greatest accuracy was the percentile method. The methodology used to analyze the tomographic image allowed quantifying the porosity of the soil under different soil management. The method enabled the characterization of soil porosity in a non-evasive and non-destructive way.
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    Tidal volume is a major determinant of cyclic recruitment-derecruitment in acute respiratory distress syndrome
    (EDIZIONI MINERVA MEDICA, 2011) Bruhn, A.; Bugedo, D.; Riquelme, F.; Varas, J.; Retamal, J.; Besa, C.; Cabrera, C.; Bugedo, G.
    Background. Overdistension and cyclic recruitment-derecruitment contribute to ventilator-induced lung injury. High tidal volumes are thought to increase mortality mainly by inducing overdistension. However, experimental evidence suggests that tidal volume (VT) may also influence cyclic recruitment-derecruitment. Our main goal was to determine whether high tidal volumes increase cyclic recruitment-derecruitment in acute respiratory distress syndrome (ARDS) patients, as measured by dynamic computed tomography (CT).