A health and lifestyle framework for management of post covid-19 syndrome based on evidence-informed management of post-polio syndrome: a narrative review

Abstract

Post covid-19 syndrome includes symptoms common to post-polio syndrome, i.e. weakness; fatigue and pain like myalgic encephalomyelitis/chronic fatigue syndrome; breathlessness; and cognitive disturbances. We conducted a narrative review to establish the basis for an evidence-informed health and lifestyle framework, that underlies the management of post-polio syndrome, as a prototype for managing post covid-19 syndrome. Multi-morbidity, the non-communicable diseases (NCDs) and their risk factors, is strongly associated with SARS-CoV-2 susceptibility and poor outcomes including death. Poliomyelitis survivors may exhibit debilitating sequelae decades after infection, thus their presentations are often confounded by limitations associated with NCDs and their risk factors. An evidence-informed health and lifestyle framework is described. Its three levels of analysis and intervention include: (1) health status; (2) lifestyle practices (smoking; nutrition; weight; sedentariness, activity/exercise; sleep; stress); and (3) the three levels of the WHO’s International Classification of Functioning, Disability and Health (body structures and function consistent with the conventional biomedical approach; activity; and participation). Maximising health practices of covid-19 survivors, like poliomyelitis survivors, augments function, and strengthens immunity and patients’ capacities to heal, repair, and recover; as well as reduce manifestations of NCDs and their risk factors. Avenues for future research are proposed to complement findings from clinical trials.

Keywords:

• Covid-19 virus disease
• health promotion
• life style
• rehabilitation

Individuals who recover from acute covid-19 are reporting symptoms common to post-polio syndrome, i.e. weakness; fatigue and pain resembling that of myalgic encephalomyelitis/chronic fatigue syndrome; shortness of breath; and cognitive disturbances [1,2]. These have become termed post covid-19 syndrome and those affected have been termed ‘long haulers’.

Until a body of evidence is established to inform best practice management of covid-19 syndrome [3,4], we propose that an evidence-informed health and lifestyle framework, that underlies the management of post-polio syndrome based on 40 years of health systems’ experience, could serve as a prototype for the management of post covid-19 syndrome. To examine this proposition, we conducted a narrative review with the following aims: (1) to establish the status of rehabilitation for post covid-19 syndrome; (2) to examine the commonalities and differences between post covid-19 syndrome and post-polio syndrome; (3) based on (2), to extract those elements of a health and lifestyle framework documented for the management of post-polio syndrome, that could be applicable in the management of patients with post covid-19 syndrome; and (4) to detail research directions for covid-19 syndrome management. Management of covid-19 syndrome based on a health and lifestyle framework could reduce its disabling symptoms and speed recovery. In addition, such a framework would reduce the impact of lifestyle-related NCDs and their risk factors, in turn, maximise immunity and overall health and wellbeing.

Status of rehabilitation for post covid-19 syndrome

After the initial onset of the pandemic of covid-19, reports began to emerge about its late effects. As time progressed during the sub-acute period, other organ systems were reported to be affected [5,6]. The more severe the respiratory presentation and the more organ involvement, generally the poorer the functional prognosis, however this was not a consistent finding. Even those who were not so severely affected acutely can have significant late effects.

Other symptoms that may be reported with covid-19 across the continuum of care include headache, fever, cough, chest pain and palpitations. Less common but serious complications include myocardial inflammation, ventricular dysfunction; clotting disturbances; pulmonary dysfunction; kidney injury; neurological complications such as neuropathies and sensory dysfunction (olfactory and gustatory dysfunction); sleep disturbances; depression and mood disturbance [7,8]. Although, as yet, there is no consensus about the management of post covid-19 syndrome, its diverse presentation and signs and symptoms support the need for a multipronged interprofessional approach. Given their commonalities while appreciating distinctions, we propose that insight into management and outcomes of post covid-19 syndrome may be augmented based on our knowledge and understanding of another syndrome, also of initial viral origin, namely, post-polio syndrome. We present a review of what is known and not known in the related literature to evaluate the potential merit for this position.

