CHAPTER 25 Promoting sleep

Introduction

Sleep is a fundamental element of life. We know that everybody needs sleep and yet people find it difficult to describe exactly what sleep is. We are all intrigued, for instance, by what happens when we fall asleep, why we dream and why our sleep patterns alter. However, despite centuries of observing sleep, extensive and systematic research, and the creation of both physiological and behavioural theories to explain sleep, the mechanisms and functions of sleep still elude us. The aim of this chapter is to enable nurses to understand more about sleep by considering what is meant by sleep, to identify factors that impact on the ability to sleep and to think about the ways in which they can assess a patient’s sleeping patterns. Reading this chapter should help nurses feel more confident in providing nursing care that helps patients to overcome some of the problems associated with sleeplessness.

Before reading on, reflect on the two scenarios detailed in Box 25.1. In the first, you are lying awake at home at 3 a.m. and in the second, you are awake in hospital. These two scenarios emphasise the importance that we attach to sleep. They also show how, in different situations, sleep means different things to different individuals, is affected by different environmental circumstances and the way we feel, and our ability to control how we help ourselves to sleep (Box 25.1).

Box 25.1 Reflection

Thinking about sleep

Scenario one

Imagine you are at home. You went to bed as usual at 11 p.m. but it is now 3 a.m. and you are still awake. There is nothing stopping you sleeping except the gentle workings of your mind: you are warm and comfortable, there is no noise to disturb you and you don’t have anything to worry about…yet you still can’t sleep. You know you need to, because you have to get up in the morning and go to work, be level headed and awake…you toss and turn with frustration then decide to get up and make a drink. You return to bed to sip it and slowly, very slowly, feel the drowsy sleepiness that you’ve been hoping for wash over you.

Scenario two

Imagine that you are awake during the night in hospital. You are too warm and your bed is unfamiliar. You can hear the constant breathing of other patients, the nurses as they walk past the bay and the intermittent ring of the telephone at the nurses’ station, all of which keep interrupting the attempts to sleep. You are anxious about the results of the tests that have been taken and are due tomorrow. It seems as if everything is stacked against your sleeping: there is nothing that will help you to sleep without disturbing someone else or ringing for a sleeping pill and it is almost too late in the night to do that. You stare into the darkness willing sleep to overtake you, but it does not.

Activities

• Reflect on how the two scenarios are different.

• Consider whether being at home and able to make decisions such as putting on the light to read or making a drink would alter how you would feel about not sleeping. Consider how the hospital environment, your dependence on the nurses (for example for a hot drink), different anxieties and not wishing to disturb others would influence how you feel about not sleeping.

• If you have had sleepless nights, or had difficulty getting off to sleep, in what ways have you tried to deal with your sleeplessness? Try listing these, and then think how successful or otherwise your strategies were.

• Consider how patients you have nursed might deal with sleeplessness, and the various factors that might influence their ability to sleep – even the simple options you listed for yourself might be difficult for them to achieve.

• Access the paper by Cmiel et al (2004). Reflect on their innovative approach to sleep promotion in hospital and discuss it with your mentor or lecturer.

What is sleep?

We spend so much of our lives asleep that one would expect it should be easy to define sleep but, paradoxically, once we are asleep, we remember little about it. One online dictionary definition (www.answers.com/topic/sleep) suggests that sleep can be defined as:

A natural periodic state of rest for the mind and body, in which the eyes usually close and consciousness is completely or partially lost, so that there is a decrease in bodily movement and responsiveness to external stimuli. During sleep the brain in humans and other mammals undergoes a characteristic cycle of brain-wave activity that includes intervals of dreaming.

This definition seems to reflect what many of us remember from our own experiences of going to or waking from sleep and also our observations of others as they sleep. For the most part, modern scientific researchers have tended to use objective criteria to describe sleep, usually in terms of physiological events occurring during specific stages of sleep. These include changes in the electrical activity of the brain and fluctuations in the secretion of various hormones.

However, it is important to bear in mind that it is the individual’s subjective experience of sleep that is of greatest importance in an assessment of the quality of sleep. Even when an electroencephalograph (EEG) indicates that sleep has been long and continuous, if the individual complains of sleeping badly, this cannot be contradicted. Conversely, if an individual habitually sleeps for only 2 hours during the night, but feels that this amount is adequate, leaving them rested and refreshed, then there is nothing wrong with their sleep. The most important element of any nursing assessment of sleep is therefore to find out and to respect the patient’s experiences and interpretations of their own sleep/waking patterns.

