Differential effects of remifentanil and sufentanil anesthesia on post-operative pain and cognitive functions

This study aimed to investigate the differential effects of remifentanil and sufentanil anesthesia on post-operative pain and recovery of cognitive functions following surgical resection of human colon cancer orthotopically transplanted in rats. Human colon cancer cells HT-29 were used to establish a rat model of orthotopically transplanted colon cancer on to the cecal wall of rats. The transplanted tumors were then surgically removed after 5 weeks, using different doses of remifentanil and sufentanil anesthesia. At 24 h after the surgery, von Frey test, hot plate test and voluntary wheel running test were used to evaluated post-operative pain in the rats. Morris water maze test and fear conditioning test were employed to assess cognitive functions. Serum and colon tissues of the rats were also subjected to ELISA to measure levels of stress response factors, while colon tissues were analyzed by RT-PCR and Western blot to measure expression of inflammation response factors and NF-κB pathway-related factors. Sufentanil showed better effect in reducing post-operative pain, while remifentanil showed better recovery of cognitive functions after surgery. In addition, remifentanil resulted in less stress and inflammation response, caused milder activation of NF-κB pathway-related factors after surgery. Remifentanil and sufentanil exhibited differential effects on post-operative pain and recovery of cognitive function. Specifically, remifentanil caused lower stress and inflammation response, associated with dampened activation of the NF-κB pathway. Our results could provide theoretical basis for adopting appropriate analgesic strategy and agents according to the characteristics of individual patients.