Journal of Advanced Nursmg, 1991,16,1503-1510
Why do we need sleep? Relating theory to nursing practice Linda A Hodgson SRN DNCert CertEd Matron, The Heart of Kent Hospice, Maidstone, Kent, England
Accepted for publication 24 June 1991
HODGSON L A (1991) Journal of Advanced Nursmg 1 6 , 1 5 0 3 - 1 5 1 0 Why do we need sleep? Relating theory to nursing practice By reviewing the literature, this paper explores the nature and function of sleep Most of the evidence for the functional theones of sleep has been obtained as a result of examining the effects of sleep depnvation, the physiological, emotional and behavioural effects of which are discussed There is a discussion on how an awareness of the theoretical knowledge may help in the nursmg care of patients with advanced cancer and other chrome diseases, as well as their carers The physiological effects of stress, and the possible relationship to patients and their carers, leads the author to highlight the need for further research, and possible benefit of proactive intervention for the bereaved The effects of poor nutntion and common symptoms such as pam and dyspnoea on sleep, and the latrogenic causes of sleep disturbances, are discussed The importance of mdividualized patient care is stressed The conclusion is drawn that although researchers do not seem to have been able to prove conclusively any essential function of sleep, the nurse is m a uruque position to facihtate and enable patients and their carers to cope dunng the wakmg hours, without the added stress that sleep disruption and deprivation bnng
INTRODUCTION
Defining sleep
"Early to bed, early to nse, makes a man healthy, wealthy and wise' a much loved saying by many, in the belief that sleep IS good for you, it helps children to grow, and is important if you are ill Is this true? Sleep IS a phenomenon common to all humans We spend on average a third of our lives asleep, and m that state we are unable to seek food or shelter and have a reduced ability to defend ourselves from danger It has been descnbed as 'a regular, recurrent, easily reversible state of the orgarusm, charactenzed by relative quiescence and by a great mcrease in the threshold of response to extemal stimuli' (Hartmann 1973) Turpm (1986), however states that 'sleep is not a penod of mere physiological quiescence, but a complex phenomena wbch results from numerous different physiological processes'
Fordham (1988) has said that there are two possible ways of definmg sleep, first as a discrete state and second as being part of a continuous cyclical change in level of consciousness The discrete state descnbes sleep as 'a state of reduced responsiveness to extemal stimuli, an altered state of consaousness from which a person can be aroused if the stimulus IS of sufficient magnitude' (Fordham 1988) The second part descnbes sleep as the physically mactive part of the circadian (around a day) sleep-wake-activity cycle, and IS charactenzed by cyclical changes m the electroencephalogram (EEG) and other physiological parameters (Webb I97I) The significance of descnbmg sleep m this way IS that sometimes patients have problems with the state of sleep, sometimes with the schedulmg of sleep, and sometimes with both There has been much research undertaken by psydiologists and psychiatnsts in an attempt to understand the
Correspondence Unda A Hodgson, 55 Wykeham Road Htstmgs TN34 lUA Biglmd
East Sussex
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physiological correlates of sleep, and the emohonal and behavioural concomitants and consequences of normal and abnormal sleep patterns (Home 1983, Oswald 1980a) Accordmg to Gnbbm (19W), 'It is easier to say what sleep IS, than why we sleep' For the purpose of this paper, what follows IS a discussion of some of the research that has examined the nature and function of sleep and how an awareness of this knowledge may help m the care of patients, particularly those with advanced cancer and other disease STAGES OF SLEEP Sleep IS characterized by several distmct phases or types which cycle throughout the sleep penod These stages do not occur once, but cycle several times dunng the course of sleep Identification is based upon the frequency and amplitude of the electroencephalogram (EEG) and the presence of charactenstic EEG patterns Sleep stages are also defined with respect to patterns of eye movements and electromyogram activity
at any other stage REM sleep occupies about 20% of an adult's sleep The other stages constitute non-REM or orthodox sleep and research has shown that the complete cycle IS passed through approximately every W mmutes (Turpin 1986) Sleep research has therefore ldentihed that the vanous sleep stages represent two quite different sleep states, evidence for which is denved from the physiological dififerences underlying sleep mechanisms and revolutionary differences in sleep states
CONTROL OF SLEEP
Research suggests that sleep is mduced by complex neurochemical reactions ansing in the tissues of the brain stem knovwi as the reticular formation, mediated by neurotransmitters including serotonin and nor-adrenalin (Borbely 1987) Supenmposed on any other sleep-regulatmg mechanism which may exist is 'a arcadian rhythm controlled by an area of the hypothalamus known as the body clock, which Stage 1 the lightest sleep, charactenzed by a low voltage shows a cyclical diumaifluctuation,at any one time havmg desynchroruzed EEG, and a reduction in autona greater or lesser effect on the inclination to sleep' (Turpin omic activities, 1 e heart rate, blood pressure, 1986) This arcadian rhythm closely follows an mverse sweating relationship with the cycle of body temperature, which Stage 2 12-14 Hz sleep spmdles and high voltage K begins to warm up a few hours before the time of usual complexes appear awakening, to ensure ideal conditions for optimum body Stage 3 Delta waves become apparent and there is a function decline m physiological reactivity to external Weizman et al (1983), however, consider that although stimuli, and the sleeper is more difficult to 'regular mght time sleep is synchronized with other cirarouse cadian rhythms such as hormone levels, temperature and Stage 4 Delta waves predormnate There is considerable metabolic rate, the major determinants of human sleepmg reduction in physiological reactivity are external tune cues, light/dark, and particular social In stages 3 and 4, hormonal changes occur, e g secretion of events' human growth hormone Followmg stage 4, sleepers start to reverse back through the sleep stages, until an apparent stage 1 is reached Cortical inhibition However, tbs is different from the ongmal stage 1 The sleeper is very difficult to arouse, shows bursts of heart Jouvet (1969) suggested that slow wave (non-REM sleep) rate acceleration, and rapid breathmg and oxygen uptake resulted from cortical inhibition due to the raphe system increases The male has perule erections, female has He also postulated that serotonin was the neurotransmitter increased vaginal lubncatioa and there is loss of muscle responsible for cortical inhibition He suggested that the tone, although there may be body jeiks Rapid eye move- locus coeruleus was responsible for paradoxical (REM) ment occurs under d o ^ d lids and the EEG looks akin to sleep and its accompanjnng muscle atoma However, there wakmg patterns has been further research that questions the simphaty of Tbs stage 1 is often known as rapid eye movement Jouvet's(I969)woric(Hobsoneffl/ 1975,Lidovrffl/ 1980) (REM) or paradoxical sleep The sleeper is variably responAccordmg to Fordham (1988), 'simple explanations or sive to external stimuli, he may aw^e spontaneously, or smgle controls of sleep do not fit wittt the evidence may be very difficult to waken If awakened at this stage, Current researchfindingssuggest that the control of sleep the sleeper is more likely to recall dreams than if awakened is not confined to one localized part of the bram' 1S04
Nature and function of deep
The conclusion that we can make is that sleep is an extremely complex physiological phenomenon which results from the interaction of many different neurochemical systems withm the brain
1 2 3 4
FUNCTIONS OF SLEEP 5 Many functions of sleep have been proposed including describing sleep as restorative, protective, mstmctive or ethnologically adaptive Others beheve sleep functions to 'conserve energy or to periodically readjust biological systems' (Chuman 1983)
