Effects of different doses of dexmedetomidine on cognitive dysfunction in elderly patients early after laparoscopic surgery for colorectal cancer / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effect of different doses of dexmedetomidine (Dex) on early postoperative cognitive dysfunction in elderly patients undergoing laparoscopic surgery for colorectal cancer.</p><p><b>METHODS</b>Eighty ASAI-III elderly patients (over 65 years) were randomized equally into 4 groups including a control group without dexmedetomidine and 3 dexmedetomidine groups (groups D1, D2, and D3) with loading dexmedetomidine doses of 0.2, 0.5, and 0.8 µg/kg and maintenance doses of 0.2, 0.5, and 0.8 µg·kg(-1)·h(-1), respectively. Dex was discontinued 30 min before the end of surgery. The time of operation, adverse reactions, time from the end of surgery to spontaneous breathing recovery (TR), time from spontaneous breathing recovery to opening eyes (TO), and time from opening eyes to extubation (TE) were recorded. Mini-Mental State (MMSE) test was used to assess the cognitive function 1 day before and at 1 day and 3 days after the operation.</p><p><b>RESULTS</b>The incidence of postoperative cognitive dysfunction (POCD) was significantly lower in groups D2 and D3 than in the control group and group D1 (P<0.05). The incidences of hypotension and bradycardia were the highest in group D3 (P<0.05), which also had longer significantly TO and TE than the other 3 groups (P<0.05).</p><p><b>CONCLUSION</b>Dexmedetomidine with a loading dose of 0.5 µg/kg followed by maintenance doses of 0.5 and 0.8 µg·kg(-1)·h(-1) (preferentially 0.5 µg·kg(-1)·h(-1)) can reduce the incidence of POCD in elderly patients undergoing laparoscopic surgery for colorectal cancer.</p>