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LONG COVID: Ongoing respiratory problems



Many recovering patients suffer the effects of lung damage including coughing, breathlessness and an inability to exercise.

The Covid-19 pandemic hit Western Europe over a year ago and has altered our lives in ways we could barely imagine only a few months beforehand. Despite the effective UK vaccination campaign so far, it is becoming increasingly apparent that for many people the shadow of Covid continues to fall across their lives long after their initial infection appears to have settled. It is estimated that there are currently over a million people in private households in the UK reporting symptoms of ‘long Covid’.

Although definitions are still fairly fluid, for the purpose of this article I will refer to post-Covid as being symptoms extending beyond three weeks from the onset of first symptoms and ‘long’ or chronic Covid as extending beyond 12 weeks. For those experiencing long Covid, there are an average of nine persistent symptoms with the most common being fatigue, breathlessness, myalgia, slowness of movement, poor sleep, joint pain or swelling, generalised pain, memory loss and poor cognitive function – so-called ‘brain fog’, which seems to occur more in older males. Females appear to most adversely affected by long Covid, with a mean age of 45 and it is more common in people with pre-existing, activity-limiting health conditions and in health and social care workers.

Long Covid can significantly impact the respiratory system. Many recovering patients suffer the effects of lung damage including coughing, breathlessness and an inability to exercise. This is likely due to a combination of the body’s exaggerated immune system reaction to the virus, and the lung inflammation it triggers. We know that in severe cases lung scarring occurs which in turn stiffens lung tissue and so reduces efficient blood oxygenation and increases breathlessness on exertion – classical symptoms of interstitial lung disease. Early studies suggest lung damage has occurred in around a fifth of Covid patients post-discharge from hospital but the longer-term impact of patients in the community is still to be assessed.

It is still unclear why some people are affected so adversely long-term. Postulated reasons include persisting viraemia from pockets of persisting infection in the body, hyper-inflammatory reactions, deconditioning, PTSD and absent antibody responses.

The British Thoracic Society has defined a chronic cough as one that lasts more than eight weeks, and for many post-Covid patients their respiratory symptoms gradually settle over this time with a degree of breathlessness being common post-hospital discharge. However, if respiratory symptoms persist it is essential that primary care health professionals have a plan of action as to how best help these patients.

If cough is the predominant symptom – and conditions such as pleurisy and pneumonia have been excluded – then breathing control exercises can be highly effective. Many post-Covid 19 patients have a pattern of dysfunctional breathing, partly linked to deconditioning and reduced movement of the diaphragm as well as being more likely to use their upper body accessory muscles to help with breathing. This results in shallow breathing and increased fatigue. Simple breathing control exercises can be dramatically effective at helping to restore normal diaphragmatic breathing and can be performed regularly through the day for 10-15 minutes at a time. Whilst the patient is sitting upright and comfortably, ask them to breathe slowly in through their nose and out through their mouth whilst keeping their upper body as relaxed as possible. They should let their abdomen move in and out and have an inspiration to expiration ratio of 1:2. This allows for breathing patterns to normalise and in doing so cause less airway irritation, dyspnoea and fatigue.

Breathing exercises can also help with long-term breathlessness but there should be a high index of suspicion in patients who become suddenly breathless. Home pulse oximetry can be a useful tool here, especially in patients where no obvious cause is found for their dyspnoea. The British Thoracic Society guidelines are that the target range for oxygen saturation should be 94-98% and – unless the patient is in chronic respiratory failure – a level of 92% or below requires assessment and supplementary oxygen. (For patients with normal assessment values, a saturation of 96% or above without desaturation on exertion should be reassuring.) Patients using pulse oximeters should take a daily reading on a warm, clean finger with no nail polish present, resting for 20 minutes before any reading is taken. The device should be left to stabilise, and the best of 3 readings recorded.

General points to remember with breathlessness are that it is very common post Covid, with exertional breathlessness often persisting for many weeks before there is a gradual recovery. If there are unexplained crackles on auscultation, refer to the GP who will likely order a chest X-ray and, depending on the result of this, further scans may also be required. There is an increased risk of thrombosis and PE post-COVID, and myocarditis can present with shortness of breath as a primary symptom.

Investigations that will be helpful are bloods including FBC, U&E, LFT, calcium, TFTs and BNP, and a sputum sample if the cough is productive. An ECG can help to eliminate cardiac causes and oxygen saturation readings can be useful in determining if an acute event is occurring.

Red flag symptoms in the post-Covid breathless patient include;

•             Sudden onset (within the last 24- 48 hours) dyspnoea or severe breathlessness.

•             An oxygen saturation below 93% if this is new for the patient.

•             A bradycardia of less than 60bpm, or a tachycardia of more than 100bpm.

•             A respiratory rate greater than 30 breaths per minute.

If the patient reports haemoptysis, unintentional weight loss, night sweats and/or a strong smoking history then the GP must be informed and an urgent two week referral is appropriate.

Pulmonary rehabilitation assessment or referral to the local community respiratory team is appropriate if the patient has an underlying respiratory condition, is not improving or has worsening breathlessness, or if ambulatory oxygen becomes necessary. It should also be considered in any patient experiencing a disproportionate shortness of breath or altered breathing patterns.

Key points

•             Patients can be referred to local long-Covid clinics even in the absence of a previous positive Covid test.

•             There are a number of possible causes of breathlessness in the long-Covid patient including respiratory and cardiac causes. Taking a detailed history is vital in helping elicit a diagnosis.

•             Many cases of long-Covid breathlessness will resolve without treatment over time.

Resources

Prevalence of ongoing symptoms following coronavirus (COVID-19) infection in the UK: 1 April 2021 Prevalence of ongoing symptoms following coronavirus (COVID-19) infection in the UK – Office for National Statistics (ons.gov.uk)

New national study of long-term impacts of lung damage from COVID-19 New national study of long-term impacts of lung damage from COVID-19 | Imperial News | Imperial College London

Facing up to long Covid; The Lancet. Editorial. Vol.396 December 12 2020 Management of post-acute covid-19 in primary care. Greenhalgh T et al. BMJ 2020;370:m3026

Considering the long-term respiratory effects of Covid-19. Occupational Medicine. Editorial. doi:10.1093/occmed/kqaa224

Covid-19 rapid guideline: managing the long-term effects of Covid-19. NICE guideline [NG188]. Published 18 Dec 2020