[Effective Dexmedetomidine Administration for the Prevention of Emergence Agitation and Postoperative Delirium in Patients with a History of Postoperative Delirium].

We successfully performed intraoperative dexmedetomidine (DEX) administration for the prevention of emergence agitation or postoperative delirium after lung resection in four patients (71.3 ± 5.7 year old, 3 males and 1 female) with a past history of postoperative delirium. DEX was started at 0.35-0.45 μg x kg(-1) x hr(-1) continuously without loading. The average time from DEX initiation to extubation was 141.3 ± 94.4 minutes. No patient had emergence agitation, and DEX administration was continued until the following morning with monitoring in all patients without any symptoms of delirium. Intraoperative DEX administration may be beneficial for the prevention of emergence agitation or postoperative delirium in patients with a past history of postoperative delirium.