Walker James, Maccallum Matt, Fischer Carl, Kopcha Robert, Saylors Roy, McCall John
Department of Anesthesiology, University of Cincinnati Medical Center, Cincinnati, Ohio, USA.
J Burn Care Res. 2006 Mar-Apr;27(2):206-10. doi: 10.1097/01.BCR.0000200910.76019.CF.
Maintaining appropriate sedation and analgesia in pediatric burn patients can be quite challenging and often requires high doses of analgesics and anxiolytics because tolerance quickly develops. Escalating doses of opioids and benzodiazepines provide little additional benefit while increasing the incidence of side effects. Dexmedetomidine (DEX) is a novel alpha2-adrenergic agonist that provides sedation, anxiolysis, and analgesia with much less respiratory depression than other sedatives. In addition, DEX stimulation of alpha2 receptors on pancreatic beta cells may inhibit insulin secretion. Hyperglycemia has not been studied specifically in patients receiving DEX. Therefore, we hypothesized that DEX would improve sedation compared with our standard sedation regimen. In addition, we studied the effects of DEX on blood glucose levels. We performed a retrospective chart review of 65 pediatric burn patients (42 boys, 23 girls) in the intensive care unit admitted between 2001 and 2004 who received DEX infusion because of failure to achieve adequate sedation with our standard regimen of opioids and benzodiazepines. We recorded age, TBSA burn size, weight, dose and duration of infusion, adequacy of sedation before and after initiation of DEX, blood glucose levels before and after DEX, and the presence or absence of mechanical ventilation. The mean age was 5 years (range, 0.6-17), burn size was 36% TBSA (range, 3-94), and weight was 26 kg (range, 8-100). All patients were rated "inadequately sedate" before DEX infusion was initiated at 0.2 mug/kg/hr and titrated to effect. Twenty-six patients received a loading dose of 1 mug/kg. The average duration of DEX infusion was 11 days (range, 2-50), and no tachyphylaxis was noted. The mean dose was 0.5 mug/kg/hr (range, 0.1-2). Infusions were weaned over the course of 12 to 24 hours without evidence of rebound hypertension or withdrawal. With DEX titration, all patients were rated "adequately sedate," even though all were sedation failures with opioids and benzodiazepines. Eleven of 42 patients receiving ventilatory support were extubated while on DEX infusion, and no patient showed evidence of DEX induced respiratory depression. Patient's blood glucose levels averaged 121.2 +/- 8.9 mg/dl while on DEX infusion and 117.1 +/- 12.1 mg/dl while off, a nonsignificant difference.
在小儿烧伤患者中维持适当的镇静和镇痛颇具挑战性，且往往需要大剂量的镇痛药和抗焦虑药，因为耐受性会迅速形成。阿片类药物和苯二氮䓬类药物剂量的增加几乎不会带来额外益处，反而会增加副作用的发生率。右美托咪定（DEX）是一种新型的α2肾上腺素能激动剂，它能提供镇静、抗焦虑和镇痛作用，且呼吸抑制作用比其他镇静剂小得多。此外，DEX对胰腺β细胞上α2受体的刺激可能会抑制胰岛素分泌。尚未对接受DEX治疗的患者的高血糖情况进行专门研究。因此，我们假设与我们的标准镇静方案相比，DEX能改善镇静效果。此外，我们研究了DEX对血糖水平的影响。我们对2001年至2004年间入住重症监护病房的65例小儿烧伤患者（42例男孩，23例女孩）进行了回顾性病历审查，这些患者因使用阿片类药物和苯二氮䓬类药物的标准方案未能达到充分镇静而接受DEX输注。我们记录了年龄、烧伤总面积（TBSA）、体重、输注剂量和持续时间、开始使用DEX前后的镇静充分程度、使用DEX前后的血糖水平以及是否进行机械通气。平均年龄为5岁（范围0.6 - 17岁），烧伤面积为36% TBSA（范围3 - 94%），体重为26 kg（范围8 - 100 kg）。在以0.2μg/kg/hr的速度开始输注DEX并根据效果进行滴定之前，所有患者的镇静程度均被评为“不充分”。26例患者接受了1μg/kg的负荷剂量。DEX输注的平均持续时间为11天（范围2 - 50天），未观察到快速耐受性。平均剂量为0.5μg/kg/hr（范围0.1 - 2μg/kg/hr）。输注在12至24小时内逐渐减量，未出现反弹性高血压或戒断的迹象。通过DEX滴定，所有患者的镇静程度均被评为“充分”，尽管所有患者使用阿片类药物和苯二氮䓬类药物时镇静均失败。42例接受通气支持的患者中有11例在输注DEX期间拔管，且没有患者出现DEX诱导的呼吸抑制的证据。患者在输注DEX期间血糖水平平均为121.2±8.9 mg/dl，停药后为117.1±12.1 mg/dl，差异无统计学意义。
