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Background Cognitive dysfunction after surgery is a major issue in older adults. Here, we determined the effect of APOE4 on perioperative neurocognitive function in older patients. Methods We enrolled 140 English-speaking patients ≥60 yr old scheduled for noncardiac surgery under general anaesthesia in an observational cohort study, of whom 52 underwent neuroimaging. We measured cognition; Aβ, tau, p-tau levels in CSF; and resting-state intrinsic functional connectivity in six Alzheimer's disease-risk regions before and 6 weeks after surgery. Results There were no significant APOE4-related differences in cognition or CSF biomarkers, except APOE4 carriers had lower CSF Aβ levels than non-carriers (preoperative median CSF Aβ [median absolute deviation], APOE4 305 pg ml−1 [65] vs 378 pg ml−1 [38], respectively; P=0.001). Controlling for age, APOE4 carriers had significantly greater preoperative functional connectivity than non-carriers between several brain regions implicated in Alzheimer's disease, including between the left posterior cingulate cortex and left angular gyrus (β [95% confidence interval, CI], 0.218 [0.137–0.230]; PFWE=0.016). APOE4 carriers, but not non-carriers, experienced significant connectivity decreases from before to 6 weeks after surgery between several brain regions including between the left posterior cingulate cortex and left angular gyrus (β [95% CI], –0.196 [–0.256 to –0.136]; PFWE=0.001). Most preoperative and postoperative functional connectivity differences did not change after controlling for preoperative CSF Aβ levels. Conclusions Postoperative change trajectories for cognition and CSF Aβ, tau or p-tau levels did not differ between community dwelling older APOE4 carriers and non-carriers. APOE4 carriers showed greater preoperative functional connectivity and greater postoperative decreases in functional connectivity in key Alzheimer's disease-risk regions, which occur via Aβ-independent mechanisms.

Paragangliomas and pheochromocytomas are rare neuroendocrine tumors that can have high morbidity and mortality if undiagnosed. Here we report a case of an undiagnosed paraganglioma in a 58-year-old female who underwent tumor resection. The patient became severely hypertensive intraoperatively with paroxysmal swings in blood pressure and then later became acutely hypotensive after tumor removal. She was managed in the surgical intensive care unit (SICU) postoperatively and discharged from the hospital without acute complications. We briefly discuss the epidemiology, clinical presentation, perioperative management, and possible complications of these tumors to assist healthcare providers if one were to encounter them.

A case of MR progression after single-lung transplant as a significant contributor to postoperative respiratory failure is reported. Pre-existing MR may progress due to the decompressive effects of lung transplantation on RV dimension and consequent alteration of MV geometry. This case highlights the importance of intraoperative TEE findings, especially pertaining to valvulopathies in the setting of lung transplantation. Postoperative surveillance of significant findings is imperative when any new symptoms are being investigated.