P287 Intrapulmonary shunt detection in HHT: standardized technique for agitated saline (bubble echo) studies
Bibliographic record
Abstract
Introduction and Objectives Intrapulmonary right-to-left shunts (RLS) are an important clinical concern in individuals with Hereditary Hemorrhagic Telangiectasia (HHT). Along with respiratory symptoms like dyspnea, serious neurological complications can arise including ischemic strokes and brain abscess. HHT is an autosomal dominant genetic disorder characterized by arteriovenous malformations (AVMs), with pulmonary AVMs (PAVMs) being a common manifestation that contributes to intrapulmonary shunting. Screening for PAVMs is important in HHT to prevent risks of paradoxical embolization, appropriate management and rarely death from pulmonary hemorrhage. Agitated saline contrast echocardiography (‘bubble echo studies’) are done through HHT Centers to identify RLS and grading the same when present, and are recommended through the International HHT Guidelines. Western Canada has a large rural/remote population, and therefore satellite HHT clinics by health jurisdiction and associated echo labs performing these studies have been recommended to improve access to care and hopefully maintain quality of RLS assessments. This policy study aimed to assess the written policies governing bubble echo techniques and protocols in use within accredited echo labs across the province of Alberta, Canada. Methods We conducted an observational cross-sectional study at a single time point (as of July 15, 2024) to evaluate the practices and protocols used in echocardiographic assessments for RLS to screen individuals with HHT - working with the provincial accreditation body, the College of Physicians and Surgeons of Alberta (CPSA). All CPSA-accredited adult echo lab facilities were contacted (telephone/email/in-person). Policy data was collected on the proportion of CPSA-accredited labs specifically performing shunt assessments, including review of available written policies for the shunt assessment protocols. Results A total of 62 CPSA-accredited adult echocardiography facilities were reviewed, of which only 12 reported performing bubble echo studies for RLS assessment. The policy review of the participating echo labs revealed notable variations in the saline injection techniques and the grading scales/criteria used for shunt evaluation in bubble echo studies. Conclusion Current accreditation criteria in Alberta and other health jurisdictions do not mandate a standardized protocol for bubble echo shunt assessments. Considering a standardized protocol could reduce variability between labs and allow for more reliable comparisons over time.
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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 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| 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".