n_insomnia
insomnia
Introduction:
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consequences of acute sleep deprivation include:
impaired passive vigilance
impaired reaction time
impaired hand-eye coordination - ever tried playing a musical instrument or even golf after little sleep?
impaired clerical accuracy
impaired memory
impaired reasoning
increased sleepiness and micro-sleep events (eg. when driving a car)
increased risk of car accident and other accidents
consequences of slow wave (delta wave) sleep deprivation include:
consequences of REM sleep deprivation include:
moodiness and risk of both depression and hypomanic states
hypersensitivity to stimuli (and perhaps lowering of the migrain threshold)
inability to consolidate complex learning
consequences of long term sleep deprivation include:
sleep debt:
sleep latency can be measured
very poor correlation between self-reported sleepiness and objective measures of
fatigue
alcohol intake causes sleep fragmentation and decreased REM sleep - hence one feels tired the next day
most sedative-hypnotics disrupt sleep architecture and are associated with impaired quality of sleep
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250mg improves psychomotor performance if sleep deprived but 500mg gives no further improvement but adds side effects
brewed coffee has ~135mg, while tea has 35-50mg.
benefit subject to tachyphylaxis
constant high doses may cause withdrawal headaches
adversely effects sleep latency and sleep quality
micro-awakenings decrease time in slow wave sleep and decrease time in REM sleep
a regular siesta may reduce coronary mortality by 37%
1)
the only way to reverse the need for sleep is to sleep
insomnia or difficulty in getting to sleep is a symptom and thus a cause should be sought
Aetiology:
psychiatric factors:
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depression - tends to cause sleep which is interrupted by frequent awakenings
environmental factors:
bedroom too hot, too cold, too noisy (eg. crying baby, restless child, partner with snoring)
bed cramped or uncomfortable
physical factors:
disturbed sleep cycles:
Clinical approach:
behavioural Rx of insomnia:
see sleep hygiene to ensure lifestyle maximises probability of quality sleep
consider anxiety management & relaxation techniques if pts worried & anxious they will not be able to get to sleep
consider cognitive behavioural therapy techniques
address learned association between going to bed and being unable to sleep
go to bed only when tired, and only use bed for sex or sleep
get out of bed if not asleep within a perceived 20 minutes - but DO NOT watch the clock
repeat each night until a stable sleep-wake schedule is established
restrict sleep time in bed to actual sleep duration (but at least 5 hours sleep) and have a set wake up time
drug Rx of insomnia:
ceasing hypnotic medications
prolonged Rx with hypnotic medications for > 4 weeks increases risk of dependence
this is particularly a problem with the elderly who are most at risk of adverse effects such as increased falls
rebound insomnia may occur even with short term hypnotic use of less than 2 weeks and thus gradual dose reduction may be needed
step 1 - raise awareness of the need to stop
step 2 - STOP guide to reducing hypnotic Rx
Share views and agree on a stopping plan
discuss goals for stopping or reducing use
agree on rate and duration of cessation
outline the type, nature and expected duration of withdrawal symptoms
advise on strategies to Mx withdrawal symptoms
Taper dosage gradually
modify dose and/or frequency based on severity of withdrawal symptoms
all time to stabilise between dosage reductions - at least a few days
consider referral to a specialist if dose reduction proves too difficult
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reduce dose by 10-20% per week if it is within or slightly above the recommended dose
stabilise on an equivalent dose of diazepam (unless elderly) for a few days before dose reduction if patient was on a higher than recommended dose or finding it difficuklt to wean a short-acting agent.
if multiple benzodiazepines are used, the dose of each drug may be reduced one after the other
Ongoing review
weekly monitor effect of cessation on sleep patterns, mood, withdrawal symptoms and use of other substances (eg. alcohol, caffeine)
encourage use of non-drug therapies
suggest coping strategies
Provide support and reassurance
engage family, carers, staff in residential facilities
if unsuccessful, reassure that further attempts are worthwhile
repeat STOP steps when patient willing to try again
n_insomnia.txt · Last modified: 2013/08/24 01:20 by gary1