Sleep Flashcards
Ideal length of sleep
Infants: 14-16 hours
Children: 9 hours
Adults; 7-8 hours
Factors that determine sleep length
Circadian rhythm, genets, voluntary control (i.e. alarm clock)
Stages of sleep
Non REM (N1 - transition to sleep 2-5%, N2 - sleep 45-55%, N3 - deep sleep 15-20%) REM
Aging and sleep stages
Young infants and children: increased REM and N3
Elderly: decreased N3
Sleep waves
Beta: 13-30Hz (wakefullness) Alpha: 8-12 Hz (relaxed wakefullness) Theta: 4-8Hz (N1 and REM) Delta: 1-4 Hz (N3) K complex (N2) Vertex sharp waves (N1) Sleep spindle (N2) Sawtooth waves (REM)
Sleep wake cycles
Homeostatic drive (process S; increasing sleep propensity with wakefullness) Circadian rhythm (Process C; internal sleep/wake cycle)
Sleep centers of the brain
Reticular activating system
Hypothalamus
Basal forebrain
Thalamus
Sleep related brain nuclei
- Locus coeruleus
- Substantia nigra
- Ventral tegmental region
- Laterodorsal tegmental nuclei
- Pedunculopontine nuclei
- Dorsal raphe nucleus
Hormones related to sleep function
- Cortisol (rises at night and peaks in the morning)
- TSH (circadian regulated, rise and fall with sleep)
- Growth hormone (increased initially during sleep and then decrease throughout the night, association with slow wave sleep)
- Prolactin (increases with sleep and is sleep modulated)
- Glucose/insulin (increase during sleep)
- Hypocretins/orexins
- Melatonin (rises and falls with sleep)
- Leptin
- Ghrelin
Muscles that maintain airway patency
- Tensor veli palatini
- Pterygoid
- Genioglossus
- Geniohyoid
- Sternohyoid
Apnea
> 90% cessation of airflow by the nose or mouth lasting 10 seconds or longer
Hypopnea
Decrease in airflow >30% for at least 10 seconds with >4% o2 desaturation or a reduction in airflow >50% for 10 seconds and an o2 desat >3%
RERA
10 seconds or more of increasing respiratory effort leading to arousal that does not meet criteria for apnea or hypopnea
Types of apneas
Obstructive, central, mixed
Nonsurgical management of snoring
- Weight loss
- Eliminate alcohol, tobacco, caffeine and sedatives
- Positioning while asleep
- Medically treat reflux, sinusitis, nasal polyps
- Nasal breathing strips
- Oral appliance
Surgical management of snoring
- Septoplasty/turbinate reduction
- Radiofrequency palatoplasty
- Palatal implants
Upper airway resistance syndrome
- 15 or more RERAs per hour
- Characterized by excessive daytime somnolence but normal sleep studies. Esophageal pressure monitoring shows increased negative intrathoracic pressure leading to increased work of breathing and sleep arousals
- Associated with crescendo snoring
Risk factors for upper airway resistance syndrome
- Female
- nonobese
- Younger age
- Nasal obstruction
OSA diagnosis
- > 5 respiratory events an hour with respiratory effort and symptoms OR
- > 15 respiratory events with respiratory effort without symptoms
OSA pathophysiology
- Upper airway collapse
- Inability for airway dilators to respond
- Decreased sensitivity of chemoreceptors
- Decreased central respiratory drive
- Defective ventilatory response
OSA risk factors
- Obesity
- Family history
- Anatomy (maxillary hypoplasia, retrognathia)
- Increased age
- Allergies
- Postmenopausal
- Sedatives and alcohol
- Smoking
Clinical consequences of OSA
- Sleep related: daytime somnolence, fatigue, morning headaches, car accidents, poor job performance, depression, stress
- Cardiovascular: HTN, CAD, arrhythmias, CVAs
- Pulmonary: pulmonary HTN, cor pulmonale
- Shorter life expectancy
Physical exam findings of OSA
- Neck circumference (> 17 in males and > 15.5 in females)
- waste/hip ratio (> 0.9 males, >0.85 females
- Cricomental distance (> 15mm excludes OSA)
- Kyphosis
- Micro/retrognathia
- Enlarged tonsils
- High arched palate
- Maxillary retrusion
- Tracheo/laryngomalacia
- Enlarged tongue
Evaluation of maxillary retrusion
