Objective    To study the correlation between early cognitive function and severity of pain in elderly patients after operation.      Methods    Selective open abdominal operation was performed in 30 elderly patients admitted to our department from January 2009 to June 2009. Severity of pain was assessed using visual analogue scale (VAS) and cognitive function was scored with MiniMental State Examination (MMSE)

animal fluency test (AFT) and clock drawing test (CDT)

respectively

in 24 and 48 h after operation. Cognitive function of the patients was assessed from the view of neurophysiology. Pain was scored after operation with VAS. Variables were analyzed with the linear correlation analysis. Correltion between early cognitive function and severity of pain in elderly patients was observed after operation.     Results    No linear correlation was observed between scores on MMSE

VAS and AFT scales in 24 and 48 h after operation (r=-0.053

P=0.786; and r=-0.052

P=0.783; and r=-0.323

P=0.082; and r=-0.038

P=0.841). A negative linear correlation was found between scores on CDT and VAS scales in 24 and 48 h after operation (r=-0.731

P=0.000; and r=-0.636

P=0.001).     Conclusion    Cognitive function including visual space structure function and implementing function in elderly patients after operation is correlated with the pain scores on VAS scale.