Long Covid: breathlessness

In our series on managing long Covid, Reyenna Sheehan and Jemma Haines describe how to help patients who have ongoing breathlessness

Is ongoing shortness of breath a specific complication of Covid-19?

Breathlessness (dyspnoea) and persistent breathlessness are common symptoms of long Covid.¹ The primary driver of breathlessness in Covid-19 is a coronavirus lung infection that can cause an interstitial pneumonia, with a reduction in lung-diffusing capacity. In severe cases this can progress to acute respiratory distress syndrome (ARDS).²

Respiratory complications

Post-acute Covid-19, referred to as long Covid, appears to be a multi-system disease that can occur even after a milder initial Covid-19 illness.³

The symptoms of long Covid include profound fatigue and persistent breathlessness, with emerging data indicating radiological and physiological features suggesting interstitial lung diseases as a respiratory complication. Of those hospitalised, up to 10% have demonstrated pulmonary fibrosis and organising pneumonia.⁴ Long-term fibrotic changes and reductions in lung function have also been described post-Covid-19 infection following pneumonias and ARDS.^5,6

The Office for National Statistics conducted a UK community population survey and identified that, following a Covid-19 infection, an estimated one in five respondents had ongoing symptoms at five weeks after a positive Covid-19 test; one in 10 had symptoms for 12 weeks or longer, with breathlessness estimated in 5% of ongoing cases⁷.

Could this be unrelated to Covid-19?

Ongoing breathlessness may have multiple causes, separate from Covid-19 infection.² These include respiratory disease, cardiac involvement, neurological and metabolic disorders. It is essential to exclude these possibilities.⁸ NICE advice is to suspect Covid-19 as a cause of symptoms if a patient presents with new or ongoing symptoms four to 12 weeks after acute Covid-19 infection or if symptoms have not resolved in 12 weeks.⁸

Breathlessness may also be linked to a disturbance in the function of breathing. Emerging evidence suggests this can occur in long Covid.¹⁴ For an individual to be efficiently and functionally breathing they must be able to adapt appropriately to stimuli with co-ordination and contraction of the diaphragm, abdominal muscles and muscles of the rib cage.⁹ This should not cause distress, and when it does it may be attributable to a breathing pattern disorder. Chronic changes in the function of breathing can result in dyspnoeic symptoms in the absence of, or in excess of what would be expected in, respiratory disease.⁹ ‘Breathing pattern disorder’ (historically known as hyperventilation) refers to a group of breathing disorders and may co-exist with respiratory conditions such as asthma.¹⁰ It is thought to be a result of an alteration in biochemical, biomechanical or psychophysiological factors.¹¹ If other causes of breathlessness have been excluded, consider referral to respiratory physiotherapists.¹⁴

Investigations and assessment

The priority is to establish the medical cause for the breathlessness. It could be a short-term complication of Covid, a longer-term complication such as interstitial lung disease or fibrosis, or a non-Covid disease.⁸

Observe the patient for cyanosis, excessive accessory muscle use, their ability to speak in sentences, altered respiratory rate and oxygen saturations.3 Outcome tools such as Medical Research Council (MRC) Dyspnoea Scale¹² may be helpful to determine patient perception of breathlessness and impact on activity.¹

Investigations should be tailored to the clinical history, signs and symptoms and follow guidelines.⁸

Further research is needed to refine the indications for, and interpretation of, Covid-19 diagnostic testing and monitoring.³ Clinical history should review the timescale and symptom onset to determine the likelihood of post-Covid-19 infection.⁸ Current guidelines suggest investigations could include CXR to exclude radiologically visible causes and malignancy.^8,14 If symptoms are not explained on CXR consider referral for pulmonary function testing and cardiac investigations.¹⁴ Blood tests may be required for clinical indications depending on patient presentation and to exclude other causes of breathlessness such as anaemia or thromboembolic disease, or to assess for other elevated biomarkers such as C-reactive protein, white cell count, natriuretic peptides, ferritin and troponin. ^3,8

Management and follow-up

There is emerging evidence of the post-acute and recovery process for Covid-19. However, to date there is little evidence of the long-term implications and ongoing patient morbidity. Requirements for follow-up, investigations and implications after initial infection have yet to be identified.¹³

