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Dexmedetomidine (DEX) for sedation in diagnostic and interventional cardiac catheterization (DICC) has been reported to require other drugs or rescue drugs because of its insufficient sedative effect when used alone. We administered DEX and adjusted its dose according to the bispectral index (BIS) monitor™ for DICC in a toddler; consequently, a high dose of DEX had to be administered. The patient was a 1-year and 4-month-old boy who was scheduled to undergo DICC after intracardiac repair. We used DEX alone as the sedative because this was expected to avoid oxygen supply and mechanical ventilation and to produce a safe situation for procedures around the neck. DEX was administered at the dose of 1-15 μg/kg/h according to BIS monitor™; administration of cardiovascular drugs or oxygen supply or assist ventilation, except chin lift, were not needed. The maximum predicted plasma concentration (pCp) of DEX and mean pCp were calculated as 6.1 and 4.1 ng/mL, respectively. A high dose of DEX may be required for DICC sedation, as for MRI sedation, in many cases. Although further studies should be conducted to reveal the merits and demerits of DEX in cardiac catheterization, a high dose of DEX may be useful in some cases. [ABSTRACT FROM AUTHOR]

Purpose: We previously confirmed the effectiveness of dexmedetomidine (DEX) for stabilizing hemodynamics as well as sparing anesthetics during anesthetic induction in patients undergoing cardiac surgery (Kunisawa et al. in J Clin Anesth 21:194-199, ). In this study, we investigated whether these effects of DEX continue until the start of cardiopulmonary bypass (CPB). Methods: Twenty-two patients with mild to moderate cardiovascular disease were randomized into two groups [DF2 group: DEX dose of 0.7 μg/kg/h after initial dose and effect-site concentration (ESC) of fentanyl of 2 ng/ml; PF4 group: saline and ESC of fentanyl of 4 ng/ml]. Propofol was administered for anesthetic induction and maintenance. Hemodynamics, cardiovascular drugs, ESC of propofol, and cardiovascular responses to skin incision (SI) and sternotomy (St) were measured or calculated. Results: Blood pressure (BP) at the pre-/post-SI periods was higher in the DEX group (137 ± 17/140 ± 16 mmHg) than in the placebo group (85 ± 9/109 ± 24 mmHg). Percent increases in cardiovascular response to SI or St were lower in the DEX group than in the placebo group (for example, 1.9 ± 2.2 vs. 27.4 ± 19.9% in systolic BP due to SI). ESCs of propofol at SI and St in the DEX group were lower than those in the placebo group. Conclusions: DEX combined with 2 ng/ml fentanyl before CPB can suppress the decrease in blood pressure at the pre- and post-SI periods, can blunt the cardiovascular responses to SI and St, and can spare the required ESC of propofol despite fentanyl concentration, which was half of that in the placebo group. [ABSTRACT FROM AUTHOR]

We report the clinical management of 2 adults with mental retardation because of trisomy 21 who were sedated with high-dose dexmedetomidine (DEX) alone during diagnostic cardiac catheterization (DCC). The first patient was a 25-year-old man with aortic regurgitation and ventricular septal defect. DEX increased his Ramsay sedation score; however, a high dose and bolus injection of DEX were required to perform an invasive procedure. Cardiovascular drugs were not administered and heart rate was maintained in the low 40s. The maximum predicted plasma concentration (pCp) of DEX was 2.3 ng/mL. The second patient was a 26-year-old woman who had developed hypoxia 20 years after palliative surgery for tetralogy of Fallot. High-dose DEX was administered to keep the bispectral index value below 70 and maintain an immobile state; her maximum pCp of DEX was 4.3 ng/mL. Percutaneous oxygen saturation was kept above 83%, because of the suspicion that DEX may increase the ratio of pulmonary artery flow to systemic artery flow. In both cases, no respiratory system complications occurred despite inspiration of room air, indicating the usefulness of DEX for DCC. However, because of DEX may affect DCC data, it is necessary to pay careful attention to the use of DEX during DCC. [ABSTRACT FROM AUTHOR]