Dexmedetomidine and Long-term Outcomes in Elderly Patients After Cardiac Surgery

"Before anesthesia, dexmedetomidine hydrochloride for injection (200 ug/2 ml) will be diluted with normal saline to 50 ml (final dexmedetomidine concentration 4 ug/ml).~Before anesthesia induction, a loading dose will be administered by intravenous infusion at a rate of \[0.9\*kg\] ml/h for 10 minutes (i.e., dexmedetomidine 0.6 ug/kg in 10 minutes), followed by continuous infusion at a rate of \[0.1\*kg\] ml/h (i.e., dexmedetomidine at a rate of 0.4 ug/kg/h) until the end of surgery.~After surgery, the infusion rate will be decreased to \[0.025\*kg\] ml/h (i.e., dexmedetomidine at a rate of 0.1 ug/kg/h) and continued until the end of mechanical ventilation."

"Before anesthesia, 0.9% sodium chloride for injection 50 ml will be prepared.~Before anesthesia induction, a loading dose will be administered by intravenous infusion at a rate of \[0.9\*kg\] ml/h for 10 minutes, followed by continuous infusion at a rate of \[0.1\*kg\] ml/h until the end of surgery.~After surgery, the infusion rate will be decreased to \[0.025\*kg\] ml/h and continued until the end of mechanical ventilation."