Gajić, Ognjen

The practice of platelet transfusion in the intensive care unit varies, and liberal use may not be associated with improved outcome. This study reviewed the medical records of 117 patients with moderate-to-severe thrombocytopenia and without active bleeding who were admitted to intensive care unit beds during a 6-month period. The primary outcome measures were new bleeding episodes and platelet transfusion complications. Ninety (77%) received a platelet transfusion. Significant new bleeding developed in 1 patient who received a transfusion. Six patients (8%) developed transfusion complications: 2 transfusion-related acute lung injury, 2 allergic, and 2 febrile reactions. Patients who did not receive platelet transfusion had a higher severity of illness than transfused patients. Predictors of platelet transfusion were platelet count and postoperative status, but not invasive procedure. The practice of platelet transfusion in critically ill patients with thrombocytopenia varies. Prospective studies evaluating restrictive versus liberal platelet transfusion strategies are warranted.

Abstract The objective of this study was to assess the effects of hypercapnic acidosis on lung cell injury and repair by confocal microscopy in a model of ventilator-induced lung injury. Three groups of normocapnic, hypocapnic, and hypercapnic rat lungs were perfused ex vivo, either during or after injurious ventilation, with a solution containing the membrane-impermeant label propidium iodide. In lungs labeled during injurious ventilation, propidium iodide fluorescence identifies all cells with plasma membrane wounds, both permanent and transient, whereas in lungs labeled after injurious ventilation propidium iodide fluorescence identifies only cells with permanent plasma membrane wounds. Hypercapnia minimized the adverse effects of high-volume ventilation on vascular barrier function, whereas hypocapnia had the opposite effect. Despite CO2-dependent differences in lung mechanics and edema the number of injured subpleural cells per alveolus was similar in the three groups (0.48 ± 0.34 versus 0.51 ± 0.19 versus 0.43 ± 0.20 for hypocapnia, normocapnia, and hypercapnia, respectively). However, compared with normocapnia the probability of wound repair was significantly reduced in hypercapnic lungs (63 versus 38%; p < 0.02). This finding was subsequently confirmed in alveolar epithelial cell scratch models. The potential relevance of these observations for lung inflammation and remodeling after mechanical injury is discussed.