Effect of Hypothermia During Cardiopulmonary Bypass on Neurocognition After Cardiac Surgery in Adults

Background: The use of Hypothermia during Cardiopulmonary bypass (CPB) is a beneficial approach regarding neurocognitive protection to the patients, but at the same time, the added effects of hypothermia also carry some potential adverse outcomes.Objective: To compare the effects of mild and moderate hypothermia during cardiopulmonary bypass on post-operative neurocognitive function in patients undergoing elective cardiac surgeries.Methods: Patients undergoing on-pump Cardiac Surgery were assigned to the two groups according to the degree of hypothermia they received. The two groups, namely, mild hypothermia (31 °C to 35 °C) and moderate hypothermia (25 °C to 30 °C). Each group has thirty patients. The Mini-Mental State Examination (MMSE) is a standardized 30-point cognitive assessment tool, selected for this study due to its validated reliability in detecting post-operative neurocognitive decline, and was administered both pre-operatively and post-operatively.Results: A total of 72 patients were received for Cardiac Surgery, out of which 60 (83.3%) patients met our inclusion criteria and underwent elective cardiac surgery using CPB by the same surgeon, and other team members. The study found no significant difference in post-operative neurocognitive decline between the mild and moderate hypothermia groups when comparing their post-operative MMSE scores. We found no significant difference in blood loss, hours of ventilation and inotropic support. However, the adrenaline infusion rate with the mild hypothermia group exhibited a slightly higher value while the ICU stay with moderate hypothermia was longer compared to those with mild hypothermia group (p-value of 0.045).Conclusion: Our study demonstrates that the use of either mild or moderate hypothermia during CPB resulted in no significant difference in postoperative neurocognitive function. However, the duration of stay in the ICU and inotropic support in terms of adrenaline infusion rate varied among the groups, indicating that patients may recover differently depending on whether they received mild or moderate hypothermia during CPB.