Humoral theory The humoral theory of sleep proposes that dunng the waking state there is a build up of a chemical toxin which induces tiredness and sleep During sleep this 'hypnotoxin' IS flushed away from the body at which point we wake However, accordmg to Canavan (1986), as a theory there is msufftcient evidence to support it For mstance, it seems that Siamese twins shanng the same blood supply sleep at different tunes and have varying sleep patterns However, physiologists and biochemists have identified vanous endogenous sleep-promoting substances, e g pjeptides, prostaglandms, melatomn and other hormones found in the fluids and tissues of animals and humans 'A progressive build up of these substances and a resultant relaxation process may account for tiredness and the need for sleep' (Turpin 1986)
Restihihon theory The body restitution theory of sleep has promoted much research The physiologist Shermgton (1906) considered sleep to be 'a state of enhanced tissue growth and repair, following the wear and tear of wakefulness' Our tissues are continuously bemg renewed and are continuously decaying According to Oswald (1987), 'decay, degradation, breakdown or catabohsm is maximal durmg wakefulness, while renewal or anabohsm is maximal durmg sleep' The shift in balance towards greater renewal durmg sleep has been demonstrated in a large number of animal tissues However, is this shift part of the &xed arcadian rhythm, or does it depend on sleep? Accordmg to Fordham (1988), arguments for and against the restitution theory rest on the mterpretation of
Fmdmgs of a peak in human growth hormone in slow wave sleep (Takahashi 1979) No sleep-related msulm release (Jefferson 1980) Cellular energy charge levels (Adam 1980) Mitosis f>eaks durmg usual sleep penods, but which are found even in the absence of sleep (Schevmg 1959, Parker e^fl/ 1980) Efifects of sleep depnvahon (Home 1978, Martm 1981)
Some believe that during sleep optimum conditions for protein synthesis are created by a combination of the presence of high energy levels (adenosme tnphosphate stores) within resting cells, the tnggermg of anabohc human growth hormone release, and the occurrence of the arcadian low point of the level of the catabolic hormones, corticosteroids and adrenalme at night (Oswald 1980b) Adrenaline released durmg wakefulness is thought to prevent the cell division for healmg to occur Dunng non-REM sleep, particularly dunng the first 3 hours of sleep, growth hormone is secreted from the antenor pituitary in an episodic or pulsatile manner (Gnbbin 1990) Growth hormone enhances ammo tiad transport into cells, it also promotes protem and nbonucleic aad (RNA) synthesis (Komer 1965) It raises bloodfree fatty aads whose subsequent degradation is a source of cellular energy (adenosme tnphosphate), thereby savmg ammo acids from catabohsm and increases their availabihty for protem synthesis dunng sleep (Adam & Oswald 1977) However, it has been argued that protein synthesis is stimulated by ammo acid absorption from the mteshne, somethmg that would be minimal durmg the normally fasting state of sleep (Dorociak 1990) It has also been argued that stimulation of cells to grow, which mvolves protein synthesis, requires a good supply of msulm to be present and there is no surge of msulm m the early hours of sleep (Gnbbm 1990) Home (1983) indicates that the functions of growth hormone are not fully understood m wakmg adults, let alone in the sleep state In contrast to Adam & Oswald (1977), he states that m sleep 'the release is unrelated to blood levels of glucose, ammo acids and fatty acids present m normal amounts at the time It therefore seems not to be under the usual metabohc control, but under the control of obscure neuronal mechanisms' (Home 1983) His conclusion IS that it IS more hkely to be an action to spare protem from bemg broken down so readily for use as a reserve energy source In the view of Waterlow et al (ated by Home 1983), 'because of man's mght time fast, often lasting 12 hours from everung meal to breakfast, protem synthesis during 1505
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sleep IS low' Recent research by these authors demonstrated that dunng sleep, because of the fast, protein breakdown exceeded synthesis, leading to an overall condition of tissue degradation These findmgs, however, related to the body as a whole, and the authors pointed out that certain tissues, the brain for example, have shown opposite trends dunng sleep, with other tissues displaying even greater protein losses The course of brain protein turnover dunng sleep is not however known' (Home 1983) Some human tissues, e g epidermis, have a daily peak in division which appears withm usual sleep penods, and seems to support the restitutional hypothesis of sleep However, this also occurs dunng sleep depnvation, 'therefore it IS not caused by sleep but a hme of day comadent with sleep' (Home 1983) Accordmg to Doroaak (1990), 'what is conceded, though, IS that if the body must be at rest for protem synthesis to go ahead and, smce the bram cannot relax dunng wakefulness, sleep, in particular short wave sleep, is necessary to allow its repair processes to occur' Learning and memory The view that sleep and dreantmg are somehow related to learning and memory is not new The 19th century neurologist Hughlmgs Jackson (ated by Canavan 1986) profjosed two related functions for sleep The first is to sweep away unnecessary memones from the day and the second, to consolidate the most important expenences As protem synthesis is believed to occur dunng REM sleep and smce memory is thought to involve the deposition of proteins withm nerve cells, 'REM sleep is linked with memory storage, memory consohdation and learning' (Fishbem & Gutwem 1981, Squire & Davis 1981) SLEEP DEPRIVATION
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slight changes m cardiovascular and respiratory function, slight hormonal changes which may be related to stress, changes in control of eye movements, and musculature mvolved with accommodation and convergence, enhancement of epileptic-like EEG activity m some people
Psychological effects Emotionally, mdividuals have been found to become mcreasmgly aggressive, lmtable and anhsoaal (Hartmann 1973, Gemer et al 1979, Mclntosh 1989) This depression of mood IS seen after relatively bnef penods, l e 24-28 hours However, even the longest documented studies of 8—11 nights of total sleep loss did not report senous neurological or psychiatnc impairment, and Dement et al (1967) state that There is no evidence to suggest that emotional changes persist beyond the duration of the depnvation expenment' Behavioural changes have been observed m tests which require speed and prolonged concentrated attention or vigilance, rather than physical efiFort It is difficult to maintam focused attention or to shift attention when required, but it is the undemanding, tedious, uninteresting and simple task that is thefirstto become impaired Demandmg, mterestmg tasks that encourage motivation are not sigruficantly impaired, although after 2-3 days of depnvation, ability does decline TTie effects of sleep depnvation on mental functiorung provide part of the argument in favour of sleep as essential for bram restitution
Recovery sleep
Following prolonged sleep depnvation, it has been found consistently that there is a failure to make up all the lost sleep, when given the opportunity to do so According to Bermot ei al (1980), 'most of the lost stage 4 is recouped, only arouruJ one third of REM, some of stage 3, and almost none of stages I and 2' This appears to support the suggestion by Home (1983) that sleep serves both a restorative, le body and/or bram reshtuhon, and a non-restorahve function of occupying ui^roductive hours, providmg safety and conservmg energy Physiological effects A fiirther mdication that not all human sleep is essential The physiological effects of sleep depnvation, as discussed IS researdi mvolvu^ volunteers successfully acquirmg the by Home (1983) and Canavan (1986) are habit of takmg 1-2 hours less sleep per day for at least 8—12 1 fall m body tonperature and less eSiaent temperahire months without any consequence, such as day-hnw sleepiness (Home 1983) Home (1983) has observed that 'it is regulation.
