Limitations
blood loss, inflammation
BLOOD LOSS, INFLAMMATION
The present study had several limitations. First, the patients’ cognitive status could not be directly evaluated. The patients were formally assessed for POD only when they outwardly manifested obvious abnormal behaviours, and the incidence of POD might be underestimated. Second, except for CRP, biomarkers of inflammation were not measured in our study, and it is not possible to assess whether dexmedetomidine could suppress the inflammation caused by surgical stress. Third, the amount of blood loss, blood transfusion, and the frequency and dose of vasoactive drug administration in each patient were not recorded and statistically analysed. These issues need to be explored in future studies.