Commonalities and differences between post covid-19 syndrome and post-polio syndrome

Despite their aetiological distinctions, covid-19 and polio present similarly in their acute stages with respect to their flu-like respiratory presentation. Many, if not most people who are infected but not know it, present with minor respiratory or flu-like symptoms. Late effects of polio are largely associated with worsening neurological, musculoskeletal, and respiratory complaints; and cognitive and sleep impairments [2]. Cardiovascular and hematological consequences are not part of post-polio syndrome as they may be for survivors of severe covid-19. Despite these differences however the patients’ principal concerns are impaired exercise tolerance and functional capacity and cognitive ‘fogginess’.

In both syndromes, pre-morbid conditions warrant particular attention given they can independently impact functional capacity and recovery after illness. Specifically, non-communicable diseases (NCDs) and their risk factors are prevalent in the populations of industrialised countries where they are the leading causes of disability and premature death [9,10]. Individuals who are more susceptible to SARS-CoV-2 and have poor outcomes including risk of death, are those with multi-morbidity, predominantly the NCDs and their risk factors [11–15]. These include cardiovascular disease, hypertension, type 2 diabetes mellitus, obesity, cancer, chronic obstructive lung disease, and renal disease. NCDs develop over a life time, thus the elderly have been disproportionately affected by covid-19. Because post-polio syndrome occurs several decades after initial disease onset, NCDs and their risk factors similarly complicate the clinical picture and recovery trajectory. Of clinical relevance is that chronic low-grade systemic inflammation (CLGSI) underlies NCDs as well as the lifestyle practices that largely contribute to them [16–21]. The inflammatory load of these conditions or their risk factors appears implicated in lowering susceptibility threshold to the initial SARS-CoV-2 infection and ensuing cytokine storm, and may be implicated in re-infection after recovery. The hypothesis of sustained and prolonged systemic inflammation in covid-19 survivors potentially explaining persistent systemic complaints including weakness, fatigue, pain, and brain fog (neuroinflammation), is compelling. Interestingly, initial severity of infection does not appear associated with persisting impaired health after covid-19 [22], supporting the need for early detection and intervention.

For both syndromes, managing and controlling patients’ symptoms are fundamental to the successful recovery or mitigation of symptoms. Further, for both syndromes, effective rehabilitation management and recovery trajectory depend on patients being followed along the continuum of care with on-going evaluation and progression of interventions. In this way, intervention prescriptions are revised commensurate with improvement, with the recognition that progress will likely be slow and set-backs anticipated, hence the term, ‘long haulers’. Differences between the two syndromes, e.g. secondary cardiac and hematological dysfunction in post covid-19 syndrome, mostly implicate monitoring and prescription parameters of interventions rather than the rehabilitation interventions themselves, given that inappropriate prescription may worsen symptoms. Further, the trajectory and rate of recovery may be correspondingly affected.

As the post-polio cohort aged, underlying NCDs and their risk factors complicated the clinical picture and course, as well as the diagnosis of post-polio syndrome, largely one of exclusion. Thus, comparable to patients with post-polio syndrome, a focus on overall health, multi-morbidity and NCD risk factors is justifiable. Whether SARS-CoV-2 infection can persist even when the patient is seemingly recovered or whether an individual who has been diagnosed with covid-19 can be re-infected with SARS-CoV-2 is being studied. Even with polio, until recently the virus was believed to be dormant [23]. The implications of this new evidence are yet unclear. Nonetheless, it is prudent that immune status is supported and strengthened in both cohorts by maximising their general health and wellbeing, and that clinicians appreciate that the functional status of patients with either syndrome may be worsened with injudicious interventions including injudicious exercise prescription.

