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 Table of Contents  
Year : 2022  |  Volume : 66  |  Issue : 5  |  Page : 51-55  

Impact of early pulmonary rehabilitation in postacute COVID Disease: A single-center experience from India – A quasi-experimental study

1 Professor, Department of Respiratory Medicine, Coordinator Amrita Pulmonary Rehabilitation Program, Amrita Institute of Medical Sciences, Amrita Viswa Vidyapeetham, Kochi, Kerala, India
2 MD Resident, Department of Respiratory Medicine, Amrita Institute of Medical Sciences, Amrita Viswa Vidyapeetham, Kochi, Kerala, India
3 Biostatistician, Department of Clinical Epidemiology, Rajagiri Hospital, Aluva, Kerala, India
4 Physiotherapist, Department of Respiratory Medicine, Amrita Pulmonary Rehabilitation Program, Amrita Institute of Medical Sciences, Kochi, Kerala, India
5 Associate Practitioner, Pulmonary Rehabilitation, Provide Community, Cambridgeshire, United Kingdom
6 Professor and Head, Department of Respiratory Medicine, Amrita Institute of Medical Sciences, Amrita Viswa Vidyapeetham, Kochi, Kerala, India

Date of Submission10-Aug-2022
Date of Acceptance19-Aug-2022
Date of Web Publication11-Nov-2022

Correspondence Address:
Akhilesh Kunoor
Kunoor House, Mekkad P.O, Manakkapady, Ernakulam - 683 589, Kerala
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijph.ijph_1087_22

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Background: It was observed that post-COVID patients reported persistent exertional dyspnea, cough, fatigue, or chest pain. About 10%–20% of patients may progress to pulmonary fibrosis. Pulmonary rehabilitation has been proven to be useful in improving effort tolerance and quality of life in chronic respiratory diseases. Objectives: The objective of this study was to assess the effectiveness of pulmonary rehabilitation in improving 6-min walk distance (6 MWD), peak flow, fatigue, anxiety, and depression in early postacute COVID disease. Materials and Methods: This quasi-experimental study was conducted during January 2021 to March 2021. The patients who recovered from COVID-19 and having persistent exertional dyspnea and fatigue after 3 weeks of recovery were included in the study. Baseline and postintervention assessment of 6 MWD, Visual Analog Scale for Fatigue (VAS-F), peak flow, and Hamilton rating scales (HAM) scales after 4 weeks were done. Compliance was ensured with weakly telemonitoring. Results: Significant improvement in peak flow, 6 MWD, Hamilton Anxiety Rating Scale (HAM-A), Hamilton Depression Rating Scale (HAM-D), and VAS-F (P < 0.01) after 4 weeks of pulmonary rehabilitation. Conclusion: Early pulmonary rehabilitation in post-COVID syndrome can contribute to statistically significant improvement in functional and psychological parameters as well as post-COVID fatigue.

Keywords: Effort tolerance, postacute COVID, pulmonary rehabilitation

How to cite this article:
Kunoor A, Surendran D, Hari H, Viswan V, Harikrishnan K, Mehta AA. Impact of early pulmonary rehabilitation in postacute COVID Disease: A single-center experience from India – A quasi-experimental study. Indian J Public Health 2022;66, Suppl S1:51-5

How to cite this URL:
Kunoor A, Surendran D, Hari H, Viswan V, Harikrishnan K, Mehta AA. Impact of early pulmonary rehabilitation in postacute COVID Disease: A single-center experience from India – A quasi-experimental study. Indian J Public Health [serial online] 2022 [cited 2023 Apr 1];66, Suppl S1:51-5. Available from:

