{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T11:43:19Z","timestamp":1768218199871,"version":"3.49.0"},"reference-count":17,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T00:00:00Z","timestamp":1768176000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Med."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>While head-of-bed (HOB) elevation is standard in neurocritical care for managing intracranial hypertension, its optimal angle for patients after elective craniotomy remains undefined. This study aimed to evaluate the effects of different HOB angles on cerebral hemodynamics, oxygenation, and cerebral autoregulation (CA) in patients during the early postoperative period following elective craniotomy.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>In a prospective observational study, 21 patients underwent sequential positioning at HOB 45\u00b0, 30\u00b0, 15\u00b0, and 0\u00b0. Each angle was maintained for 15\u202fmin, with multimodal data including intracranial pressure (ICP), cerebral perfusion pressure (CPP), mean flow velocity (mFV) and pulsatility index (PI) of the middle cerebral artery (MCA) M1 segment, tissue oxygenation index (TOI) and the mean flow index (Mx-a) for CA recorded during the final 5\u202fmin. Linear mixed-effects models assessed the main effects of HOB angle, baseline ICP status (Elevated: &amp;gt;15\u202fmmHg vs. Normal), and baseline CA status (Impaired: Mx-a\u202f&amp;gt;\u202f0.3 vs. Intact).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      The 0\u00b0 position significantly increased ICP (coefficient +8.95\u202fmm Hg, 95% CI 7.02 to 10.88\n                      <jats:italic>p<\/jats:italic>\n                      \u202f&amp;lt;\u202f0.001) and decreased CPP (coefficient \u22127.65\u202fmm Hg, 95% CI \u221213.13 to \u22122.17\n                      <jats:italic>p<\/jats:italic>\n                      \u202f&amp;lt;\u202f0.05). Conversely, 45\u00b0 elevation significantly lowered ICP (coefficient\u22121.64\u202fmm Hg, 95% CI \u22122.87 to \u22120.41). A significant reduction in Mx-a was observed at 0\u00b0 (coefficient \u22120.13, 95% CI \u22120.25 to \u22120.007,\n                      <jats:italic>p<\/jats:italic>\n                      \u202f&amp;lt;\u202f0.05). Both the 15\u00b0 and 0\u00b0 postures were associated with significant decreases in PI (coefficient \u22120.12, 95% CI \u22120.21 to \u22120.03,\n                      <jats:italic>p<\/jats:italic>\n                      \u202f&amp;lt;\u202f0.05 and coefficient \u22120.13, 95% CI \u22120.23 to \u22120.03,\n                      <jats:italic>p<\/jats:italic>\n                      \u202f&amp;lt;\u202f0.05, respectively). TOI remained unchanged across all positions. The Elevated ICP group maintained higher ICP and lower CPP throughout. Baseline impairment of CA (Mx-a\u202f&amp;gt;\u202f0.3) was independently and significantly associated with an increase in the Mx-a index itself during the study period (coefficient +0.26, 95% CI 0.13 to 0.40,\n                      <jats:italic>p<\/jats:italic>\n                      \u202f&amp;lt;\u202f0.001).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>HOB significantly modulates cerebral hemodynamics after elective craniotomy. The 0\u00b0 position is particularly detrimental, elevating ICP, reducing CPP, and potentially exhausting cerebrovascular regulatory reserve. Patient\u2019s baseline ICP and CA status are key determinants of their hemodynamic response. Postoperative management must extend beyond the prevention of intracranial hypertension to also include the vigilant avoidance of CA impairment.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fmed.2025.1713881","type":"journal-article","created":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T08:30:52Z","timestamp":1768206652000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["A prospective observational study of head-of-bed adjustment for patients following elective craniotomy based on cerebral 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