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OpenTrials
Completed

NCT Number: NCT03981393

Cardinality Matching Study of Early v.s. Delayed VV ECMO in Severe Respiratory Failure

Clinical reasoning and recent data suggest that early use of venovenous extracorporeal membrane oxygenation in refractory respiratory failure may confer a survival advantage.

This retrospective matched study will assess whether patients who received VV ECMO at less severe hypoxaemia had differing outcomes to those who received ECMO with very severe hypoxaemia.

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Key information

Conditions

Acute Respiratory Failure ECMO

Age range

16 year and older

Sex eligibility

All sexes

Study type

Observational

About this study

VV ECMO is increasingly used in refractory respiratory failure. Despite advances in lung protective ventilation strategies, patients who have severe respiratory failure often develop complications from mechanical ventilation, including volutrauma and barotrauma. ECMO allows gas exchange to occur extracorporeally and may reduce the potential burden of iatrogenic lung injury by allowing a reduction of volume and pressure support - a 'lung rest' strategy. It is theorised that earlier intitiation of ECMO may allow for better outcomes, as there will have been less time for iatrogenic lung injury to occur.

The UK ECMO registry has been collected of patients treated under the NHS England commissioned respiratory ECMO service since 2011. This study has been previously registered and publication is intended shortly.

Patients will be extracted from this registry if they received VV ECMO. Propensity matching scores will be created and patients will be stratified into groups of 'early' vs 'delayed' ECMO, based on their probability of being in either group.

Patients will be divided into cohorts based on the median PaO2/FiO2 ratio at decision to cannulate ('less severe hypoxaemia') and ('very severe hypoxaemia'). Matched cohorts will be created correcting for key confounding factors (age, primary diagnosis, duration of pre-ECMO ventilation and PaCO2), using cardinality matching (a novel technique described by Zubizaretta et al. in 2014) and traditional propensity-score-based methods.

The technique with greater balance and statistical power (as defined by sample size) will be selected for the primary analysis.

Further analyses will assess the relationship between hypoxaemia at decision-to-cannulate and confounding factors as above.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients included in the UK ECMO registry (see previous registration; NCT number awaited; protocol ECMO-001)
  • Patients with VV ECMO

Exclusion criteria

  • Patients with inadequate or missing data for creation of propensity score models.

Treatment and study plan

Primary outcomes

  1. Survival to ECMO ICU discharge

    Time frame: Up to 90 days.

    Percentage of patients alive at discharge from the ICU at the specialist ECMO centre

Secondary outcomes

  1. Duration of ECMO treatment

    Time frame: Up to 90 days.

    Duration spent supported by active ECMO treatment.

Sponsors and collaborators

Lead sponsor

University of Cambridge

Other

Registry information

Important dates

Study start
2011
Primary completion
2017
Study completion
2018
First posted
Jun 10, 2019
Registry last updated
Apr 27, 2021

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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