Titrated versus standard oxygen for prehospital treatment of COPD exacerbations

Standard vs Targeted Oxygen Therapy Prehospital for Chronic Obstructive Pulmonary Disease

PHASE4 · Central Denmark Region · NCT05703919

This trial tests whether giving oxygen adjusted to keep blood oxygen (SpO₂) at 88–92% instead of using 100% oxygen during prehospital treatment of adults 40 and older with suspected COPD exacerbations lowers 30-day death.

Quick facts

PhasePHASE4
Study typeInterventional
Enrollment1888 (estimated)
Ages40 Years and up
SexAll
SponsorCentral Denmark Region (other)
Locations1 site (Aarhus N)
Trial IDNCT05703919 on ClinicalTrials.gov

What this trial studies

The STOP-COPD trial randomizes adults aged 40 and older with suspected acute COPD exacerbation treated by Emergency Medical Services in the Central Denmark Region to receive inhaled bronchodilators driven by either compressed air with supplemental oxygen titrated to SpO₂ 88–92% or by 100% compressed oxygen. The trial is patient-blinded, conducted in the prehospital setting, and enrolls 1,888 participants in a 1:1 parallel-group, superiority design. The primary outcome is 30-day all-cause mortality, and secondary outcomes include 24-hour and 7-day mortality, need for invasive or non-invasive ventilation, respiratory acidosis on hospital arrival, ICU admission and lengths of stay, patient-reported dyspnea, and readmission rates. Enrollment occurs under emergency research regulations with informed consent obtained as soon as feasible after hospital admission.

Who should consider this trial

Good fit: Ideal candidates are adults aged 40 or older in the Central Denmark Region with EMS-suspected acute COPD exacerbation who require inhaled bronchodilators in the prehospital setting.

Not a fit: Patients with bronchospasm due to asthma or non-COPD causes, known or suspected pregnancy, those already receiving assisted ventilation, inter-hospital transfers, or those with suspected acute coronary syndrome are excluded and unlikely to benefit from this intervention.

Why it matters

Potential benefit: If successful, titrated oxygen during prehospital bronchodilator treatment could reduce 30-day mortality and lower the risk of hypercapnia-related complications in COPD exacerbations.

How similar studies have performed: Previous in-hospital and some ambulance-based studies have suggested conservative, titrated oxygen targets can reduce hypercapnia and harm in COPD exacerbations, but high-quality randomized evidence specifically for nebulizer-driven oxygen in the prehospital setting is limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Patients over the age of 40
* EMT or Paramedic suspected AECOPD
* Confirmed suspicion of COPD

Exclusion Criteria:

* Bronchospasm due to asthma, allergic reaction or non-COPD conditions
* Known or suspected pregnancy
* Prehospital Non-invasive, invasive or assisted bag mask ventilation
* Allergy to inhaled bronchodilators (Salbutamol)
* Inter-hospital transfer
* More than 2 doses (5 mg salbutamol) inhalation drug, acute treatment by EMS (emergency medical service) personnel, before allocated treatment is initiated
* Suspicion of acute coronary syndrome

Where this trial is running

Aarhus N

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: COPD Exacerbation, COPD Exacerbation Acute, Titrated Oxygen, Prehospital, COPD

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.