The primary problem with COVID-19 patients is they compromised lung function. The lungs are where gas exchange occurs to get oxygen that we breath into the blood which is carried to the muscles so they can work. Then Oxygen is then exchanged for carbon dioxide, a waste product from muscle work, which is carried back to the lungs for us to breath out. With COVID-19 patients, depending on severity of the illness, the gas exchange is not as efficient making patients feel shortness of breath or fatigue with activity.
The secondary problem results from long-term bed rest. Patients coming out of weeks of intensive care suffer muscle weakness, bone mass loss, skin breakdown, and potentially cognitive impairment. Disuse of muscles leads to atrophy and loss of strength at a rate of 12% per week. After 3-5 weeks, almost half the normal strength is lost. During muscle disuse there is also a detrimental effect on the neuromuscular function, there is an inability of the muscle to be recruited by the nerve properly. In other words the muscle “forgets” how to contract when asked. The tendons lose stiffness making them more susceptible to overuse with exercise. There are significant deficiencies with endurance making even basic tasks like standing from a seated position, walking across the room, or other activities of daily living very challenging. As There is a great importance placed on pacing these patients carefully to avoid complications with breathing or overuse injuries like tendonitis. Disuse weakness, presumably with healthy lungs, reverses at a rate of 6% per week but with compromised lung function it will likely take longer to reverse all of these effects.
Finally, one the most complicating factors for the physical therapist in treating the COVID-19 patient is the co-morbidities of diabetes, high blood pressure, and obesity along with the associated medications they require. Clinical decision making is complex even though the actual progression of exercise is straight forward.
What will physical therapy look like for COVID-19 patients?
COVID-19 patients will first receive PT in the acute setting (in the hospital) provided there are enough resources available with PPE and healthcare workers. As they recover and meet certain medical and rehab milestones, they will be discharged to a pulmonary rehab facility if they are not ready to be independent at home. If they are medically stable and able to meet more stringent milestones to prove they are capable of independence at home, they will be discharged and proceed to outpatient physical therapy or home health. In my experience, the bar for “capability of independent living” is based more on being medical stable vs. a true ability to care for oneself. This can put an unexpected strain on family members who may not be prepared to care for a family member – keeping them safe from falls to helping with bathing, dressing, or cooking. It can be a very stressful time.
Physical therapists, in any of these settings, will evaluate vitals like blood pressure (BP), oxygen saturation levels (O2 sat), and heart rate (HR) being cautious of the effects medications have on these numbers. For instance, many of these patients with cardiac co-morbidities will be on a beta-blocker which work to regulate the heart rate – therefore, the HR vital will not raise as expected during exercise. The PT must frequently check vitals in response to exercise or activity like a sit to stand, walking, or going up and down stairs. If the patient is unable to tolerate lower level exercise because their O2 sats drop below 90, then supplemental oxygen may be required until lung function improves.
As the goals of the most basic level of activities are met, then we can begin to on increasing muscle strengthening for improved quality of life and the ability for the patient to return their active lifestyle. Progressive exercises are given to improve their major problems of strength, endurance, and oxygen deficits. The goal is to work up to 30 minutes of continuous exercise starting in 5 min bouts if necessary.
Yes this can be a difficult road but we can do this!
- Knight J et al (2019) Effects of bedrest 5: the muscles, joints and mobility. Nursing Times [online]; 115: 4, 54-57.
- Extrem Physiol Med. 2015; 4: 16. Published online 2015 Oct 9.