CONSEQUENCES OF SLEEP LOSS Flashcards
CENTRAL VS OBSTRUCTIVE SLEEP APNOEA
Central sleep apnea occurs because your brain doesn’t send proper signals to the muscles that control your breathing. This condition is different from obstructive sleep apnea, in which you can’t breathe normally because of upper airway obstruction. Central sleep apnea is less common than obstructive sleep apnea.
- IN OBSTRUCTIVE SLEEP APNEA, THERE IS CONTINUING RESPIRATORY EFFORT
Example of a severe obstructive sleep apnea case, characteristics?
This patient has severe obstructive sleep apnoea (OSA). The moment he goes to sleep,
his pharyngeal airway collapses, he struggles to breathe for about 30-40 seconds until
the falling oxyhaemoglobin saturation wakes him up. He takes 3-4 breaths after a loud
“snort” and falls asleep again. He averages 73 apnoeas per hour of sleep. Every time he
wakes up, his blood pressure and heart rate rise sharply.
Nocturnal polyuria with multiple visits to the toilet are common in severe OSA.
These people are very sleepy and often sleep in a separate room from their partners
because of the loud snoring. They are 20 times more likely than normal to crash their
cars. They are at increased risk of hypertension, myocardial infarction and stroke.
The typical patient is overweight with a large neck circumference. They may have a
relatively retrognathic jaw also.
OSA is common in patients with the metabolic syndrome (abdominal obesity, type II
diabetes, cardiovascular disease.
TREATMENT FOR SEVERE OBSTRUCTIVE SLEEP APNEA?
Treatment is with nasal CPAP (continuous positive airway pressure, pronounced
ceepap)
A CPAP machine uses a hose connected to a mask or nosepiece to deliver constant and steady air pressure to help you breathe while you sleep.
Common problems with CPAP include a leaky mask, trouble falling asleep, a stuffy nose and a dry mouth.
WHAT IS RESTLESS LEG SYNDROME OFTEN ASSOCIATED WITH?
IRON DEFICIENCY
RLS?
Restless Legs Syndrome (RLS), also known as Willis-Ekbom Disease, is a neurological condition associated with abnormal sensations in the legs. It is estimated that 5% of the general population and as many as 10% of those over the age of 65 have this disorder.
(CAN OCCUR IN ANY AGE GROUP, INCLUDING CHILDREN, BUT MORE COMMON IN OLDER ADULTS)
MEDICATION FOR TREATING RESTLESS LEGS SYNDROME?
Anti-Parkinsonian drugs (L-dopa, pramipexole, ropinirole), benzodiazepines
(clonazepam) and opioids (codeine) may be helpful
MOVEMENT IN RESTLESS LEG SYNDROME?
The symptoms of restless can be very distressing. Patients are unable to keep their legs
still and any attempt to do so results in distressing “crawling” or burning discomfort in
the legs. Movement and cold are often the only way of achieving relief. Patients often
keep their legs out from under the bedclothes and have to get out of bed repeatedly to
“walk the legs off”.
The limbs, usually the legs but sometimes the arms as well, twitch repeatedly during
sleep. These myoclonic jerks occur about every 30-60 seconds in bouts of 10-30
minutes in duration. The twitches cause brief arousals from sleep making sleep
unrefreshing. The patients are sleepy during the day
What is the Arnold-Chiari malformation and what sleep disorder can it cause?
- a defect of occipital bone development which puts pressure on the medulla, cerebellum and mid-brain
- can be surgically improved
- may lead to central sleep apnea (There is no respiratory effort on the
chest and abdominal bands during the periods of zero airflow. The small oscillations on the airflow trace are cardiac in origin. Each heart beat causes a small amount of lung compression and a small movement of air at the lips. This is further confirmation of central apnoea as it confirms a fully open airway from nose to bronchi. Impairment of the respiratory centre results in failure of generation of respiratory
rhythmicity during sleep. Cortical control maintains breathing wakefulness but this is
lost during sleep.)
Cheyne-Stokes breathing (CSB)
- typical crescendo/decrescendo pattern with a gradually increasing depth of breathing to a peak followed by a decline to a central apnoea
- respiration restarts with gradually increasing breaths rather than a sudden large breath as seen in obstructive sleep apnoea and central sleep apnoea
- CSB is common in heart failure and is often viewed as a poor prognostic sign. It occurs
also in normal subjects exposed to hypoxia, for example at altitude. It is thought that
the low cardiac output causes a delay in changing oxygen saturations and carbon
dioxide levels reaching the carotid and central chemoreceptors allowing the respiratory
control system to oscillate or “ring”.
Patients may have very few symptoms.
Treatment of Cheyne-Stokes breathing (CSB)
Treatment is designed to dampen the oscillations. Oxygen therapy reduces the
ventilatory drive. Acetazolamide, a carbonic anhydrase inhibitor, causes a mild metabolic acidosis which stimulates breathing and reduces the ringing as does low dose inhaled carbon dioxide. Hypnotics also dampen the oscillations by reducing arousal. Mechanical ventilatory support may be effective. The evidence for benefit in treating CSB is limited.
CAUSES OF FREE RUNNING CIRCADIAN CLOCK?
The circadian rhythm is normally entrained to 24 hours by light through the
melanopsin illuminance system. Patients who have been completely blind, with no
light perception, from birth usually free run. Those who became blind later in life or
who have some light perception generally entrain. A patient with this disorder being sighted is the most unusual case. He may have a genetically determined abnormality of either one of his clock genes or the illuminance system. Alternatively, he is driving this himself.
This condition can be socially very isolating as the patient spends much of the time
asleep when the world is awake.
TREATMENT FOR FREE RUNNING CIRCADIAN CLOCK
Treatment is generally with exogenous melatonin and light therapy
DELAYED SLEEP PHASE SYNDROME
This is like permanent jet lag where one’s body clock is delayed so they do not feel sleepy until 4 or 5 in the morning. They then sleep for 8 or 9 hours.
This is most common in teenagers and young people (especially undergraduates!) and
is very disrupting for schooling and work.
There is much interest at the moment in the role of the clock gene in this and other
circadian disorders
DELAYED SLEEP PHASE SYNDROME TREATMENT
Treatment is with bright light administered in the morning which tends to advance the
sleep phase. Simply advancing the phase (go to bed and get up an hour earlier each
day) is often resisted as the patient will be trying to sleep when they do not feel sleepy.
It may be better to delay the bedtime and rising time by 2hrs each day until they have
achieved an agreed target bedtime and rising time (sleeping the clock round). The
bright light is then used to “hold” them at the target time
SLEEP DEPRIVATION RATES IN ADULTS?
- MOST ADULTS ARE MODERATLEY TO SEVERLY SLEEP DEPRIVED
- 70% OF ADULTS GET 6 HRS/NIGHT OR LESS DURING WORK WEEK
- 63% OF ADULTS EXPERIENCE SLEEP PROBLEMS
