Sleep

• Sleep is a basic human need
• Reasons we sleep:

  • Cope with stress
  • Conserve energy
  • Restore mind and body
  • Vital for cognitive, psychosocial & physiological functioning
• Physiology of Sleep:

  • Altered state of consciousness
  • Perception of/reaction to environment decreased
  • Minimal physical activity
  • Changes in physiological processes
  • Decreased responsiveness to external stimuli
• Neurotransmitters affecting sleep-wake cycle:

  • Serotonin
  • GABA
  • Melatonin
  • Cortisol levels
  • Acetylcholine, dopamine, noradrenaline
• Circadian Rhythms:

  • Biological rhythms
  • Normal sleep-wake cycle
  • Awake when body temperature highest
  • Asleep when body temperature lowest
  • Begins to develop by sixth week of life
• Types of Sleep:

  • NREM sleep
  • REM sleep
• NREM sleep:

  • Stage I: very light sleep, lasts a few minutes
  • Stage II: light sleep
  • Stages III and IV: deepest sleep
  • Physiological changes
• Physiological Changes During NREM Sleep:

  • Arterial blood pressure falls
  • Pulse rate decreases
  • Peripheral blood vessels dilate
  • Cardiac output decreases
  • Skeletal muscles relax
  • Basal metabolic rate decreases 10% to 30%
  • Growth hormone levels peak
  • Intracranial pressure decrease
• REM sleep:

  • Every 90 minutes, lasts 5 – 30 minutes
  • Brain highly active
  • Dreaming
• Sleep Cycles:

  • 90 – 110 minutes/cycle in adults
  • Four to six cycles during 7 – 8 hours
  • Sleeper awakened during any stage must start anew at stage I NREM
  • Duration of NREM/REM sleep varies throughout sleep period
  • Deep sleep longer in early part of night
• Functions of Sleep:

  • Physiological effects:
  • Restores normal levels of activity
  • Necessary for protein synthesis
  • Psychological effects:
  • Inadequate sleep leads to irritability, poor concentration, difficulty making decisions
• Normal Sleep Patterns and Requirements:

  • Newborns: 12 – 18 hours/day, irregular schedule, enter REM sleep immediately, sleep cycle is 50 minutes
  • Infants: 14 – 15 hours/day, awaken every 3 – 4 hours, sleep through the night, daytime naps by 6 months, half of time in light sleep, active during light sleep, putting to bed when sleepy but not asleep helps self-soothe
• Normal Sleep Patterns and Requirements, continued:

  • Toddlers: 12 – 14 hours/night with nap(s), nighttime fears, nightmares common, security object can help, consistent bedtime routine, sleep schedule help
  • Preschoolers: 11 – 13 hours/night, need fluctuates in relation to activity, growth spurts, restless, irritable if not enough sleep, maintain consistent sleep schedule, may fear dark or have night terrors, nightmares
• Normal Sleep Patterns and Requirements, continued:

  • School age: 10 – 11 hours/night, most get less, demands of homework, sports, social activities, spend more time at computer, TV, caffeinated beverages, consistent sleep schedule, routine help
  • Adolescents: 9 – 10 hours/night, most get less, later sleep-wake patterns conflict with daily schedule
• Normal Sleep Patterns and Requirements, continued:

  • Adults: 7 – 8 hours/night, individual variation, signs of not enough sleep include falling asleep or getting drowsy during nonfatiguing task, inability to concentrate or remember information, unreasonable irritability
• Lifestyle:

  • Irregular morning or nighttime schedule
  • Exercise:
  • Moderate in morning or early evening leads to good sleep
  • Late in the day can delay sleep
  • Emotional stress
  • Stimulants, alcohol
• Diet:

  • Weight gain reduces total sleep time
  • Weight loss increases total sleep time
• Motivation:

  • Can increase alertness in some situations
  • Won't overcome sleepiness
• Smoking:

  • Difficulty falling asleep
  • Easily aroused
• Medications:

  • Hypnotics interfere with deep sleep, suppress deep REM sleep
  • Beta-blockers cause insomnia, nightmares
  • Narcotics suppress REM sleep, cause frequent awakenings, drowsiness
  • Antidepressants suppress REM sleep, therapeutic
  • REM rebound, intense dreams when hypnotics and antidepressants are discontinued
• Insomnia:

  • Inability to fall asleep or remain asleep
  • Main risk factors are older age and female gender
  • Treatment: stimulus control, cognitive therapy, sleep restriction
• Excessive Daytime Sleepiness:

  • Hypersomnia: affected individual obtains sufficient sleep at night but still cannot stay awake during the day
  • Narcolepsy: disorder of excessive daytime sleepiness caused by the lack of the chemical hypocretin in the area of the CNS that regulates sleep
• Cataplexy:

  • Sudden onset of muscle weakness or paralysis in association with strong emotion
  • Symptoms include sleep paralysis, hypnagogic hallucinations, and fragmented nighttime sleep
• Treatment for excessive daytime sleepiness:

  • CNS stimulants such as methylphenidate or amphetamines
  • Antidepressants, both older monamine oxidase inhibitors (MAOIs) and the newer serotonergic antidepressants
  • Modafinil
• Sleep apnea:

  • Characterized by frequent short breathing pauses during sleep
  • Types: obstructive apnea, central apnea, mixed apnea
  • Treatment: enlarged tonsils may be removed, surgical procedures, nasal continuous positive airway pressure (CPAP) device, weight loss
• Insufficient sleep:

  • Parasomnias: behavior that may interfere with sleep and may even occur during sleep
  • Types include non-rapid eye movement, rapid eye movement, and miscellaneous with no specific stage of sleep
• Sedative-hypnotic medications produce a general CNS depression and alter REM or NREM sleep

  • Can cause daytime drowsiness and a morning hangover effect
• Antianxiety medications decrease levels of arousal by facilitating the action of neurons in the CNS that suppress responsiveness to stimulation
• Sleep medications:

  • Vary in onset and duration of action
  • Impair waking function as long as they are chemically active
  • Affect REM sleep more than NREM sleep
  • Initial doses should be low and increases added gradually based on client's response
  • Regular use can lead to tolerance and rebound insomnia
  • Abrupt cessation of barbiturate sedative-hypnotics can lead to withdrawal symptoms such as restlessness, tremors, weakness, insomnia, increased heart rate, seizures, convulsions, and death