In the next few months there's a good chance we're going to be asked to help Covid-19 sufferers get back into the mountains. Here's a case to get us thinking (and a useful reference to guide us!)...
A few weeks ago a friend of mine received an email from a patient who’d been treated on his ITU. During his admission he had got to know John well. Much of their conversation had centred around a shared love of the outdoors and what they wanted to do once the Covid-19 pandemic was over.
Working long hours, in a highly stressful job, John had put on weight during his 30's and 40's. At one stage, he'd reached 25 stone (158kgs) and this had proved to be a turning point. Over the course of the next 3 years John lost 10 stone (62kgs) - thanks in large part to a healthy diet and a growing passion for hillwalking and mountaineering!
John's 3 week stay on ITU had been very difficult. Although he had avoided intubation and mechanical ventilation, long and uncomfortable periods of continuous positive airway pressure (CPAP) were often needed to improve oxygenation. A CT pulmonary angiogram revealed extensive pulmonary emboli and widespread changes consistent with Covid-19 pneumonia. During his admission he had also developed a superimposed bacterial infection. This all came at an enormous cost. By the time he was discharged from ITU John was barely able to stand. It would take a further 6 weeks of rehabilitation before he was able to eventually return home. It was therefore a wonderful surprise for my friend to read this request…
"I've started to get out and walk again - slowly! It's hard work and frustrating at times. To help me I've set a goal and this is it - I want to climb Mt Blanc (4801m) - can I do it?"
Up until June 2021, more than 470,000 people in the UK had been admitted to hospital with Covid-19 infection. In a follow up study of 47,780 discharged patients, 12% had died and 29% of patients were readmitted within 140 days. The long term effects of Covid-19 remain to be seen (Image: Nick Mason)
To try and answer John's question it's worth taking a look at a recent article by Andy Luks and Colin Grissom published in High Altitude Medicine and Biology. This describes, in detail, the long term impact of Covid-19 infection on survivors and provides a practical algorithm for those who’ve been infected and subsequently want to return to the mountains.
Before we look at the direct impact of Covid-19 it's worth spending a few moments focusing upon the wider effects of an ITU admission. Irrespective of the disease process, a common pattern is often seen. This is often described as Post-ITU Syndrome and a very readable summary of this condition can be found here. Unfortunately, the long term effects can be wide reaching and in some cases never fully resolve. Musculoskeletal problems are particularly common. Symptoms of weakness, pain and stiffness can often persist for many months. Patients also describe skin changes such as hair loss, pruritis and rashes. Sleep is often disturbed and changes in memory and cognitive function are often reported. It's also worth highlighting the fact that pre-existing medical problems, such as ischaemic heart disease and chronic obstructive pulmonary disease, often deteriorate after an ITU stay.
Whilst the physical impact of Post-ITU Syndrome is often clearly visible it's also important to recognise the psychological issues that may also be present. Post Traumatic Stress Disorder (PTSD) and Chronic Fatigue Syndrome are particularly common and can be an enormous source of distress for patients.
Three months after being diagnosed with Covid-19 John was finally able to take walks near to his house. Living in Derbyshire, it was suggested to him that he should try some of the Ethel's. For those of you who don't know, the Ethel's are a collection of 95 hilltops in the Peak District National Park that are named after the environmental campaigner Ethel Haythornthwaite. Since almost a third are below a height of 400m, they're a very good place to build up strength and stamina. Further information can be found here
If the physical and psychological challenges of Post-ITU Syndrome weren't enough, we now know that Covid-19 infection can have long term effects upon the organs - especially the heart and lungs...