Most of the evidence for vanous functional theones of sleep has been obtained as a result of exammmg what effect lack of sleep (sleep depnvation) has on performance and moods and noting any sigruficant electncal changes It has been found that the overwhelmmg tiredness that occurs is more stnkmg than the biochemical, emotional or behavioural changes that take place
1S06
Nature and function of skep
interrupted or dishxrbed sleep which is the major cause of day-tune sleepiness, not simply less sleep' Therefore, 5-6 hours of unmtemipted sleep is better than 8 hours of disturbed sleep It IS commonly assumed that sleep loss heightens susceptibility to infection, although two investigations have demonstrated that 71 hours of sleep depnvation produced small changes m the immune system The researchers would not interpret these changes as being senous, simply changes of unknown consequence (Home 1983) The body restitution theory is m doubt when the 'ml' hndings of physiological efifects of total sleep depnvation are considered Rapid eye movement sleep depnvation The type of sleep lost seems to have some relevance Dunng REM sleep depnvation, the subject was awakened at the onset of each penod of REM activity, but allowed sleep dunng non-REM sleep penods Such depnvation appears to affect mood and basic dnves There are reports of hyperachvity, emotional instability, agitation, mood disruption and decreased impulse control (Naitoh et al 1971) However, studies of depnvmg people of REM sleep do not produce any mental disorder m normal subjects, and under certain circumstances, particularly for endogenous depression, depnvation of REM sleep seems benefeaal (Home 1983) Gnbbm (1990) suggests that it may be that REM sleep is what we need sleep for and that non-REM sleep IS far less important for our well-being The psychological importance of dreams, which are frequently assoaated with this phase of sleep, has been demonstrated in dream curtailment expenments (Dement 1960, Sampson 1966) Expenments suggest that our brams require a mirumum 'ration' of fantasy dreams each day, whether all whilst asleep or both awake and asleep 'It seems that REM sleep at least serves a function in keeping us sane, although it is not clear exactly how dreams serve that purpose' (Gnbbin 1990) Is dreaming 'an automatic process that occurs while the flood of information from the previous day's expenences is being collated, sorted and filed away' (Gnbbin 1990)? REM sleep is only onequarter of the total m adults, and it may be that as long as one's quota of REM sleep is achieved, then this may explain why some people need less sleep than others Non-REM sleep deprivation Non-REM depnvahon is unpossible to achieve without also depnvmg REM sleep (Hartmann 1973) However, up
to 1(K) hours of such depnvation have failed to produce dear behavioural results, although subjects reported feeling lethargic and depressed There is concern about vague physical symptoms, m contrast to the more agitated and lmtable response often seen after REM depnvation The reason why we have so much non-REM sleep is not certam, but researchers argue that such sleep may have evolved as 'a handy way to keep our bodies out of mischief in between meals' (Gnbbm 1990) There remain several body systems where the effects of sleep depnvahon are relahvely unexplored, so the picture IS far from complete, but, as far as is known, no organ apart from the brain enters a physiological state which is clearly unique to sleep Dunng wakefulness, the EEG mdicates that even when we are relaxed the brain is in a state of quiet readmess, prepared to act on any sensory stimulus Hence, it appears that sleep may be the only state of rest for the brain It is the brain that controls sleep, and it is the bram functions such as span of attention that are most obviously unpaired by sleep depnvation At the present tune, if sleep does uideed serve a physiological or psychological purpose then, theoretically, a loss of sleep should result m alterations of function However, as Webster & Thompson (1986) have stated, 'widespread research has failed to reveal a dear cause and effect relationship between sleep depnvahon and speafic bodily function' It IS important to note, however, that much of the theorehcal basis of sleep research has been obtamed firom evidence from healthy volunteers, m falsely modified laboratory condihons RELATING THEORY TO PRACTICE Stress Many patients with advanced cancer and other chroruc illnesses, as well as their families/carers, may already be anxious, imtable, suspiaous or depressed This nay be the result of sleep depnvatioa or some other psychological problem, e g fear and worry over the illness and its outcome, the treatments involved, or an inability to plan for the future Expenence suggests that some pahents are afraid to sleep m case they die, a fear also expressed by the relahves regarding their loved one A further problem may be very disturbuig rughtmares Are these the unvoiced feju^ and womes tickmg over while the owner is not in control? It seems that pahents are most at nsk of sleep disturbances at hme of diagnosis, when receiving chemotherapy or radiotherapy, when secondary growth is diagnosed, and 1507
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those with end-stage symptomology, times of heightened anxiety Kleitman (1963) conduded that 'ease of going to sleep was greatly altered when the person was anxious or depressed' Haynes et al (1974) found support for the hypothesis that anxiety is an aetiological factor in insomnia, and Karacan et al (1983) found that sleep disturbance was found to be directly assoaated with vanables, causing or resulting from anxiety and stress StonehiU et al's (1976) findings that 'sadness results in early falling asleep and early awakening, anxiety in difficulty falling asleep and later awakening, and anger m difficulty both m falling asleep and remaining asleep, resulting in repeated awakenings'
vigilance of the situation and somnolence conserving energy' (Fordham 1988)
Physical pathology Many sleep abnormalities are caused by, or are secondary to, physical pathology Conditions which increase lntracranial pressure, or alter central nervous system physiology, are particularly liable to affect sleep adversely Pathologies of the bram stem and hypothalamus and cerebral atrophy may disrupt sleep onset and maintenance Excessive day-time sleeping may also occur with tumours of the pineal, post-hypothalamus, and any which impinge on the third ventncle
Anxiety and depression When assessing the efifects of anxiety and depression on sleep, it seems that, as anxiety and depression increase, so does lack of sleep and, as sleep decreases, anxiety and depression also increase — a viaous arde According to Kleitman (1939), both anxiety and depression also tended to result in increased mobility dunng sleep, a more disruptive sleep and decrease in the overall feeling of being rested upon wakening Patients or their carers who are stressed will release extra corhcosteroids and adrenalin, because of enhanced sympathetic activity This leads to more catabolism, more sleeplessness, and more anxiety As Doroaak (1990) stated, 'high levels of corticosterotds depress the immune system, inhibit protein synthesis and could reduce wound healing' Another hypothesis put forward by Oswald (1987) is that 'the high mortality rate assoaated with the months after bereavement is presumably mediated by, among other things, high catecholamines and cortisol' The bereaved often expenence problems assoaated with sleep, due to fear of intruders, loneliness, and the dreams or nightmares that may occur involving the loved one who had died If Oswald's (1987) hypothesis is supported, then there should surely be an mcrease m proactive intervention for the bereaved 'Fatigue assoaated with the expenditure of nervous energy,, e g sustained emotion, and anxiety, seems to necessitate sleep rather than rest' (Home 1983) This may be because of an increased need for brain restitution following heightened brain metabolism produced by tbs increase in psychological arousal, or merely a withdrawal respond — an escape into sleep A small number of people respond to threat by excessive sleq> ratl:ttr than insomma Qether reaction could be seen as adaptive, 'ueomma rtuuntauung 1508
