Dexmedetomidine for prevention of postoperative delirium in older adults undergoing oesophagectomy with total intravenous anaesthesia: A double-blind, randomised clinical trial

BACKGROUND – Dexmedetomidine is known to be a sedative. Recent studies suggest that administration of dexmedetomidine can prevent postoperative delirium (POD) which has been confirmed as a common complication after major surgery. However, its effects in patients undergoing oesophagectomy are scarce. OBJECTIVE – To investigate the efficacy and safety of dexmedetomidine in reducing POD in elderly patients after transthoracic oesophagectomy with total intravenous anaesthesia (TIVA). DESIGN – A randomised, double-blind, placebo-controlled trial. SETTING – Single-centre, tertiary care hospital, November 2016 to September 2018. PATIENTS – Eligible patients (n = 177) undergoing transthoracic oesophagectomy were randomly assigned to receive total intravenous anaesthesia (TIVA, n = 87) or dexmedetomidine with TIVA (DEX-TIVA, n = 90). INTERVENTIONS – Patients receiving DEX-TIVA received a loading dose of dexmedetomidine (0.4 μg kg−1), over 15 min, followed by a continuous infusion at a rate of 0.1 μg kg−1 h−1 until 1 h before the end of surgery. Patients receiving TIVA received physiological saline with a similar infusion rate protocol. OUTCOME MEASURES – The primary outcome was the incidence of POD. The secondary endpoints were the incidence of emergence agitation, serum interleukin-6 (IL-6) levels and haemodynamic profile. RESULTS – All randomised patients were included with planned intention-to-treat analyses for POD. Delirium occurred in 15 (16.7%) of 90 cases given dexmedetomidine, and in 32 (36.8%) of 87 cases given saline (P = 0.0036). The DEX-TIVA group showed less frequent emergence agitation than the TIVA group (22.1 vs. 48.0%, P = 0.0058). The incremental change in surgery-induced IL-6 levels was greater in the TIVA group than DEX-TIVA group (P < 0.0001). CONCLUSION – Adding peri-operative dexmedetomidine to a total intravenous anaesthetic safely reduces POD and emergence agitation in elderly patients undergoing open transthoracic oesophagectomy. These benefits were associated with a postoperative reduction in circulating levels of the pro-inflammatory cytokine IL-6 and stabilisation of the haemodynamic profile. TRIAL REGISTRATION – Chinese Clinical Trials Register Identifier: ChiCTR-IPR-17010881.