This article was written by Ryan Prior in CNN:
About three-quarters of those hospitalized for Covid-19 could become long haulers, according to a paper uploaded to the pre-print server medRxiv on August 14 without having yet been vetted by outside experts or accepted for publication.
Researchers from the Academic Respiratory Unit of the North Bristol NHS Trust in the UK looked at 110 Covid-19 patients, whose illnesses required hospital stays for a median of five days between March 30 and June 3.
Twelve weeks after patients were released from the hospital, 74% of them reported symptoms, including breathlessness and excessive fatigue.
Despite these symptoms, however, 104 of the 110 patients in the study had normal basic blood test results, with just 12% showing an abnormal chest X-ray and 10% showing restrictive lung function through spirometry tests.
The British Medical Journal released new guidance for health providers in August on how to treat long-haul Covid-19 patients, estimating that up to 10% of all people who have tested positive could develop a prolonged illness. The guidance includes specific blood tests to perform, possibly referring patients to pulmonary rehabilitation and having them use pulse oximetry at home to measure oxygen saturation in the blood.
Results like these fly in the face of a narrative that took hold early in the pandemic, in which many medical professionals believed that the average Covid-19 patient would be sick for a couple weeks, clear the virus and be fine afterward.
That turns out not to be the case for everyone. The BMJ guidance cited "weak or absent antibody response, relapse or reinfection, inflammatory and other immune reactions, deconditioning, and mental factors such as post-traumatic stress" as contributing to longer-term symptoms. It acknowledged that similar parallels had occurred in patients with SARS and MERS.
"The classic case we all have in our hands is not always what really happens," said Dr. MeiLan King Han, a pulmonologist and professor of medicine at the University of Michigan. "For the patients I have followed, many continue to complain of cough, breathing issues and severe fatigue long after their first infection."
- Long haulers and dysautonomia
One of the key issues in caring for each long-haul Covid-19 patient is to figure out how many of their symptoms can be chalked up to the heart and lungs and how much of the illness is actually the result of a deeper form of neurological dysfunction the coronavirus has unspooled, according to Noah Greenspan, a New York-based physical therapist and founder of the Pulmonary Wellness Foundation.
Before engaging in physical or respiratory therapy, he asks that all his patients get a full workup from their doctor to rule out a cardiac condition, stroke or pulmonary embolism before starting physical therapy.
Some patients' symptoms are mild and can start a more traditional rehab plan, he said, "but there are others, which are turning into the biggest group of people, which are these long haulers."
The primary trend across the Covid-19 long haulers that Greenspan is working with is a condition called dysautonomia, a condition marked by a miscommunication between the autonomic nervous system and the rest of the body.
The autonomic nervous system regulates automatic body functions such as breathing, sleep and digestion. When it's not working, symptoms can present in myriad different ways, depending on the person.
"Reach into a bag of symptoms and pull out a bag of symptoms, and that's what they have for the day," Greenspan said. "It's a twisted ball of yarn and takes a week to unravel one string."
While shortness of breath and cardiovascular problems do present in his patients, Greenspan said, these are not usually the most common underlying cause of their misery.
Gahan and others with long-haul Covid-19 symptoms face a condition called postural orthostatic tachycardia syndrome, which refers to a sharp rise in heart rate that occurs when moving from a reclining to standing position. The pull of gravity causes blood to pool in the legs. This condition can cause dizziness, lightheadedness and fainting.
"Their heart rate goes up 50 to 75 points if they get up to get water," Greenspan said. "They have fast heart rates that don't have anything to do with what they're actually doing, that are not commensurate with their workload."
Many patients are exhibiting neurological symptoms consistent with myalgic encephalomyelitis/chronic fatigue syndrome, according to the BMJ and National Institute of Allergy and Infectious Diseases Director Dr. Anthony Fauci. That diagnosis requires at least six months of symptoms, a benchmark most long haulers haven't yet reached.