Lower Preoperative and Postoperative Hemoglobin Levels in Patients with Postoperative Cognitive Dysfunction Compared to Those Without Postoperative Cognitive Dysfunction Following Heart Valve Replacement

Background: Postoperative cognitive dysfunction (POCD) is a prevalent complication that occurs after surgery, impacting cognitive function. Cognitive performance may be hindered by anemia, as it reduces the delivery of oxygen to the brain and leads to tissue hypoxia, affecting metabolism and ultimately diminishing cognitive function.Objective: The objective of this study is to examine the potential correlation between hemoglobin levels and the occurrence of POCD in individuals undergoing heart valve replacement surgery.Methods: This retrospective cohort study included all individuals aged 20 years and above who underwent heart valve replacement surgery from July to December 2021. Hemoglobin levels were assessed both before and after the surgical procedure, and cognitive function was evaluated using the Indonesian-adapted Montreal Cognitive Assessment (MOCA-INA) on the third day after the operation. Statistical analysis involved the use of either Student's t-test or the Mann–Whitney nonparametric test.Results: A total of 70 participants were included in the study from July to December 2021. The majority of the participants were female (57.1%), and a significant proportion were below 60 years old (81.4%). The average preoperative hemoglobin levels were higher (13.30 g/dL) than the average postoperative hemoglobin levels (10.78 g/dL). In terms of cognitive function, 61.4% of participants experienced postoperative cognitive dysfunction (POCD), with a higher mean MoCA-INA score before surgery (28.41) than after surgery (22.37), along with a delta Hb of -0.27. Furthermore, postoperative hemoglobin levels were significantly lower in POCD patients than preoperatively (p = 0.003).Conclusion: The occurrence of postoperative cognitive dysfunction (POCD) was linked to the hemoglobin levels after heart valve replacement.