Finally, the covid-19 pandemic has superimposed another layer of health challenges. For example, physical and social restrictions have curtailed usual activity, work and leisure engagement, and interpersonal interactions contributing to social isolation for well over a year, affecting both people’s physical and mental health and wellbeing [24]. These restrictions can contribute to stress, anxiety, depression, and sleep disturbances [25]. Thus, these confounding factors need to be addressed in the assessment and on-going-evaluation of post covid-19 survivors to establish the degree to which their signs and symptoms are exacerbated because of them.

Health and lifestyle framework: management principles

A health and lifestyle framework for rehabilitation management of covid-19 syndrome, based on that for post-polio syndrome [26–28] which has persisted [29], is outlined in the Supplementary Appendix. Targets and suggested tools for assessment and on-going evaluation and interventions are shown for three levels: (1) health and health status; (2) lifestyle attributes and practices; and (3) the three levels of the International Classification of Functioning, Disability and Health (ICF), i.e. limitations of structure and function (includes the elements of the traditional, biomedical approach to management), activity, and social participation (Figure 1) [30]. These components of the health and lifestyle framework shown in the Supplementary Appendix are detailed below. They incorporate a contemporary behavioural medicine approach to the management of chronic conditions.

Figure 1. Flowchart showing the principal elements of analysis, assessment, and intervention based on the International Classification of Functioning, Disability and Health or model of ability [30].

Health and health status

The ICF is predicated on the World Health Organization’s definition of health in which health is not merely the absence of disease and disability. Thus, a comprehensive multi-system baseline and on-going assessments including health-related quality of life, are initiated early to inform early intervention. Examples of questionnaire tools are listed.

Lifestyle practices and attributes

Lifestyle practices and attributes can be generally classified an anti-inflammatory or pro-inflammatory in terms of their effects on the immune system. Anti-inflammatory lifestyle behaviour change interventions are a major component of a health and lifestyle framework designed to maximise health, minimise disease risk while strengthening immunity to maximise healing and repair, and capacity for functional recovery. As shown in the Supplementary Appendix, these include not smoking [31–33]; quality nutrition (whole food plant-based, e.g. Mediterranean diet or the Dietary Approaches to Stop Hypertension diet) [34] and weight control [35,36]; reduced sedentariness, increased physical activity and exercise [37–39]; as well as moderate, if any, alcohol use [40,41]; healthy sleep practices [42], and manageable stress [43,41]. Conversely, each negative lifestyle practice independently compromises functional capacity, as well as collectively. Thus, the overriding principles of the health and lifestyle framework is to maximise anti-inflammatory practices and minimise pro-inflammatory practices, in the interest of overall health and wellbeing, thereby augment patients’ immune status and functional capacity.

International classification of functioning, disability and health

The ICF has three principal levels, namely, limitations of structure and function (includes the elements of the traditional, biomedical approach to patient management), activity, and social participation; these levels are modulated by environmental and contextual factors (see Figure 1) [30] . The three principal levels are assessed based on the principles of pulmonary, cardiac, and neurological and musculoskeletal rehabilitation; interventions being instituted in accordance with indications identified in comprehensive multi-system assessments and evaluations. Examples of resources to support these levels of assessment and on-going evaluation and intervention are shown in the Supplementary Appendix. Assessment of not only the three primary levels of functioning is essential, but also environmental and contextual factors to better elucidate the role of these factors on the patient’s overall presentation and rehabilitation needs.

Because subjective symptoms constitute the primary complaints of patients that lead to a diagnosis of post covid-19 syndrome, and functional limitations comparable to post-polio syndrome, symptom logs provide a basis for activity recommendations and exercise prescription. Activity-rest logs recorded over several successive days, for example, provide semi-quantitative data about levels of activity that contribute to weakness, fatigue, shortness of breath, and discomfort/pain, and the degree to which rest and a night’s sleep offset these symptoms [27]. Pre- and post-morbid assessment of sleep is also an essential component of assessment, as sleep is fundamental to healing, repair and recovery mediated by the immune system, as well as ensuring patients’ exercise tolerance is not compromised by sleep deprivation. In addition, superimposing exercise on sleep deprived patients could further compromise immune status [16]. Physiologic correlates are recorded in conjunction with subjective complaints at rest and during and after standardised activity or exercise tests.