   Introduction Top

COVID-19 infection mainly affects the lung though several other systems are also involved. The symptoms may vary from minor symptoms such as fever, myalgia, and diarrhea to breathlessness needing oxygen therapy or ventilatory support. Almost 40% of the patients develop acute respiratory distress syndrome and almost 20% of those are found to be severe.[1] Early analysis suggests that one-third of hospital patients develop pulmonary fibrosis.[2] No effective therapy is recommended for fibrosis but antifibrotics and steroids are being used with varying efficacy. The long-term consequences of COVID-19 are not well known, and even in mild COVID survivors, persistent symptoms are reported. COVID survivors experience exertional breathlessness, wheezing, fatigue, chest pain, palpitation, muscle pain, anxiety, or depression. This may reduce the quality of life (QOL) and contribute to their morbidity. Pulmonary rehabilitation is widely recommended for alleviating the symptoms and improving QOL in various chronic respiratory diseases like chronic obstructive pulmonary disease (COPD). It is suggested as a management option in post-COVID diseases also, but the original researches which elicited the effectiveness are not widely available. The primary objective of this study was to assess the effectiveness of pulmonary rehabilitation in improving 6-min walk distance (6 MWD), peak flow, and QOL in post-COVID syndrome. We also tried to assess the effectiveness of pulmonary rehabilitation in improving anxiety and depression in post-COVID syndrome and to find out the effectiveness of Pulmonary Rehabilitation in reducing post-COVID fatigue.

   Methods Top

This study was conducted as a quasi-experimental model, which was referred to the Pulmonary Rehabilitation Clinic, Department of Respiratory Medicine at Amrita Institute of Medical Sciences, Kochi. The total duration of the study was 3 months from January 2021 to March 2021.

Institutional ethical clearance was taken for the study and informed consent was taken from all the study participants.

Inclusion criteria

All the patients who were diagnosed with severe acute respiratory syndrome coronavirus-2 (SARS-COV-2) with Reverse transcription-polymerase chain reaction (RT–PCR), SARS-CoV-2 antigen or nucleic acid amplification test, and later declared as cured based on a negative COVID antigen test were included in the study as per the national protocol for COVID management at that moment during the first wave of COVID. Among this group, the patients with persistent symptoms after 3 weeks of COVID negativity were included within the age group of 18–80 years with no gender difference.

Exclusion criteria

The patients who were excluded consisted of lack of consent, recent coronary artery disease, unstable cardiac rhythm, acute pulmonary embolism, extreme fatigue with severe cachexia, and ventilated patients.

Statistical analysis

Based on the mean and standard deviation of 1-min sit-to-stand test before (13.3 ± 3.56) and after (26.2 ± 5.73) intervention and 1-min squat test before (13.2 ± 6.89) and after (24.8 ± 10.17) intervention were observed in an earlier publication[3] and with 95% confidence and 80% power sample size is decided as 6.

The basic demographic details and comorbidities were noted. All the patients underwent baseline and 4 week evaluation of 6 MWT, peak flow, Dyspnea Borg scale, Visual analogue scale for fatigue (VAS-F), Numerical Rating Scale for pain, Hamilton Anxiety Rating Scale (HAM-A), and Hamilton Rating Scale for Depression (HAM-D). Patients were counseled regarding the nature of disease, course of illness and prognosis, and pulmonary rehabilitation procedures in detail. Nutritional assessment and interventions for each patient were done. The study participants were subjected to graded exercises initiated as low-intensity training which include flexibility exercises, ventilatory muscle training, lower limb and upper limb endurance, and resistance training based on exercise prescription and the institutional protocol. All the participants were subjected to minimum 4 weeks of training which was extended as per symptoms or as maintenance rehabilitation. Patients underwent supervised exercise training once every 2 weeks and other sessions (minimum 5 days/week) were telemonitored. To test the statistical significance, the difference in the median 6 MWD, peak flow, depression, anxiety, and Fatigue Severity Scale in post-COVID syndrome between before and after intervention, Wilcoxon signed-rank test was applied.

   Results Top

A total of 39 patients were included in the study. Out of that 26 were males and 13 were females. In our study, the common age group presented to pulmonary rehabilitation clinics was 35–65 (53.85%), and the mean age was 53 ± 14.87 years.

Twelve patients were diabetic and 14 patients were hypertensive. One patient had lymphoma, four patients had obstructive airway diseases, and two patients had interstitial lung disease. The median duration from COVID positivity to negativity is 11 (10, 16.5).

