Observational studyJournal of anesthesia2026
Effect of intraoperative position on the zero flow pressure of the cerebral circulation under propofol anesthesia: a prospective observational study.
Observational study in Journal of anesthesia, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
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Who cites it
3 citing papers in PubMed.
- Cerebral hemodynamics, autoregulation, and neurocognitive outcomes during Trendelenburg positioning in robot-assisted abdominopelvic surgery: a narrative review.Journal of robotic surgery · 2026Review
- In Reply to: Comment on "Effect of intraoperative position on the zero flow pressure of the cerebral circulation under propofol anesthesia: a prospective observational study".Journal of anesthesia · 2026Article
- Comment on "Effect of intraoperative position on the zero flow pressure of the cerebral circulation under propofol anesthesia: a prospective observational study".Journal of anesthesia · 2026Article
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Authors and funding
6 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
purposeThe effect of intraoperative position on cerebral perfusion remains unclear. We examined changes in zero flow pressure (ZFP) relative to the supine position in the beach-chair, Trendelenburg, and prone positions under propofol anesthesia. ZFP is defined as the arterial pressure at which cerebral blood flow theoretically ceases, and it can represent effective downstream pressure, including cerebrovascular tone and intracranial pressure.
methodsThis prospective, observational study conducted at two institutions included patients undergoing shoulder surgery, robotic-assisted laparoscopic prostatectomy, or lumbar spine surgery (n = 15 for each position) under propofol anesthesia. The flow velocity of the middle cerebral artery was recorded using transcranial Doppler. ZFP was determined by linear regression analysis of the pressure-flow velocity plot, with a pressure transducer calibrated at the heart level regardless of patient posture.
resultsHead height relative to the heart increased by 25 cm in the beach-chair position, decreased by 13 cm in the Trendelenburg position, and was unchanged in the prone position. ZFP significantly increased by 12 and 5 mmHg in the beach-chair and Trendelenburg positions, respectively, whereas no significant change was observed in the prone position.
conclusionsThe beach-chair and Trendelenburg positions increased ZFP. In both positions, it might be preferable to maintain mean arterial pressure higher than in the supine position to preserve cerebral perfusion.
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