Pain and other symptoms Many common symptoms are worse at night Patients whose cardiac or respiratory function is compromised by day, are liable to further detenoration dunng sleep, resulting m angina, palpitations, cardiac arrhythmias, nocturnal dyspnoea, etc According to Glyn et al (1976), 'chronic pain may have a arcadian rhythm of increasing intensity at night' From observation, many patients with cancer do indeed complain of more pain at night However, this may well be due to the fear and anxiety expenenced m the quiet of night, when less distraction demands more thought and reflection on one's plight Patients will not sleep if they are m pain Marks & Sacher (1973), m a study of medical patients, found that sleep was the function most commonly affected by pam Over threequarters of the patients reported significant difificulty in sleepmg Expenence suggests that some patients are not prescnbed analgesia dunng the night, although it is suggested that the increasing use of controlled-release morphine has much improved pain control throughout the 24-hour penod The drug control of other symptoms assoaated with advanced disease may result m latrogenic causes of sleep disturbances, eg steroids, antimetabolites and other cancer chemotherapeuhc agents, anticonvulsants, bronchodilators and central adrenergic blockers
Nutrition It IS also important to consider the rebhonship l»tween nutntion and sleep Many pahatts with advanced cancer are anorexic have lost weight aid may be cachectic. Many studies including those on tr^ted anorexics support the
Nature and function of sleep
conclusions of Cnsp & Stonehill (1973), that weight loss is associated with reduction m total sleep, compounded by more broken sleep and earlier awakening, weight gam is associated with an increase m total sleep compounded by less broken sleep and later wakening It IS suggested that much can be done for the nutntional needs of patients, that will both relieve and prevent further symptoms, and may well improve their ability to have a good night's sleep It may be that for these patients sleep as opposed to rest may be the only way for the body to maximize its resources
Care of the carers When considenng the carers of patients with advanced disease at home, it is important to consider the possible long-term effects of continued sleep disruption £ind depnvation It may well increase anxiety, lessen motivation and consequently the ability to cope The carers may be suffenng as much if not more than the patient, from desynchronization of their arcadian rhythms This will mevitably result m anxiety, depression, lmtability, and decreased accuracy in task performance as previously outlined The sleep-depnved carer may often be looking after the well-rested patient and respite in-patient care will be needed
INDIVIDUALIZED CARE PLAN In order to plan mdividualized patient and family care, it is suggested that the following aspects need to be considered in assessment 1 2 3 4 5 6 7 8 9 10 11
age the normal pattem of sleep dunng health current pattem of sleep nutntional status emotional status, e g anxiety, depression day-time and night-time symptoms, e g pam, dyspnoea sleeping environment sleep-related ntuals, e g bed-time dnnks, reading, television presence of dreams or nightmares present medication wake-time behaviour, e g naps, mental efifiaency
Assessment is, of course, subjective, as much depends on the individual's defirution of quality of sleep However, much can be leamed from both patient and carer and, by setting realistic goals with them, it is possible to plan
nursing interventions that may avoid the use of hypnotics and tranquillizers
CONCLUSION As yet, reseiirchers do not seem to have been able to prove conclusively any essential function of sleep which cannot be fulfilled dunng the wakmg state As Fordham (1988) has stated, 'if sleep is essential for survival or health we need to take sleep problems very senously, but if sleep is an urmecessary tune filling behaviour or luxury, we could be justified in considenng many sleep problems as tnvial' A long-time researcher Jack Empson (1989) sums it up 'it must be admitted straight away that the function of sleep remains a mystery, and its evolution remains a matter for conjecture' However, patients and their carers should not need to endure the added stress that sleep disruption and depnvation bnng They should be encouraged to take extra rest and to have the amount of sleep that leaves them feelmg refreshed and able to cope dunng the wakmg hours The nurse, m my view, is m a unique position to faahtate and enable this goal to be achieved
References Adam K (1980) Sleep is a restorative process and a theory to explain why Progress m Brain Research 5 3 , 289-305 AdamK & Oswald I (1977) Sleep is for tissue restoration JoMraa/ of the Royal College of Physicians 11(4), 376-388 Bennot O , Foret J, Bouard G , Merle B, Landau J & Marc M E (1980) Cited m Wilson-Bamett J & Bateup L (1988) Patient Problems A Research Base for Nurstng Care Scutan Press, London, p 153 Borbely A (1987) Cited m Doroaak Y (1990) Aspects of sleep Nursmg Ttmes 86(51), 38-40 Canavan T (1986) The functions of sleep Nursing 3(9), 321-324 Chuman M (1983) The neurological basis of sleep Heart and Lung 12(2), 177-182 Cnsp A H & Stonehill E (1973) Cited in Wilson-Bamett J & Bateup L (1988) Patient Problems A Research Base for Nursing Care Scutan Press, London, p 161 Dement W (1960) Cited in Carter D (1985) In need of a good night's sleep Nursing Times 81(46), 24-26 Dement W , Henry P , Cohen H & Ferguson J (1967) Cited m Canavan T (1986) The functions of sleep Nursmg 3(9), 321-324 Doroaak Y (1990) Aspects of sleep Nursing Ttmes 86(51), 38-40 Empson J (1989) Now I lay me down to sleep Nursing Times 85(47), 34-35 1509
LA FishbemW &GuhveinBM (19SI)GtedinChuinanM (19S3) Maries R M & Sacher EJ (1973) Undertreatment of medical mpatients with narcohc analgesics Annals of Internal Mediane The neurological basis for sleep Heart and Lung 12(2), 78,173-181 177-182 Fordham M (1988) In Patient Problems A Research Bau for MarhnBJ (1981) Oted m Wilson-Bamett J & Bateup L (1988) Patient Problems A Research Base for Nursing Care Scutan Press, Nwrsm^ Care (Wilson-Bamett J &BateupL eds), Scutan Press, London, pp 148-181 L o n d o a p 153 Gemer R H , Post R.M, Gillm J C & Bunney W E (1979) Cited in Naitoh P , Pasnau R & Kollar E (1971) Oted in Chuman M QiumanM (1983) TTie neurological basis for sleep Heart and (1983) The neurological basis of sleep Heart and Lung 12(2), Lung 12(2), 177-182 177-182 Glyn C I , Lloyd J W & Folkard S (1976) The diumal vanation m Oswald I (1980a) Oted m Wilson-Bamett J & Bateup L (1988) perception of pam Proceedings of the Royal Soaety of Mediane Patient Problems A Research Base for Nursing Care Scutan Press, 69, 369-372 London, p 151 Oswald 1 (1980b) Oted m Doroaak Y (1990) Aspects of sleep Gnbbin M (1990) All in a night's sleep New Saenttst 7(36), 1-4 Nursmg Times 86(51), 38-^0 Hartmann E (1973) Oted in Turpm G (1986) Psychophysiology Oswald I (1987) The benefit of sleep Holistic Medicine 2, of sleep A?Mrsing 3(9), 313-320 137-139 Haynes S N , Follmgstad D R. & McGowan W T (1974) Oted m Parker D C, Rossman L G, Knpke D F, Hershman J M , Gibson Webster R.A & TTiompson D R (1986) Sleep m hospital W , Davis D et al (1980) Oted m Wilson-Bamett J & Bateup Journal of Advanced Nursing 11(4), 447-457 L (1988) Patient Problems A Research Base for Nursing Care Hobson J A , McCarley R W & Wyzmski P W (1975) Cited m Scutan Press, London, p 153 Turpm G (1986) Psychophysiology of sleep Nursing 3(9), Sampson H (1966) Oted m Carter D (1985) In need of a good 