In order to help us to understand patients’ sleep difficulties and the implications of these in planning care, some basic knowledge about the structure and function of sleep is useful. A summary of the two distinct types of sleep – non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep – and their function is briefly given below.

Non-rapid eye movement (NREM) sleep

NREM sleep comprises four stages associated with differing electrical activity of the brain.

• Stage 0 or wakefulness – a person is awake with their eyes closed.

• Stage 1 or drowsing – this is the lightest stage of sleep during which the pupils constrict and dilate at intervals of approximately 1–3 seconds. If asked, people may report feeling drowsy, but be awake. Even though the subject may feel fully alert, it is likely that observers will note reduced attentiveness.

• Stage 2 or light sleep – this phase of altered consciousness is such that, if awakened, most people recognise that they have been asleep. Body movements begin to diminish and dreams involving a storyline first appear. Dream recall on waking is far less vivid than for the second type of sleep, REM sleep.

• Stage 3 or slow wave sleep – body movements continue to diminish.

• Stage 4 or slow wave sleep – is associated with a high degree of immobility, and intense external stimuli are required to rouse a person in this stage of sleep.

Note: Stages 3 and 4 are often considered together and termed slow wave sleep (SWS).

Rapid eye movement (REM) sleep

REM sleep is characterised by dreaming, muscular relaxation and high levels of physiological arousal. During REM sleep, muscle tone is lower than in any other sleep stage. Blood pressure fluctuates, pulse and respiration rates increase and may become irregular, oxygen consumption increases, premature ventricular contractions may occur and there is penile tumescence in men and increased vaginal secretion in women.

The eye movement which occurs in REM sleep usually consists of rapid darting movements of the eyes under closed lids, occurring in bursts of 3–10 seconds at intervals of about 30–40 seconds. If people are woken up, they often say that they have been dreaming; consequently, REM sleep is frequently referred to as dreaming sleep.

During a night’s sleep both REM sleep and all four NREM stages may occur many times, usually in a cyclical fashion (Figure 25.1). The first part of the night tends to contain more SWS, while the latter part of the night contains a higher proportion of REM. Interestingly, even during the day people have cycles of alertness and drowsiness although they are usually unaware of these.

Figure 25.1 Sleep pattern. The electrical activity of the brain during various stages of sleep can be shown on electroencephalograms. During the night, people go through 3–5 90-minute sleep cycles. Each cycle includes a sequence of sleep stages. REM, rapid eye movement.

(From Solomon EP, Schmidt RR, Adranga RJ 1990 Human anatomy and physiology, 2nd edn. Philadelphia: Saunders College, with permission.)

Precisely how and why people sleep remains the subject of much research (see Further reading, e.g. Pocock & Richards 2006 and Widmaier et al 2007).

Normal sleep

No matter what objective recordings of sleep might indicate about its duration, continuity or ‘architecture’, if the sleeper is satisfied with their sleep, then it may be considered to be normal. A good, restful night’s sleep and a good day’s refreshed and efficient wakefulness are, of course, inter-related. Even though their relationship is not one of simple cause and effect, each depends on the quality of the other.

Individual requirements for sleep vary enormously. Russo (2005) highlights the differences in sleep required through the life course. For example, adults tend to need an average of 8 hours sleep each night, whereas older people generally seem to need less than this, with children and young infants needing more. Some people habitually take a nap during the day. Some are early risers, while others are more active in the evening and tend to go to bed late. Hospital routines, for instance early or late medication rounds and/or the taking of regular observations, tend to override these individual variations in behaviour, with a possible outcome of disturbed sleep patterns for some (Jarman et al 2002, Cmiel et al 2004).

Factors affecting normal sleep

There are many factors that may naturally affect and may disturb normal sleep, several of which are described below. These include, for example, age and gender, diet, noise, ambient temperature and pain. Each of these influences should be taken into account in nursing assessments of each patient’s sleep, since the normal habits and needs of one person may vary from those of another.

