Long-COVID Infections and Infestations
Conditions
Interventions
The mechanistic hypothesis is that the carotid chemoreflex is persistently hyperactive at rest and during exercise, driving hyperventilation and persistent breathlessness in long-COVID patients. To in
Sponsors
University of Bristol
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: All participants: 1. 18-75 years old 2. Self-reported positive PCR or antibody test before vaccination Long-COVID patients only: 1. Breathlessness affecting their daily lives measured by the Modified Yorkshire COVID-19 Rehabilitation Scale (used in long-COVID clinics) Age and sex-matched controls only: 1. Asymptomatic or symptoms lasting less than 4 weeks after COVID-19 infection 2. Must not have breathlessness affecting their daily life (checked on screening call and by questionnaire during lab screening)
Exclusion criteria
Exclusion criteria: 1. Body mass index =30 kg/m2 2. Diagnosed with severe asthma or uncontrolled asthma 3. Pregnancy/breastfeeding women 4. Ongoing requirement for oxygen therapy 5. Taking antihypertensive, nitrate, steroid or immunosuppressant medication or medication 6. Major illness e.g., cancer, inflammatory disease (including vasculitis) or receiving palliative care 7. History of organ transplantation or are candidates for organ transplantation at the time of screening 8. History of Chronic Fatigue Syndrome prior to COVID-19 infection 9. Diagnosed cardiovascular disease (including current non-benign arrhythmia, chronic heart failure) 10. History of major psychiatric disorder including bipolar disorders, schizophrenia, schizoaffective disorder, major depression 11. Diagnosis of structural lung disease (such as COPD or pulmonary fibrosis) 12. Diagnosed renal disease 13. Congenital or acquired neurological conditions (including dementia), language disorders, repeated or chronic pain conditions (excluding menstrual pain and minor sporadic headaches) 14. Diabetes mellitus 15. Symptoms of febrile illness 2 weeks before experiment 16. Lower respiratory tract symptoms at time of screening visit 17. Excessive alcohol consumption (>28 units/week) or use of illicit drugs 18. History of tobacco smoking within the last 12 months 19. Inability to understand instructions given in English 20. Surgery under general anaesthesia within 3 months 21. History of stroke 22. Heart transplant 23. Coronary revascularisation 24. Haemodialysis or peritoneal dialysis 25. Participating in another study for an investigational medicinal product 26. Known allergy to dopamine
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Chemoreflex sensitivity calculated by the increase in minute ventilation divided by the SpO2%; this is termed the hypoxic ventilatory response or HVR and is expressed as L/min/SpO2% | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. Hypoxic blood pressure measured using a Finapres, continuous beat-to-beat blood pressure throughout infusion 2. Heart rate during hypoxia measured using a 3-lead ECG continuously throughout infusion 3. Resting minute ventilation and breathing frequency measured via a face mask and gas analyser and will be measured continuously (breath-by-breath) throughout infusion 4. Minute ventilation, respiratory rate and oxygen consumption (VO2) measured using a face mask and gas analyser continuously (breath-by-breath) throughout exercise 5. Dyspnoea score measured using the Borg scale 1-10 every 2 minutes throughout exercise 6. Heart rate measured using a 12-lead ECG continuously throughout exercise 7. Blood pressure measured using a blood pressure cuff every minute throughout exercise | — |
Countries
England, United Kingdom
Contacts
Public ContactEmma Hart
Outcome results
None listed