Beyond Sleep Apnoea Dr Justin Pepperell DA SODIT 2017
disclosures
Introduction Sleep and its disorders Obstructive sleep apnea Other common sleep disorders Critical illness sleep disorders Bonus BIS monitoring videos
What is sleep? Cortical EEG Sleep is characterised by a relative lack of responses by the organism, i.e. a reduced sensitivity to the outside environment e.g., in response to an auditory click the EEG response seen is altered*, and it is progressively harder to wake someone up as they go from shallow stage 1 to deep SWS sleep As such it represents a state of relative brain shutdown *Auditory click elicits a deepening of cortical sleep rather than arousal From Williams et al, Science 1962
Why do we sleep? No one really knows why sleep is necessary. All we really know is that we get sleepy if we don t get enough of it! Suggested theories:- 1) Whole body energy conservation 2) Brain rest a time when the brain can switch off? 3) Perhaps to allow brain maintenance activities e.g. memory consolidation
Sleep versus sedation similarities Overlapping neurophysiologic pathways Muscle hypotonia Temperature dysregulation Disconjugate eye movements (REM) Altered sensorium and mentation Respiratory depression differences Sleep is spontaneous; circadian; an essential biologic function Sleep is completely reversible with external stimuli Sleep decreases release of NA Sleep is cyclic progression of EEG stages; sedation variably alters normal sleep architecture
Sleep wake drive
Free running
Required sleep
Sleep stages Stage 1 4-5% Stage 2 45-55% Stage 3 4-6% Stage 4 12-15% REM 20-25%
Normal hypnogram
Sleep with age
Sleep deprivation
Dolphins sleep
Classification of Sleep Disorders!
Common disorders of Sleep Non-REM - Sleep Walking Night terrors Periodic leg movements Sleep automatism REM - Nightmares REM sleep behaviour disorder Cataphrenia (REM sleep groaning) Narcolepsy Both - Obstructive sleep apnoea, central sleep apnoea Unrelated - Circadian rhythm disorders Drug effects Sleep in other medical disorders (e.g. heart failure, depression)
Why is OSA important? OSA is common (2-4%) of adult males Obesity is increasing (& OSA) CVD common cause of death & increasing OSA may cause much CVD overall Is treatable Sleepiness predicts CVD risk May promote taking a sleep history Priorities for preventative healthcare
Risks of osa 20% AHI >5 2-9% with symptoms Obesity Male Diabetes Hypertension Age Smoking Nasal disease Nocturia
Assessment History / symptoms Age Race Sleepiness Signs of secondary causes Investigations Secondary causes Target organ damage Cardiovascular risk Vascular tone Confirm blood pressure Sleep apnoea severity BERLIN / STOP BANG EPWORTH SLEEPINESS SCALE Name:. Date:. Age:.. Sex: M F We are trying to find out how likely you are to doze off or fall asleep in the following situations, in contrast feeling just tired. This refers to your usual way of life in recent times. Even if you have not done some of this recently, try to work out how they would have affected you. Use the following scale to choose the most appropriate number for each situation: 0 would never doze 1 slight change of dozing 2 moderate chance of dozing 3 high chance of dozing SITUATION Chance of dozing Sitting and reading Watching television Sitting, inactive in a public place As a passenger in a car for an hour without a break Lying down to rest in the afternoon when circumstances permit Sitting and talking to someone Sitting quietly after lunch without alcohol In a car, while stopped for a few minutes in the traffic Listening to the last talk before lunch
TD Bradley Ed, Marcel Dekker 2000
OCT measures of treatment repsonse ODI 60, ESS 5
Sympathetic activation?
PLMS
Periodic limb movements during sleep Thought to be due to increased nerve traffic from the legs causing repeated withdrawal reflex, as if pinching the toe. Can occur in paraplegics indicating it can be a spinal reflex. Every 40 seconds, because level of sleep fluctuates with this periodicity (so call cyclical alternating pattern), occurs at lightest sleep level. May or may not lead to cortical arousals. May or may not lead to daytime sleepiness (usually symptomless, especially in the elderly). Often noticed by partner (may be kicked). Cause unknown, related to many other disorders, genetic component. Can arise after sleep apnoea treated (mechanism unknown).
Narcolepsy Same prevalence as MS excessive daytime sleepiness abnormal REM sleep sleep paralysis unable to move for a few minutes, most often upon falling asleep or waking up Cataplexy equivalent of REM sleep atonia unique to narcolepsy, is a striking, sudden episode of muscle weakness triggered by emotions Reflexes are abolished during the attack hypnagogic hallucinations dream-like auditory or visual hallucinations, while dozing or falling asleep are pathological equivalents of REM sleep.
