Critical care : the official journal of the Critical Care Forum
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We found that pulse pressure variation (PPV) did not predict volume responsiveness in patients with increased pulmonary artery pressure. This study tests the hypothesis that PPV does not predict fluid responsiveness during an endotoxin-induced acute increase in pulmonary artery pressure and right ventricular loading. ⋯ Fluid responsiveness cannot be predicted with PPV during acute pulmonary hypertension in porcine endotoxemia. Even following severe hemorrhage during endotoxemia, the predictive value of PPV is marginal.
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In this month's issue of Critical Care, Determann and colleagues report the results of a randomized controlled trial comparing the effects of mechanical ventilation (MV) with two tidal volumes (6 versus 10 ml/kg predicted body weight) on cytokine levels in lung lavage fluid and plasma as a surrogate for early identification of acute lung injury (ALI) and/or acute respiratory distress syndrome (ARDS). The study was stopped early after an interim analysis - when 150 patients were enrolled - showing that the incidence of ALI/ARDS according to the current definition was 10.9% higher in the 10 ml/kg group, although duration of MV and mortality was similar in both groups. We examine these interesting results after providing a brief historical perspective and discuss the limitations and implications of the study.