Resp Care
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Randomized Controlled Trial
The effects of apparatus dead space on P(aCO2) in patients receiving lung-protective ventilation.
Lung-protective ventilation using tidal volume (V(T)) of 4-6 mL/kg (predicted body weight) reduces mortality (compared with traditional V(T)) in patients with acute respiratory distress syndrome and acute lung injury. Standardized use of lower V(T) can result in respiratory acidosis and has raised new concerns about the appropriate configuration of the ventilator circuit, especially in regard to the dead space (V(D)) of the apparatus. We hypothesized that, with a patient receiving lung-protective ventilation, the removal of all apparatus dead space from the circuit would reduce P(aCO2) and allow a reduction in minute ventilation. ⋯ In patients receiving lower-V(T) ventilation, removing all the apparatus V(D) from the ventilator circuit reduces P(aCO2) and increases pH, at a lower minute ventilation. This information will help guide ventilator-circuit configuration for patients receiving lung-protective ventilation.
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Since there is a growing use of analgesia and sedation in spontaneously breathing patients undergoing diagnostic or therapeutic interventions, recommendations by national societies of anesthesiologists call for the application of capnometry during all anesthetic procedures. ⋯ Both the Tosca and Microcap Plus provide just an approximate estimation of P(aCO2). Clinical use of these monitors can not be proposed under actual conditions but will be advantageous after correction of the limiting errors.
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Randomized Controlled Trial Comparative Study
Chest physiotherapy with positive airway pressure: a pilot study of short-term effects on sputum clearance in patients with cystic fibrosis and severe airway obstruction.
The periodic administration of positive airway pressure combined with directed cough could aid mucus clearance in patients with cystic fibrosis (CF) and severe airway obstruction. ⋯ There were no differences in sputum clearance or pulmonary-function measures between mask PEP and short-term administration of either CPAP or NPPV combined with directed cough. After mask PEP these patients felt more tired than after CPAP or NPPV secretion-clearance therapy.
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Clinical Trial
A decremental PEEP trial identifies the PEEP level that maintains oxygenation after lung recruitment.
To assess the ability of a decremental trial of positive end-expiratory pressure (PEEP) to identify an optimal PEEP level that maintains oxygenation after a lung-recruitment maneuver. ⋯ A decremental PEEP trial identifies a PEEP setting that sustains for 4 h the oxygenation benefit of a 40-cm H2O, 40-s lung-recruitment maneuver.
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Multicenter Study
The long-term stability of portable spirometers used in a multinational study of the prevalence of chronic obstructive pulmonary disease.
We report the performance of an ultrasound-based portable spirometer (EasyOne) used in a population-based survey of the prevalence of chronic obstructive pulmonary disease, conducted in 5 Latin American cities: São Paulo, Brazil; México City, México; Montevideo, Uruguay; Santiago, Chile; and Caracas, Venezuela (the Latin American COPD Prevalence Study [PLATINO]). ⋯ In these 70 EasyOne spirometers neither calibration nor linearity changed during the study. Such calibration stability is a valuable feature in spirometry surveys and in the clinical setting.