Dexmedetomidine vs. Propofol: Haemodynamic Changes in Conscious Sedation in Arthroscopic Shoulder Surgery in the Beach Chair Position: A Randomized Control Trial

Background: Interscalene brachial plexus block (ISB) combined with conscious sedation is a viable alternative to general anaesthesia for arthroscopic shoulder surgery in the beach chair position. The purpose of the trial was to compare the haemodynamic instability and safety of Dexmedetomidine vs Propofol for conscious sedation in arthroscopic shoulder surgery in the beach chair position.
Method: A single-blinded prospective randomized trial was conducted in 56 patients randomly allocated into Dexmedetomidine and Propofol groups for conscious sedation following ISB placement. The primary outcome was to measure intraoperative haemodynamic variations (systolic blood pressure, mean arterial pressure, heart rate) in the two groups maintaining adequate conscious sedation during arthroscopic shoulder surgery in the beach chair position.   
Results: In the dexmedetomidine group a significantly higher percentage of systolic blood pressure (21.86 𝑣𝑠 10.81%, p = 0.001, 𝑑 = 1.05) and a higher percentage heart rate (18.52 vs 9.02%, p = 0.002, 𝑑 = .98)  drop from baseline measurements was noted. A large (d ≥ 0.8) Cohen’s effect size suggested the high practical significance of the finding. Perioperative hypotensive (f=19, p<0.001) and bradycardic (f=21, p=0.003) episodes were significantly more frequent in the dexmedetomidine group. The propofol group had a greater incidence of airway complications requiring intervention (f=6 vs f=0, p=.023).   
Conclusion: Dexmedetomidine leads to significant blood pressure and heart rate reductions from baseline values in the beach chair position providing controlled hypotension and has minimal airway complications in patients undergoing arthroscopic shoulder surgery in the beach chair position under ISB and conscious sedation compared to Propofol.