Term
| what is the definition of obstructive sleep apnea? how many people does it affect? |
|
Definition
| repeated episodes of obstructive apnea and hypopnea during sleep, together *w/daytime sleepiness or *altered cardiopulmonary function. it affects 2-4% of middle age adults |
|
|
Term
| what do pts w/sleep apnea have an increased risk of? |
|
Definition
| diurnal/nocturnal HTN, pulmonary HTN, R/L ventricular failure, MI, stroke, morbidity/mortality due to cardiovascular and cerebrovascular causes |
|
|
Term
| what are the manifestations of upper airway closure during sleep? |
|
Definition
| obstructive sleep apnea, obstructive sleep hypopnea, and upper airway resistance |
|
|
Term
| how long does airflow need to be stopped in order for it to be considered obstructive sleep apnea? |
|
Definition
| there needs to be a cessation of airflow for *10+ sec despite *continuing ventilatory effort *5x per hr of sleep |
|
|
Term
| what is the decrease in oxyhemoglobin saturation associated with obstructive sleep apnea? |
|
Definition
| there is a *decrease of 4%+ in oxyhemoglobin saturation associated with obstructive sleep apnea (this is what separates obstructive sleep apnea from central sleep apnea) |
|
|
Term
| what is obstructive sleep hypopnea? is there an association w/oxyhemoglobin saturation? |
|
Definition
| a decrease in 30-50% in airflow for 10+ sec 15x per hour (not a complete cessation). there may be an association with a 4%+ decrease in oxyhemoglobin saturation |
|
|
Term
| what is the definition for upper airway resistance? is there an association with oxyhemogloblin saturation? |
|
Definition
| there is no significant decrease in airflow (snoring is usual), but there are 15+ episodes of arousal per hour of sleep (due to increased effort to overcome the resistance). there is no significant decrease in oxyhemoglobin saturation. |
|
|
Term
| what are features common to all three syndromes (obstructive sleep apnea, obstructive sleep hypopnea, and upper airway resistance)? |
|
Definition
| arousal associated with increasing ventilatory effort and excessive daytime sleepiness |
|
|
Term
| what is central sleep apnea? (*know this definition*) |
|
Definition
| cessation of breathing during sleep as a result of transient abolition of drive to the respiratory muscles (apnea in the absence of ventilatory effort -> not *obstructive*) |
|
|
Term
| what is obesity-hypoventilation syndrome? |
|
Definition
| pts w/obesity-hypoventilation syndrome or pickwickian syndrome have chronic CO2 retention while awake (too fat, so can't breath deeply) and may or may not have associated sleep apnea |
|
|
Term
| what are the different portions of the upper airway that can be obstructed? |
|
Definition
| the naropharynx, the oropharynx, and the hypopharynx |
|
|
Term
| what is the patency of the upper airway dependent on? |
|
Definition
| the underlying *neuromuscular tone, upper airway muscle *synchrony, stage of sleep (REM - when most apneic events occur), and factors that affect *airway size (adipose tissue in neck, tonsillar hypertrophy, craniosacral skeletal abnormalities, and genetic/environmental factors) |
|
|
Term
| what are possible anatomic causes of obstruction in the nasal cavity? |
|
Definition
| septal and turbinate deformity, mucosal disease (rhinitis, polyps), sinusitis, and atresia/cleft deformity |
|
|
Term
| what are possible anatomic causes of obstruction in the nasopharynx? |
|
Definition
|
|
Term
| what are possible anatomic causes of obstruction in the nasopharyngeal inlet? |
|
Definition
| palatous soft palate/uvula, palatal synechia (adhesions), and posterior displacement of maxillae |
|
|
Term
| what are possible anatomic causes of obstruction in the oropharynx? |
|
Definition
| hypertrophic tonsils, tumors and macroglossia |
|
|
Term
| what are possible anatomic causes of obstruction in the hypopharynx? |
|
Definition
| posterior tongue displacement, micrognathia/retrognathism, lingual toncil hypertrophy, cysts/tumors, and omega-shaped epiglottis |
|
|
Term
| what are possible anatomic causes of obstruction in the larynx? |
|
Definition
| bilateral vocal cord paralysis and tumors |
|
|
Term
| what happens specifically when a pt develops an apneic event? |
|
Definition
| during sleep there is *reduced central output to upper airway muscles which dilate the oropharynx and larynx at inspiration, leading to increased upper airway resistance. the body senses this and produces enhanced diaphragmatic contraction in an attempt to overcome the resistance - however this generates increasingly negative subatmospheric pressure in the hypopharynx - causing greater instability of the segment, resulting in collapse. |
|
|
Term
| what are the physiologic consequences (and associated pathologies) of the lower O2, higher Co2 and lower pH due to sleep apnea (acute resp acidosis)? |
|
Definition
| the pt will have vagal bradycardia (unexplained nocturnal death from arrhythmia), pulmonary vasoconstriction (pulm HTN, R heart failure), systemic vasoconstriction due to catecholamine surge (systemic HTN), and acute CO2 retention (= desensitized CO2 receptors: chronic hypoventilation) |
|
|
Term
| what are the physiologic consequences (and associated pathologies) of arousal from sleep due to sleep apnea? |
|
Definition
| cerebral dysfunction/loss of deep sleep/sleep fragmentation (excessive daytime sleepiness, intellectual deterioration, personality changes, behavioral disorders), and excessive motor activity (restless sleep) |
|
|
Term
