Bibliographic record
Abstract
Apnea test in the diagnosis of brain deathGuidelines for the diagnosis of brain death have been recently published by the Canadian Neurocritical Care Group in the Journal.' Apnea testing is an important component in the determination of brain death.In the recent guidelines it is suggested to insufflate 100% oxygen via a cannula inserted in the endotracheal tube to prevent hypoxemia during the apneic period.This is in agreement with the classic method of apnea testing.However, we would like to warn about serious complications of such a technique of apneic oxygenation.A few years ago we experienced a case of subcutaneous emphysema, tension pneumothorax followed by 'cardiac arrest during the performance of an apnea test with the classic method of inserting an oxygen catheter into the endotracheal tube.Subsequent investigation revealed that the oxygen catheter was wedged in the endotracheal tube.The 6 1/min flow of oxygen rapidly produce lung hyperinflation and major barotrauma.More recently, two very simitar eases have been very well described by Bar-Joseph et al. 2 Brandsetter et al 3 have also reported a similar complication.The consequences of such complications can be catastrophic, especially when the patient is a candidate for organ donation.Moreover, they could be easily prevented by simple modification of the technique of apnea testing.The first important step is to ensure a careful preoxygenation with 100% oxygen while maintaining normoventilation (PaCO 2 40±5mmHg) during at least 10 minutes.Then the endotracheal tube can be connected either to a T-piece or to a high flow continuous positive airway pressure (CPAP) system.If the patient required a FiO 2 less than 0.50 prior to apnea testing, a T-piece system delivering 100% oxygen will suffice to maintain an adequate arterial oxygenation throughout the apneic period.Alternatively, if prior to apnea testing the patient has hypoxic respiratory failure requiring a high FiO 2 , the endotracheal tube can be connected to a high flow CPAP system of 5 to 10 CffiHjQ delivering 100% oxygen.Practically, we use a PEEP valve (Vital Signs®, Totowa, N.J.) that we adapt to the distal extremity of the T-piece.A similar but more complex technique, the "bulk diffusion" technique, has also been described by Al Jumah et al. 4 With these techniques the risk of barotrauma and tension pneumothorax is minimal and probably entirely eliminated.Therefore, we suggest that the Guidelines for the Diagnosis of Brain Death should be amended to revise the technique of apnea testing.
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 | 0.003 | 0.016 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.002 | 0.002 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.003 | 0.002 |
| Research integrity | 0.032 | 0.023 |
| Insufficient payload (model declined to judge) | 0.031 | 0.024 |
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".