The Ohio State University, Columbus, OH, USA.
Ann Pharmacother. 2011 Jun;45(6):740-7. doi: 10.1345/aph.1P726. Epub 2011 Jun 10.
Dexmedetomidine is an α(2)-receptor agonist used for sedation in the intensive care unit (ICU). Although dexmedetomidine is labeled for sedation in critically ill patients at doses up to 0.7 μg/kg/h, recent studies have used more liberal dosing regimens. However, to our knowledge, no study has assessed the clinical impact of doses greater than 0.7 μg/kg/h when compared to doses within the Food and Drug Administration--approved labeling.
To compare the clinical efficacy and safety of high (HD) and low (LD) doses of dexmedetomidine for sedation in the ICU.
This retrospective study included a sample of patients who received dexmedetomidine in medical, surgical, medical/surgical, and cardiothoracic ICUs between January 1, 2008, and December 1, 2009. Patients were included in the LD group if their maximum dose was less than 0.7 μg/kg/h or in the HD group if any dose was more than 0.7 μg/kg/h. Efficacy was determined by the percentage of Richmond Agitation and Sedation Scale (RASS) scores for each patient maintained at goal sedation (-1 to +1), and safety was determined by the incidence of hypotension and bradycardia.
Forty-three of 133 patients received HD dexmedetomidine. Patients in the LD group had a significantly higher percentage of RASS scores at goal (60.0% vs 48.6%; p = 0.03), while those in the HD group experienced a higher percentage of RASS scores classified as undersedated (19.2% vs 4.9%; p = 0.001). There was no significant difference in the incidence of hypotension or bradycardia between groups.
Patients treated with HD dexmedetomidine had fewer RASS scores at goal. Our data suggest that increasing the dose of dexmedetomidine may not enhance sedation efficacy or lead to an increased incidence of adverse effects. Patients who have not achieved goal sedation at doses of 0.7 μg/kg/h or less may not respond further to increased doses.
右美托咪定是一种用于重症监护病房（ICU）镇静的 α(2)-受体激动剂。虽然右美托咪定在标签上注明可用于危重症患者镇静，剂量高达 0.7μg/kg/h，但最近的研究使用了更宽松的给药方案。然而，据我们所知，尚无研究评估与食品和药物管理局批准的标签内剂量相比，剂量大于 0.7μg/kg/h 的临床影响。
比较 ICU 中高（HD）和低（LD）剂量右美托咪定镇静的临床疗效和安全性。
这项回顾性研究纳入了 2008 年 1 月 1 日至 2009 年 12 月 1 日期间在医学、外科、医学/外科和心胸 ICU 接受右美托咪定治疗的患者样本。如果患者的最大剂量小于 0.7μg/kg/h，则纳入 LD 组，如果任何剂量大于 0.7μg/kg/h，则纳入 HD 组。通过每位患者维持目标镇静（-1 至+1）的 Richmond 躁动镇静量表（RASS）评分的百分比来确定疗效，通过低血压和心动过缓的发生率来确定安全性。
在 133 例患者中，有 43 例接受了 HD 右美托咪定治疗。LD 组的患者达到目标的 RASS 评分百分比显著更高（60.0%比 48.6%；p=0.03），而 HD 组的患者中被评为镇静不足的 RASS 评分百分比更高（19.2%比 4.9%；p=0.001）。两组之间低血压或心动过缓的发生率无显著差异。
接受 HD 右美托咪定治疗的患者达到目标的 RASS 评分百分比更少。我们的数据表明，增加右美托咪定的剂量可能不会增强镇静效果，也不会导致不良反应发生率增加。在 0.7μg/kg/h 或更低剂量下未达到目标镇静的患者可能不会对增加的剂量有进一步的反应。