| can recurrent nocturnal hypoxemia stimulate higher RBC formation levels? |
|
Definition
| yes, which is referred to as polycythemia |
|
|
Term
| what characteristics on a pt hx are consistent w/obstructive sleep apnea? |
|
Definition
| pts are often males over 40 presenting w/daytime hypersomnolence, loud habitual snoring, fatigue, nocturnal gasping, choking, snorting, observed apnea, hx of systemic HTN, unrefreshing sleep, morning headaches, cognitive impairment, depression and nocturia. additionally: heavy habitual snoring, nocturnal epilepsy, obesity, hypothyroidism/acromegaly, impotence, and 7x risk of motor vehicle accidents |
|
|
Term
| what characteristics on a physical exam are consistent with obstructive sleep apnea? |
|
Definition
| retrognathia (weak chin), enlarged soft palate, tonsillar hypertrophy, HTN, increased neck circumference (M >18" & F >16"), and increased upper body obesity |
|
|
Term
| what are the 2 diagnostic studies for sleep apnea? |
|
Definition
| sleep oximetry and nocturnal polysomnogram |
|
|
Term
|
Definition
| a screening evaluation where the pt wears a pulse oximeter throughout the night and arterial O2/pulse are measured every 30 sec. this is not diagnostic, but if the pt desaturates in their sleep, then they need to be entered in a formal sleep study |
|
|
Term
| what does a nocturnal polysomnogram (sleep study) consist of? |
|
Definition
| the pt spends the night sleeping in a monitored room for 8 hrs and brain wave activity, EKG, respiratory movement, and airflow are all recorded |
|
|
Term
| what are indications for a nocturnal polysomnogram (sleep study)? |
|
Definition
| clinical suspicion for obstructive sleep apnea, habitual snorers w/daytime hypersomnolence, and habitual snorers w/observed apnea |
|
|
Term
| what is the apnea-hypopnea index (AHI)? |
|
Definition
| the AHI is calculated at the end of a nocturnal polysomnogram (sleep study) and the avg number of apneas/hypopneas per hr of sleep is calculated, and an AHI of >10 is diagnostic for obstructive sleep apnea |
|
|
Term
| what directives given to pts w/obstructive sleep apnea? |
|
Definition
| weight loss, avoid alcohol/sedatives, avoid sleep deprivation, good nocturnal positioning |
|
|
Term
| what does first-line medical therapy for obstructive sleep apnea consist of? |
|
Definition
| nasal CPAP - prevents narrowing and closure of upper airway regardless of site of obstruction (pneumatic splint) |
|
|
Term
| what does second-line medical therapy for obstructive sleep apnea consist of? |
|
Definition
|
|
Term
| what are other medical therapies for obstructive sleep apnea? |
|
Definition
| fluxetine/protriptyline (anti-depressants with central respiratory stimulatory effect - good for central sleep apnea), thyroid hormone (in hypothyroid pts), and nocturnal O2 (for pts waiting for a sleep study won't tx obstruction) |
|
|
Term
| how many pts generally tolerate CPAP? |
|
Definition
|
|
Term
| what are the benefits of nasal CPAP? |
|
Definition
| nasal CPAP improves neuropsychiatric function, lessens daytime sleepiness, lessens nocturnal desaturations, decreases nocturnal dysrhythmias, reverses pulm HTN/R sided heart failure, improves control of diurnal HTN (esp if pt loses wt), and improves survival (retrospective data) |
|
|
Term
| what are ADRs w/nasal CPAP? |
|
Definition
| rhinorrhea, nasal dryness/congestion, increased resistance to exhalation, pressure sensation in nose, claustrophobia, noise disturbance, mask nasal discomfort/irritation, and low compliance (46-62%) |
|
|
Term
| what is the oral appliance? what level of sleep apnea is this good for? |
|
Definition
| a mouthpiece that fixes the mandible in a more anterior position and pulls the soft tissue (tongue) w/it, preventing airway closure during sleep. this is good for mild-moderate sleep apnea |
|
|
Term
| what are the 2 major categories of obstructive sleep apnea sx therapy? |
|
Definition
| upper airway bypass and upper airway reconstruction |
|
|
Term
| what specific sx procedure accomplishes an upper airway bypass? |
|
Definition
| a tracheotomy, which is the most definitive sx where the pt can cap the bypass during the day to speak normally and open the tube at night |
|
|
Term
| what are the different forms of upper airway reconstruction? |
|
Definition
| uvulopalatopharyngoplasty, genioglossal advancement, and maxillomandibular advancement |
|
|
Term
| what is a uvulopalatopharyngoplasty (UPP/UP3)? |
|
Definition
| this is the *most common sx performed, where an incision is made in front of and behind the uvula to remove it, which opens up the airway (however food can come into the nose during swallowing). |
|
|
Term
| what is a uvulapalatal flap? |
|
Definition
| similar to the UP3, this procedure opens up the airway via making an incision in the uvula and folding it up to the roof of the mouth |
|
|
Term
| what is genioglossus advancement? |
|
Definition
| in this procedure, the insertion of the tongue is pulled forward and rotated 90 degrees, which moves it out of the airway |
|
|
Term
| what is maxillomandibular advancement? |
|
Definition
| the maxilla and mandible are broken, and the entire complex is pulled forward |
|
|
Term
| what is the hyoid advancement? |
|
Definition
| the hyoid bone is pushed down and sutured to the underlying cartilage - this creates a lever effect that pushes the tongue forward and out of the way |
|
|
Term
| what is maxillary expansion? |
|
Definition
| the mandible is split and widened, which creates more space for the tongue to flop forward |
|
|
