Case 3 wake problems
Jordan: sleep apnoea
- Obstructive sleep apnoea is an increasingly common disorder of repeated upper airway
collapse during sleep, leading to oxygen desaturation and disrupted sleep. Features
include snoring, witnessed apnoeas, and sleepiness. Pathogenesis varies; predisposing
factors include small upper airway lumen, unstable respiratory control, low arousal
threshold, small lung volume, and dysfunctional upper airway dilator muscles. Risk
factors include obesity, male sex, age, menopause, fluid retention, adenotonsillar
hypertrophy, and smoking. Obstructive sleep apnoea causes sleepiness, road traffic
accidents, and probably systemic hypertension. It has also been linked to myocardial
infarction, congestive heart failure, stroke, and diabetes mellitus though not
definitively. Continuous positive airway pressure is the treatment of choice, with
adherence of 60–70%. Bi-level positive airway pressure or adaptive servo-ventilation
can be used for patients who are intolerant to continuous positive airway pressure.
Other treatments include dental devices, surgery, and weight loss. Disturbances in gas
exchange lead to oxygen desaturation, hypercapnia, and sleep fragmentation, which
contribute to the consequences of obstructive sleep apnoea.
- Patients with obstructive sleep apnoea report snoring, witnessed apnoeas, waking up
with a choking sensation, and excessive sleepiness. Other common symptoms are non-
restorative sleep, difficulty initiating or maintaining sleep, fatigue or tiredness, and
morning headache
- The best test for obstructive sleep apnoea is overnight polysomnography in a
laboratory with the primary outcome measure of apnoea–hypopnoea index (number of
apnoeas plus hypopnoeas per h of sleep). This test involves concurrent monitoring of
both sleep and respiration. To monitor sleep–wake state, electro encephalogram, left
and right electro-oculogram, and chin electromyogram are recorded. The respiratory
recordings should include: respiratory effort measurement, airflow monitoring by
nasal air pressure and thermal air sensor, and arterial oxygen saturation.
Electromyography of the anterior tibialis is also often done to assess limb movements
that might alter sleep stage or respiration and body position is monitored because of
the position-specific nature of obstructive sleep apnoea in many patients. home testing
is not appropriate for all patients. However, for some patients, carefully designed
home management procedures can provide timely and costeffective management of
obstructive sleep apnoea
- different definitions of hypopnoea might predict different consequences of obstructive
sleep apnoea.
- craniofacial structure or body fat decreased the size of the pharyngeal airway lumen,
leading to an increased likelihood of pharyngeal collapse. During wakefulness, the
airway is held open by the high activity of the numerous upper airway dilator muscles,
but after the onset of sleep, when muscle activity is reduced, the airway collapses.
- Respiratory control instability: When the central respiratory output waxes and wanes,
the activity of the upper airway dilator muscles varies accordingly so that periods of
low central respiratory drive are associated with low upper airway dilator muscle
activity, high airway resistance, and a predisposition to airway collapse.
- Arousal threshold: After arousal, most people hyperventilate briefly and if the
hyperventilation is large enough, CO2 concentration in blood can fall below the
chemical apnoea threshold, resulting in a central apnoea
- Lung volume: the airway is smaller and collapses more easily when lung volume is
small. Increased lung volume also probably stabilises the respiratory control system by
1
, increasing the stores of O2 and CO2 and thus, buffering the blood gases from changes
in ventilation.
- Fluid retention and shift of fluid overnight from the legs to the neck might also affect
airway mechanics. Oedema can be especially problematic in states of excess
extracellular fluid volume.
- Risk factors: obesity, men (more fat in upper airways), age (Older individuals might
have reduced tethering of the upper airway by lung volume because of loss of elastic
recoil in the lung. Also airway collapses more easy due to lack of collagen).
Additional risk factors for the development of obstructive sleep apnoea include genetic
factors and race, which affect craniofacial anatomy, obesity, and perhaps lung volume.
Menopause, smoking
- Consequences: sleepiness, higher risk traffic accidents, lower quality of life,
hypertension, cardiovascular diseases (not sure yet), diabetes mellitus (correlation)
- Management: Nasal continuous positive airway pressure: involves maintenance of a
positive pharyngeal transmural pressure so that the intraluminal pressure exceeds the
surrounding pressure. Continuous positive airway pressure also increases end-
expiratory lung volume, which stabilises the upper airway through caudal traction.
