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Record W3159131944 · doi:10.24908/iqurcp.8712

A Study of Gas-Exchange Variability in the Hepatopulmonary Syndrome

2016· article· en· W3159131944 on OpenAlexvenueaboutno aff
Dhruv Nayyar

Bibliographic record

VenueInquiry Queen s Undergraduate Research Conference Proceedings · 2016
Typearticle
Languageen
FieldMedicine
TopicLiver Disease and Transplantation
Canadian institutionsnot available
Fundersnot available
KeywordsCutoffHepatopulmonary syndromeMedicineInternal medicineArterial bloodCardiologyCirrhosisPortal hypertensionPhysics

Abstract

fetched live from OpenAlex

The hepatopulmonary syndrome (HPS) is a rare condition defined as the triad of cirrhosis, intrapulmonary vascular dilatations (IPVDs), and abnormal gas-exchange. Recently, there has been controversy in the scientific literature regarding the criterion for abnormal gas-exchange that should be used in this syndromic definition. Although current expert recommendations call for an alveolar-arterial oxygen gradient cutoff of >20 mm Hg (a low threshold cutoff), other authors have suggested higher threshold cutoffs. In our clinical experience, we have noted significant variability in the alveolar-arterial oxygen gradient over time among patients with possible HPS. Our objectives were to characterize and formally describe this variability in order to propose a new, more stable diagnostic cutoff. We analyzed longitudinal gas-exchange data over five years from 58 patients who were referred to the Toronto HPS Clinic. Each patient had an average of 4.19 visits on file. Using the expert recommended cutoffs, we found that 20.69% of patients fluctuate above or below the threshold for abnormal gas-exchange despite stability of clinical symptoms. Using a stricter two-visit partial pressure of arterial oxygen cutoff of <80mm Hg, no patients fluctuate above or below the cutoff. The stricter cutoff also has stronger correlations with clinical indicators of disease progress and severity. The currently recommended cutoffs for abnormal gas-exchange in HPS patients may not be the best threshold to establish a stable diagnosis and distinguish patients with respect to disease progress and severity.

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 imitation

Not 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.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.007
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.012
Threshold uncertainty score0.023

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.007
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.001
Science and technology studies0.0000.000
Scholarly communication0.0010.000
Open science0.0000.000
Research integrity0.0000.001
Insufficient payload (model declined to judge)0.0010.000

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.

Opus teacher head0.121
GPT teacher head0.377
Teacher spread0.256 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

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".

Quick stats

Citations0
Published2016
Admission routes2
Has abstractyes

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