Rapid reduction of oxygenation index by employment of a recruitment technique in patients with severe ARDS

Mechanical ventilation of patients with acute respiratory distress syndrome (ARDS) may contribute to pulmonary injury and systemic inflammation. The o bjective of this study was to examine the safety and efficacy of a recruitm ent maneuver that rapidly improves atelectasis and oxygenation, and in so d oing may reduce the potential for ventilator-induced lung injury Nineteen p atients with severe ARDS (defined as PaO2:FiO(2) less than or equal to 150) from diverse etiologies were turned prone and a positive pressure of 40 cm H(2)O was applied for a period of 90 seconds. This pressure was increased i n 5 cmH(2)O increments in subsequent maneuvers to a maximum of 50 cmH(2)O i f there was an inadequate initial response. Subsequently pressure-limited m echanical ventilation with a PEEP of 15 cmH(2)O was instituted to prevent d erecruitment. Peak pressures were maintained at less than or equal to 35 cm H(2)O. Outcome measures were oxygenation index, PaO2: FiO(2) ratio, and alv eolar-arterial oxygen difference. The oxygenation index decreased from a me dian of 31 cmH(2)O/mmHg to 14 cmH(2)O/mmHg immediately after recruitment an d to 11 cmH(2)O/mmHg (p < 0.0001) 24 hours later. The A-aDO(2) improved fro m 454 mmHg to 128 mmHg (p < 0.0001) and the PaO2:FiO(2) ratio from 75 to 21 8 (p < 0.0001) 24 hours later Twenty-five percent of patients had PaO2:FiO( 2) ratios of more than 300 mmHg at 24 hours. Mean airway pressure increased by 3 cmH(2)O initially, from 23 cmH(2)O to 26 cmH(2)O as a consequence of the increase in PEEP, but this had decreased to 25 cmH(2)O after 24 hours. There were no significant complications. Rapid reductions in FiO(2) can he achieved safely by the implementation of a relatively simple recruitment te chnique.