Effects of dexmedetomidine on hemodynamics and respiration in intubated, spontaneously breathing patients after endoscopic submucosal dissection for cervical esophageal or pharyngeal cancer.

Abstract

We evaluated the hemodynamic and respiratory effects of dexmedetomidine in intubated, spontaneously breathing patients after endoscopic submucosal dissection (ESD) for cervical esophageal or pharyngeal cancer. This retrospective study included 129 patients aged 66.5±8.3years, who underwent ESD under general anesthesia, and who were kept intubated overnight to prevent airway obstruction, receiving sedation with dexmedetomidine. Constant dexmedetomidine infusion at 0.51±0.16μg/kg/h was started intraoperatively (n=109) or postoperatively (n=20), following (n=29) or not following (n=100) loading doses, and continued until extubation. Hemodynamic and respiratory variables, and Richmond Agitation-Sedation Scale (RASS) score, were recorded. Postoperatively, 129 patients remained intubated while breathing spontaneously for 16.4±3.3h, and 124 patients could be sedated solely with dexmedetomidine, whereas 5 required rescue sedatives. During infusion, blood pressure decreased progressively until 12h, whereas heart rate decreased only at 3h. Hemodynamic alterations during dexmedetomidine infusion greatly depended not only on its hemodynamic effects but also on baseline hemodynamics before anesthesia. No serious adverse effect was noted. Dexmedetomidine in intubated, spontaneously breathing patients after ESD was safe and effective. Patient baseline hemodynamics could significantly affect hemodynamics during drug infusion. Without loading doses, plasma drug concentrations were expected to increase progressively. A progressive decrease in blood pressure and unchanged heart rate after an initial decrease suggested that hemodynamic effects of dexmedetomidine in our patients might differ from those reported in young volunteers, although further studies are required to elucidate these points.