Evidence map›Paper›PMID 35859332›Full record

ArticlePhysiological reports2022

Does hyperbaric oxygen cause narcosis or hyperexcitability? A quantitative EEG analysis.

Xavier C E Vrijdag, Hanna van Waart, Chris Sames, Simon J Mitchell, Jamie W Sleigh

Open access · goldAbstract read
In one paragraph

Article in Physiological reports, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
5citing papers in PubMed, 1 pooled it
1.3field-weighted citation impact, top 19% 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

5 citing papers in PubMed, 1 synthesis or guideline pooled it, 9 citations in OpenAlex.

  1. Pooled it
  2. Trial
  3. Review
  4. Article
  5. 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

5 authors at 2 institutions in 1 country.

Xavier C E VrijdagDepartment of Anaesthesiology, University of Auckland, Auckland, New Zealand.ORCID https://orcid.org/0000-0001-5907-6083
Hanna van WaartDepartment of Anaesthesiology, University of Auckland, Auckland, New Zealand.ORCID https://orcid.org/0000-0002-6931-0168
Chris SamesSlark Hyperbaric Unit, Waitemata District Health Board, Auckland, New Zealand.ORCID https://orcid.org/0000-0002-8747-1360
Simon J MitchellDepartment of Anaesthesiology, University of Auckland, Auckland, New Zealand.ORCID https://orcid.org/0000-0002-5149-6371
Jamie W SleighDepartment of Anaesthesiology, University of Auckland, Auckland, New Zealand.ORCID https://orcid.org/0000-0002-1966-5825
University of Auckland · NZWaitemata District Health Board · NZ

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Divers breathe higher partial pressures of oxygen at depth than at the surface. The literature and diving community are divided on whether or not oxygen is narcotic. Conversely, hyperbaric oxygen may induce dose-dependent cerebral hyperexcitability. This study evaluated whether hyperbaric oxygen causes similar narcotic effects to nitrogen, and investigated oxygen's hyperexcitability effect. Twelve human participants breathed "normobaric" air and 100% oxygen, and "hyperbaric" 100% oxygen at 142 and 284 kPa, while psychometric performance, electroencephalography (EEG), and task load perception were measured. EEG was analyzed with functional connectivity and temporal complexity algorithms. The spatial functional connectivity, estimated using mutual information, was summarized with the global efficiency network measure. Temporal complexity was calculated with a "default-mode-network (DMN) complexity" algorithm. Hyperbaric oxygen-breathing caused no change in EEG global efficiency or in the psychometric test. However, oxygen caused a significant reduction of DMN complexity and a reduction in task load perception. Hyperbaric oxygen did not cause the same changes in EEG global efficiency seen with hyperbaric air, which likely related to a narcotic effect of nitrogen. Hyperbaric oxygen seemed to disturb the time evolution of EEG patterns that could be taken as evidence of early oxygen-induced cortical hyperexcitability. These findings suggest that hyperbaric oxygen is not narcotic and will help inform divers' decisions on suitable gas mixtures.

Indexed as

DivingHyperbaric OxygenationStuporElectroencephalographyHumansNitrogenOxygenNitrogenOxygencomplexitydivingEEGfunctional connectivityoxygen narcosis

Identifiers

PMID35859332
PMCPMC9300958
OpenAlexW4286508556

What OpenQuestion holds

Textmetadata
LicenceCC BY
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.