Investigating Association between Intraoperative Hypotension and Postoperative Neurocognitive Disorders in Non-Cardiac Surgery: A Comprehensive Review

Abstract

Postoperative delirium (POD) and postoperative cognitive decline (deficit) (POCD) are related to a higher risk of postoperative complications and long-term disability. Pathophysiology of POD and POCD is complex, elusive and multifactorial. Intraoperative hypotension (IOH) constitutes a frequent and vital health hazard in the perioperative period. Unfortunately, there are no international recommendations in terms of diagnostics and treatment of neurocognitive complications which may arise from hypotension-related hypoperfusion. Therefore, we performed a comprehensive review of the literature evaluating the association between IOH and POD/POCD in the non-cardiac setting. We have concluded that available data are quite inconsistent and there is a paucity of high-quality evidence convincing that IOH is a risk factor for POD/POCD development. Considerable heterogeneity between studies is the major limitation to set up reliable recommendations regarding intraoperative blood pressure management to protect the brain against hypotension-related hypoperfusion. Further well-designed and effectively-performed research is needed to elucidate true impact of intraoperative blood pressure variations on postoperative cognitive functioning.

Early Cognitive Dysfunction in Elderly Patients after Total Knee Arthroplasty: An Analysis of Risk Factors and Cognitive Functional Levels

“…Cerebral hypoperfusion occurring with or as a result of controlled hypotension seems inevitable. Surprisingly, no international recommendations or high quality evidence for diagnostics and treatment of neurocognitive impairment that may arise from hypotension-related hypoperfusion is available [16,17]. Consistent with this result, this study reported the reduction in L-SBP, M-SBP, and M-DBP in patients with severe POCD, but the differences were not statistically significant.…”

Incidence and factors associated with postoperative delirium in patients undergoing transurethral resection of bladder tumor

“…However, it did not affect the occurrence of POD. Previous studies focusing on the relationship between intraoperative hypotension and POD had significant heterogeneity, thus generating conflicting results regarding the association between hypotension and POD [ 8 , 25 , 26 ]. Furthermore, although the exact mechanism of delirium is unclear, neuro-inflammation may play an important role in its development [ 27 ].…”

Perioperative neurocognitive disorders: A narrative review focusing on diagnosis, prevention, and treatment

“…A 2020 comprehensive review included 13 studies with 3017 patients undergoing noncardiac surgery, 177 a 2021 systematic review included 6 studies with 1222 patients undergoing cardiac surgery 178 ; both reviews did not find a significant association between intraoperative hypotension and postoperative cognitive impairment. Two other systematic review/meta‐analysis included studies of patients undergoing either cardiac or noncardiac surgeries also gave similar results 176,246 .…”

“…176 Two systematic reviews also conclude that there is no convincing evidence that intraoperative hypotension is a risk factor of postoperative delirium. 177,178 Nevertheless, intraoperative hypotension should be avoided considering the harmful effects on other organs.…”