Discussion
bradycardia, postoperative pain, postoperative adverse events, Emergence agitation, hypoxemia, agitation, hypotension
TRANSIENT HYPERTENSION
In this study, a prospective randomized double-blind controlled clinical trial was performed on elderly patients who underwent hip replacement surgery under intravenous general anaesthesia combined with inhaled sevoflurane. We compared the influences of dexmedetomidine at different initial doses and midazolam on perioperative haemodynamics and recovery quality after general anaesthesia. The results showed that dexmedetomidine could reduce cardiovascular responses caused by surgical stress throughout the perioperative period, such as endotracheal intubation, skin incision and extubation. However, higher loading doses of dexmedetomidine (D0.5 and D0.75 groups) were more likely to lead to hypotension and bradycardia. On the other hand, the higher doses of dexmedetomidine (D0.5 and D0.75 groups) seemed to reduce agitation and improve tolerance to endotracheal catheters after general anaesthesia without delayed recovery.Surgical stimuli activate the sympathetic nervous system and initiate a cascade of stress responses [Individualized intra- and postoperative anaesthesia management to maintain haemodynamic stabilization, control effective postoperative pain and prevent hypoxemia will reduce postoperative adverse events in the elderly [The common dosage of dexmedetomidine infusion during general anaesthesia in elderly patients undergoing major noncardiac surgery was shown in previous research: a loading dose of 0.5–1.0 μg/kg within 10–15 min or intraoperative continuous infusion at 0.2–0.7 μg/kg/h according to anaesthesia system records [Dexmedetomidine has typical biphasic haemodynamic effects, including transient hypertension, bradycardia and hypotension [Emergence agitation is also common in adult patients after general anaesthesia [