Age

Changes in sleep patterns associated with age have been well documented, with neonates usually spending around 18 hours asleep in every 24, young adults sleeping for an average of 8 hours each night, and older people sleeping for 6 hours (see Further reading, Johnson 2006).

Problems such as getting to sleep or staying asleep also tend to be more common in older people (Rush & Schofield 1999); however, research reported by Klerman et al (2003) showed that although older people wake up more frequently than younger people, they do fall back to sleep at the same rate as their younger counterparts. These changes have been attributed to age-related loss of neurones and progressive fragmentation of circadian rhythmicity (Hood et al 2004). Older people also have increased amounts of wakefulness after sleep onset. Ersser et al (1999) attributed a high proportion of night-time awakenings among older people to pain and physical discomforts such as bladder distension and urinary urgency. Awareness of such problems should prompt nurses to alleviate discomfort as far as possible, to encourage regular bowel and bladder habits and ensure that optimal fluid intake is achieved by approximately 18.00 h. For those who enjoy tea or coffee, decaffeinated options should be encouraged for later in the day and evening.

Maher (2001) and Closs (2006) discuss ways of assessing and improving disrupted sleep in older people.

For older people and their carers, the knowledge that changes in sleep patterns are commonly experienced and are therefore not necessarily pathological will be reassuring. Although some caution should be exercised, lest treatable problems relating to sleep are overlooked, nurses have an important role to play in educating patients and their carers about the predictable changes that occur in sleep habits with advancing age (Box 25.2). See Further reading, Maher (2004) and Closs (2006).

Gender

Research has shown that there are some interesting differences between men and women in terms of their satisfaction with sleep. Studies report that men have more disturbances in sleep than women from early adulthood onwards (Webb 1982), frequently due to nocturnal penile tumescence occurring during REM sleep, whilst others have highlighted that women, despite sleeping significantly longer than men, also report disturbances due to menstruation, pregnancy and climacteric (Krishnan & Collop 2006). Phillips et al (2007) remind us that women and men are differently affected by sleep disorders and also have their sleep disrupted differently by pain, depression and hormonal or psychological changes associated with major life events. These gender-based differences should be considered when assessing patients’ sleeping patterns and views.

Heredity

Sleep quality and length appear to be influenced by genetic factors. De Castro (2002), in a study of self-reported sleep patterns in identical and fraternal twins, demonstrated significant genetic influences on the time individuals went to sleep and woke up, how often they woke up during the night, the duration of their sleep and wakefulness and their feelings of alertness both upon waking up and during the day. Familial clustering of narcolepsy (when sleep frequently intrudes into wakefulness) and idiopathic insomnia has also been observed. It is therefore worth noting in a nursing assessment whether there is a family history of sleep difficulties. It may not, however, always be possible to remedy inherited sleep problems by means of nursing interventions.

Body weight

Weight gain is associated with an increased duration of sleep, while weight loss is often associated with shorter sleep. This has been confirmed by several studies of people with anorexia, including one suggesting that anorexia and bulimia were both linked to sleep disorders (Della Marca et al 2004). As body weight falls, so does total sleep, which also becomes more broken and is interrupted by earlier waking.

Exercise

The effect of exercise on normal sleep is not straightforward and research studies have produced conflicting evidence: some have shown that exercise increases the duration of SWS, whereas some have found no effect and others a negative effect on sleep. Youngstedt et al’s (1997) meta-analysis of 38 studies showed that exercise had different effects on different stages of sleep. The changes were somewhat modest, the greatest being an increase of 10 min on SWS. However, most of this research has focused on good sleepers. A randomised controlled trial of depressed older people showed that exercise had a more profound effect on poor than on good sleepers (Singh et al 1997).

Li et al (2004), also in a randomised controlled trial, studied the effectiveness of tai chi in improving sleep quality in older people who had disturbed sleep. Results demonstrated that older people who took part in the 6 month low to moderate intensity tai chi programme reported significantly improved sleep quality including shorter time to sleep onset and longer sleep duration.

A Cochrane Review of interventions for sleep problems in older age cites one study (Montgomery & Dennis 2005) which found that sleep quality improved after a short (16 week) exercise programme consisting of 30–40 min of walking or low impact aerobics four times a week when compared with no treatment.

