Evidence map›Paper›PMID 41697432›Full record

ArticleSleep & breathing = Schlaf & Atmung2026

Effects of rostral fluid shift on small airway narrowing in asthma before and after bronchodilation.

Xiaoshu Cao, Cristina O Francisco, Behrad TaghiBeyglou, Sania Aftab, Matthew B Stanbrook, Susan M Tarlo, Kenneth R Chapman, T Douglas Bradley, Mark D Inman, Azadeh Yadollahi

Abstract readControlled Clinical Trial
PubMed Publisher
In one paragraph

Article in Sleep & breathing = Schlaf & Atmung, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0cells of the map it votes in
0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

10 authors.

Xiaoshu CaoInstitute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada.
Cristina O FranciscoKITE, University Health Network Toronto Rehabilitation Institute, 550 University Ave., Toronto, ON, M5G 2A2, Canada.
Behrad TaghiBeyglouInstitute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada.
Sania AftabInstitute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada. sania.aftab@mail.utoronto.ca.ORCID 0009-0004-7239-5926
Matthew B StanbrookDepartment of Medicine, University of Toronto, Toronto, ON, Canada.
Susan M TarloDepartment of Medicine, University of Toronto, Toronto, ON, Canada.
Kenneth R ChapmanDepartment of Medicine, University of Toronto, Toronto, ON, Canada.
T Douglas BradleyKITE, University Health Network Toronto Rehabilitation Institute, 550 University Ave., Toronto, ON, M5G 2A2, Canada.
Mark D InmanFaculty of Medicine (Respirology), McMaster University, Hamilton, ON, Canada.
Azadeh YadollahiInstitute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeThe recumbent posture during sleep increases small airway narrowing and nocturnal asthma despite optimal asthma treatment. Fluid accumulation in the chest can narrow the airway lumen, contributing to small airway narrowing. We hypothesized that in people with asthma, treatment with a short-acting bronchodilator cannot fully prevent airway narrowing attributable to rostral fluid shift.

methodsUsing a cross-over design, participants laid supine for 30 minutes and received lower body positive pressure (LBPP) to reproduce overnight fluid shift out of the legs. They either inhaled salbutamol before lying down (bronchodilator arm) or received no bronchodilator (control arm). Airway narrowing was evaluated while participants were supine at 0 and 30 minutes. Oscillometry was used to estimate reactance at 5 Hz (X5), reactance area (AX), overall resistance of the respiratory system at 5 Hz (R5), and the difference in resistance between frequencies of 5 and 19 Hz (R5–19). Thoracic fluid volumes (TFV) were measured using bioelectrical impedance.

resultsWe enrolled 21 people with asthma. TFV increased similarly in both study arms (58.6±57.5 ml vs 73.8±84.2 ml, p=0.37). In both control and intervention arms, small airway narrowing was observed, with significant decreases in X5 (–0.18±0.34 vs –0.26±0.40 cmH₂O/L/s, p=0.21) and increases in Ax (2.82±4.01 vs 2.23±4.46 cmH₂O/L/s, p=0.61), R5 (0.45±0.49 vs 0.64±0.58 cmH₂O/L/s, p=0.26), and R5–19 (0.20±0.26 vs 0.16±0.37 cmH₂O/L/s, p=0.59). The changes were similar between the two study arms.

conclusionBronchodilator treatment did not prevent the airway narrowing related to rostral fluid shift. These results support a role for rostral fluid shift in the pathophysiology of nocturnal asthma even among appropriately treated patients.

Indexed as

Airway ResistanceAlbuterolAsthmaBronchodilator AgentsFluid ShiftsAdultCross-Over StudiesFemaleHumansMaleMiddle AgedAlbuterolBronchodilator AgentsAirway narrowingAsthmaRespiratory physiologyRostral fluid shiftSleep apnea

Identifiers

PMID41697432

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.