Take into account: Intensive support can be beneficial, some patients have nasal
difficulties that limit their ability to tolerate nasal treatment with continuous positive
airway pressure, although randomised trials have not shown one type of mask to be
better than another, some patients prefer a full face mask to a nasal mask, while others
prefer a nasal pillow device. some patients respond to hypnotherapy if they develop
insomnia or frequently wake when using continuous positive airway pressure. Other
options: Bi-level positive airway pressure, expiratory pressure relief strategies, oral
devices, upper airway surgery, positional therapy, and other conservative measures.
- Prevention: weight loss (though diet and exercise), and avoidance of cigarettes,
alcohol, and other myorelaxant drugs can be beneficial, avoid benzodiazepines
- Appendix 3 used in sleep apnea.
- N1 and N2 increase , N3 and Rem often reduced or absent.
Van der Heijde: Narcolepsy
- Narcolepsy is best characterized as a disorder of the regulation of sleep and
wakefulness, resulting in a variety of symptoms such as excessive daytime sleepiness
(EDS), cataplexy, hypnagogic hallucinations, sleep paralysis, and disturbed nocturnal
sleep. According to the current classification of sleep disorders, narcolepsy can be
divided into narcolepsy with and without cataplexy. Narcolepsy with cataplexy is
considered to be a homogeneous disease entity, a “morbus sui generis”, of which the
pathophysiological hallmark is a disturbed hypocretin transmission. Narcolepsy
without cataplexy may be no more than a heterogeneous group of disorders
characterized by EDS in combination with abnormal expressions of REM sleep on
polysomnography (PSG).
- Prevalence: 25–50 per 100 000, equal men and women, often starts in adolescence,
second onset peak at 35 y/o.
- Excessive daytime sleepiness: develops over weeks-months, almost continuous feeling
of sleepiness dependent upon the level of activity, inability to stay awake, Sleep
attacks tend to be short, usually less than 20 min, and refreshing for some time. The
number of attacks may vary from 1 to over 10 each day, depending on the severity of
the narcolepsy and the circumstances, EDS is typically accompanied by a pronounced
difficulty to concentrate and to sustain attention, leading to an impaired performance.
2
Jordan: sleep apnoea
- Obstructive sleep apnoea is an increasingly common disorder of repeated upper airway
collapse during sleep, leading to oxygen desaturation and disrupted sleep. Features
include snoring, witnessed apnoeas, and sleepiness. Pathogenesis varies; predisposing
factors include small upper airway lumen, unstable respiratory control, low arousal
threshold, small lung volume, and dysfunctional upper airway dilator muscles. Risk
factors include obesity, male sex, age, menopause, fluid retention, adenotonsillar
hypertrophy, and smoking. Obstructive sleep apnoea causes sleepiness, road traffic
accidents, and probably systemic hypertension. It has also been linked to myocardial
infarction, congestive heart failure, stroke, and diabetes mellitus though not
definitively. Continuous positive airway pressure is the treatment of choice, with
adherence of 60–70%. Bi-level positive airway pressure or adaptive servo-ventilation
can be used for patients who are intolerant to continuous positive airway pressure.
Other treatments include dental devices, surgery, and weight loss. Disturbances in gas
exchange lead to oxygen desaturation, hypercapnia, and sleep fragmentation, which
contribute to the consequences of obstructive sleep apnoea.
- Patients with obstructive sleep apnoea report snoring, witnessed apnoeas, waking up
with a choking sensation, and excessive sleepiness. Other common symptoms are non-
restorative sleep, difficulty initiating or maintaining sleep, fatigue or tiredness, and
morning headache
- The best test for obstructive sleep apnoea is overnight polysomnography in a
laboratory with the primary outcome measure of apnoea–hypopnoea index (number of
apnoeas plus hypopnoeas per h of sleep). This test involves concurrent monitoring of
both sleep and respiration. To monitor sleep–wake state, electro encephalogram, left
and right electro-oculogram, and chin electromyogram are recorded. The respiratory
recordings should include: respiratory effort measurement, airflow monitoring by
nasal air pressure and thermal air sensor, and arterial oxygen saturation.
Electromyography of the anterior tibialis is also often done to assess limb movements
that might alter sleep stage or respiration and body position is monitored because of
the position-specific nature of obstructive sleep apnoea in many patients. home testing
is not appropriate for all patients. However, for some patients, carefully designed
home management procedures can provide timely and costeffective management of
obstructive sleep apnoea
- different definitions of hypopnoea might predict different consequences of obstructive
sleep apnoea.
