<i>In vitro</i> performance of an improved collapsible holding chamber (CHC) for the delivery of bronchodilators to patients receiving mechanical ventilation
Bibliographic record
Abstract
Bronchodilator delivery by pressurized metered-dose inhaler (pMDI) to patients on mechanical ventilation is best achieved without breaking the breathing circuit. We describe an evaluation of an improved CHC (AeroVent Plus*, Trudell Medical International, London, Canada (n=5 devices, 1 measurement/device)), in which the pMDI canister receptacle is offset from the CHC axis to reduce internal impaction, and can also accept GSK pMDI canisters having a dose counter. Delivery of 3-actuations of salbutamol (HFA-Ventolin*, GSK (Canada); 100-μg/actuation) was assessed with the expanded CHC inserted in the inspiratory limb of an adult breathing circuit equipped with a 7-mm diameter endotracheal tube (ETT). An adult test lung (Michigan Instruments) was used to simulate the patient. The circuit was humidified near to body conditions (T = 36°C, 100%RH), and tidal breathing (600-mL, duty cycle = 33%, 10 breaths/min) was simulated by a servo ventilator (Siemens, model 900C). A filter was located between the distal end of the ETT and test lung to collect the aerosol. Total mass (TM) of salbutamol after 6 respiratory cycles was determined by HPLC-UV spectrophotometry. Similar measurements were undertaken with a Spirale* CHC (Armstrong Medical), providing benchmark data from a European marketed CHC having the pMDI receptacle in-line with the axis of the device. TM (mean ± S.D.) from the AeroVent Plus and Spirale CHCs was 22.7±3.1 and 4.7±0.7 μg/actuation respectively. Clinicians using these devices should be aware of the implications of the difference in drug output between these apparently similar devices.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| 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".