Chest
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Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
Assessment of physiologic variables and subjective comfort under different levels of pressure support ventilation.
To evaluate the effects of 12 ventilator settings (pressure support ventilation [PSV] plus positive end-expiratory pressure [PEEP], 30 + 0 cm H(2)O; 25 + 5 cm H(2)O; 25 + 0 cm H(2)O; 20 + 5 cm H(2)O; 20 + 0 cm H(2)O; 15 + 5 cm H(2)O; 15 + 0 cm H(2)O; 10 + 5 cm H(2)O; 10 + 0 cm H(2)O; 5 + 5 cm H(2)O; 5 + 0 cm H(2)O; and 0 + 5 cm H(2)O) on physiologic variables; the percentage of ineffective efforts; patient comfort; and whether the diagnosis of COPD may influence results. ⋯ The following conclusions are made: (1) physiologic variables followed a linear trend, while comfort followed a U-shaped trend under different levels of PSV (irrespective of COPD diagnosis); (2) high assistance caused an increase in ineffective efforts; (3) only the breathing pattern significantly changed when total assistance was given as PSV plus PEEP when compared to PSV alone (PSV plus ZEEP); and (4) the extreme levels of PSV are not associated with the best comfort.