Evidence map›Paper›PMID 35687543›Full record

Observational studyPloS one2022

Dynamic blood oxygen indices in mechanically ventilated COVID-19 patients with acute hypoxic respiratory failure: A cohort study.

Luke Bracegirdle, Alexander Jackson, Ryan Beecham, Maria Burova, Elsie Hunter, Laura G Hamilton, Darshni Pandya, Clare Morden, Michael P W Grocott, Andrew Cumpstey and 2 more

Open access · goldAbstract readObservational Study
In one paragraph

Observational study in PloS one, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
0.8field-weighted citation impact, top 28% 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

3 citing papers in PubMed, 5 citations in OpenAlex.

  1. Article
  2. Article
  3. 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

12 authors at 1 institution in 1 country.

Luke BracegirdleGeneral Intensive Care Unit, University Hospital Southampton NHS Foundation Trust, Southampton, Hampshire, United Kingdom.ORCID 0000-0002-6321-7587
Alexander JacksonGeneral Intensive Care Unit, University Hospital Southampton NHS Foundation Trust, Southampton, Hampshire, United Kingdom.ORCID 0000-0002-3153-9231
Ryan BeechamGeneral Intensive Care Unit, University Hospital Southampton NHS Foundation Trust, Southampton, Hampshire, United Kingdom.
Maria BurovaGeneral Intensive Care Unit, University Hospital Southampton NHS Foundation Trust, Southampton, Hampshire, United Kingdom.
Elsie HunterGeneral Intensive Care Unit, University Hospital Southampton NHS Foundation Trust, Southampton, Hampshire, United Kingdom.
Laura G HamiltonGeneral Intensive Care Unit, University Hospital Southampton NHS Foundation Trust, Southampton, Hampshire, United Kingdom.ORCID 0000-0002-9377-216X
Darshni PandyaGeneral Intensive Care Unit, University Hospital Southampton NHS Foundation Trust, Southampton, Hampshire, United Kingdom.
Clare MordenGeneral Intensive Care Unit, University Hospital Southampton NHS Foundation Trust, Southampton, Hampshire, United Kingdom.
Michael P W GrocottGeneral Intensive Care Unit, University Hospital Southampton NHS Foundation Trust, Southampton, Hampshire, United Kingdom.ORCID 0000-0002-9484-7581
Andrew CumpsteyGeneral Intensive Care Unit, University Hospital Southampton NHS Foundation Trust, Southampton, Hampshire, United Kingdom.ORCID 0000-0001-6257-207X
Ahilanandan DushianthanGeneral Intensive Care Unit, University Hospital Southampton NHS Foundation Trust, Southampton, Hampshire, United Kingdom.ORCID 0000-0002-0165-3359
REACT COVID-19 Investigators
University Hospital Southampton NHS Foundation Trust · GB

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundAcute hypoxic respiratory failure (AHRF) is a hallmark of severe COVID-19 pneumonia and often requires supplementary oxygen therapy. Critically ill COVID-19 patients may require invasive mechanical ventilation, which carries significant morbidity and mortality. Understanding of the relationship between dynamic changes in blood oxygen indices and clinical variables is lacking. We evaluated the changes in blood oxygen indices-PaO2, PaO2/FiO2 ratio, oxygen content (CaO2) and oxygen extraction ratio (O2ER) in COVID-19 patients through the first 30-days of intensive care unit admission and explored relationships with clinical outcomes. METHODS AND

findingsWe performed a retrospective observational cohort study of all adult COVID-19 patients in a single institution requiring invasive mechanical ventilation between March 2020 and March 2021. We collected baseline characteristics, clinical outcomes and blood oxygen indices. 36,383 blood gas data points were analysed from 184 patients over 30-days. Median participant age was 59.5 (IQR 51.0, 67.0), BMI 30.0 (IQR 25.2, 35.5) and the majority were men (62.5%) of white ethnicity (70.1%). Median duration of mechanical ventilation was 15-days (IQR 8, 25). Hospital survival at 30-days was 72.3%. Non-survivors exhibited significantly lower PaO2 throughout intensive care unit admission: day one to day 30 averaged mean difference -0.52 kPa (95% CI: -0.59 to -0.46, p<0.01). Non-survivors exhibited a significantly lower PaO2/FiO2 ratio with an increased separation over time: day one to day 30 averaged mean difference -5.64 (95% CI: -5.85 to -5.43, p<0.01). While all patients had sub-physiological CaO2, non-survivors exhibited significantly higher values. Non-survivors also exhibited significantly lower oxygen extraction ratio with an averaged mean difference of -0.08 (95% CI: -0.09 to -0.07, p<0.01) across day one to day 30.

conclusionsAs a novel cause of acute hypoxic respiratory failure, COVID-19 offers a unique opportunity to study a homogenous cohort of patients with hypoxaemia. In mechanically ventilated adult COVID-19 patients, blood oxygen indices are abnormal with substantial divergence in PaO2/FiO2 ratio and oxygen extraction ratio between survivors and non-survivors. Despite having higher CaO2 values, non-survivors appear to extract less oxygen implying impaired oxygen utilisation. Further exploratory studies are warranted to evaluate and improve oxygen extraction which may help to improve outcomes in severe hypoxaemic mechanically ventilated COVID-19 patients.

Indexed as

COVID-19Respiratory Distress SyndromeRespiratory InsufficiencyAdultCohort StudiesFemaleHumansHypoxiaMaleOxygenRespiration, ArtificialRetrospective StudiesSARS-CoV-2Oxygen

Identifiers

PMID35687543
PMCPMC9187096
OpenAlexW4281958044

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.