Professor John A Groeger and Kate Bosak of Nottingham Trent University’s Sleep Well Science project
Sleep responds systematically to gradual biological changes that see us develop from being children into adolescents, from women who might give birth to no longer ovulating, and as we approach and hopefully enjoy old age.
We conceptualise these changes in our capacity to have restorative sleep as the waxing, waning, and interplay of two pervasive influences – circadian fluctuation and the build-up and release of sleep pressure. Abrupt challenges to either process, such as losing a night’s sleep or intercontinental travel, immediately bring home the easy dependence we typically have on these continuous influences on our lives.
For most of us, these challenges are either temporary, which allows us to re-adjust, or gradual, which allows a more easily paced adaptation of life’s demands, lifestyles and the sleep which enables recovery and change.
This is not the case for those who encounter events which result in major trauma- which NICE defines as “an injury or combination of injuries that are life-threatening and could be life changing because it may result in long-term disability”.
What we may not realise is that the profile of those living after major injury has changed very dramatically over the last couple of decades.
It was once overwhelmingly young males, often as the result of traffic accidents, who sustained and survived life-changing injury. However, partly as the result of demography and more immediate and effective care, the median age for survivors is now 63.6 years, of whom 55.1% are male. There is still a preponderance of higher speed/ greater impact events leading to trauma in younger people, but the overwhelming sex difference has narrowed.
Crucially, there is now a high proportion of older patients, more often female, sustaining lower energy injuries which nevertheless have high severity. There are obvious differences in the physical robustness and potential frailty of these groups, and very importantly, for the older injured the likelihood of pre-existing co-morbidities is, of course, greater. Even in those without health challenges there are very substantial differences in the capacity for restorative sleep as we age, but for those surviving major injury the challenge to do so are so much greater.
It is easily assumed that these clients, or the professionals working with them, can describe the sleep challenges they are facing. This, unfortunately, is rarely sufficient to understand what is wrong with sleep and particularly what is needed to change it. Besides that, the precision and reliability of reports when describing periods of weeks or months, is likely to be lacking.
For many, life after major injury begins in intensive care- and of course, the emphasis of that care needs to be on survival. However, the light, noise and other inevitable sleep disruptors mean those leaving after a longer ICU stay will inevitably have disrupted sleep and, perhaps, circadian functioning. Difficulties sleeping for hospitalised patients are not unique to intensive care, as the necessary regimens followed in providing care in multi-bedded wards inevitably results in poor, disrupted or very little sleep.
The pain, and sometimes its management, that persists long after hospital stays can make getting to and remaining asleep very difficult. In particular, opioids, non-steroidal anti-inflammatory drugs, beta-adrenergic blocking agents, and corticosteroid medications affect many of the physiological systems on which sleep relies; not sleeping well intensifies feelings of pain. Sleeping poorly increases our vulnerability to everyday viruses, and the protection against and response to infection and inflammation are also compromised by poor sleep. These same sleep-related immune systems mechanisms are associated with chronic musculoskeletal pain.
The relief of being home, and of being again in a familiar sleeping environment, changes rather than reduces sleep problems. Beds and mattresses may no longer provide the sleep support sleep they once did, where the needs of the sleeper’s body, now changed irrevocably by injury, are different. Similarly, the effects of noise and light may provide prove still more disruptive for sleep that has become more fragile. Traumatic experiences of being injured and apprehensions about the implications for life in the future may lead to anxiety, if not PTSD, resulting in disturbed sleep, sleep terrors, nightmares, and an inability to return to sleep when the nocturnal awakenings we all experience, occur.
Reduced activity as muscles and bones repair may also provoke movement related sleep disorders – such as periodic limb movements of restless legs syndrome. That same reduced mobility may restrict outdoor exercise, or simply the exposure to sunlight, that will aid the resynchronising of the biological clock. Compromised sleep and circadian function may themselves delay the turnover and repair of bones. Limited mobility and reduced ability to burn calories and tendency towards emotional eating may increase the likelihood of apnea, or sub-apnic symptoms, and reduce the scope for modifying sleeping postures, causing profound sleep disruption.
There are other pernicious, and perhaps more pervasive, effects of sleeping poorly. Particularly for younger children, the anxious attachment that accompanies the return home can leave enduring difficulties separating from parents and settling to the night’s sleep. For adults, who have previously slept with others, the need for the reassurance of intimacy, whilst being a more disruptive sleeping partner, may affect not only the survivor’s mood and ability to manage that mood, but also that of those they love and rely upon for care.
Finally, damage to the different parts of the brain, different levels of the spine, different limbs or internal organs, or some combination of these, might all be classed as major injury – but it would be naïve to expect them all to have the same consequences for sleep. Nor do they, but all will to some extent result in the generic sleep impairments described above.
The challenge for those of us who work in this area is to determine what, specifically, goes wrong with sleep after major injury. But that is not enough. Given the limiting factors associated with age and sex, we need to devise programmes tailored to each survivor that can improve the sleep that is possible to facilitate the process of rehabilitation that will enable survivors to lead the most fulfilling lives they can.
At Sleep Well Science we are endeavouring to apply our scientific knowledge of sleep and human functioning to provide a bespoke, client-centred, multifaceted sleep assessment service, to enhance survivors’ sleep and that of those who care for them.
We believe that, along with detailed pre-assessment interviews with clients and their carers, the use of a range of technology and methods is vital in providing client-focused remediation support.
For example, we use actigraphy – sensing the motion of the wrist – to not only measure sleep duration and disturbances – but also environmental conditions such as heat and light, providing more insight into whether individuals are actually waking in the night, or merely moving.
Moreover, analyses approaches we have adopted can provide this information for different parts of the night and day, allowing us to identify whether, for example, individuals are complying with advice to walk outside early in the morning sunlight, whether bedrooms are too hot to enable sleep,
We use very simple and highly portable EEG recording to assess sleep at home, for days on end- that the client can easily apply themselves. This provides precise information about the brain activity during sleep and waking, allowing us to identify why, for example, sleep may not feel sufficiently refreshing or restorative.
A final measurement approach in some cases is 36–48-hour monitoring of core body temperature, or the hormones naturally secreted in saliva. This allows us to quantify the client’s 24 hour cycling of physiological activity known as the circadian system. By doing so we can assess whether, for example, the physiological changes that occur as night approaches are sufficiently strong to allow the client to get to sleep successfully, or whether, for example, this might benefit from the provision of supplements or behavioural interventions to reschedule or boost the sleep system.
At the centre of these methods and technologies, however, is the survivor, and their need for improved sleep to facilitate rehabilitation and quality of life. We believe by knowing more about clients’ individual sleep patterns, their injuries and the life changes these have resulted in, we, and other health and support services, can work collaboratively with clients and carers to develop remedial approaches which actually work.
