Purpose
To compare the efficacy of dexmedetomidine (dex) vs. propofol (prop) in vitreoretinal surgery under local block.
Methods
An IRB approved double-masked, prospective randomized study. Enrollment criteria include subjects between ages 18 and 65 years, ASA 1-3, with good liver and renal function. Procedures were performed at UMDNJ's outpatient surgery center by the same surgeon (NB) under retrobulbar block administered using sub-Tenon approach. Patients are randomized into group P (prop) and group D (dex). Group P receives a bolus of 1 mg/kg of prop intravenously (IV) followed by a 25-100 ug/kg/min infusion. Group D receives a bolus of 0.5 ug/kg of dex IV followed by a 0.2-0.7 ug/kg/hr infusion. T-test and Mann-Whitney test are used for statistical analysis.
Results
76 patients have been enrolled; 39 - group P, 37 - group D with one patient excluded due to claustrophobia when draped and subsequent conversion to general anesthesia. Comparisons of parameters are outlined in the table below. Intraoperative blood pressure (BP) and respiratory rates (RR) were similar in both groups, with Group P having significantly lower average systolic BP at 5 and 10 minutes (min) and higher average RR at 15 min. Average heart rates (HR) for all patients were between 49 and 95 beats per min. In the Post-Anesthesia Recovery Unit (PACU), Group D had statistically significant decreased systolic and diastolic BPs at all time points during the two-hour follow-up period. Mean systolic BP in Group P and Group D was 124.9 ±16.2 and 114.6 ±14.5, respectively (p =0.005), and mean diastolic BP was 73.6 ±12.5 and 66.2 ±10.8, respectively (p =0.002). There was no difference in PACU HR and RR. Oxygen saturation did not drop below 92% at any time.
Conclusions
In the 76 patients recruited, dex provided adequate sedation, patient and surgeon satisfaction, and hemodynamic stability, with no difference in incidence of adverse effects compared to prop. In fact, Group D shows a significantly higher surgeon satisfaction at 10 min and level of sedation as measured by the BIS. The only significant hemodynamic parameters between groups were in systolic and diastolic BP in the PACU. There were not any clinically significant events that warranted use of rescue medications for bradycardia or hypotension. No patient experienced post-operative nausea or vomiting. The mean patient and surgeon satisfaction was between good and excellent in both groups.
Keywords: 762 vitreoretinal surgery •
697 retinal detachment