Maximal exercise testing using a treadmill or cycle ergometer can provide essential information in most patients except those who are severely physically comprised. However, sub-maximal tests such as the one-minute sit-to-stand test and the six-minute walk distance test provide both subjective and objective assessment information about exercise capacity, and can serve as a basis for prescription and evaluation of improved exercise capacity, e.g. comparing hemodynamic and subjective responses at standard submaximal exercise work rates [45]. A profile of exercise response minimally includes resting and exercise heart rate, blood pressure, and SpO₂, and symptom rating based on Borg’s rating of perceived exertion scale, and modified Borg scales for ratings of fatigue and discomfort/pain. A clinically useful version of this scale is a chart showing a scale from 0 to 10 with 0 being no subjective complaint at all (for example, exertion) and 10 and over being maximal. Because activity and exercise are symptom-limited in post covid-19 syndrome as well as post-polio syndrome by one or more subjective responses, semi-quantitative measures of these with tools such as the modified Borg scale can be all important. The limiting symptom or symptoms largely guide the prescription parameters of exercise, i.e. intensity, frequency, and duration.

Finally, a fundamental cornerstone of management is effective patient education which crosses all levels of rehabilitation management including the management of post covid-19 syndrome. Examples of various behavioural medicine approaches including strategies to effect health behaviour change are shown in the Supplementary Appendix.

Research directions

With the advent of post covid-19 syndrome, funding competitions have sprung up to encourage researchers to identify effective rehabilitation interventions. Clinicians have been seeking guidance about how to ensure patient safety while maximising patients’ functional capacity and minimising long-term complications, in turn minimising health care costs. Tightly controlled randomised controlled clinical trials have potential limitations in the study of complex patients [46]. First, comparable to patients with post-polio syndrome, those who have survived covid-19 are heterogeneous and complex. They are variably affected at onset. Often, they are older, and likely to present with other pre-morbid conditions that further compromise functional capacity. They are often taking medications that can further compromise exercise capacity and tolerance. Covid-19 survivors typically have at least one underlying NCD or their risk factors; all of which can contribute to physical limitations, and inflammatory load and CLGSI. Such clinical presentation calls for an individualised health and lifestyle management program to promote health and reverse or at least mitigate NCD symptoms, in turn their impact of physical capacity and function. Refinement of the elements of the health and lifestyle framework to address post covid-19 syndrome is warranted to elucidate those lifestyle practices that most augment recovery.

Second, randomised controlled trials often require structured protocol-driven interventions, thus the attention of the clinician may be diverted from individualised response-driven interventions that are based on an individualised comprehensive multi-system assessment and examination, leading to targeted prescribed treatment plan. Research paradigms for rehabilitation for post covid-19 syndrome are needed that are designed to elucidate clinical reasoning and decision making processes for maximising functional recovery in individuals with covid-19, a disease with a variable presentation and confounded by pre-existing conditions, most notably NCDs and their risk factors, and their biomedical treatments.

Last, to establish the impact of various lifestyle factors on clinical presentation and outcomes, the findings of studies need to analyse the data based on stratification of various lifestyle practice adherence. Such studies are needed to elucidate the role of health lifestyles on level of functional recovery and rate of return and the degree to which these effects augment conventional interventions.

Conclusions

The proposition that a health and lifestyle framework can maximise outcomes of individuals with post-covid-19 syndrome as for those with post-polio syndrome, is compelling given several common presenting complaints and symptoms. This review showed that guidelines for rehabilitation for post covid-19 syndrome is meagre given it is evolving, and that knowledge about the effective management of post-polio syndrome could provide both clinical and research direction.

Abbreviations
NCD	=	non-communicable disease
ICF	=	International Classification of Functioning, Disability and Health

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No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors reported there is no funding associated with the work featured in this article.