What is optimal flow using a mini-bypass system?
Bibliographic record
Abstract
The purpose of this study is to determine the appropriate arterial pump flow /cardiac index (CI) utilizing a mini-bypass system. The unique feature of most mini-bypass systems is that the centrifugal pump combines the function of kinetic venous drainage with arterial pump flow. Therefore, if drainage is reduced, arterial pump flow is also reduced. Managing this system can present challenges to the clinical perfusionist. We reviewed fifteen cases, using the Medtronic Resting Heart System (RHS). This retrospective study examined the arterial pump flow, measured as cardiac index (CI), mean arterial pressure, inlet venous saturation, urine output, vasopressor use, and lactate production during routine cardiac surgery. The mean cardiac index for all patients was 1.90 +/- 0.14, range 1.63-2.08 L/min/m(2). The mean hemoglobin on cardiopulmonary bypass (CPB) was 10.6 +/- 1.2, with a range of 9.2-13.3 g/dL. The lactate produced on CPB was 2.03 +/-0.67 with a range of 1.5-3.5 mmol/L. The mean change in lactate measured from pre CPB to post CPB was 0.85 +/- 0.71 with a median lactate of 0.6 mmol/L. The venous saturation was 65.53 +/- 6.03% with a median of 65% and a range of 57-82%. The mean arterial pressure was 67.04 +/- 10.45 mmHg with a median of 62.5 mmHg. The median urine output was 125 mls. The vasopressor median was 2200 microg. All patients were maintained on CPB with a mean nasopharyngeal temperature of 35.43 degrees Celsius. Despite using lower than predicted flows, it would appear that adequate perfusion is provided. The higher hemoglobin content achieved through reduced hemodilution and reduced inflammation appears to enable this system to deliver adequate flow and perfusion at reduced cardiac indices. This research provides evidence which challenges longstanding beliefs that a cardiac index of 2.4 L/min/m(2) is required for all cases.
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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 | 0.002 | 0.008 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".