Reversing lung collapse and hypoxemia in early ARDS

Barry Fuchs (Medical Director of MICU, HUP, UPENN) calls our attention to a recent paper on the use of the recruitment maneuver to reverse lung collapse.  The new information in this paper relates to the degree and duration of the recruitment maneuver.  From the abstract: Objectives: To test if a bedside recruitment strategy, capable of reversing hypoxemia and collapse in 95% of lung units, is clinically applicable in early acute respiratory distress syndrome.  Measurements and Main Results: Twenty-six patients received sequential increments in inspiratory airway pressures (5 cm water steps) until the sum of PaO2 + PaCO2 was greater than or equal to 400 mm Hg or preset stopping criteria of mixed venous saturation less than 80%, mean arterial pressure less than 60 mmHg or barotrauma identified by CT was met.  Whenever the primary target was not met, despite inspiratory pressures reaching 60 cm H2O, the maneuver was considered incomplete. Late assessment of recruitment efficacy was performed by computed tomography (9 patients) or by online continuous monitoring in the intensive care unit (15 patients) for up to 6 h. It was possible to open the lung and to keep the lung open in the majority (24/26) of patients, at the expense of transient hemodynamic effects and hypercapnia but without major clinical consequences.  No barotrauma directly associated with the maneuver was detected. There was a strong and inverse relationship between arterial oxygenation and percentage of collapsed lung mass (R 0.91; p < 0.0001).  From Borges JB et al: Am J Respir Critic Care Med 2006;174:268.

David S. Smith, M.D., Ph.D.