Chapter 35: Rest and Sleep

1. Physiology of Sleep

Stages of Sleep

• Sleep alternates between NREM and REM, each serving unique functions.

NREM Sleep (75-80% of Sleep):

• Stage I (Light Sleep):

  • Transition between wakefulness and sleep.

  • Muscle activity slows, and people may experience hypnic jerks (sudden muscle contractions).

  • Lasts about 5–10 minutes.

• Stage II:

  • Represents about 50% of total sleep.

  • Body systems slow further; eye movements cease.

  • Sleep spindles (short bursts of brain activity) occur, aiding memory consolidation.

• Stage III & IV (Deep Sleep):

  • Also called slow-wave sleep due to delta waves on an EEG.

  • Crucial for restorative processes like tissue repair, muscle growth, and immune strengthening.

REM Sleep (20-25% of Sleep):

• Brain becomes highly active; vivid dreams often occur.

• Vital for emotional regulation and memory processing.

• Heart rate, breathing, and blood pressure increase but muscles remain paralyzed (atonia) to prevent acting out dreams.

Sleep Cycle

• Each cycle consists of four NREM stages followed by REM.

• The first cycle has more deep sleep (Stage III/IV), while later cycles have more REM.

Sleep Regulation

• The reticular activating system (RAS) in the brainstem and the bulbar synchronizing region work together to regulate wakefulness and sleep onset.

• Circadian Rhythms:

  • Biological clock regulated by the hypothalamus.

  • Influences sleep-wake cycles, appetite, and hormone release (e.g., cortisol and melatonin).

2. Functions of Sleep

Physical Health

• Promotes repair and growth of cells, tissues, and muscles.

• Strengthens immune function to fight infections.

Cognitive Function

• Sleep enhances memory consolidation by organizing and storing new information.

• REM sleep specifically supports creative thinking and problem-solving.

Emotional Regulation

• Adequate sleep reduces stress hormones like cortisol and stabilizes mood.

• Lack of sleep increases irritability, anxiety, and depression.

3. Factors Affecting Sleep

Lifestyle and Habits

• Irregular bedtimes, late-night screen use, or frequent naps disrupt sleep rhythms.

• Poor sleep hygiene (e.g., eating heavy meals before bed) impairs quality.

Environmental Factors

• Noise: Sudden loud sounds (e.g., snoring, traffic) interrupt sleep.

• Light: Exposure to blue light from screens delays melatonin production.

• Temperature: Extremes can make sleeping uncomfortable.

Medical Conditions

• Chronic Pain: Conditions like arthritis or fibromyalgia make it hard to relax.

• Respiratory Issues: Sleep apnea or asthma disrupts breathing during sleep.

• GERD: Lying down may worsen acid reflux, causing discomfort.

Medications

• Stimulants (e.g., amphetamines, caffeine): Interfere with sleep onset.

• Diuretics: Can cause frequent urination, disrupting sleep.

• Sedatives: Help with sleep but may reduce restorative REM sleep if misused.

Age Variations

• Infants: Sleep is polyphasic, with frequent naps during the day.

• Adults: Often require 7–8 hours; reduced deep sleep occurs with aging.

• Older Adults: Experience frequent nighttime awakenings and lighter sleep.

4. Common Sleep Disorders

Insomnia

• Persistent difficulty falling or staying asleep.

• Can be caused by stress, anxiety, or poor sleep hygiene.

• Chronic insomnia leads to fatigue, cognitive impairment, and mood disturbances.

Sleep Apnea

• Temporary cessation of breathing during sleep, leading to fragmented sleep.

• Obstructive Sleep Apnea (OSA): Caused by upper airway collapse.

• Symptoms include loud snoring, daytime drowsiness, and morning headaches.

Narcolepsy

• A neurological disorder causing sudden, uncontrollable sleep episodes.

• May include cataplexy, a loss of muscle control triggered by strong emotions.

Restless Legs Syndrome (RLS)

• Tingling or crawling sensations in the legs, usually at night.

• Movement provides relief but disrupts sleep continuity.

Parasomnias

• Sleepwalking: Occurs during deep sleep; person may perform complex behaviors while unconscious.

• Night Terrors: Sudden arousal from sleep with intense fear, more common in children.

5. Assessment of Sleep

Sleep History

• Ask about:

  • Bedtime and wake-up routine.

  • Sleep quality (how refreshed the patient feels).

  • Use of medications or substances that affect sleep.

  • Symptoms like snoring, nightmares, or leg movements.

Sleep Diary

• Record sleep habits over 1–2 weeks:

  • Bedtime, wake time, interruptions, and naps.

Physical Exam

• Look for signs of sleep deprivation:

  • Dark circles, irritability, reduced alertness.

Diagnostic Tests

• Polysomnography: Measures brain activity, oxygen levels, and body movements during sleep.

• Actigraphy: A wearable device that tracks rest and activity cycles.

6. Nursing Interventions

Sleep Hygiene

• Establish a fixed bedtime and wake time.

• Limit stimulants (e.g., caffeine) and alcohol in the evening.

• Create a calming pre-sleep routine (e.g., reading or warm baths).

Environment Optimization

• Keep the bedroom dark, quiet, and cool.

• Use white noise machines if needed.

• Ensure the bed and pillows are comfortable.

Lifestyle Adjustments

• Encourage regular physical activity, but not close to bedtime.

• Promote relaxation techniques, such as deep breathing or meditation.

Pharmacologic Interventions

• Use hypnotics sparingly for short-term relief.

• Recommend melatonin for circadian rhythm disorders if appropriate.

7. Patient Education

• Stress the importance of consistent routines.

• Teach relaxation strategies to reduce bedtime anxiety.

• Educate on the effects of alcohol, nicotine, and caffeine on sleep quality.

• Highlight the importance of seeing a specialist for persistent sleep issues.

8. Evaluation

• Review the patient’s sleep diary to monitor progress.

• Ask about changes in energy levels, mood, and cognitive performance.

• Adjust interventions if the patient reports persistent difficulties