Impact of inhalation delay on medication delivery from a salbutamol HFA pressurized metered dose inhaler used with and without a new prototype portable valved holding chamber
Bibliographic record
Abstract
Rationale: Valved Holding Chambers (VHCs) / spacers are commonly prescribed for patients if they are not able to coordinate actuation of the pressurized Metered Dose Inhaler (pMDI) with inhalation. It is well known however that many patients do not use VHCs for their reliever medication when ‘on the go’ due to a number of reasons, including portability and appearance. This study evaluated the medication delivery performance when using a Ventolin® HFA pMDI with and without a prototype portable VHC. Methods: The adult Aerosol Delivery to an Anatomic Model (ADAM) oropharyngeal airway was used in order to provide a clinically relevant laboratory determination of pMDI medication delivery at various locations of the model using a constant flow rate of 30 L/min. Inhalation 0s after pMDI actuation simulated perfect coordination, with delays of 1,2 and 5s also being investigated (for pMDI alone and pMDI with prototype VHC). Results: The mean results of the medication deposited on the filter (simulating medication delivered to the carina) indicated that when the pMDI was used alone, even a 1-second inhalation delay reduced medication delivery to the filter (carina) by approximately 80% compared to perfect coordination (0-seconds delay). The prototype portable VHC had similar delivery to pMDI alone (perfect coordination) after 2-seconds delay and even after a delay of 5-seconds was only approximately 20% reduced. Conclusions: The prototype VHC may provide a potential option for patients previously unwilling to carry more conventional VHCs with them, in order to give delivery assurance of their reliever medication.
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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 | 0.002 |
| 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 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 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".