Monitoring of the rehabilitation therapy of COVID-19 effort dyspnea

Coronavirus disease (COVID-19), caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), ranges from no symptoms to severe respiratory failure.¹ However, the disease does not end with the acute stage. A previous study reported that 56% of patients continued to present symptoms such as palpitations, chest pain, dyspnoea at rest and dyspnoea on exertion with exercise, even after negative reverse transcription polymerase chain reaction (RT-PCR) test results and hospital discharge.²

We report the case of a 26-year-old patient, a member of our hospital's healthcare staff, with no personal history of note, who sought hospital care as she had started to experience dyspnoea on exertion (when engaging in moderate-intensity sport). A previous serology study to screen for asymptomatic carriers at the same hospital (chemiluminescence and enzyme-linked immunosorbent assay) had detected IgG⁺ IgM– serology for SARS-CoV-2. The patient remained asymptomatic up to that time.

Physical examination revealed no findings of note, and lung auscultation was normal. At that time, the patient refused a computed tomography (CT) scan of the chest. Instead, a lung ultrasound was performed with a portable ultrasound device (Butterfly iQ — Butterfly Network, Guilford, CT, United States). The examination regimen followed included 12 areas of the thorax, 6 in each hemithorax (anterior, lateral and posterior, subdivided into superior and inferior).³ This revealed a thickened, irregular pleural line with prominent B lines in the left posterosuperior lobe — the only pathological finding on examination.

The patient was referred to the pulmonary rehabilitation clinic. Her oxygen saturation (SO₂) was 97% and her heart rate (HR) was 64 bpm. In the initial assessment, a six-minute walk test was performed, in which she walked a total of 720 m with a final O₂ sat. of 95% and a maximum HR of 166 bpm. In the stress test, eight minutes of exertion and a maximum load of 100 watts yielded an O₂ sat. of 94% and a maximum HR of 160 bpm. The patient's score on the Borg scale was 15, meaning that her perceived exertion intensity was hard.

For this reason, an at-home pulmonary rehabilitation programme was designed. This programme included the following exercises:

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  Slow, deep breaths sustained over time (with shoulders lifted)

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  Diaphragmatic breathing, pursed-lip expiration (noting improvement in desaturation)

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  Diaphragmatic training: placing a weight of 1−3 kg on the abdomen in a supine position and stretching the rib cage⁴

Two sessions of 10 min a day were done for six weeks, instead of one session a day;⁵ thus the training was customised to our patient's age and greater functional capacity.

At the end of the programme, the lung ultrasound was repeated and showed resolution of the previously reported abnormalities. An improvement was also observed in the six-minute walk test and stress test, with the previously observed desaturations disappearing.

The usefulness of imaging tests for the diagnosis of the disease is indisputable. A prior study found that residual lesions were common on chest CT scans after SARS-CoV-2 pneumonia, and could persist up to 4 weeks after the onset of symptoms.² Therefore, it is advisable to do follow-up of lung lesions until they resolve. However, performing this follow-up using chest CT scans carries a number of disadvantages, such as limited access due to high numbers of patients and radiation exposure on the part of the patients. On the other hand, pulmonary ultrasound is proving a suitable imaging tool for diagnosis and follow-up in this type of patient. It is harmless; it is done quickly following simple, easy-to-use protocols; and its findings correlate well with chest CT scan findings.³

Residual pulmonary fibrotic changes can lead to a restriction of physical activity due to the shortness of breath caused by decreased lung function, resulting in a lower quality of life.²

In the short term, pulmonary rehabilitation is aimed at relieving dyspnoea and anxiety; in the long term, it is aimed at recovering the patient's maximum functionality, improving their quality of life and facilitating their integration into society.⁶ It is important that respiratory physiotherapy exercises are indicated on an individual basis. Therefore, it will be necessary to perform a prior comprehensive evaluation by means of a six-minute walk test and a stress test.³

A previous study⁷ found that the majority of asymptomatic COVID-19 patients did not develop symptoms during a brief three-week follow-up period. As far as we know, this is the first case that has suggested the possibility that asymptomatic patients may also develop late symptoms in the natural course of the disease. It is expected that, as the prevalence of the disease increases, visits will also increase for persistent symptoms after recovery from the infection.⁸ Some of these symptoms may not be easily attributed to COVID-19, such as dyspnoea on exertion, and may show a suitable response to home-based pulmonary rehabilitation, if detected.

Serological diagnosis may be important in confirming SARS-CoV-2 infection, especially in cases in which RT-PCR testing is not available and cases in which the onset of symptoms was more than two weeks earlier.⁹ Still, the risk of false positive results, especially if interpreted in isolation, should not be overlooked.^9,10

For epidemiological surveillance and disease detection campaigns, a combination of RT-PCR, serology and lung ultrasound could more accurately diagnose current and past COVID-19 infection.¹⁰ In this health emergency, it is important to use a suitable strategy for diagnosis to identify asymptomatic carriers who could be responsible for the spread of the disease, especially in places where the prevalence of the disease is high, such as hospitals.¹¹