BACKGROUND: @entity281 ( @entity281 ) after colorectal surgery is the leading cause of postoperative morbidity. Opioids induce immunosuppression through activation of  -opioid receptors expressed on leucocytes, and through opioid withdrawal. A high dose of opioid administered as @entity1937 during surgery may induce immunosuppression, leading to the development of @entity281 . AIM: The purpose of this study was to investigate the influence of @entity1937 on the development of @entity281 . METHODS: Adult @entity1 who underwent elective colorectal surgery from January 2009 to December 2012 (N  =  286) were prospectively investigated according to the guidelines of the US Centers for Disease Control and Prevention. After exclusion of 51 @entity1 , propensity matching was performed in 235 @entity1 . To reduce the influence of selection on SSIs, propensity score pairwise matching was performed for @entity1 maintained with @entity1937 and for @entity1 maintained with @entity3575 . FINDINGS: The number of @entity1 who developed @entity281 was higher after @entity1937 -based anaesthesia compared with @entity3575 -based anaesthesia [11.6% (17/146) vs 3.4% (3/89), @entity1937 vs @entity3575 , P  =  0.03] before propensity matching. Propensity matching yielded 61 pairs of @entity1 anaesthetized with @entity1937 or @entity3575 , and corrected several biases in the preoperative @entity1 characteristics. After propensity matching, the number of @entity1 who developed @entity281 was still higher after @entity1937 -based anaesthesia than after @entity3575 -based anaesthesia [16.4% (10/61) vs 3.3% (2/61), @entity1937 vs @entity3575 , P  =  0.029]. CONCLUSION: @entity1937 -based anaesthesia increased the incidence of @entity281 . A possible reason may be opioid-induced immunosuppression or opioid withdrawal-induced immunosuppression.

@entity1937 -based anaesthesia increases the incidence of postoperative XXXX .

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity281 :: ('MESH:D007239', 'Disease') :: ['Surgical site infection', 'SSI'] @entity3575 :: ('MESH:D005283', 'Chemical') :: ['fentanyl'] @entity1937 :: ('MESH:C071741', 'Chemical') :: ['remifentanil', 'Remifentanil']
@entity281 :: (MESH:D007239,Disease) :: ['surgical site infection']