It appears that, overall, exercise has a small sleep-promoting effect for many people, provided that it is not taken late in the evening.

Anxiety and depression

Anxiety and depression frequently interfere with sleep. Most people experience these at some time in their lives, associated with, for example, occupational stress, family tension, bereavement, illness or other traumatic events (Lavie 2001). Admission to hospital may be a major cause of anxiety, with all the accompanying worries with regard to illness, investigations or surgery. See Further reading, Carter (2003), Clark et al (2004) and Vena et al (2004).

Depressed patients tend to experience difficulty falling asleep, an increased number of awakenings during the night and early morning waking. Nursing staff should encourage depressed and anxious patients to discuss their feelings and, if possible, assist them to deal with underlying difficulties. Alerting medical staff to the apparent existence of anxiety and depression should ensure that the patient receives appropriate medical or psychological treatment.

See website Critical thinking question 25.1

Physical illness

Cardiac and pulmonary diseases often worsen during the night (Redeker & Hedges 2002, Sutherland et al 2003, Redeker et al 2004). For example, the incidence of asthma attacks increases during the latter half of the night, while angina, cardiac dysrhythmias and nocturnal dyspnoea are all likely to worsen during sleep (see Chs 2 and 3). Metabolic disorders such as Cushing’s disease, Addison’s disease, hyper/hypothyroidism and diabetes mellitus may disrupt normal sleep patterns (see Ch. 5). Diseases that mobilise the immune system, whether viral, bacterial or fungal, may be associated with increased sleepiness (see Ch. 16).

Since many areas of the brain are implicated in sleep regulation, any pathology impinging on these sites can cause problems (see Chs 9, 28 and 29). A rise in intracranial pressure, regardless of cause, increases sleepiness, sometimes leading to altered consciousness and death. Interference with the brain stem or hypothalamus may affect the onset and maintenance of sleep.

Pain

People who live with chronic pain commonly experience sleep problems (see Ch. 19). Some types of chronic pain, such as that from peptic ulceration or gastro-oesophageal reflux disease (GORD), have a circadian rhythm of increasing intensity at night. General practitioners tend to manage such pain by using medication, sometimes by aiming to relieve the cause, but more often providing symptomatic relief by means of analgesics or antacids. Sometimes the use of antidepressants, as adjuvant therapies, is successful in promoting sleep, since some chronic pain syndromes can be associated with depression.

Nurses are closely involved in giving pain-relieving agents in hospital because of their continuous contact with patients. There has long been an association between pain and sleep loss. Pain has been shown to be a major cause of sleep loss in intensive care units (Jones et al 1979) and the postoperative period (Box 25.3) (Closs 1992, Closs & Briggs 1997). Postoperative patients have strong views about sleep and pain (Closs 1991; Box 25.4).

Box 25.3 Evidence-based practice

A study of patients’ and nurses’ assessments of sleep in hospital

In a study by Southwell & Wistow (1995), 454 hospital patients completed questionnaires about their sleep. This included patients on medical, surgical, care of older people and acute psychiatric wards. Questionnaires were also distributed to 129 nurses working on those wards. Patients and nurses then answered questions concerning the same nights in hospital.

Half of the patients reported that they could not sleep through the night and were consequently sleep deprived. The main factors which patients reported as disturbing their sleep were discomfort (including beds and pillows and particularly the use of plastic covers on these), pain, noise, being too warm and worries. Half were dissatisfied with both settling and waking times.

There were differences in emphasis between patients’ and nurses’ views of environmental factors disruptive to sleep. More patients than nurses reported noise outwith the ward, emergencies, patients making a noise, nurses’ shoes and nurses talking to one another. More nurses than patients reported treatments, commodes/bedpans, toilets flushing and nurses talking with patients. Nurses were more aware of noise generated by their own work and were largely unaware of the noise they caused by chatting to each other and from their shoes.

In view of the mismatch between nurses’ and patients’ perceptions, the authors emphasised the need to elicit patients’ perspectives on care. However, the two groups were in agreement that patients did not get as much sleep as they needed. It was recommended that nurses, managers and others should take action to ensure that patients’ sleep should be disrupted as little as possible. Nurses need to be aware when patients are awake, and take steps to ease pain, discomfort and worries. It is also important to minimise the wide range of possible disturbances during the night.