Unclamping the inferior vena cava during retrograde cerebral perfusion increases the safe range of retrograde perfusion pressures and improves brain perfusion
Bibliographic record
Abstract
We investigated the effect of different methods of management of the inferior vena cava (IVC) during retrograde cerebral perfusion (RCP) on the relationships between RCP pressure, regional cerebral blood flow, tissue oxygenation, and intracranial pressure (ICP). Fourteen pigs were subjected to hypothermic (15 degrees C) RCP at RCP pressures varying from 10 to 110 mmHg with clamping (closed group, n=7) or without clamping of the IVC (open group, n=7). Intracranial pressures increased more slowly in the open group than in the closed group and were significantly lower at any level of RCP pressure in the open group than in the closed group. In the closed group, RCP pressures of 20-30 mmHg resulted in an ICP of 25 mmHg. In contrast, in the open group, when RCP pressures were maintained below 70 mmHg, ICP never reached 25 mmHg. Brain tissue blood flow and CO2 production were relatively higher in the open group than in the closed group. The maximum brain tissue blood flow was achieved at an RCP pressure of 40 mmHg in the open group. We conclude that the maximum safe RCP pressure differs according to the type of management of the IVC. Opening the IVC during RCP not only improves brain tissue perfusion, but also significantly increases the safety margin of RCP pressures. In the pig model, when the IVC is not clamped, the optimal RCP pressure appears to be 40 mmHg.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".