Whilst we tend to think of Covid-19 as an infection that predominantly affects the respiratory tract, a small but significant number of patients suffer heart damage too. My experience of patients on our unit was that the disease often triggered exacerbations of pre-existing conditions. Examples included those with a history of paroxysmal atrial fibrillation developing a permanent form of the arrhythmia or individuals with ischaemic heart disease experiencing a myocardial infarction or congestive cardiac failure. In addition, we also encountered a small number of patients who’d suffered a direct injury from Covid-19 itself. On more than one occasion we found patients presenting with persistent chest pain and a raised Troponin T blood test who, following a slow recovery, were diagnosed with myocarditis after a cardiac MRI. Unfortunately it is not known how quickly this condition resolves or what impact this has upon long term health. For screening purposes, a combination of echocardiography, 12 lead ECG and Troponin T blood tests have been proposed to identify those with ongoing myocarditis.
The red arrows highlight the "ground glass" findings typically seen on the CT scans of those with Covid-19 infection. These changes are thought to represent extensive damage to the bronchi, bronchioles and alveoli caused by the virus. Following infection these changes take several days to develop. In some instances they are still present many months later. A comprehensive review of CT changes in Covid-19 infection can be found here
Devastating lung injuries were a common feature in patients we admitted to critical care. The combination of direct damage to the small airways and clots in the small blood vessels, often meant that there was simply no way for gas exchange to take place. Amongst ITU survivors damage to the lungs can still be present many months after discharge. Like the impact of Covid-19 upon the heart, it is still not clear to what degree these patients will recover.
Given the uncertainties of Covid-19 infection there is clear value in closely assessing those who want to ascend to high altitude. The fall in oxygen availability that is seen on ascent stretches even the most healthy heart and lungs. Exposing those with damage from Covid-19 infection may reduce the ability to function effectively and in some cases, precipitate life threatening complications. Andy and Colin's article outlines an algorithm that clearly matches up the testing an individual needs with the severity of their acute illness.
A good alternative to the Ethel’s is the 88 trig points found in the Peak District National Park. On completing the Ethel's, John set to work on these too! Once finished, it was off to the Lakes to walk some of the Wainwright's and then Scotland for the Munro's. In little over a year he'd completed more than a hundred tops and even managed to run one or two - a fantastic recovery!
Lets start with the obvious. The algorithm recommends that asymptomatic individuals do not require further investigation. Similarly, those who are fully recovered can be safely encouraged to return to the hills. So far, so good. However things now get a little more complicated. Those who remain symptomatic for at least 2 weeks after a positive test are encouraged to undergo further investigation. I suspect that this can be delayed by several weeks in critically ill patients. Many of these will still be in the early stages of Post-ITU syndrome and be making very slow progress. Very few will have any inclination to climb mountains at this stage! It's worth noting that it took John almost 3 months before he sought help. On visiting his GP, a series of tests were organised. These were similar to those recommended by Andy and Colin. Pulse oximetry during rest and exercise was normal (>96%). So too, was a 12 lead ECG and spirometry assessment. John had undergone an echocardiogram in the days prior to his discharge and since this was normal the GP decided not to repeat it. Trop T and BNP measurements were not obtained for the same reason. A CT scan of the chest was reported as normal. Following a discussion with the clinicians on John's ITU it was decided that a cardiopulmonary exercise (CPET) test should be undertaken. This confirmed that John's heart and lungs were working well. The reassurance of normal tests proved to be just what John needed. In the days that followed he started to take walks and never looked back!
A CPET test is normally undertaken on a static bicycle. Along with standard monitoring (heart rate, 3 lead ECG, blood pressure and pulse oximetry), oxygen consumption and carbon dioxide production are measured during rest and gradually increasing exercise. A beginner's guide to CPET testing can be found here!
Whilst John clearly demonstrated that he was able to undertake long periods of physical activity in the year after Covid-19 infection, it was not clear whether this could be undertaken in the high altitude environment. When it is finally possible to travel freely to Europe, he is planning to spent several days walking at altitudes of up to 3000m. Provided this is successful, John and his wife are planning to hire a guide for 2 weeks and thoroughly acclimatise before making their attempt on Mt Blanc.
We wish them the best of luck!
Thanks to Andy, Colin and the team at High Altitude Medicine and Biology for publishing their fascinating article.
*Please note that John is not his real name.