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Background Dexmedetomidine reduces cytokine production in septic patients and reduces inflammation and mortality in experimental models of endotoxemia and sepsis. This study investigated whether dexmedetomidine attenuates endothelial dysfunction, intestinal microcirculatory dysfunction, and intestinal epithelial barrier disruption in endotoxemic rats. Methods Ninety-two male Wistar rats were randomly assigned to the following four groups: (1) Sham; (2) lipopolysaccharide, received IV lipopolysaccharide 15 and 10 mg/kg at 0 and 120 min; (3) dexmedetomidine, received IV dexmedetomidine for 240 min; and (4) lipopolysaccharide + dexmedetomidine, received both lipopolysaccharide and dexmedetomidine. Sidestream dark-field videomicroscope, tissue oxygen monitor, and full-field laser perfusion image were used to investigate the microcirculation of the terminal ileum. Serum endocan level was measured. The Ussing chamber permeability assay, lumen-to-blood gadodiamide passage by magnetic resonance imaging, and bacterial translocation were conducted to determine epithelial barrier function. Mucosal apoptotic levels and tight junctional integrity were also examined. Results The density of perfused small vessels in mucosa, serosal muscular layer, and Peyer patch in the lipopolysaccharide + dexmedetomidine group was higher than that of the lipopolysaccharide group. Serum endocan level was lower in the lipopolysaccharide + dexmedetomidine group than in the lipopolysaccharide group. Mucosal ratio of cleaved to full-length occludin and spleen bacterial counts were significantly lower in the lipopolysaccharide + dexmedetomidine group than in the lipopolysaccharide group. Conclusion The study finding suggests that dexmedetomidine protects against intestinal epithelial barrier disruption in endotoxemic rats by attenuating intestinal microcirculatory dysfunction and reducing mucosal cell death and tight junctional damage. (Anesthesiology 2016; 125:355-67)

One-lung ventilation in thoracic surgery provokes profound systemic inflammatory responses and injury related to lung tidal volume changes. We hypothesized that the highly selective a2-adrenergic agonist dexmedetomidine attenuates these injurious responses. Sixty patients were randomly assigned to receive dexmedetomidine or saline during thoracoscopic surgery. There is a trend of less postoperative medical complication including that no patients in the dexmedetomidine group developed postoperative medical complications, whereas four patients in the saline group did (0% versus 13.3%, p = 0.1124). Plasma inflammatory and injurious biomarkers between the baseline and after resumption of two-lung ventilation were particularly notable. The plasma high-mobility group box 1 level decreased significantly from 51.7 (58.1) to 33.9 (45.0) ng.ml−1 (p < 0.05) in the dexmedetomidine group, which was not observed in the saline group. Plasma monocyte chemoattractant protein 1 [151.8 (115.1) to 235.2 (186.9) pg.ml−1, p < 0.05] and neutrophil elastase [350.8 (154.5) to 421.9 (106.1) ng.ml−1, p < 0.05] increased significantly only in the saline group. In addition, plasma interleukin-6 was higher in the saline group than in the dexmedetomidine group at postoperative day 1 [118.8 (68.8) versus 78.5 (58.8) pg.ml−1, p = 0.0271]. We conclude that dexmedetomidine attenuates one-lung ventilation-associated inflammatory and injurious responses by inhibiting alveolar neutrophil recruitment in thoracoscopic surgery.

BackgroundThe abdominal insufflation and surgical positioning in the laparoscopic surgery have been reported to result in an increase of airway pressure. However, associated effects on changes of endotracheal tube cuff pressure are not well established.Methods70 patients undergoing elective laparoscopic colorectal tumor resection (head-down position, n = 38) and laparoscopic cholecystecomy (head-up position, n = 32) were enrolled and were compared to 15 patients undergoing elective open abdominal surgery. Changes of cuff and airway pressures before and after abdominal insufflation in supine position and after head-down or head-up positioning were analysed and compared.ResultsThere was no significant cuff and airway pressure changes during the first fifteen minutes in open abdominal surgery. After insufflation, the cuff pressure increased from 26 ± 3 to 32 ± 6 and 27 ± 3 to 33 ± 5 cmH2O in patients receiving laparoscopic cholecystecomy and laparoscopic colorectal tumor resection respectively (both p < 0.001). The head-down tilt further increased cuff pressure from 33 ± 5 to 35 ± 5 cmH2O (p < 0.001). There six patients undergoing colorectal tumor resection (18.8%) and eight patients undergoing cholecystecomy (21.1%) had a total increase of cuff pressure more than 10 cm H2O (18.8%). There was no significant correlation between increase of cuff pressure and either the patient's body mass index or the common range of intra-abdominal pressure (10-15 mmHg) used in laparoscopic surgery.ConclusionsAn increase of endotracheal tube cuff pressure may occur during laparoscopic surgery especially in the head-down position.