Sleep

 

Introduction

`A regular recurrent easily reversible state of the organism characterised by relative quiescence and by a great increase in the threshold of response to external stimuli`, (Hartmann 1973)

 

List ways in which sleep differs from unconsciousness

 

 

 

 

 

 

 

List factors which may inhibit sleep

Environment

Noise

Cold or heat

Discomfort

Pain

 

 

Physiology

 

Co-ordination between the CNS, PNS, CVS, endocrine, respiratory and muscular systems

 

Sleep is produced by reduced RAS (reticular activating system) activity in the brain stem and wakefulness promoted by increased RAS activity

 

Wakefulness seems to be promoted by release of Noradrenaline and sleep promoted by release of serotonin. Other proteins and hormones are also involved.

 

EEG

 

Electroencephalography

 

Two phases REM and NREM

 

 

 

Stage I

Lightest level of sleep

Just dropped "off", relaxed, floating thoughts

Lasts for few minutes

Gradual reduction in vital signs and metabolism

 

Stage 2

Greater relaxation, vague dream experiences, look asleep, but easily waken up.

Lasts for 10-30 minutes

Body functions continue to slow

 

Stage 3

Initial stages of deep sleep

Complete relaxation, pulse rate down, metabolism down and not easily waken up.

Lasts for about 30 minutes  

 

Stage 4

Deepest stage

Very relaxed, difficult to awaken

Sleep walking and enuresis may occur during this stage

 

REM sleep

Occurs 50 - 90 minutes after falling asleep

About 20% of sleeping time

Variations in vital signs

Loss of skeletal muscle tone

Period of light sleep in which dreaming occurs

REM backwards and forward, babies have more REMs but are decreased with age.

If awaken suddenly people may report vivid dreams.

REM period is said to promote mental restoration, psychological integration, update memory and integrate emotionally meaningful experience.

 

 

List factors which may give rise to variation in the amount of sleep required

 

Age

Individual variation

Quality of sleep enjoyed

Alcohol or drug consumption

Mood

Anxiety

Boredom

Sex - women sleep more than men

Body weight - weight gain leads to more sleep, weight loss to less

Exercise - promotes sleep if not taken immediately before sleep

 

Functions of sleep

 

Unborn children sleep

Children need more sleep than adults: growth takes place during sleep

Growth hormone reaches peak production in stages 3 and 4

Children have more REM sleep than adults

Adults spend up to 1/3 of their time sleeping.

Increased levels of protein synthesis - repair of tissues

Provides greater degree of rest

Reduced metabolic requirements

Increases levels of ATP

 

 

 

 

 

Effects of sleep deprivation

 

Fall in body temperature and less effective Thermoregulation

Difficulty in focusing

Reduced orientation

Reduced concentration

Impaired judgement

Irritability and restlessness

Impaired healing

Hallucinations

Ultimately death

 

 

Circadian rhythms

 

The 24 hour cycle

Rhythms of temperature, heart rate, blood pressure, urine production, hormonal secretions

Jet lag and shift work may disrupt these rhythms

 

 

List ways in which nurses can promote normal sleep patterns in their patients

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sleep

 

Introduction

`A regular recurrent easily reversible state of the organism characterised by relative quiescence and by a great increase in the threshold of response to external stimuli`

 

List ways in which sleep differs from unconsciousness

 

 

 

 

List factors which may inhibit sleep

 

 

 

 

Physiology

Co-ordination between the CNS, PNS, CVS, endocrine, respiratory and muscular systems

 

Sleep is produced by reduced RAS (reticular activating system) activity in the brain stem and wakefulness promoted by increased RAS activity

 

Wakefulness seems to be promoted by release of Noradrenaline and sleep promoted by release of serotonin. Other proteins and hormones are also involved.

 

EEG

Electroencephalography                             

Two phases REM and NREM

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Stage I

Lightest level of sleep                                   Just dropped "off", relaxed, floating thoughts

Lasts for few minutes                                    Gradual reduction in vital signs and metabolism

 

Stage 2

Greater relaxation, vague dream experiences, look asleep, but easily waken up.

Lasts for 10-30 minutes                               Body functions continue to slow

 

Stage 3

Initial stages of deep sleep              Lasts for about 30 minutes  

Complete relaxation, pulse rate down, metabolism down and not easily waken up.

 

Stage 4

Deepest stage                                              Very relaxed, difficult to awaken

Sleep walking and enuresis may occur during this stage

 

REM sleep

Occurs 50 - 90 minutes after falling asleep

About 20% of sleeping time                        Variations in vital signs

Loss of skeletal muscle tone                       Period of light sleep in which dreaming occurs

REM backwards and forward, babies have more REMs but are decreased with age.

If awaken suddenly people may report vivid dreams.

REM period is said to promote mental restoration, psychological integration, update memory and integrate emotionally meaningful experience.

 

 

List factors which may give rise to variation in the amount of sleep required

 

 

 

 

 

 

 

Functions of sleep

Unborn children sleep

Children need more sleep than adults: growth takes place during sleep

Growth hormone reaches peak production in stages 3 and 4

Children have more REM sleep than adults

Adults spend up to 1/3 of their time sleeping.

Increased levels of protein synthesis - repair of tissues

Provides greater degree of rest                  Reduced metabolic requirements

Increases levels of ATP

 

Effects of sleep deprivation

Fall in body temperature and less effective thermoregulation

Difficulty in focusing                                      Reduced orientation

Reduced concentration                                Impaired judgement

Irritability and restlessness                           Impaired healing

Hallucinations                                                Ultimately death

 

Circadian rhythms

The 24 hour cycle

Rhythms of temperature, heart rate, blood pressure, urine production, hormonal secretions

Jet lag and shift work may disrupt these rhythms

 

List ways in which nurses can promote normal sleep patterns in their patients