A recent UK prospective observational study* found in its research that up to 74% of patients reviewed had persistent ongoing symptoms, most notably breathlessness and fatigue but with only 35% of post-Covid patients having clinically significant changes in radiology, blood tests or spirometry.¹³

Long Covid clinics

Referral to long Covid clinics should be considered following exclusion of other non-Covid causes if there is breathlessness more than 12 weeks after infection, or debilitating symptoms due to breathlessness, fatigue or psychological disturbance.⁸ Refer patients whose symptoms affect day-to-day activities, such as return to work. Hospitalised patients should be followed up according to the British Thoracic Society guidelines¹⁴ and local policy. Patients with evidence of lung function abnormalities or persistent radiological features of lung fibrosis should be referred to specialist services.¹⁴

Long Covid clinics may be able to refer to specialist respiratory physiotherapists who can help patients self-manage and retrain their breathing. Physiotherapy teams may also be able to help.

Self-management

There are self-management techniques that can help patients with a variety of post-Covid issues.

Reyenna Sheehan is a clinical lead respiratory specialist physiotherapist and Jemma Haines is a consultant speech and language therapist, at Manchester university NHS foundation trust

For more respiratory articles, see our dedicated area

References

¹ Marshall K. Breathlessness: causes, assessment and non-pharmacological management. Nursing Times 2020;116:24-6

² Bajwah S, Wilcock A, Towers R et al. Managing the supportive care needs of those affected by Covid-19. European Respiratory Journal 2020, 2000815; DOI: 10.1183/13993003.00815-2020

³ Greenhalgh T, Knight M, A’Court C et al. Management of post-acute Covid-19 in primary care. BMJ 2020;370:m3026 doi.org/10.1136/bmj.m3026

⁴ Hu B, Guo H, Zhou P et al. Characteristics of SARS-CoV-2 and COVID-19. Nat Rev Microbiol 2021;19:141-54 doi.org/10.1038/s41579-020-00459-7

⁵ Xie L, Liu Y, Xiao Y et al. Follow-up study on pulmonary function and lung radiographic changes in rehabilitating severe acute respiratory syndrome patients after discharge. Chest 2005;127:2119-24

⁶ Hui D, Joynt G, Wong K et al. Impact of severe acute respiratory syndrome (SARS) on pulmonary function, functional capacity and quality of life in a cohort of survivors. Thorax 2005; 60:401-9

⁷ Office for National Statistics. The prevalence of long Covid symptoms and COVID-19 complications. 2020.tinyurl.com/a7rbfy5ds

⁸ NICE. Covid-19 Rapid Guideline: Managing Symptoms (Including at the End of Life) in the Community. NG163 2020

⁹ Boulding R, Stacey R, Niven R et al. Dysfunctional breathing: a review of the literature and proposal for classification. European Respiratory Review 2016;25:287-94. Doi: 10.1183/16000617.0088-2015

¹⁰ Thomas M, McKinley R, Freeman E et al. Prevalence of dysfunctional breathing in patients treated for asthma in primary care: cross sectional survey. BMJ 2001;322:1098-100

¹¹ Courtney R. A Multi-Dimensional Model of Dysfunctional Breathing and Integrative Breathing Therapy – Commentary on The functions of Breathing and Its Dysfunctions and Their Relationship to Breathing Therapy. J Yoga Phys Ther 2016;6:257. doi:10.4172/2157-7595.1000257

¹² The Primary Care Respiratory Society. MRC Dyspnoea Scale. 2021 pcrs-uk.org/mrc-dyspnoea-scale

¹³ Arnold D, Hamilton F, Milne A et al. Patient outcomes after hospitalisation with Covid-19 and implications for follow-up: results from a prospective UK cohort. Thorax 2020 3:thoraxjnl-2020-216086. doi: 10.1136/thoraxjnl-2020-216086. Epub ahead of print. PMID: 33273026; PMCID: PMC7716340

¹⁴ British Thoracic Society. Guidance on Respiratory Follow Up of Patients with a Clinical-Radiological Diagnosis of Covid-19 Pneumonia. 2020 brit-thoracic.org.uk