BACKGROUND
Postoperative cognitive decline (POCD) is defined as a new cognitive impairment arising after surgical intervention. Cognitive function can be assessed using validated tests including: N Back, Stroop; and Lexical Decision Making Task.
There is some concern that prolonged Trendelenburg positioning during laparoscopic colorectal surgery may cause POCD. Patients with POCD may experience prolonged hospitalisation and take longer returning to their normal level of functioning.
OBJECTIVE
To assess percentage of short or long-term POCD following laparoscopic colorectal surgery.
METHODS
Methods
Patients undergoing laparoscopic colorectal surgery were recruited. Cognitive tests including: 1, 2 and 3 back, lexical decision making task and stroop task were carried out pre-operatively and repeated Day 1, and minimum 3 months post-operatively. For assessment of POCD, Day 1 the baseline was subtracted from Day 1 results for each test. This result was then divided by the standard deviation of the control group to give a Z score. A large positive Z score (>1.96) showed a deterioration in cognitive function from baseline for accuracy, and a large negative Z score (> -1.96) for response time.[1] An individual Z score of 1.96 or more was defined as cognitive dysfunction.
RESULTS
Forty-six patients were recruited (26 males, 24 female), mean age 66years (SD± 5.18). Of which 55% had POCD on Day 1; and 37 patients completed long-term follow up of which 32% had POCD.
CONCLUSIONS
Our study does show a significant number of patients develop both long and short term POCD following laparoscopic colorectal surgery.
Does laparoscopic colorectal surgery result in short and long term post-operative cognitive decline (POCD)? (Preprint)
