Siobal Mark S, Kallet Richard H, Kivett Valerie A, Tang Julin F
Respiratory Care Services, Department of Anesthesia and Perioperative Care, San Francisco General Hospital, CA 94110, USA.
Respir Care. 2006 May;51(5):492-6.
Dexmedetomidine is a selective alpha-2 adrenergic receptor agonist that exhibits sedative, analgesic, anxiolytic, and sympatholytic effects without respiratory-drive depression. We prospectively evaluated the use of dexmedetomidine to facilitate the withdrawal of mechanical ventilation and extubation in 5 trauma/surgical intensive-care-unit patients who had failed previous weaning attempts due to agitation and hyperdynamic cardiopulmonary response.
Intravenous infusion of dexmedetomidine commenced at 0.5 or 0.7 microg/kg/h without a loading dose. Background sedation and analgesia with propofol, benzodiazepines, and opiates was discontinued or reduced as tolerated. Dexmedetomidine infusion was titrated between 0.2 and 0.7 microg/kg/h to maintain a stable cardiopulmonary response and modified Ramsay Sedation Score between 2 and 4.
Following dexmedetomidine administration, propofol infusion was weaned and discontinued in 4 patients. In the fifth patient, benzodiazepine and opiate infusions were reduced. Ventilatory support in all patients could be weaned to continuous positive airway pressure of 5 cm H2O without agitation, hemodynamic instability, or respiratory decompensation. All patients were extubated while receiving dexmedetomidine infusion (mean dose of 0.32 +/- 0.08 microg/kg/h). One patient required reintubation for upper-airway obstruction.
Dexmedetomidine appears to maintain adequate sedation without hemodynamic instability or respiratory-drive depression, and thus may facilitate extubation in agitated difficult-to-wean patients; it therefore deserves further investigation toward this novel use.
右美托咪定是一种选择性α-2肾上腺素能受体激动剂,具有镇静、镇痛、抗焦虑和抗交感神经作用,且不会抑制呼吸驱动。我们前瞻性地评估了右美托咪定在5例创伤/外科重症监护病房患者中的应用,这些患者因躁动和高动力心肺反应导致先前的撤机尝试失败。
静脉输注右美托咪定,起始剂量为0.5或0.7μg/kg/h,不给予负荷剂量。根据耐受情况,停用或减少丙泊酚、苯二氮䓬类药物和阿片类药物的背景镇静和镇痛。将右美托咪定输注速度滴定至0.2至0.7μg/kg/h之间,以维持稳定的心肺反应和改良Ramsay镇静评分在2至4分之间。
给予右美托咪定后,4例患者的丙泊酚输注逐渐减量并停用。在第5例患者中,苯二氮䓬类药物和阿片类药物的输注量减少。所有患者的通气支持均可降至5 cm H2O的持续气道正压,且无躁动、血流动力学不稳定或呼吸代偿失调。所有患者在接受右美托咪定输注(平均剂量为0.32±0.08μg/kg/h)时均成功拔管。1例患者因上呼吸道梗阻需要重新插管。
右美托咪定似乎能维持充分的镇静,而无血流动力学不稳定或呼吸驱动抑制,因此可能有助于躁动且难以撤机患者的拔管;因此,值得对这种新用途进行进一步研究。