Major symptoms experienced by patients were exertional breathlessness, inefficient breathing, and fatigue. About 5/31 (16.1%) patients had severe inefficiency in breathing, 8/32 (25%) patients had severe fatigue, and 9/32 (28.2%) patients had moderate fatigue as per VAS-F. The baseline demography of the study population is shown in [Table 1].
Table 1: Baseline demographics of the study participants

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There was a significant improvement in pulmonary function variables such as peak flow, 6 MWD, percentage desaturation during 6-min walk test, and Dyspnea Borg Scale after 4 weeks of pulmonary rehabilitation with a P (< 0.001) [Table 2]. There was a median improvement of 80 m in 6 MWD, and 40% in peak flow after pulmonary rehabilitation.
Table 2: Effect of pulmonary rehabilitation in pulmonary functions

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The median Visual Anaolgue Scale for fatigue (VAS-F) at baseline is 3 (1, 4) and postintervention is 2 (0, 2) which shows statistical significance with P < 0.001. The result shows that there is a significant improvement of fatigue after pulmonary rehabilitation. It is also evident from the box and whisker plot depicted in [Figure 1].
Figure 1: Effect of post-COVID pulmonary rehabilitation in VAS-F. VAS-F: Visual Analog Scale for Fatigue

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There was a significant improvement in anxiety and depression after 4 weeks of pulmonary rehabilitation which have been assessed by HAM-A and HAM-D. The median HAM-A at baseline is 9 (5, 12.5) and postintervention is 5 (2, 8) which shows statistical significance with P < 0.001. The median HAM-D at baseline is 8 (5, 11) and postintervention is 4 (2,7) which shows statistical significance with P < 0.001.

   Discussion Top

COVID-19 leads to persistent symptoms and morbidity to patients even after disease cure. This is generally called post-COVID syndrome although the exact definition is not clear cut. However, it can be considered if persisting symptoms 3 weeks after the first onset of the manifestation and these persist >12 weeks, it is called chronic COVID disease.[4] Post-COVID manifestation can present with several manifestations and it may involve multiple systems in the human body. It may lead to respiratory symptoms such as dyspnea, cough, or rarely hemoptysis and may lead to pulmonary fibrosis in 5%–10% of survivors. It can also lead to arrhythmia, myocarditis, neuropathy, myopathy, or joint pain.

Pulmonary rehabilitation is a multidisciplinary therapeutic intervention which aims to have an optimal QOL and reduction in effort tolerance in chronic respiratory disease patients. It has shown proven benefits in COPD and bronchiectasis and improvement in exercise tolerance in interstitial lung diseases, chronic asthma, and Pulmonary arterial hypertension (PAH).[5] The primary goal of pulmonary rehabilitation is to achieve or maintain patient autonomy by optimization in QOL.

Post-COVID diseases cause significant morbidity and mortality. In the UK, approximately one in five people are estimated to have COVID-19 symptoms beyond 5 weeks, and one in 10 report symptoms persisting for 12 weeks or more.[6]

In our study, major symptoms included exertional dyspnea (87.2%) and fatigue (82.1%). In a study conducted by Carfi et al.,[7] only 13% of long COVID patients were asymptomatic. In that study, the most common symptoms were fatigue (53%) and dyspnea (43%). The difference may be due to the inclusion of patients after 3 weeks of COVID negativity, as study population.

Fatigue is usually associated with post-COVID patients irrespective of the severity of illness during COVID-19. The exact mechanism of fatigue in postacute COVID is not well understood. SARS-CoV-2 can trigger oxidative stress also. Overexpression of proinflammatory cytokine is attributed to the cytokine storm syndrome in COVID-19. Regular physical activity is known to reduce free radicals-induced injuries and also reduce sarcopenia in the skeletal muscles.[8] Hypometabolism in the frontal lobe and cerebellum has also been implicated in COVID-19 patients with fatigue and is likely caused by systemic inflammation and cell-mediated immune mechanisms. Negative psychological and social factors associated with the COVID-19 pandemic have also been linked to chronic fatigue. Peripheral factors such as direct SARS-CoV-2 infection of skeletal muscles resulting in damage, weakness, and inflammation to muscle fibers, and neuromuscular junctions which may contribute to fatigue.[9]

The study by Fortini et al. reported only 37.5% of their study population had exertional dyspnea which was present after 3 months of COVID symptoms.[10] Exertional dyspnea in post-COVID diseases can be due to reduced physical activity, medication-related myopathy, pulmonary embolism, and reduction in gas exchange secondary to post-COVID sequelae and fibrosis.

