Obstructive Sleep Apnea Flashcards
Normal sleep is a delicate balance between ___ and ___. Regulation of the sleep-wake-cycle is complex in nature involving what things?
Hypersomnia and insomnia
Light-dark cues
Retinothalamic tract
Suprachiasmatic nucleus
Cortisol
What is the difference between NREM and REM?
NREM: steady slow HR and respiratory rate. Low BP
REM: rapid eye movement, increased autonomic activity and dreaming, stimulated brain activity, decreased muscular activity
What are the physiologic changes during sleep in normal pts?
Decreased tidal volume, decreased minute ventilation, increased pCO2
Decreased SaO2
Increased upper airway resistance
10-20% decrease in metabolic rate
Decreased HR and BP
Name 6 sleep apnea syndromes
Obstructive sleep apnea syndrome (OSA) - absence of airflow with continued respiratory effort
Central apnea (nothing you can really do about this) - lack of airflow from absence of respiratory effort
Mixed apnea - combination of obstructive and central
Obesity hypoventilation syndrome
Pickwickian syndrome
Sudden infant death syndrome
Define obstructive sleep apnea
Periodic obstruction of upper airway during sleep that is marked by either apneic or hypopneic events
What is the difference between apneic and hypopneic ecents?
Apneic - cessation of ventilation for 10 seconds or longer, leading to an arousal (these occur normally)
Hypopneic - tidal volume decreased by >50% for greater than 10s. Decreased airflow with arousal or desaturation of 2-4%
To be diagnosed with obstructive apnea you must have more than ___ apneic events per hour
5
__% of the adult population has OSA. __% of OSA pts have HTN. __% of HTN pts have OSA.
5%
50%
25%
Describe the pathophysiology behind OSA
Anatomic narrowing/pharyngeal collapse
Decreased airway patency
Increase inspirations pressures
Abnormal neuromuscular control
Reflex activation of dilatory in response to airway obstruction often fils
Becomes a viscous cycle
What is a definitive event?
Occlusion of upper airway
Apnea leads to progressive ____ until brief arousal form sleep occurs and airflow resumes
Up to ___times or greater per night in some patients
This leads to sleep fragmentation
Asphyxia
400
Why does the airway collapse in osa?
Sleep reduces activity of airway dilator muscles and their reflex response to subatmospheric airway pressures
OSA pateints demonstrate high airway compliance (floppy airway)
Some patients have obvious anatomic problem
Where do most sites of obstruction occur in osa?
50% occur at base of tongue
18% occur at soft palate
Most are due to combination
What tools are used to diagnose osa?
History (abnormal snoring, excessive daytime fatigue, restless sleep, impaired cognitive function, morning headaches, personality changes, sexual dysfunction, poor job performance)
Physical exam (vitals, head and neck exam, flexible endoscopy) males >17.5” color size with snoring have a 50% likelihood of OSA
Radiographs
Polysomnogram
What are some things you may find in a head and neck exam that may lead you to think the pt has osa?
Mandibular retrognathia
Macroglossia
Adenotonsillar hypertrophy
Large neck circumference
Airway anatomy (mallampati classification)
What is a nasopharyngoscope used for?
Evaluation of the nose, oropharynx, and hypopharnx is best accomplished using a flexible nasopharyngoscope
What is muller’s maneuver?
Inspire against closed nostrils and mouth, reveal the site and degree of obstruction (use a nasopharyngoscope)
Measured from 1-4 (total collapse)
Measured at soft palate and at base of tongue
Done in the supine and upright positions
What are some cardiovascular manifestions of osa?
Hypoxemia, hypercarbia result in multiple problems..
Tachycardia/bradycardia
MI
Ventricular ectopic
Systemic and pulmonary HTN
Decreased CO
Polycythemia
Ventricular hypertrophy
Congestive heart failure
What are some non-surgical treatment options for osa?
Weight loss
Sleep hygiene
Oral appliances
CPAP, BiPAP
What are some surgical treatment options for osa?
Uvulopalatopharyngoplasty
Radio frequency ablation of tongue base/palate
Tongue reduction
Genial surgery
Maxillomandibular advancement
Nasal surgery
Tracheostomy
What is the gold standard non-surgical treatment for osa?
CPAP (continuous positive airway pressure)
Subjective symptoms and long-term sequence eliminated if CPAP used
Patient compliance is a problem
True or false… CPAP is effective for part-time use
False
What is the goal of oral appliances that are used to treat osa?
Advance the mandible
Retain the tongue anteriorly
Most helpful in cases of mild disease
Oral appliances for osa are best in which cases? What are some side effects?
Most effective in non-obese patients with retro or micrognathia
Better for mild-moderate cases (less likely in severe disease)
Side effects: TMJ symptoms, excess salivation, occlusal changes
