Evidence map›Paper›PMID 25197804›Full record

Trial reportSleep2014

Influence of cerebral blood flow on central sleep apnea at high altitude.

Keith R Burgess, Samuel J E Lucas, Kelly Shepherd, Andrew Dawson, Marianne Swart, Kate N Thomas, Rebekah A I Lucas, Joseph Donnelly, Karen C Peebles, Rishi Basnyat and 1 more

Open access · bronzeAbstract readRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in Sleep, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
6citing papers in PubMed, 1 pooled it
0.9field-weighted citation impact, top 30% of its field
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

6 citing papers in PubMed, 1 synthesis or guideline pooled it, 17 citations in OpenAlex.

  1. Pooled it
  2. Article
  3. Article
  4. Review
  5. Pathophysiology of central sleep apneas.Sleep & breathing = Schlaf & Atmung · 2016
    Review
  6. Article
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

11 authors at 4 institutions in 4 countries.

Keith R BurgessPeninsula Sleep Laboratory, Sydney, New South Wales, Australia and Department of Medicine, University of Sydney, Sydney, New South Wales, Australia.
Samuel J E LucasUniversity of Otago, Dunedin, New Zealand.
Kelly ShepherdPeninsula Sleep Laboratory, Sydney, New South Wales, Australia.
Andrew DawsonPeninsula Sleep Laboratory, Sydney, New South Wales, Australia.
Marianne SwartPeninsula Sleep Laboratory, Sydney, New South Wales, Australia.
Kate N ThomasUniversity of Otago, Dunedin, New Zealand.
Rebekah A I LucasUniversity of Otago, Dunedin, New Zealand.
Joseph DonnellyUniversity of Otago, Dunedin, New Zealand.
Karen C PeeblesUniversity of Otago, Dunedin, New Zealand.
Rishi BasnyatNepal International Clinic, Kathmandu, Nepal and Banner Good Samaritan Medical Center, Phoenix, Arizona.
Philip N AinslieCentre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Okanagan Campus, Canada.
University of Otago · NZBanner - University Medical Center Phoenix · USThe University of Sydney · AUUniversity of British Columbia · CA

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

STUDY

objectivesTo further our understanding of central sleep apnea (CSA) at high altitude during acclimatization, we tested the hypothesis that pharmacologically altering cerebral blood flow (CBF) would alter the severity of CSA at high altitude.

designThe study was a randomized, placebo-controlled single-blind study.

settingA field study at 5,050 m in Nepal. PATIENTS OR

participantsWe studied 12 normal volunteers.

interventionsBetween days 5 to 10 at high altitude, CBF velocity (CBFv) was increased by intravenous (IV) acetazolamide (10 mg/kg) and reduced by oral indomethacin (100 mg). MEASUREMENTS AND

resultsArterial blood gases, hypoxic and hypercapnic ventilatory responses, and CBFv and its reactivity to carbon dioxide were measured awake. Overnight polysomnography was performed. The central apnea-hypopnea index was elevated following administration of indomethacin (89.2 ± 43.7 to 112.5 ± 32.9 events/h; mean ± standard deviation; P < 0.05) and was reduced following IV acetazolamide (89.2 ± 43.7 to 47.1 ± 48.1 events/h; P < 0.001). Intravenous acetazolamide elevated CBFv at high altitude by 28% (95% confidence interval [CI]: 22-34%) but did not affect ventilatory responses. The elevation in CBFv was partly mediated via a selective rise in partial pressure of arterial carbon dioxide (PaCO2) (28 ± 4 to 31 ± 3 mm Hg) and an associated fall in pH (P < 0.01). Oral indomethacin reduced CBFv by 23% (95% CI: 16-30%), blunted CBFv reactivity, and increased the hypercapnic ventilatory response by 66% (95% CI: 30-102%) but had no effect on PaCO2 or pH.

conclusionOur findings indicate an important role for cerebral blood flow regulation in the pathophysiology of central sleep apnea at high altitude.

Indexed as

AltitudeAcclimatizationAcetazolamideAdministration, IntravenousAdministration, OralAdultCarbon DioxideCardiovascular AgentsCerebrovascular CirculationFemaleHumansHypercapniaHypoxiaIndomethacinMaleMiddle AgedAcetazolamideCarbon DioxideCardiovascular AgentsIndomethacincentral sleep apneacerebral blood flowcerebral vascular reactivityhigh altitudeventilatory responses

Identifiers

PMID25197804
PMCPMC4173924
OpenAlexW2086588571

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

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.