Fifty-one patients were identified in the acute lung injury screening database between September 2009 and March 2010. Twenty-two met criteria for ALI and did not have confirmed or suspected H1N1 infection and were thus included in the noninfluenza group (ALI/ARDS secondary to noninfluenza etiologies). Thirty-six patients in the H1N1 patient log had confirmed influenza A testing. Of those, 23 had ALI requiring mechanical ventilation (MV) during their MICU stay and were included in our analysis.