RESUMO
Dexmedetomidine hydrochloride (DEX) is a newly developed alpha-2 adrenergic agonist sedative and has been shown to be effective in post-surgical patients, providing not only unique sedation but also stabilization of hemodynamic and respiratory function. We investigated the hemodynamic and respiratory effects and efficacy of DEX in 84 consecutive patients (age <6 months: 18, 6-12 months: 13, 1-3 years: 29, 4-9 years: 18, >10 years: 5, male:female = 44:40) who were sedated by DEX in combination with a small dose of midazolam and morphine. DEX was commenced at an initial dose of 0.7 microg/kg/hr during surgery, approximately 1 hour prior to transfer to the intensive care unit (ICU). DEX infusion was maintained at a rate of 0.2-0.7 microg/kg/hr after ICU admission throughout weaning from mechanical ventilation and extubation. The dose of the sedatives was optimized by scoring on Ramsay's sedative scale. There were no undesirable hemodynamic changes throughout the DEX infusion. Respiration was maintained and all patients were extubated uneventfully. Optimal level of sedation was achieved in all patients. There were no adverse events related to DEX administration. Moreover, junctional ectopic tachycardia (JET) and severe pulmonary hypertension (PH) leading to clinical deterioration, which are the major causes of postoperative morbidity in pediatric cardiac surgery, occurred at a low incidence in this series. Our DEX protocol provided 1) satisfactory postoperative sedation without compromising hemodynamics and respiration, and 2) prevention and amelioration of postoperative morbidity caused by sympathomimetic stimulation, in pediatric cardiac surgery.
