Working in the intensive care unit: an interview with Dr. Robert Stevens

When patients are discharged from the intensive care unit it’s great news for everyone. However, it doesn’t necessarily mean the road to recovery is straight. As breakthroughs and new technology increase the survival rate for highly critical patients, the number of possible further complications rises, meaning life after the ICU can be complex. Joe Hitchcock from Oxford University Press’s medical publishing team spoke to Dr. Robert D. Stevens, Associate Professor at Johns Hopkins University School of Medicine, to find out more.

Can you tell us a little about your career?

As a junior doctor in the intensive care unit, I observed that prowess in resuscitation is a double edged sword. We were getting better and better at promoting survival, but at what cost in the long term? I decided I would dedicate my career to the recovery process that follows severe illnesses and injuries. Currently, my team has several cohort studies under way in human subjects with head injury, stroke and sepsis. We’re looking at their long term outcomes and also imaging their brains. I have a laboratory in which we are studying a range of neurologic readouts in mice following brain injury. We’re looking at the biology of neuronal plasticity and studying stem cells as a treatment to promote recovery of function.

What is Post-ICU medicine and what does it aim to achieve?

Medicine is increasingly a victim of its own successes. People are surviving complex and terrifying illnesses, which only years ago would almost certainly have been fatal. This means there is an ever-growing population of “survivors”. Like survivors of cancer, survivors of intensive care bring with them an entirely new set of clinical problems, demanding new approaches. We propose Post-ICU Medicine as an umbrella term for this new domain of medical practice and research, which is specifically concerned with the biology, diagnosis and treatment of illnesses and disabilities resulting from critical illness.

What do you mean by the “legacy” of critical illnesses?

The “legacy” of critical illness refers to what people “carry with them” after living through a life threatening illness in the intensive care unit (ICU). It is the sum of consequences, both physical and mental, some temporary others permanent, which unfold in the weeks, months and years after someone is discharged from the ICU.

In what ways might a patient’s post-ICU experience differ from public/idealized expectations?

There is a widely held perception, or perhaps an anticipation, that acute and severe illnesses, such as sepsis or respiratory failure, are a zero-sum game: You may die from this illness, but if you survive you have a good chance of recovering completely and of going on with your life as if nothing had happened. This notion has been turned on its head. We know now that the post-ICU experience presents physical and psychological challenges for a high proportion of patients. Even the most fortunate, those we might regard as having recovered successfully, often acknowledge problems months after they have left the hospital. They report that they feel weak, have difficulties concentrating, are impulsive, anxious or depressed. When tested formally, they are often score below population means on tests of memory, attention, and functional status.

Have you observed patterns in the way patients recover?

I do not know that there are any easily classifiable patterns. There are countless possible trajectories of recovery which we are only beginning to characterize with some degree of scientific rigor. In reality, just as each patient is biologically unique, so too is his or her recovery. One of the main tasks of Post-ICU Medicine is to identify and validate markers (e.g. genetic variants, protein expression) that allow us to predict and track recovery patterns with a much higher level of confidence and reliability.

 How do you assess and treat patients who have a multitude of Post-ICU conditions, psychological and physical?

Ideally, a single provider would be able to follow and treat patients in the post-ICU period. However, the range of different problems — neurologic, cognitive, psychological, cardiac, pulmonary, renal, musculoskeletal, digestive, nutritional, endocrine, social, economic — which these patients present with, are beyond the scope of even a very knowledgeable practitioner. Some groups that specialize in post-ICU follow up care have adopted a different approach, in which patients are evaluated by a multi-disciplinary “Recovery Team” with a wide array of minimally-overlapping knowledge and skills. The latter may include internists, specialists in rehabilitation, psychiatrists, neuropsychologists, neurologists, physical therapists, occupational therapists, orthopaedic surgeons, rheumatologists, and social workers. Patients recovering from critical illness are evaluated periodically and referred to the different members of the Recovery Team depending on clinical symptoms and signs. While evidence is mounting regarding the benefits of integrated post-ICU Recovery Team approach, such interventions area resource intensive and costly and are not currently available to the vast majority of recovering post-ICU patients.

Is it possible to accurately predict patient rehabilitation and recovery trajectories?

This is the “holy grail” of post-ICU medicine, and even of critical care medicine more generally. We desperately need discriminative methods to predict recovery trajectories. Current predictive approaches rely on multiple logistic regression models often using a mix of demographic and clinical severity variables. These models are terribly inaccurate, to the point of being quite useless in the clinical setting. New approaches are needed which analyse large biological datasets – patterns of gene and protein expression, changes in the microbiome, changes in carbohydrate and lipid metabolism, alterations in brain functional and metabolic activity. The great hope is that models emerging from these more sophisticated data sets will allow individualized or personalized approaches to outcome prediction and treatment.

If recovery is considered a gradated process, when is a patient “cured”?

The World Health Organization states that physical and mental well-being are a right of all human beings. It is likely that the insults and injuries suffered in the ICU can never be completely healed or cured. However, the good news is that some ICU survivors achieve astonishing levels of recovery. We need to study these individuals – the ones who do very well and surpass all expectations for recovery– as they seem to  have biological or psychological characteristics (e.g. resilience factors, motivation) which set them apart. Knowing more about these characteristics may help us treat those with less favorable recovery profiles.

What might the post-ICU medicine look like in the distant future?

I believe that mortality will continue to decline for a range of illnesses an injuries encountered in the ICU. The key task will be to maximize health status in those who survive.  I expect that major discoveries will be made regarding organ-specific patterns of gene and protein expression and molecular signalling which drive post-injury recovery versus failure — and that this knowledge will enable novel treatment strategies. I anticipate that important advances will be made in the regeneration tissues and organs using stem cell and tissue engineering approaches.