313-320 night's sleep Nursing Times 81(46), 24—26 Home J A. (1978) Gted in WiJson-Bamett J & Bateup L (1988) Schevmg L E (1959) Oted m Wilson-Bamett J & Bateup L Patient Problems A Research Base For Nursing Care Scutan (1988) Patient Problems A Research Base for Nursir^ Care Press, London, p 153 Scutan Press, London, p 153 Home J.A (1983) Sleep and tissue repair ftycfciafry m Practice Shenngton (1906) Oted m Canavan T (1986) The functions of 2(18), 9-12 sleep Nursing 3(9), 321-324 Jefferson L5 (1950) Oted m Wilson-Bamett J & Bateup L (1988) Patient Problems A Research Base for Nursing Care Scutan Press,Squire L R & Davis H P (1981) Oted m Chuman M (1983) The London, p 153 neurological basis of sleep Heart and Lung 12(2), 177-182 JouvetM (1969) Oted m Turpm G (1986) PsyAophysiology of Stonehill E, Cnsp A.H & Koval J (1976) Cited m Wilson-Bamett J & Bateup L (1988) Patient Problems A Research Base for sleep Nursing 3(9), 313-320 Nursing Care Scutari Press, London, p 156 Karacan I, Thomby JJ k Williams R.L (1983) Oted m Webster R.A & Thompson D R (1986) Sleep m hospital Journal of TakahashiY (1979) Cited m Wilson-Bamett J & Bateup L (1988) Patient Problems A Research Base for Nursing Care Scutan Press, Advanced Nursmg 11(4), 447—457 London, p 153 Kleitman N (1939) Oted m Lamb MA. (1982) TTie sleqjmg Turpm G (1986) Psychophysiology of sleep Nursmg 3(9), patterns of patients with malignant and non-malignant disease 313-320 Cancer Nursing, October, 389-395 W e b b W B (1971) Oted m Wilson-Bamett J & Bateup L (1988) Kleitman N (1963) Oted m Webster R.A & Thompson D R (1986) Sleep m hospital Journal of Advanced Nursmg 11(4), Patient Problems A Research Base for Nursing Care Scutan Press, 447-457 L o n d o a p 149 Komer A (1965) Oted m Adam K & Oswald L (1977) Sleep is Webster R A & Thompson D R (1986) Sleep in hospital Journal for tissue restorahon Journal of the Royal College of Physicians of Advanced Nursing 11(4), 447-457 Weizman E D , Czeisler CA, Zimmerman J C „ Moore-Ede M C 11(4), 376-388 Lidov H G W , Grzanna R & Molliver M E (1980) Oted in & Ronda J M (1983) Oted m Wdson-Bamett J & Bateup L (1988) Patient Problems A Research Base for Nursing Care Turpm G (1986) Psychophysiology of sleep Nursing 3(9), 313-320 Scutan Press, Londoa p 149 Mdntosh A. (1989) Sleep depnvahon m cnhcally ill patients Nursmg 3(35), 44-45
1510
Why do we need sleep? Relating theory to nursing practice Linda A Hodgson SRN DNCert CertEd Matron, The Heart of Kent Hospice, Maidstone, Kent, England
Accepted for publication 24 June 1991
HODGSON L A (1991) Journal of Advanced Nursmg 1 6 , 1 5 0 3 - 1 5 1 0 Why do we need sleep? Relating theory to nursing practice By reviewing the literature, this paper explores the nature and function of sleep Most of the evidence for the functional theones of sleep has been obtained as a result of examining the effects of sleep depnvation, the physiological, emotional and behavioural effects of which are discussed There is a discussion on how an awareness of the theoretical knowledge may help in the nursmg care of patients with advanced cancer and other chrome diseases, as well as their carers The physiological effects of stress, and the possible relationship to patients and their carers, leads the author to highlight the need for further research, and possible benefit of proactive intervention for the bereaved The effects of poor nutntion and common symptoms such as pam and dyspnoea on sleep, and the latrogenic causes of sleep disturbances, are discussed The importance of mdividualized patient care is stressed The conclusion is drawn that although researchers do not seem to have been able to prove conclusively any essential function of sleep, the nurse is m a uruque position to facihtate and enable patients and their carers to cope dunng the wakmg hours, without the added stress that sleep disruption and deprivation bnng
INTRODUCTION
Defining sleep
"Early to bed, early to nse, makes a man healthy, wealthy and wise' a much loved saying by many, in the belief that sleep IS good for you, it helps children to grow, and is important if you are ill Is this true? Sleep IS a phenomenon common to all humans We spend on average a third of our lives asleep, and m that state we are unable to seek food or shelter and have a reduced ability to defend ourselves from danger It has been descnbed as 'a regular, recurrent, easily reversible state of the orgarusm, charactenzed by relative quiescence and by a great mcrease in the threshold of response to extemal stimuli' (Hartmann 1973) Turpm (1986), however states that 'sleep is not a penod of mere physiological quiescence, but a complex phenomena wbch results from numerous different physiological processes'
Fordham (1988) has said that there are two possible ways of definmg sleep, first as a discrete state and second as being part of a continuous cyclical change in level of consciousness The discrete state descnbes sleep as 'a state of reduced responsiveness to extemal stimuli, an altered state of consaousness from which a person can be aroused if the stimulus IS of sufficient magnitude' (Fordham 1988) The second part descnbes sleep as the physically mactive part of the circadian (around a day) sleep-wake-activity cycle, and IS charactenzed by cyclical changes m the electroencephalogram (EEG) and other physiological parameters (Webb I97I) The significance of descnbmg sleep m this way IS that sometimes patients have problems with the state of sleep, sometimes with the schedulmg of sleep, and sometimes with both There has been much research undertaken by psydiologists and psychiatnsts in an attempt to understand the
Correspondence Unda A Hodgson, 55 Wykeham Road Htstmgs TN34 lUA Biglmd
East Sussex
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physiological correlates of sleep, and the emohonal and behavioural concomitants and consequences of normal and abnormal sleep patterns (Home 1983, Oswald 1980a) Accordmg to Gnbbm (19W), 'It is easier to say what sleep IS, than why we sleep' For the purpose of this paper, what follows IS a discussion of some of the research that has examined the nature and function of sleep and how an awareness of this knowledge may help m the care of patients, particularly those with advanced cancer and other disease STAGES OF SLEEP Sleep IS characterized by several distmct phases or types which cycle throughout the sleep penod These stages do not occur once, but cycle several times dunng the course of sleep Identification is based upon the frequency and amplitude of the electroencephalogram (EEG) and the presence of charactenstic EEG patterns Sleep stages are also defined with respect to patterns of eye movements and electromyogram activity
at any other stage REM sleep occupies about 20% of an adult's sleep The other stages constitute non-REM or orthodox sleep and research has shown that the complete cycle IS passed through approximately every W mmutes (Turpin 1986) Sleep research has therefore ldentihed that the vanous sleep stages represent two quite different sleep states, evidence for which is denved from the physiological dififerences underlying sleep mechanisms and revolutionary differences in sleep states
CONTROL OF SLEEP
