Chronic heart failure modifies the response to positive end-expiratory pressure in patients with chronic obstructive pulmonary disease

Bihari S et al. – In subjects with severe chronic obstructive pulmonary disease (COPD) alone, caution must be used when administering positive end–expiratory pressure (PEEP) 10cm H2O or greater. Subjects with COPD+chronic heart failure (CHF) may benefit from higher levels of PEEP.

Methods

• Positive end-expiratory pressure was administered at 0, 5, 10, 15, and 0cm H2O for 15minutes with pressure support maintained at 10cm H2O.
• Data are expressed as mean±SD, and the effect of PEEP and differences between COPD alone and COPD + CHF were tested with repeated-measures analysis of variance.

Results

• Subjects were elderly (72.5±13.3years) with severe COPD (force expired volume in 1second, 1.3±0.6L; force expired volume in 1 second/force vital capacity, 40%±15%).
• With increasing PEEP in COPD subjects, dead space ratio increased (P<.001), minute alveolar ventilation decreased (P=.001), and Paco2 increased (P=.013), with no change in COPD+CHF subjects.
• Subjects with COPD+CHF had improvement in Pao2 and lower mean arterial pressure, whereas both were unchanged in subjects with COPD alone.

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