Role of Dexmedetomidine in Early POCD in Patients Undergoing Thoracic Surgery

Abstract

Importance. Postoperative cognitive dysfunction (POCD) occurs in 6%–53% of elderly patients receiving major surgery and is related to longer hospital stays, increased hospital costs, and 1-year mortality. An increasing number of studies suggest that using dexmedetomidine (Dex) in critical care units is associated with reduced incidence of delirium. However, perioperative use of Dex for the prevention of POCD has not been well studied. Objective. To evaluate whether a low-dose perioperative infusion of Dex reduces early POCD. Design. This study was a double-blind, randomized, placebo-controlled trial that randomly assigned patients to Dex or saline placebo infused during surgery and patient-controlled intravenous analgesia (PCIA) infusion. Patients were assessed for postoperative cognitive decline. Interventions. Dex was infused at a loading dose of 0.5 μg/kg intravenously (15 min after entering the operation room) followed by a continuous infusion at a rate of 0.5 μg/kg/h until one-lung ventilation or artificial pneumothorax ended. Patients in the Dex group received regular PCIA pump with additional dose of Dex (200 μg). Results. In total, 126 patients were randomized, and 102 patients were involved in the result analysis. The incidence of POCD was 36.54% (19/52) in the Dex group and 32.00% (16/50) in the normal saline (NS) group, with no statistic difference. No significant difference was observed between the two groups in terms of Telephone Interview for Cognitive Status-Modified (TICS-m) scores at different times. However, the TICS-m score at 7 days after surgery was significantly lower than that at 30 days in 102 patients ( $32.93\pm 0.42$ vs. $33.92\pm 0.47$ , $P=0.03$ ). The visual analogue scale scores in the Dex group were significantly lower than those in the NS group 1 day postoperation at rest and activity (2.00 [1.00–3.00] vs. 3.00 [2.00–4.00], $P<0.01$ ; 4.00 [3.00–5.00] vs. 5.00 [4.00–6.00], $P<0.05$ , respectively). Patients receiving Dex or NS had no statistical difference in activities of daily living (ADLs) scores at 7 and 30 days after surgery, but the ADL score at 30 days after surgery showed a significant reduction compared with that at 7 days ( $P<0.01$ ). Patients in the Dex group had a shorter hospital length of stay ( $15.26\pm 3.77$ vs. $17.69\pm 5.09$ , $P=0.02$ ) and less expenses ( $52458.71\pm 10649.30$ vs. $57269.03\pm 9269.98$ , $P=0.04$ ) than those in the NS group. Conclusions. Low-dose Dex in the perioperative period did not reduce the incidence of early POCD in thoracic surgery. However, it relieved postoperative pain, decreased the hospitalization expenses, and shortened the length of stay.