Anesthesiology
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Observational Study
The Association between Preoperative Blood Pressures and Postoperative Adverse Events.
The relationship between postoperative adverse events and blood pressures in the preoperative period remains poorly understood. This study tested the hypothesis that day-of-surgery preoperative blood pressures are associated with postoperative adverse events. ⋯ Preoperative blood pressures both less than and above a specific threshold were independently associated with a higher number of postoperative adverse events, but the data do not support specific strategies for managing patients with low or high blood pressure on the day of surgery.
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Impaired glymphatic clearance of cerebral metabolic products and fluids contribute to traumatic and ischemic brain edema and neurodegeneration in preclinical models. Glymphatic perivascular cerebrospinal fluid flow varies between anesthetics possibly due to changes in vasomotor tone and thereby in the dynamics of the periarterial cerebrospinal fluid (CSF)-containing space. To better understand the influence of anesthetics and carbon dioxide levels on CSF dynamics, this study examined the effect of periarterial size modulation on CSF distribution by changing blood carbon dioxide levels and anesthetic regimens with opposing vasomotor influences: vasoconstrictive ketamine-dexmedetomidine (K/DEX) and vasodilatory isoflurane. ⋯ K/DEX and isoflurane overrode carbon dioxide as a regulator of CSF flow. K/DEX could be used to preserve CSF space and dynamics in hypercapnia, whereas hyperventilation was insufficient to increase cerebral CSF perfusion under isoflurane.