Background and Goal: Dexmedetomidine is a specific α2 adrenoreceptor agonist with sedative, analgesic and anesthetic-sparing effects (1). This prospective, randomized study evaluated the effects of dexmedetomidine during patient controlled sedation (PCS) in ophthalmic surgery.
Material and Methods: After obtaining ethic committee approval and patient permission, 40 patients (ASA I-II) were randomized to receive dexmedetomidine PCS (Group D, n = 20) or no intraoperative sedation (Group C, n = 20) during ophthalmic surgery performed under peribulbar block. The PCS solution contained dexmedetomidine 2 μg/ml. The PCS parameters consisted of a loading dose of 1 μgkg−1, a PCS dose of 5 μg and a lockout interval of 10 minutes. The study groups were compared with respect to intraocular pressure, hemodynamic parameters, perception of pain during peribulbar block with numerical rating scores (NRS), anxiety and discomfort NRS, intraoperative Ramsay Sedation Scale (RSS), Aldrete Scores in postoperative first 30 minutes, incidence of intraoperative complications, patient and surgeon satisfaction. Chi-square and Mann-Whitney U tests were used for statistical analysis. P value of 0.05 was considered significant.
Results: Patients in the Group D were administered a mean dexmedetomidine dose of 66.4 ± 3.7 μg with a mean duration of 48.7 ± 3.2 min. Mean arterial pressure, heart rate, intraocular pressure, and NRS value during peribulbar block were lower in the Group D (p < 0.05). Patient satisfaction and RSS scores, incidences of dry mouth, and bradycardia were higher in the Group D (p < 0.05). Other intraoperative complications, surgeon satisfaction, anxiety and discomfort NRS and Aldrete Scores of the study groups were similar. In the PCS group none of the patients needed additional PCS dose after loading dose except two patients.
Conclusions: These results suggest that PCS with dexmedetomidine may be a useful technique in day-case ophthalmic surgery.
1 Jaakola ML, Ali-Melkkila T, Kanto J, et al. Br J Anaesth 1992; 68:570-5.