As the COVID-19 pandemic continues to impact much of the world, it has left millions of people sick in its wake. The long-haul symptoms in survivors, such as weakness and chronic debility related to prolonged stay in intensive care, or chronic respiratory compromise, have been coming to light over the last few months.
However, there is little information on the effectiveness of rehabilitation in these patients. A new study compares rehabilitation outcomes between COVID-19 patients and those with ordinary pneumonia, to evaluate the effectiveness of this intervention.
This study was published in the pre-print server medRxiv*.
Pulmonary Rehabilitation. Image Credit: samunella/Shutterstock.com
This news article was a review of a preliminary scientific report that had not undergone peer-review at the time of publication. Since its initial publication, the scientific report has now been peer reviewed and accepted for publication in a Scientific Journal. Links to the preliminary and peer-reviewed reports are available in the Sources section at the bottom of this article. View Sources
The Need for Pulmonary Rehabilitation
Severe infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is typically characterized by pneumonia, and up to 15% of infections lead to severe or critical disease. Of this proportion, many will require mechanical ventilation because of acute respiratory distress. After this, many will develop an intensive care unit (ICU)-related weakness.
Evidence points to the persistence of abnormal lung function in convalescent severe COVID-19 patients, along with debility, chronic fatigue, and reduced ability to carry out the activities of daily living. Rehabilitation thus becomes important in the management of COVID-19.
Due to the recent and urgent nature of this condition, rehabilitation protocols are guided by the opinions of the practitioners rather than by official guidelines. This is true of the interim guidelines published by the European Respiratory Society and American Thoracic Society coordinated International Task Force.
Earlier Research
There is only a single pilot study that shows that critical COVID-19 patients in the ICU showed improvement in a standard measure called the six-minute walk test (6MWT), following the use of the same rehabilitation used in other pneumonia patients.
However, this study did not make use of controls. Secondly, the investigators failed to assess the minimal clinically important difference, MCID, which detracts from the significance of the improvement in clinical parameters that were observed. The question remains whether the same level of improvement may be expected in COVID-19 patients, with relation to physical function and quality of life, as in other pneumonia patients.
Study Details
The current study is based on a cohort of 51 COVID-19 pneumonia patients, who were referred for inpatient pulmonary rehabilitation, and a historical cohort of 51 consecutive 2019 pneumonia patients who underwent the same rehabilitation program. All the patients in the latter group were above 40, had only one rehabilitation program, and had not undergone surgery on the chest or lungs.
Baseline parameters were recorded, namely, the 6MWT, the functional independence measure (FIM) [10], and chronic respiratory questionnaire (CRQ), and repeated at discharge following rehabilitation. Mean values were compared between the groups and the differences in both sets of values.
The MCID was set at 30 meters in the 6MWT, and 10 points for the CRQ (based on the original CRQ score of 140 points). The number of patients in either group who showed enough improvement to reach this set point was calculated.
The researchers found that most of the COVID-19 patients were younger than controls, and the majority were male. The cumulative illness rating scale (CIRS) at entry was higher in this group, more of them having been admitted in the ICU and having been put on mechanical ventilation before their discharge from acute care.
The odds of having coexisting chronic illnesses, namely, diabetes and hypertension, and of having a history of acute respiratory distress syndrome (ARDS), were also higher in this group. The controls had higher odds of a history of chronic obstructive pulmonary disease (COPD).
Similar Outcomes in Both Groups
Outcomes of rehabilitation in both groups showed that the 6MWT produced similar results in both groups at baseline, but CRQ and FIM scores were higher in the COVID-19 group. Most patients in both groups registered a significant increase at the second measurement in all three indices.
Comparisons of the three scores showed that COVID-19 patients showed better 6MWT and FIM scores after the program, but the CRQ scores were similar across groups. The extent of increase in the 6MWT was higher in the COVID-19 patients, but the other two scores showed similar improvements.
Adjusting for the younger age, the sex differences, and the higher CIRS scores in the COVID-19 group at baseline, the researchers found that the same patterns prevailed. The 6MWT remained similar across the groups, but the FIM score went up by ~4 points in the COVID-19 group.
When critical vs severe COVID-19 patients, that is, those treated in the ICU vs those in hospital, were analyzed separately, there was no significant difference for any of these scores.
Large Proportion of Failed Rehabilitation
The MCID for 6MWT was not observed in 7.5% of COVID-19, and ~21% of controls, after the rehabilitation program. The odds of improving the clinical outcome were not significantly different between the groups, however, despite a trend towards 70% higher odds of improving the score.
With the CRQ, ~43% of COVID-19 patients showed no significant improvement, failing to reach the MCID. Again, there was a non-significant trend towards threefold higher odds that the CRQ would not show improvement in the COVID-19 group.
What are the Implications?
The researchers concluded that a well-thought-out and executed program of pulmonary rehabilitation benefited COVID-19 patients as much as pneumonia patients, concerning their physical capacity, the disease-related quality of life, and their functional outcome.
The improvement appeared to be higher in relation to the physical outcome in COVID-19 patients, while the other two scores showed equivalent degrees of change in both groups. There was no significant difference in the outcome for critical vs severe COVID-19 patients.
This is the first study on the effectiveness of pulmonary rehabilitation for COVID-19 patients to have a control group and set an MCID as the post-rehabilitation outcome for measurement. It suggests that pulmonary rehabilitation is of benefit to accelerate recovery even after critical COVID-19.
However, there were some disturbing findings. Firstly, COVID-19 patients appeared to improve physically but still failed to register a corresponding increase in their disease-related quality of life, as assessed by the CRQ, as against the controls. Though they began with relatively high CRQ scores, they failed to achieve anywhere near the maximum by the end of the program, suggesting the possibility of residual chronic pulmonary dysfunction.
Secondly, over 40% of COVID-19 patients did not improve after rehabilitation, especially with respect to the disease-related quality of life. This was not explained in the study. The reasons may be chronic sequelae or the inability of the readymade program to cater to specific needs in the COVID-19-damaged lungs, or persistent fatigue. Many patients in the COVID-19 group had ARDS, which is again associated with disability lasting for years. This finding could suggest that worldwide, the long-term impact of COVID-19 on health and healthcare systems is likely to be very high.
Lacunae remain to be addressed in future studies. Firstly, it does not account for the differences in outcomes depending on the type of rehabilitation offered, or the presence of vascular COVID-19-related complications, since this study was based on a single-center in-house rehabilitation program. Secondly, the number of patients was small, and the CRQ scale has not been validated in COVID-19 patients.
The researchers suggest urgent validation be done, given the rapid growth of the pandemic.
This news article was a review of a preliminary scientific report that had not undergone peer-review at the time of publication. Since its initial publication, the scientific report has now been peer reviewed and accepted for publication in a Scientific Journal. Links to the preliminary and peer-reviewed reports are available in the Sources section at the bottom of this article. View Sources
Article Revisions
- Apr 2 2023 - The preprint preliminary research paper that this article was based upon was accepted for publication in a peer-reviewed Scientific Journal. This article was edited accordingly to include a link to the final peer-reviewed paper, now shown in the sources section.
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