Sleep Apnea Flashcards
What is the definition of obstructive sleep apnea?
cessation of airflow for >10 seconds despite continuing respiratory effort…. 5 or more times per hour of sleep… usually associated with decrease in arterial oxygen saturation (SaO2) of more than 4%; in short= >10sec, >5x/hour
Describe the cycle that occurs during sleep apnea.
sleep…. decrease in upper airway tone…. obstruction occurs….. apnea followed by a decrease in PO2 and increased PCO2…. resulting in a sympathetic surge leading to arousal…. increase in upper airway tone, so normal breathing resumes
What are complications that can occur during the periods of apnea (decreased O2, increased PCO2)?
systemic HTN (LVH), pulmonary HTN (RVH), arrythmias (can lead to MI)
What classifies mild, moderate, or severe sleep apnea?
mild: 5-15/hr
moderate: 15-30/hour
severe: >30/hr (and/or hypoxia 20% of total sleep time)
What is the gold standard for screening of OSA?
polysomnography; other screening methods= Berlin questionnaire (good for primary care), STOP-BANG (most practical screening tool)
What are some components of the STOP BANG questionnaire?
snore? tired? observed by anyone (stop breathing)? pressure (HTN)? BMI >35? Age >50? neck circumference >40cm? gender male?
What are some general symptoms of central sleep apnea?
fatigue, snoring, obesity
What are the 3 forms of sleep apnea?
central, obstructive, and complex (mixed); obstructive represents 84% of cases…. mixed about 15%
What is the difference in CSA, OSA, or mixed sleep apnea?
CSA- breathing is interrupted by a lack of respiratory effort (PCO2 falls below the apneic threshold) 20%??
OSA- breathing is interrupted by a physical block to airflow despite respiratory effort… snoring common…. so basically physical obstruction or central disruption of breathing
What are some common types of central sleep apnea?
Cheyne Stokes breathing: normally more common in adults suffering from CHF (periodic breathing with recurrent episodes of apnea alternating with episodes of rapid breathing)
Idiopathic central apnea: (prevalence of afib higher in this group than any other)
Narcotic induced central apnea
What are treatments options for CSA?
CPAP, oxygen, inhaled CO2, acetazolamide (aka Diamox… carbonic anhydrase inhibitor…..limited supporting evidence on use), theophylline (relaxes bronchial smooth muscle… increases HR and BP, CNS stimulant effect on medullary resp center)
What is the incidence of OSA?
male to female ratio 2:1; 1:5 patients have OSA ~25%
What is polycythemia?
disease state in which the proportion of blood volume that is occupied by RBCs increases…. overproduction of RBCs can be d\t a primary process in the bone marrow or it can be a reaction to chronically low oxygen levels
