Browsing by Author "Bachmann Barron, María Consuelo"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- ItemBeta-Lactam Antibiotics Can Be Measured in the Exhaled Breath Condensate in Mechanically Ventilated Patients: a Pilot Study(2023) Escalona Solari, José Antonio; Soto Muñoz, Dagoberto Igor; Oviedo Álvarez, Vanessa Andrea; Rivas Garrido, Elizabeth Alexis; Severino, Nicolás; Kattan Tala, Eduardo José; Andresen Hernández, Max Alfonso; Bravo Morales, Sebastián Ignacio; Basoalto Escobar, Roque Ignacio; Bachmann Barron, María Consuelo; Kwok-Yin, Wong; Pavez, Nicolás; Bruhn Cruz, Alejandro Rodrigo; Bugedo Tarraza, Guillermo Jaime; Retamal Montes, Jaime AlejandroDifferent techniques have been proposed to measure antibiotic levels within the lung parenchyma; however, their use is limited because they are invasive and associated with adverse effects. We explore whether beta-lactam antibiotics could be measured in exhaled breath condensate collected from heat and moisture exchange filters (HMEFs) and correlated with the concentration of antibiotics measured from bronchoalveolar lavage (BAL). We designed an observational study in patients undergoing mechanical ventilation, which required a BAL to confirm or discard the diagnosis of pneumonia. We measured and correlated the concentration of beta-lactam antibiotics in plasma, epithelial lining fluid (ELF), and exhaled breath condensate collected from HMEFs. We studied 12 patients, and we detected the presence of antibiotics in plasma, ELF, and HMEFs from every patient studied. The concentrations of antibiotics were very heterogeneous over the population studied. The mean antibiotic concentration was 293.5 (715) ng/mL in plasma, 12.3 (31) ng/mL in ELF, and 0.5 (0.9) ng/mL in HMEF. We found no significant correlation between the concentration of antibiotics in plasma and ELF (R2 = 0.02, p = 0.64), between plasma and HMEF (R2 = 0.02, p = 0.63), or between ELF and HMEF (R2 = 0.02, p = 0.66). We conclude that beta-lactam antibiotics can be detected and measured from the exhaled breath condensate accumulated in the HMEF from mechanically ventilated patients. However, no correlations were observed between the antibiotic concentrations in HMEF with either plasma or ELF.
- ItemEffect of positive end expiratory pressure on lung injury and haemodynamics during experimental acute respiratory distress syndrome treated with extracorporeal membrane oxygenation and near-apnoeic ventilation(2021) Araos, Joaquin; Alegría Vargas, Leyla; Garcia, Aline; Cruces, Pablo; Soto Muñoz, Dagoberto Igor; Erranz, Benjamín; Salomon, Tatiana; Medina, Tania; García Valdes, Patricio Hernán; Dubo, Sebastian; Bachmann Barron, María Consuelo; Basoalto Escobar, Roque Ignacio; Valenzuela, Emilio Daniel; Rovegno Echavarría, Maximiliano David; Vera Alarcón, María Magdalena; Retamal Montes, Jaime; Cornejo Rosas, Rodrigo Alfredo; Bugedo Tarraza, Guillermo; Bruhn, AlejandroBackground: Lung rest has been recommended during extracorporeal membrane oxygenation (ECMO) for severe acute respiratory distress syndrome (ARDS). Whether positive end-expiratory pressure (PEEP) confers lung protection during ECMO for severe ARDS is unclear. We compared the effects of three different PEEP levels whilst applying near-apnoeic ventilation in a model of severe ARDS treated with ECMO. Methods: Acute respiratory distress syndrome was induced in anaesthetised adult male pigs by repeated saline lavage and injurious ventilation for 1.5 h. After ECMO was commenced, the pigs received standardised near-apnoeic ventilation for 24 h to maintain similar driving pressures and were randomly assigned to PEEP of 0, 10, or 20 cm H2O (n¼7 per group). Respiratory and haemodynamic data were collected throughout the study. Histological injury was assessed by a pathologist masked to PEEP allocation. Lung oedema was estimated by wet-to-dry-weight ratio. Results: All pigs developed severe ARDS. Oxygenation on ECMO improved with PEEP of 10 or 20 cm H2O, but did not in pigs allocated to PEEP of 0 cm H2O. Haemodynamic collapse refractory to norepinephrine (n¼4) and early death (n¼3) occurred after PEEP 20 cm H2O. The severity of lung injury was lowest after PEEP of 10 cm H2O in both dependent and non-dependent lung regions, compared with PEEP of 0 or 20 cm H2O. A higher wet-to-dry-weight ratio, indicating worse lung injury, was observed with PEEP of 0 cmH2O. Histological assessment suggested that lung injury was minimised with PEEP of 10 cm H2O. Conclusions: During near-apnoeic ventilation and ECMO in experimental severe ARDS, 10 cm H2O PEEP minimised lung injury and improved gas exchange without compromising haemodynamic stability.