- craniofacial structure or body fat decreased the size of the pharyngeal airway lumen,
leading to an increased likelihood of pharyngeal collapse. During wakefulness, the
airway is held open by the high activity of the numerous upper airway dilator muscles,
but after the onset of sleep, when muscle activity is reduced, the airway collapses.
- Respiratory control instability: When the central respiratory output waxes and wanes,
the activity of the upper airway dilator muscles varies accordingly so that periods of
low central respiratory drive are associated with low upper airway dilator muscle
activity, high airway resistance, and a predisposition to airway collapse.
- Arousal threshold: After arousal, most people hyperventilate briefly and if the
hyperventilation is large enough, CO2 concentration in blood can fall below the
chemical apnoea threshold, resulting in a central apnoea
- Lung volume: the airway is smaller and collapses more easily when lung volume is
small. Increased lung volume also probably stabilises the respiratory control system by
1
, increasing the stores of O2 and CO2 and thus, buffering the blood gases from changes
in ventilation.
- Fluid retention and shift of fluid overnight from the legs to the neck might also affect
airway mechanics. Oedema can be especially problematic in states of excess
extracellular fluid volume.
- Risk factors: obesity, men (more fat in upper airways), age (Older individuals might
have reduced tethering of the upper airway by lung volume because of loss of elastic
recoil in the lung. Also airway collapses more easy due to lack of collagen).
Additional risk factors for the development of obstructive sleep apnoea include genetic
factors and race, which affect craniofacial anatomy, obesity, and perhaps lung volume.
Menopause, smoking
- Consequences: sleepiness, higher risk traffic accidents, lower quality of life,
hypertension, cardiovascular diseases (not sure yet), diabetes mellitus (correlation)
- Management: Nasal continuous positive airway pressure: involves maintenance of a
positive pharyngeal transmural pressure so that the intraluminal pressure exceeds the
surrounding pressure. Continuous positive airway pressure also increases end-
expiratory lung volume, which stabilises the upper airway through caudal traction.
Take into account: Intensive support can be beneficial, some patients have nasal
difficulties that limit their ability to tolerate nasal treatment with continuous positive
airway pressure, although randomised trials have not shown one type of mask to be
better than another, some patients prefer a full face mask to a nasal mask, while others
prefer a nasal pillow device. some patients respond to hypnotherapy if they develop
insomnia or frequently wake when using continuous positive airway pressure. Other
options: Bi-level positive airway pressure, expiratory pressure relief strategies, oral
devices, upper airway surgery, positional therapy, and other conservative measures.
- Prevention: weight loss (though diet and exercise), and avoidance of cigarettes,
alcohol, and other myorelaxant drugs can be beneficial, avoid benzodiazepines
- Appendix 3 used in sleep apnea.
- N1 and N2 increase , N3 and Rem often reduced or absent.
Van der Heijde: Narcolepsy
- Narcolepsy is best characterized as a disorder of the regulation of sleep and
wakefulness, resulting in a variety of symptoms such as excessive daytime sleepiness
(EDS), cataplexy, hypnagogic hallucinations, sleep paralysis, and disturbed nocturnal
sleep. According to the current classification of sleep disorders, narcolepsy can be
divided into narcolepsy with and without cataplexy. Narcolepsy with cataplexy is
considered to be a homogeneous disease entity, a “morbus sui generis”, of which the
pathophysiological hallmark is a disturbed hypocretin transmission. Narcolepsy
without cataplexy may be no more than a heterogeneous group of disorders
characterized by EDS in combination with abnormal expressions of REM sleep on
polysomnography (PSG).
- Prevalence: 25–50 per 100 000, equal men and women, often starts in adolescence,
second onset peak at 35 y/o.
- Excessive daytime sleepiness: develops over weeks-months, almost continuous feeling
of sleepiness dependent upon the level of activity, inability to stay awake, Sleep
attacks tend to be short, usually less than 20 min, and refreshing for some time. The
number of attacks may vary from 1 to over 10 each day, depending on the severity of
the narcolepsy and the circumstances, EDS is typically accompanied by a pronounced
difficulty to concentrate and to sustain attention, leading to an impaired performance.
2