Research suggests that sleep is mduced by complex neurochemical reactions ansing in the tissues of the brain stem knovwi as the reticular formation, mediated by neurotransmitters including serotonin and nor-adrenalin (Borbely 1987) Supenmposed on any other sleep-regulatmg mechanism which may exist is 'a arcadian rhythm controlled by an area of the hypothalamus known as the body clock, which Stage 1 the lightest sleep, charactenzed by a low voltage shows a cyclical diumaifluctuation,at any one time havmg desynchroruzed EEG, and a reduction in autona greater or lesser effect on the inclination to sleep' (Turpin omic activities, 1 e heart rate, blood pressure, 1986) This arcadian rhythm closely follows an mverse sweating relationship with the cycle of body temperature, which Stage 2 12-14 Hz sleep spmdles and high voltage K begins to warm up a few hours before the time of usual complexes appear awakening, to ensure ideal conditions for optimum body Stage 3 Delta waves become apparent and there is a function decline m physiological reactivity to external Weizman et al (1983), however, consider that although stimuli, and the sleeper is more difficult to 'regular mght time sleep is synchronized with other cirarouse cadian rhythms such as hormone levels, temperature and Stage 4 Delta waves predormnate There is considerable metabolic rate, the major determinants of human sleepmg reduction in physiological reactivity are external tune cues, light/dark, and particular social In stages 3 and 4, hormonal changes occur, e g secretion of events' human growth hormone Followmg stage 4, sleepers start to reverse back through the sleep stages, until an apparent stage 1 is reached Cortical inhibition However, tbs is different from the ongmal stage 1 The sleeper is very difficult to arouse, shows bursts of heart Jouvet (1969) suggested that slow wave (non-REM sleep) rate acceleration, and rapid breathmg and oxygen uptake resulted from cortical inhibition due to the raphe system increases The male has perule erections, female has He also postulated that serotonin was the neurotransmitter increased vaginal lubncatioa and there is loss of muscle responsible for cortical inhibition He suggested that the tone, although there may be body jeiks Rapid eye move- locus coeruleus was responsible for paradoxical (REM) ment occurs under d o ^ d lids and the EEG looks akin to sleep and its accompanjnng muscle atoma However, there wakmg patterns has been further research that questions the simphaty of Tbs stage 1 is often known as rapid eye movement Jouvet's(I969)woric(Hobsoneffl/ 1975,Lidovrffl/ 1980) (REM) or paradoxical sleep The sleeper is variably responAccordmg to Fordham (1988), 'simple explanations or sive to external stimuli, he may aw^e spontaneously, or smgle controls of sleep do not fit wittt the evidence may be very difficult to waken If awakened at this stage, Current researchfindingssuggest that the control of sleep the sleeper is more likely to recall dreams than if awakened is not confined to one localized part of the bram' 1S04
Nature and function of deep
The conclusion that we can make is that sleep is an extremely complex physiological phenomenon which results from the interaction of many different neurochemical systems withm the brain
1 2 3 4
FUNCTIONS OF SLEEP 5 Many functions of sleep have been proposed including describing sleep as restorative, protective, mstmctive or ethnologically adaptive Others beheve sleep functions to 'conserve energy or to periodically readjust biological systems' (Chuman 1983)
Humoral theory The humoral theory of sleep proposes that dunng the waking state there is a build up of a chemical toxin which induces tiredness and sleep During sleep this 'hypnotoxin' IS flushed away from the body at which point we wake However, accordmg to Canavan (1986), as a theory there is msufftcient evidence to support it For mstance, it seems that Siamese twins shanng the same blood supply sleep at different tunes and have varying sleep patterns However, physiologists and biochemists have identified vanous endogenous sleep-promoting substances, e g pjeptides, prostaglandms, melatomn and other hormones found in the fluids and tissues of animals and humans 'A progressive build up of these substances and a resultant relaxation process may account for tiredness and the need for sleep' (Turpin 1986)
Restihihon theory The body restitution theory of sleep has promoted much research The physiologist Shermgton (1906) considered sleep to be 'a state of enhanced tissue growth and repair, following the wear and tear of wakefulness' Our tissues are continuously bemg renewed and are continuously decaying According to Oswald (1987), 'decay, degradation, breakdown or catabohsm is maximal durmg wakefulness, while renewal or anabohsm is maximal durmg sleep' The shift in balance towards greater renewal durmg sleep has been demonstrated in a large number of animal tissues However, is this shift part of the &xed arcadian rhythm, or does it depend on sleep? Accordmg to Fordham (1988), arguments for and against the restitution theory rest on the mterpretation of
Fmdmgs of a peak in human growth hormone in slow wave sleep (Takahashi 1979) No sleep-related msulm release (Jefferson 1980) Cellular energy charge levels (Adam 1980) Mitosis f>eaks durmg usual sleep penods, but which are found even in the absence of sleep (Schevmg 1959, Parker e^fl/ 1980) Efifects of sleep depnvahon (Home 1978, Martm 1981)
Some believe that during sleep optimum conditions for protein synthesis are created by a combination of the presence of high energy levels (adenosme tnphosphate stores) within resting cells, the tnggermg of anabohc human growth hormone release, and the occurrence of the arcadian low point of the level of the catabolic hormones, corticosteroids and adrenalme at night (Oswald 1980b) Adrenaline released durmg wakefulness is thought to prevent the cell division for healmg to occur Dunng non-REM sleep, particularly dunng the first 3 hours of sleep, growth hormone is secreted from the antenor pituitary in an episodic or pulsatile manner (Gnbbin 1990) Growth hormone enhances ammo tiad transport into cells, it also promotes protem and nbonucleic aad (RNA) synthesis (Komer 1965) It raises bloodfree fatty aads whose subsequent degradation is a source of cellular energy (adenosme tnphosphate), thereby savmg ammo acids from catabohsm and increases their availabihty for protem synthesis dunng sleep (Adam & Oswald 1977) However, it has been argued that protein synthesis is stimulated by ammo acid absorption from the mteshne, somethmg that would be minimal durmg the normally fasting state of sleep (Dorociak 1990) It has also been argued that stimulation of cells to grow, which mvolves protein synthesis, requires a good supply of msulm to be present and there is no surge of msulm m the early hours of sleep (Gnbbm 1990) Home (1983) indicates that the functions of growth hormone are not fully understood m wakmg adults, let alone in the sleep state In contrast to Adam & Oswald (1977), he states that m sleep 'the release is unrelated to blood levels of glucose, ammo acids and fatty acids present m normal amounts at the time It therefore seems not to be under the usual metabohc control, but under the control of obscure neuronal mechanisms' (Home 1983) His conclusion IS that it IS more hkely to be an action to spare protem from bemg broken down so readily for use as a reserve energy source In the view of Waterlow et al (ated by Home 1983), 'because of man's mght time fast, often lasting 12 hours from everung meal to breakfast, protem synthesis during 1505
LA Hodgson
sleep IS low' Recent research by these authors demonstrated that dunng sleep, because of the fast, protein breakdown exceeded synthesis, leading to an overall condition of tissue degradation These findmgs, however, related to the body as a whole, and the authors pointed out that certain tissues, the brain for example, have shown opposite trends dunng sleep, with other tissues displaying even greater protein losses The course of brain protein turnover dunng sleep is not however known' (Home 1983) Some human tissues, e g epidermis, have a daily peak in division which appears withm usual sleep penods, and seems to support the restitutional hypothesis of sleep However, this also occurs dunng sleep depnvation, 'therefore it IS not caused by sleep but a hme of day comadent with sleep' (Home 1983) Accordmg to Doroaak (1990), 'what is conceded, though, IS that if the body must be at rest for protem synthesis to go ahead and, smce the bram cannot relax dunng wakefulness, sleep, in particular short wave sleep, is necessary to allow its repair processes to occur' Learning and memory The view that sleep and dreantmg are somehow related to learning and memory is not new The 19th century neurologist Hughlmgs Jackson (ated by Canavan 1986) profjosed two related functions for sleep The first is to sweep away unnecessary memones from the day and the second, to consolidate the most important expenences As protem synthesis is believed to occur dunng REM sleep and smce memory is thought to involve the deposition of proteins withm nerve cells, 'REM sleep is linked with memory storage, memory consohdation and learning' (Fishbem & Gutwem 1981, Squire & Davis 1981) SLEEP DEPRIVATION
