Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 58 4 2020 07 28 171 176 Bahram Ghasemzadeh Department of Cardiac Surgery, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran. Bahador Azizi Department of Anesthesia, Division of Perfusion Technology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran. Simin Azemati Department of Anesthesia, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran. Mostafa Bagherinasab Department of Anesthesia, School of Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran. 2019 11 10 2020 04 23 Anesthetized patient management for pediatric patients with pulmonary arterial hypertension (PAH) is a major challenge. The aim of this study was to evaluate the ability of dexmedetomidine to reduce pulmonary arterial hypertension in patients with pulmonary arterial hypertension undergoing cardiac surgery. Sixty-six patients with pulmonary arterial hypertension underwent the study. Patients were randomly divided into two groups: group D received a dexmedetomidine injection in a dose of 1 μg/kg in the first hour and then decreased to 0.5 μg/kg/hr, injection continued after surgery until extubation in the post-anesthetic care unit (PACU). Group C received normal saline 0.9% in a similar volume. Pulmonary artery systolic pressure (PASP) and systemic systolic blood pressure (SSBP) were recorded during and after the surgery in the post-anesthetic care unit. Needing vasodilators, sedatives, extubation time, and the length of ICU stay were recorded for all patients. Patients in the dexmedetomidine group showed a significant reduction in Pulmonary artery systolic pressure and Pulmonary artery systolic pressure/systemic systolic blood pressure rates during surgery and during the first 24 hours in the post-anesthetic care unit (P<0.001). The dexmedetomidine group, in comparison with the control group, needed a significantly lower dose of a vasodilator (P<0.001) and a lower dose of sedation (P<0.001). It is concluded that the use of dexmedetomidine during the surgery in children with pulmonary hypertension reduces pulmonary artery systolic pressure during and after the surgery. https://acta.tums.ac.ir/index.php/acta/article/view/8182 https://acta.tums.ac.ir/index.php/acta/article/download/8182/5392