Argon inhalation to protect thinking after carotid surgery.

Perioperative Argon Inhalation to Improve Neurocognitive Recovery After Carotid Surgery (PAIRS Trial)

Phase 3 Interventional Negovsky Reanimatology Research Institute · NCT07200180

This trial will test whether breathing an argon-oxygen mix during and after elective carotid surgery helps protect the brain and improve thinking while lowering the risk of postoperative delirium in adults.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment100 (estimated)
Ages18 Years and up
SexAll
SponsorNegovsky Reanimatology Research Institute Government
Locations1 site (Moscow)
Trial IDNCT07200180 on ClinicalTrials.gov

What this trial studies

Participants undergoing elective carotid revascularization under general anesthesia will receive a perioperative breathing mixture containing either argon-oxygen or a control nitrogen-oxygen mixture around the time of surgery. The study follows patients through the immediate postoperative period with monitoring for clinical and covert ischemic brain injury, standardized cognitive testing, and surveillance for delirium. The intervention is delivered at a single center and is intended to reduce microcirculatory reperfusion injury that can occur despite restored large-vessel blood flow. Outcomes will compare cognitive and delirium-related measures between the argon and control groups to see if argon provides neuroprotection.

Who should consider this trial

Good fit: Adults over 18 scheduled for elective carotid artery surgery under general anesthesia who can give informed consent and do not have major psychiatric or neuromuscular disorders meet the ideal candidate profile.

Not a fit: Patients with diagnosed mental or neuromuscular disorders, severe heart failure (NYHA class III–IV), pregnant or breastfeeding people, those unable to undergo preoperative assessment, or those having emergency procedures are unlikely to benefit or be eligible.

Why it matters

Potential benefit: If successful, argon inhalation could reduce silent perioperative strokes and lower short- and long-term cognitive decline and delirium after carotid surgery.

How similar studies have performed: Argon has shown neuroprotective effects in animal models and some small early human studies, but robust large-scale Phase 3 evidence in this surgical setting is not yet available.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* age \> 18 years
* elective carotid artery surgery
* general anesthesia
* written informed consent

Exclusion Criteria:

* The presence of any mental disorder according to the International Classification of Diseases 10th Revision which is confirmed by a psychiatrist.
* The presence of any neuromuscular disease according to the International Classification of Diseases 10th Revision
* Heart failure equal 3 or 4 class according to the New York Heart Association Functional Classification
* Pregnant or breast-feeding women
* Inability to undergo a preoperative assessment for any reason
* Previously enrolled in this trial

Where this trial is running

Moscow

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.
Conditions Carotid Artery DiseaseCarotid Artery StenosesCarotid artery diseaseCarotid artery stenosisCarotid artery surgeryNeurocognitive disorderspostoperative deliriumStroke
Last reviewed 2026-06-15 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.