2 3 4 5
slight changes m cardiovascular and respiratory function, slight hormonal changes which may be related to stress, changes in control of eye movements, and musculature mvolved with accommodation and convergence, enhancement of epileptic-like EEG activity m some people
Psychological effects Emotionally, mdividuals have been found to become mcreasmgly aggressive, lmtable and anhsoaal (Hartmann 1973, Gemer et al 1979, Mclntosh 1989) This depression of mood IS seen after relatively bnef penods, l e 24-28 hours However, even the longest documented studies of 8—11 nights of total sleep loss did not report senous neurological or psychiatnc impairment, and Dement et al (1967) state that There is no evidence to suggest that emotional changes persist beyond the duration of the depnvation expenment' Behavioural changes have been observed m tests which require speed and prolonged concentrated attention or vigilance, rather than physical efiFort It is difficult to maintam focused attention or to shift attention when required, but it is the undemanding, tedious, uninteresting and simple task that is thefirstto become impaired Demandmg, mterestmg tasks that encourage motivation are not sigruficantly impaired, although after 2-3 days of depnvation, ability does decline TTie effects of sleep depnvation on mental functiorung provide part of the argument in favour of sleep as essential for bram restitution
Recovery sleep
Following prolonged sleep depnvation, it has been found consistently that there is a failure to make up all the lost sleep, when given the opportunity to do so According to Bermot ei al (1980), 'most of the lost stage 4 is recouped, only arouruJ one third of REM, some of stage 3, and almost none of stages I and 2' This appears to support the suggestion by Home (1983) that sleep serves both a restorative, le body and/or bram reshtuhon, and a non-restorahve function of occupying ui^roductive hours, providmg safety and conservmg energy Physiological effects A fiirther mdication that not all human sleep is essential The physiological effects of sleep depnvation, as discussed IS researdi mvolvu^ volunteers successfully acquirmg the by Home (1983) and Canavan (1986) are habit of takmg 1-2 hours less sleep per day for at least 8—12 1 fall m body tonperature and less eSiaent temperahire months without any consequence, such as day-hnw sleepiness (Home 1983) Home (1983) has observed that 'it is regulation.
Most of the evidence for vanous functional theones of sleep has been obtained as a result of exammmg what effect lack of sleep (sleep depnvation) has on performance and moods and noting any sigruficant electncal changes It has been found that the overwhelmmg tiredness that occurs is more stnkmg than the biochemical, emotional or behavioural changes that take place
1S06
Nature and function of skep
interrupted or dishxrbed sleep which is the major cause of day-tune sleepiness, not simply less sleep' Therefore, 5-6 hours of unmtemipted sleep is better than 8 hours of disturbed sleep It IS commonly assumed that sleep loss heightens susceptibility to infection, although two investigations have demonstrated that 71 hours of sleep depnvation produced small changes m the immune system The researchers would not interpret these changes as being senous, simply changes of unknown consequence (Home 1983) The body restitution theory is m doubt when the 'ml' hndings of physiological efifects of total sleep depnvation are considered Rapid eye movement sleep depnvation The type of sleep lost seems to have some relevance Dunng REM sleep depnvation, the subject was awakened at the onset of each penod of REM activity, but allowed sleep dunng non-REM sleep penods Such depnvation appears to affect mood and basic dnves There are reports of hyperachvity, emotional instability, agitation, mood disruption and decreased impulse control (Naitoh et al 1971) However, studies of depnvmg people of REM sleep do not produce any mental disorder m normal subjects, and under certain circumstances, particularly for endogenous depression, depnvation of REM sleep seems benefeaal (Home 1983) Gnbbm (1990) suggests that it may be that REM sleep is what we need sleep for and that non-REM sleep IS far less important for our well-being The psychological importance of dreams, which are frequently assoaated with this phase of sleep, has been demonstrated in dream curtailment expenments (Dement 1960, Sampson 1966) Expenments suggest that our brams require a mirumum 'ration' of fantasy dreams each day, whether all whilst asleep or both awake and asleep 'It seems that REM sleep at least serves a function in keeping us sane, although it is not clear exactly how dreams serve that purpose' (Gnbbin 1990) Is dreaming 'an automatic process that occurs while the flood of information from the previous day's expenences is being collated, sorted and filed away' (Gnbbin 1990)? REM sleep is only onequarter of the total m adults, and it may be that as long as one's quota of REM sleep is achieved, then this may explain why some people need less sleep than others Non-REM sleep deprivation Non-REM depnvahon is unpossible to achieve without also depnvmg REM sleep (Hartmann 1973) However, up
to 1(K) hours of such depnvation have failed to produce dear behavioural results, although subjects reported feeling lethargic and depressed There is concern about vague physical symptoms, m contrast to the more agitated and lmtable response often seen after REM depnvation The reason why we have so much non-REM sleep is not certam, but researchers argue that such sleep may have evolved as 'a handy way to keep our bodies out of mischief in between meals' (Gnbbm 1990) There remain several body systems where the effects of sleep depnvahon are relahvely unexplored, so the picture IS far from complete, but, as far as is known, no organ apart from the brain enters a physiological state which is clearly unique to sleep Dunng wakefulness, the EEG mdicates that even when we are relaxed the brain is in a state of quiet readmess, prepared to act on any sensory stimulus Hence, it appears that sleep may be the only state of rest for the brain It is the brain that controls sleep, and it is the bram functions such as span of attention that are most obviously unpaired by sleep depnvation At the present tune, if sleep does uideed serve a physiological or psychological purpose then, theoretically, a loss of sleep should result m alterations of function However, as Webster & Thompson (1986) have stated, 'widespread research has failed to reveal a dear cause and effect relationship between sleep depnvahon and speafic bodily function' It IS important to note, however, that much of the theorehcal basis of sleep research has been obtamed firom evidence from healthy volunteers, m falsely modified laboratory condihons RELATING THEORY TO PRACTICE Stress Many patients with advanced cancer and other chroruc illnesses, as well as their families/carers, may already be anxious, imtable, suspiaous or depressed This nay be the result of sleep depnvatioa or some other psychological problem, e g fear and worry over the illness and its outcome, the treatments involved, or an inability to plan for the future Expenence suggests that some pahents are afraid to sleep m case they die, a fear also expressed by the relahves regarding their loved one A further problem may be very disturbuig rughtmares Are these the unvoiced feju^ and womes tickmg over while the owner is not in control? It seems that pahents are most at nsk of sleep disturbances at hme of diagnosis, when receiving chemotherapy or radiotherapy, when secondary growth is diagnosed, and 1507