- Line dropped from nasion to the subnasale should be perpendicular to the frankfurt plane
Evaluation of retrognathia
- Line bisecting vermillion border of the lower lip with the pogonion should be perpendicular to the frankfurt plane
PSG parameters
- EEG (allows sleep staging from brain regions)
- Electrooculum
- Electromyogram
- ECG
- Oronasal airflow
- Respiratory effort (chest effort, abdominal effort)
- Oximetry
- Vital signs
- Snoring volume
PSG report
- Sleep latency
- Sleep efficiency
- Sleep architecture
- Types of respiratory disturbances
- Volume/presence of snoring
- Effect of position on airflow
- Effect of sleep stage on airflow
- Number/severity of desaturation episodes
- Percentage of sleep time above 90% SaO2
- Lowest O2 level
Categories of sleep tests
Type 1 : in lab sleep study with sleep technologist
Type 2: home sleep test with minimum of 7 channels including EEG
Type 3: home sleep test, minimum of 4 channels including respiratory airflow, respiratory effort, EKG and oxygen saturation
Type 4: typically only measures oxygen saturation
Management sequence of OSA
- Behavioral (weigh loss, limit alcohol, tobacco, caffeine and sedatives)
- Medical management (nasal blockage, reflux)
- CPAP/BiPAP
- Oral or nasal appliances
- Mandibular repositioning
- Surgery
Increase CPAP patient compliance
- Humidity
- Treat nasal congestion/obstruction
- Desensitization
- Reassess mask
- Chin strap for mouth leak
- Pressure reduction
- Brief trial of hypnotic medication while adjusting to device
- Trial of auto PAP
BiPAP indications
- Pressure support for obesity hypoventilation
- COPD
- Hypoxemic patients
- Respiratory muscle weakness
- Neurologic dysfunction
- Poor CPAP compliance because of high PAP pressures (>16 cm H20)
CPAP/BiPAP Contraindications
- No respiratory drive
- Risk of aspiration
- Hypotension
- CSF leak
- Bullous lung disease
- Pneumocephalus
- Pneumothorax
- Skull base surgery
Pathogenesis of sleep apnea in children
- Adenotonsillar hypertrophy
- Poor muscle tone
- Upper airway narrowing
- Syndromic
Signs and symptoms of sleep apnea in children
- Snoring
- Witnessed apneas
- Restless sleep
- Enuresis
- Hyperactivity
- Chronic mouth breathing
Central sleep apnea types
- Primary CSA
- Cheyne stokes breathing
- High altitude CSA
Cheyne stokes breathing
- Three cycles of crescendo and decrescendo breathing and lasting 10 minutes or associated with 5+ central apneas/hypopneas and associated with heart failure
Causes of hypoventilation syndrome
- Obesity
- Interstitial lung disease
- Pulmonary HTN
- Sickle cell anemia
- Myxedema
Sleep related movement disorders
- Restless leg (subjective complaint)
- Periodic limb movement (repetitive contraction of anterior tibialis)
- rhythmic movement disorder
- Nocturnal leg cramps
- Excessive fragmentary myoclonus
- Bruxism
Restless leg risk factors
- Female
- Family history
- BTBD9 gene
Restless leg diagnosis
- URGE
- Urge to move legs, Rest makes worse, Gets betters with activity, Evening and nighttime symptoms
- Labs: ferritin, renal function, flucose, anemia, thyroid, B12, Mg, ANA, RF
- CSF transferrin levels
Tx of restless leg
- Address secondary causes (iron deficiency, renal failure, pregnancy, peripheral neuropathy, medications - dopamine antagonist meds)
- Behavior modifications
- Dopamine agonists (ropinirole, pramipexole)
Non obstructive Pediatric sleep disorders
- Sleep terrors: during slow wave sleep, first part of the night, usually have autonomic response
- Somnambulism - sleep walking during slow wave sleep
- Confusional arousals
- Nightmares - during REM sleep, early hours of the morning
- Sleep paralysis
- REM sleep behavior disorder
- Bruxism
- Somniloquy- sleep talking during REM and NREM
- Nocturnal enuresis
- Rhythmic movement disorders- benign, goes away by early childhood, including body rocking, head banging and head rolling, tx with safe environment
Describe the Mueller maneuver?