In our study, pulmonary rehabilitation was shown as a feasible and effective intervention in improving pulmonary functions, fatigue, anxiety, and depression associated with post-COVID status. There were not much original studies available for assessing the impact of pulmonary rehabilitation in post-COVID patients. Compared to other chronic lung diseases, pulmonary rehabilitation in post-COVID patients are more challenging as there may be a rapid fall in oxygen saturation in the early recovery period or due to very high inflammatory load or associated pulmonary embolism.[11] Several guidelines have been formulated which recommend pulmonary rehabilitation as a must-to-do intervention in post-COVID patients. It is to be noted that low-intensity training is recommended for such patients.[12],[13],[14]

The study by Gloeckl et al.[15] shows that there is a significant improvement of 48 m in mild-to-moderate disease which is beyond the suggested MID of 30 m, whereas our study also reported 80 m median improvement in 6 MWD. Early enrollment of pulmonary rehabilitation is found to be beneficial in improving 6 MWD post-intensive care unit care in COVID-19 patients.[16]

It is a well-proven fact that there will be an abnormality in pulmonary functions of post-COVID patients in the form of restrictive lung defect, small airway dysfunction, or diffusion defect depending on the severity of illness.[17] Only <15% of a study cohort had spirometric defects in a study conducted by Mo et al.[18] Spirometry was not performed in all cases as patients were not able to do or due to cough or hypoxemia. Hence, the degree of restrictive defect was difficult to measure. However, expiratory airflow limitation can be measured by peak expiratory flow although not as accurate as forced expiratory volume in 1 s. In our study, there is a statistically significant improvement in peak flow measurement after pulmonary rehabilitation. There are not much studies available on the effect of pulmonary rehabilitation in pulmonary functions in post-COVID patients.

There is a statistically significant improvement in the Visual Analog Scale for Fatigue, HAM-A, and HAM-D after pulmonary rehabilitation. The effect of pulmonary rehabilitation in reducing fatigue scores was demonstrated previously in non-COVID COPD patients.[19] This is similar to observations with Ghodge et al.[3] and with the case series by Kunoor et al.[20] The study by Gloeckl et al.[15] shows that there was a significant improvement in Forced Vital capacity (FVC) and 36-question short-form health survey with mental health component.

   Conclusion Top

Early pulmonary rehabilitation in postacute COVID can improve pulmonary function, effort tolerance, fatigue, and psychological status of the patients and should be carefully and judiciously to be selected.

Limitation of the study

The sample size of the study was low and the study results are from a single center. Enrollment of the patient in the study group was a challenge due to the ongoing fear of COVID infection and lack of awareness regarding the efficacy of pulmonary rehabilitation among physicians and patients. Multicentric studies with a larger sample size may be needed further.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