LA Hodgson
those with end-stage symptomology, times of heightened anxiety Kleitman (1963) conduded that 'ease of going to sleep was greatly altered when the person was anxious or depressed' Haynes et al (1974) found support for the hypothesis that anxiety is an aetiological factor in insomnia, and Karacan et al (1983) found that sleep disturbance was found to be directly assoaated with vanables, causing or resulting from anxiety and stress StonehiU et al's (1976) findings that 'sadness results in early falling asleep and early awakening, anxiety in difficulty falling asleep and later awakening, and anger m difficulty both m falling asleep and remaining asleep, resulting in repeated awakenings'
vigilance of the situation and somnolence conserving energy' (Fordham 1988)
Physical pathology Many sleep abnormalities are caused by, or are secondary to, physical pathology Conditions which increase lntracranial pressure, or alter central nervous system physiology, are particularly liable to affect sleep adversely Pathologies of the bram stem and hypothalamus and cerebral atrophy may disrupt sleep onset and maintenance Excessive day-time sleeping may also occur with tumours of the pineal, post-hypothalamus, and any which impinge on the third ventncle
Anxiety and depression When assessing the efifects of anxiety and depression on sleep, it seems that, as anxiety and depression increase, so does lack of sleep and, as sleep decreases, anxiety and depression also increase — a viaous arde According to Kleitman (1939), both anxiety and depression also tended to result in increased mobility dunng sleep, a more disruptive sleep and decrease in the overall feeling of being rested upon wakening Patients or their carers who are stressed will release extra corhcosteroids and adrenalin, because of enhanced sympathetic activity This leads to more catabolism, more sleeplessness, and more anxiety As Doroaak (1990) stated, 'high levels of corticosterotds depress the immune system, inhibit protein synthesis and could reduce wound healing' Another hypothesis put forward by Oswald (1987) is that 'the high mortality rate assoaated with the months after bereavement is presumably mediated by, among other things, high catecholamines and cortisol' The bereaved often expenence problems assoaated with sleep, due to fear of intruders, loneliness, and the dreams or nightmares that may occur involving the loved one who had died If Oswald's (1987) hypothesis is supported, then there should surely be an mcrease m proactive intervention for the bereaved 'Fatigue assoaated with the expenditure of nervous energy,, e g sustained emotion, and anxiety, seems to necessitate sleep rather than rest' (Home 1983) This may be because of an increased need for brain restitution following heightened brain metabolism produced by tbs increase in psychological arousal, or merely a withdrawal respond — an escape into sleep A small number of people respond to threat by excessive sleq> ratl:ttr than insomma Qether reaction could be seen as adaptive, 'ueomma rtuuntauung 1508
Pain and other symptoms Many common symptoms are worse at night Patients whose cardiac or respiratory function is compromised by day, are liable to further detenoration dunng sleep, resulting m angina, palpitations, cardiac arrhythmias, nocturnal dyspnoea, etc According to Glyn et al (1976), 'chronic pain may have a arcadian rhythm of increasing intensity at night' From observation, many patients with cancer do indeed complain of more pain at night However, this may well be due to the fear and anxiety expenenced m the quiet of night, when less distraction demands more thought and reflection on one's plight Patients will not sleep if they are m pain Marks & Sacher (1973), m a study of medical patients, found that sleep was the function most commonly affected by pam Over threequarters of the patients reported significant difificulty in sleepmg Expenence suggests that some patients are not prescnbed analgesia dunng the night, although it is suggested that the increasing use of controlled-release morphine has much improved pain control throughout the 24-hour penod The drug control of other symptoms assoaated with advanced disease may result m latrogenic causes of sleep disturbances, eg steroids, antimetabolites and other cancer chemotherapeuhc agents, anticonvulsants, bronchodilators and central adrenergic blockers
Nutrition It IS also important to consider the rebhonship l»tween nutntion and sleep Many pahatts with advanced cancer are anorexic have lost weight aid may be cachectic. Many studies including those on tr^ted anorexics support the
Nature and function of sleep
conclusions of Cnsp & Stonehill (1973), that weight loss is associated with reduction m total sleep, compounded by more broken sleep and earlier awakening, weight gam is associated with an increase m total sleep compounded by less broken sleep and later wakening It IS suggested that much can be done for the nutntional needs of patients, that will both relieve and prevent further symptoms, and may well improve their ability to have a good night's sleep It may be that for these patients sleep as opposed to rest may be the only way for the body to maximize its resources
Care of the carers When considenng the carers of patients with advanced disease at home, it is important to consider the possible long-term effects of continued sleep disruption £ind depnvation It may well increase anxiety, lessen motivation and consequently the ability to cope The carers may be suffenng as much if not more than the patient, from desynchronization of their arcadian rhythms This will mevitably result m anxiety, depression, lmtability, and decreased accuracy in task performance as previously outlined The sleep-depnved carer may often be looking after the well-rested patient and respite in-patient care will be needed
INDIVIDUALIZED CARE PLAN In order to plan mdividualized patient and family care, it is suggested that the following aspects need to be considered in assessment 1 2 3 4 5 6 7 8 9 10 11
age the normal pattem of sleep dunng health current pattem of sleep nutntional status emotional status, e g anxiety, depression day-time and night-time symptoms, e g pam, dyspnoea sleeping environment sleep-related ntuals, e g bed-time dnnks, reading, television presence of dreams or nightmares present medication wake-time behaviour, e g naps, mental efifiaency
Assessment is, of course, subjective, as much depends on the individual's defirution of quality of sleep However, much can be leamed from both patient and carer and, by setting realistic goals with them, it is possible to plan
nursing interventions that may avoid the use of hypnotics and tranquillizers
CONCLUSION As yet, reseiirchers do not seem to have been able to prove conclusively any essential function of sleep which cannot be fulfilled dunng the wakmg state As Fordham (1988) has stated, 'if sleep is essential for survival or health we need to take sleep problems very senously, but if sleep is an urmecessary tune filling behaviour or luxury, we could be justified in considenng many sleep problems as tnvial' A long-time researcher Jack Empson (1989) sums it up 'it must be admitted straight away that the function of sleep remains a mystery, and its evolution remains a matter for conjecture' However, patients and their carers should not need to endure the added stress that sleep disruption and depnvation bnng They should be encouraged to take extra rest and to have the amount of sleep that leaves them feelmg refreshed and able to cope dunng the wakmg hours The nurse, m my view, is m a unique position to faahtate and enable this goal to be achieved
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