Endoscopic evaluation during maximal inspiration against closed nose and mouth at various levels to attempt to identify anatomical regions of obstruction
Epworth Sleepiness Scale
A validated questionnaire for daytime sleepiness. Questions rated 0-3 of likelihood a person would doze off. 8 questions. Maximal score of 24 0-5: supernormal 5-10: normal 10-15: sleepy 15-20: very sleepy > 20: dangerously sleepy
Questions:
Sitting and reading
Watching TV
Sitting inactive in a public place (e.g., a theater or
a meeting)
As a passenger in a car for an hour without a
break
Lying down to rest in the afternoon
Sitting and talking to someone
Sitting quietly after a lunch without alcohol
In a car, while stopped for a few minutes in traffic
Potential complications or sequelae of UPPP
Persistent snoring or OSA, bleeding, nasopharyngeal regurgitation of liquids, oropharyngeal dryness, oropharyngeal dysphagia, globus, pharyngeal stenosis
What does the Friedman staging system assess
It is used as a clinical predictor of which patients may have successful improvement of their OSA after UPPP surgery.
Stage I patients have an 80% chance of success following a UPPP (greater than 50% reduction in preoperative AHI or a postoperative AHI < 20)
Table 1. Friedman staging system as determined by
Friedman tongue position (FTP), tonsil size, and BMI
Stage FTP Tonsil size BMI
I I, II 3 or 4 <40
II I, II 0, 1, or 2 <40
III or IV 3 or 4 <40
III III or IV 0, 1, or 2 <40
IVa I–IV 0–4 >40
a All patients with significant craniofacial or other anatomic abnormalities.
What craniofacial syndromes are closely associated with snoring and sleep apnea?
Achondroplasia, Pierre Robin sequence, Treacher-Collins, Crouzon, Down syndrome, Prader-Willi, Apert syndrome
OSAHS score
Developed by Friedman et al as a tool for predicting a diagnosis of OSAHS based on physical examination characteristics alone.
- Calculated by adding the numerical values obtained for FTP (I-IV), tonsil size (0-4), and BMI grade (1-4). The minimum OSAHS score is 2 and the maximum is 12.
- Score of 8+ have a 90% chance of having moderate OSA and 74% chance of having severe OSA
- Score less than 4 have a 67% chance of not having moderate/severe OSA
What cephalometric findings are associated with OSA
- Large tongue
- Decreased maxillary and mandibular projection
- Elongated palate (increased length and width of soft palate)
- Low hanging hyoid
- Increased vertical facial length
CPAP compliance
Usage for at least 4 hours a night for 5+ nights a week
Friedman tongue position vs mallampati score
FTP is the evaluation of the tongue’s position
relative to the tonsils/pillars, uvula, soft palate,
and hard palate. It is based on Mallampati stages,
which are used in the field of anesthesiology in the
context of difficult endotracheal intubation.
The Mallampati system has 3 grades and
evaluates the palate with the tongue protruded. Modified mallampati which is now routinely used has 4 grades.
Differences between adult and pediatric OSA
Adults: greater male predominance, more common to have nocturnal arousals, daytime hypersomnolence and obesity
Pediatrics: mouth breathing and adenotonsillar hypertrophy more common