Wu C, Chen X, Cai Y, Xia J, Zhou X, Xu S, et al. Risk factors associated with acute respiratory distress syndrome and death in patients with coronavirus disease 2019 pneumonia in Wuhan, China. JAMA Intern Med 2020;180:934-43.  Back to cited text no. 1
Rai DK, Sharma P, Kumar R. Post COVID-19 pulmonary fibrosis. Is it real threat? Indian J Tuberc 2021;68:330-3.  Back to cited text no. 2
Ghodge S, Tilaye P, Deshpande S, Nerkar S, Kothary K, Manwadkar S. Effect of pulmonary telerehabilitation on functional capacity in COVID survivors; an initial evidence. Int J Health Sci Res 2020;10:123-9.  Back to cited text no. 3
Greenhalgh T, Knight M, A'Court C, Buxton M, Husain L. Management of post-acute COVID-19 in primary care. BMJ 2020;370:m3026.  Back to cited text no. 4
Bolton CE, Bevan-Smith EF, Blakey JD, Crowe P, Elkin SL, Garrod R, et al. British thoracic society guideline on pulmonary rehabilitation in adults. Thorax 2013;68 Suppl 2:i1-30.  Back to cited text no. 5
Ayoubkhani D, editors. The Prevalence of Long COVID Symptoms and COVID-19 Complications, 2020. UK: Office for National Statistics; 2021. Available from: [Last cited on 2022 Feb 10].  Back to cited text no. 6
Carfì A, Bernabei R, Landi F, Gemelli Against COVID-19 Post-Acute Care Study Group. Persistent symptoms in patients after acute COVID-19. JAMA 2020;324:603-5.  Back to cited text no. 7
Simioni C, Zauli G, Martelli AM, Vitale M, Sacchetti G, Gonelli A, et al. Oxidative stress: Role of physical exercise and antioxidant nutraceuticals in adulthood and aging. Oncotarget 2018;9:17181-98.  Back to cited text no. 8
Crook H, Raza S, Nowell J, Young M, Edison P. Long COVID-mechanisms, risk factors, and management. BMJ 2021;374:n1648.  Back to cited text no. 9
Fortini A, Torrigiani A, Sbaragli S, Lo Forte A, Crociani A, Cecchini P, et al. COVID-19: Persistence of symptoms and lung alterations after 3-6 months from hospital discharge. Infection 2021;49:1007-15.  Back to cited text no. 10
Santana AV, Fontana AD, Pitta F. Pulmonary rehabilitation after COVID-19. J Bras Pneumol 2021;47:e20210034.  Back to cited text no. 11
Barker-Davies RM, O'Sullivan O, Senaratne KP, Baker P, Cranley M, Dharm-Datta S, et al. The Stanford Hall consensus statement for post-COVID-19 rehabilitation. Br J Sports Med 2020;54:949-59.  Back to cited text no. 12
Spruit MA, Holland AE, Singh SJ, Tonia T, Wilson KC, Troosters T. COVID-19: Interim Guidance on Rehabilitation in the Hospital and Post-Hospital Phase from a European Respiratory Society and American Thoracic Society-coordinated International Task Force. Eur Respir J 2020;56(6):2002197. doi: 10.1183/13993003.02197-2020.  Back to cited text no. 13
Swaminathan N, Jiandani M, Surendran PJ, Jacob P, Bhise A, Baxi G, et al. Beyond COVID-19: Evidence-based consensus statement on the role of physiotherapy in pulmonary rehabilitation in the Indian context. J Assoc Physicians India 2020;68:82-9.  Back to cited text no. 14
Gloeckl R, Leitl D, Jarosch I, Schneeberger T, Nell C, Stenzel N, et al. Benefits of pulmonary rehabilitation in COVID-19: A prospective observational cohort study. ERJ Open Res 2021;7:00108-2021.  Back to cited text no. 15
Al Chikhanie Y, Veale D, Schoeffler M, Pépin JL, Verges S, Hérengt F. Effectiveness of pulmonary rehabilitation in COVID-19 respiratory failure patients post-ICU. Respir Physiol Neurobiol 2021;287:103639.  Back to cited text no. 16
Torres-Castro R, Vasconcello-Castillo L, Alsina-Restoy X, Solis-Navarro L, Burgos F, Puppo H, et al. Respiratory function in patients post-infection by COVID-19: A systematic review and meta-analysis. Pulmonology 2021;27:328-37.  Back to cited text no. 17
Mo X, Jian W, Su Z, Chen M, Peng H, Peng P, et al. Abnormal pulmonary function in COVID-19 patients at time of hospital discharge. Eur Respir J 2020;55:2001217.  Back to cited text no. 18
Sadate Moazeni S, Ghaljeh M, Navidian A. The effect of pulmonary rehabilitation on fatigue and quality of life in patients with chronic obstructive pulmonary disease: A quasi-experimental study. Med Surg Nurs J 2020;9:e103899.  Back to cited text no. 19
Kunoor A, Ashok A, Moni M, Mehta A, Thomas EM, Viswan V, et al. A case series on post-COVID pulmonary rehabilitation: Early experiences from Kerala, South India. Indian J Case Rep 2020;6:672-5.  Back to cited text no. 20


  [Figure 1]

  [Table 1], [Table 2]


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