Sleep patterns in Narcolepsy
Fishing
Narcolepsy Treatment
Sleep in the critically ill Severely fragmented Total sleep time over 24 hours may be normal Sleep may be evenly distributed between day and night Increased time in stage 1 sleep Decreased time in stages 2, 3, 4, and REM Increased arousals and awakenings
Factors that disturb sleep ITU Noise Light Pain or illness and consequent psychosocial stress Patient-care activities, ie vital signs, medication administration, di- agnostic testing Dyssynchrony with mechanical ventilation Medications SEPSIS Increased NREM sleep Decreased REM sleep Increased sleep promoting cytokines TNF, IL-1β Altered EEG: low-voltage, mixed-frequency waves with variable theta and delta ( septic encephalopathy ) Loss of normal circadian melatonin secretion
Improving sleep in the ITU Environmental controls Control noise exposure Earplugs Music therapy Control light exposure (open blinds during the day; decrease light levels at night in the entire intensive care unit) Nonpharmacologic measures Minimize during the patients normal sleep hours Medications adverse effects or withdrawal mechanical ventilation dyssynchro- nous breathing and preexisting sleep disorders
REM behaviour disorder Diagnosis. History very typical. May occur infrequently, PSG or video taping often negative. Prodrome of prominent limb movements and talking (sometimes in response to others talking to them!). Often spontaneously aggressive (compare with night terrors) Strongly correlated with Parkinsons disease and multi-system atrophy Treatment. Clonazepam, two hours before bed, Tricyclic antidepressants (desipramine) or L Dopa may help Prevent harm to patient and others. Sleep alone, locked windows, safety glass, minimal furniture.
Not snoring
Cataphrenia (REM groaning) A loud and prolonged expiratory groan during REM sleep. Each groan can last over a minute, followed by a short inspiration, and the groan repeated. Similar to bruxism. Horrendous noise that is most distressing to the listener but not the perpetrator! Produced by tightly apposing the vocal cords, raising intrathoracic pressure, and forcing air out with noisy consequences Occasionally confused with snoring, leading inappropriate advice
Random Number Generator (BIS)
Neural Net Sleep Analysis - 1eeg p(w) - - 1eeg respiration - p(w) respiration 01-01- 1-1- w 01- p(r) w r 01- p(r) 01-01- s 01- p(s) c 00:00:00 1:00:00 2:00:00 3:00:00 4:00:00 5:00:00 6:00:00 7:00:00 0.95 00:00:00 hours r 00:02:00 00:04:00 01-00:06:00 00:08:00 00:10:00 01s 01- p(s) c 00:00:00 1:00:00 2:00:00 3:00:00 4:00:00 5:00:00 6:00:00 7:00:00 hours 0.95 00:00:00
Factors affecting the BIS value Sleep: BIS range is lower (20-70) during deep sleep, and BIS range is higher (75-92) during REM sleep Hypothermia: decrease in BIS value Cerebral ischemia: decrease in BIS value Neurological states: decrease in BIS value depending of location of injury and degree to which overall cerebral metabolism is affected
Factors affecting the BIS value Sedation: decrease in BIS value Analgesia: decrease in BIS value Neuromuscular blocking agents: decrease in BIS value related to attenuation of highfrequency muscle activity across the patient s forehead Painful (noxious) stimulation: if analgesia inadequate, arousal response may be produced within cerebral cortex
Potential Indications for BIS Monitoring Use with neuromuscular blockade: BIS monitoring may help to identify patients at risk of awareness, recall and pain when paralyzed Use of BIS values to guide sedation and analgesia Titrating sedation/analgesia in patients receiving controlled ventilation Avoiding extremes of under and over sedation Titration of medications for medication-induced coma
Sleep walking Subject recurrently arises from deep slow wave sleep, typically 1st third of night, and shows complex automatic behaviour including leaving the bed and walking for some distance. Minor violence is common (adult males). Usually not remembered the following morning. Common, 20% of children occasionally sleep walk, 5% repeatedly Vincenzo Bellini, La Sonnambula (Amina walking across a plank above a water wheel) Strong family history (DBQ1*05 association), no real psychiatric association, worse at times of stress, worse with alcohol/caffeine. Partial arousal disorder the cortex remains asleep when the rest of the brain wakens. Happens more when other arousing stimuli occur e.g. reported secondary to sleep apnoea and disappears with its treatment. Some believe related to SWS/REM transition.
Sleep Automatism/automatic behaviour/confusional arousals Poorly characterised. Similar to sleep walking but subject apparently able to do much more complex activities e.g.
Not osa or cataplexy
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