Dexmedetomidine is an effective adjuvant to subtenon block in phacoemulsification cataract surgery

BackgroundResearches to find a better adjuvant in regional anesthesia are still continued until now.Dexmedetomidine prolongs anesthesia and analgesia of local anesthetics in various neural blocks as well as the onset of sensory and motor block. The objective of the present study was to evaluate the effect of adding dexmedetomidine to local anesthetics on the sensory and motor block of the subtenon block in patients undergoing phacoemulsification cataract surgery.MethodsSixty patients of American Society of Anaesthesiologists (ASA) grade I–III, aged between 18 and 70 years, scheduled for phacoemulsification cataract surgery were randomly assigned to two equal groups. Group C (control group) received 2 ml of a mixture of 2% lidocaine and 0.5% bupivacaine and Group D (dexmedetomidine group) received 2 ml of a mixture of 2% lidocaine and 0.5% bupivacaine plus dexmedetomidine (0.5 μg/kg). Onset and duration of sensory and motor block was recorded. Pain during administration of anesthesia and during surgery was graded using the verbal analogue scale and recorded. Intraocular pressure, hemodynamic, and sedation parameters were recorded before and after surgery.ResultsOnset of both sensory and motor block was significantly decreased in group D (P < 0.001, P = 0.004 respectively), and duration of sensory and motor block was more prolonged in group D than in group C (P < 0.001, P = 0.961). Pain during administration of anesthesia was significantly lower in group I compared with group II, and more patients in group I compared with group II were pain free, without a significant difference between the two groups. Intraocular pressure was significantly decreased in group D (P < 0.001). More sedation score was observed in group D (P = 0.022). Heart rate and mean arterial blood pressure were insignificantly decreased in group D more than in group C.ConclusionDexmedetomidine is a safe and effective adjuvant to subtenon block in phacoemulsification cataract surgery.