ROTECTING LUNGS FROM VENTIlation-induced injury is an important principle in the management of patients with acute lung injury or acute respiratory distress syndrome (ARDS). Although the critical care community has generally endorsed lower tidal volumes and inspiratory pressures, the optimal level of positive end-expiratory pressure (PEEP) remains unestablished. 1,2 Experimental data suggest that PEEP levels exceeding traditional values of 5 to 12 cm H 2 O can minimize cyclical alveolar collapse and corresponding shearing injury to the lungs in patients with considerable edema and alveolar collapse. 3-5 For patients with relatively mild acute lung injury , however, potential adverse consequences of higher PEEP levels, including circulatory depression 6 or lung overdistension, 7 may outweigh the benefits. Several multicenter, randomized trials testing the incremental effect of higher levels See also p 883 and Patient Page.

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OBJECTIVEPrevious reviews of the effect of oral antidiabetic (OAD) agents on A1C levels summarized studies with varying designs and methodological approaches. Using predetermined methodological criteria, we evaluated the effect of OAD agents on A1C levels.RESEARCH DESIGN AND METHODSThe Excerpta Medica (EMBASE), the Medical Literature Analysis and Retrieval System Online (MEDLINE), and the Cochrane Central Register of Controlled Trials databases were searched from 1980 through May 2008. Reference lists from systematic reviews, meta-analyses, and clinical practice guidelines were also reviewed. Two evaluators independently selected and reviewed eligible studies.RESULTSA total of 61 trials reporting 103 comparisons met the selection criteria, which included 26,367 study participants, 15,760 randomized to an intervention drug(s), and 10,607 randomized to placebo. Most OAD agents lowered A1C levels by 0.5−1.25%, whereas thiazolidinediones and sulfonylureas lowered A1C levels by ∼1.0–1.25%. By meta-regression, a 1% higher baseline A1C level predicted a 0.5 (95% CI 0.1–0.9) greater reduction in A1C levels after 6 months of OAD agent therapy. No clear effect of diabetes duration on the change in A1C with therapy was noted.CONCLUSIONSThe benefit of initiating an OAD agent is most apparent within the first 4 to 6 months, with A1C levels unlikely to fall more than 1.5% on average. Pretreated A1C levels have a modest effect on the fall of A1C levels in response to treatment.