obstructive sleep apnea

osa

episodes of complete or partial collapse of upper airway → decreased oxygen saturation or arousal from sleep

risk factors

obesity (bmi ≥30), neck circumference >40cm, advanced age (>40yo), male/postmenopausal women, fam hx of osa, htn, dm, alc/sedative use

associated disorders

cardiovascular, endocrine, neurological, cancer

pathophys

airway collapse d/t antatomical abnormalities

• nasopharynx: deviated septum, enlarged structures (uvula, soft palate, tonsils)

• oropharynx: EtOH, BZDs, baclofen

• larynx/trachea: obesity, fluid shifting (hf)

decrease in lung filling → alveolar hypoventilation (poor gas exchange, hypoxia + hypercapnia)

daytime s/sx

dry mouth on awakening, sleepiness/somnolence, difficulty concentrating, waking ha (telltale sx), fatigue + mood changes

nighttime s/sx

snoring (telltale sx), apneic episode, frequent awakenings, body spasms, nocturia

in what pts is screening recommended

resistant/refractory systemic + pulmonary htn

recurrent bradyarrhythmia

recurrent afib following cardioversion or ablation

hf (class II-IV)

what acronym is used for screening

STOP-BANG; high risk ≥5, low risk <3

S: snore loudly? (heard through closed doors, or louder than talking)

T: feel tired, fatigue or sleepy during daytime

O: observed you stop breathing/choking/gasping during sleep

P: treated for high blood pressure?

B: bmi more than 35

A: age over 50

N: neck circumference, greater than 17” for males or 16” for females

G: gender (male)

what is used for evaluation

nighttime polysomnogram (PSG): measures blood oxygenation, breathing + sleep patterns

apnea-hypoxia index (AHI) event

correlation btwn a decrease in blood oxygenation following a pause in breathing

mild osa severity

5-15 AHI events per hour

moderate osa severity

>15-30 AHI events per hour

severe osa severity

>30 AHI events per hour

disease burden for mild osa

clinical implications are mixed d/t comorbidities + clinical presentation

risk for cv complications are comparable to those wo osa

prevalence of htn in osa

wisconsin sleep cohort study and sleep heart health study → both show high prevalence of HTN pts having OSA and vice versa; also show increasing HTN w/ OSA severity

pathophys of htn in osa

recurrent hypoxemia stimulates SNS → sympathetic upregulation of the RAAS system

prevalence of afib in osa

independent risk factor for afib wo other underlying cardiac disorders

shared risk factors btwn osa and afib

strong association btwn osa severity + prevalence of afib

pathophys of afib in osa

LA chemoreceptors sensitive to hypoxia

atrial remodeling + oxidative stress may contribute to formation of ectopic foci + reentry circuits

prevalence of stroke in osa

strong association btwn mod to severe osa + stroke (AHI >20 vs AHI>15)

substantial increase in stroke risk in osa and afib

improved stroke risk w/ management of osa (unclear benefit of osa management as primary stroke prevention)

pathophys of pulmonary htn in osa

airway obstruction → increase in return pressure to complete gas exchange

return pressure achieved through pulmonary vasoconstriction/remodeling

rv dyxfsn

pathophys of heart failure in osa

pulmonary vasoconstriction/remodeling decreases LA + LV return

frank-starling curve

stroke volume decreases → cardiac output decreases

pathophys of coronary artery disease in osa

recurrent hypoxemia = increase oxidative stress + systemic inflammation

contribution to atherosclerosis + its sequalae

association w/ a 2x increased risk of cv events or death

primary airway pressure therapy

CPAP: continuous positive airway pressure

limited to pt adherence

conflicting results on reduction ov cvd complications

anatomical management

often adjunct or refractory indications

tonsillectomy uvulopalatopharyngoplasty

obesity management

wt loss not recommended → b/c its not often curative

use lifestyle mods, bariatric surgery, pharm therapy

helps with improvement in associated complications + cardiovascular risk

tirzepatide brand name

zepbound

tirzepatide drug class

twincretin: GIP + GLP-1 receptor agonist

tirzepatide moa

increase glucose dependent insulin secretion

decrease inappropriate glucagon secretion

slows gastric emptying

modulates appetite

tirzepatide indications

t2dm management (mounjaro)

chronic wt management

wt related condition management

• pts w/ bmi ≥30 + conditions that may improve w/ wt loss

  • HFpEF

  • metabolic dysfxn associated w/ steatohepatitis (off label)

  • osa (fda approved (12/2024)

tirzepatide dosing

2.5mg sq once weekly (subtherapeutic)

titration: increase by 2.5mg every 4 wks

goal maintenance: 10-15 mg (max 15mg once weekly)

tirzepatide adrs

gi sx: most common! (thats why subtherapeutic starting dose), n/v/d, constipation, abd pain

thyroid cancer: c/i in personal/fam hx

pancreatitis

diabetic retinopathy, AKI, hypoglycemia

gi sx management

transient in most pts (most common during initiation + dose escalation

pt behaviors: eating habits, diet composition (avoid spicy, sweet foods), lifestyle mods (dont lay down after eating)

modification of titration schedule: extend duration of current dose (2-4 wks), if during escalation, return to previous dose, consider maintenance dose achieved

nausea management

eat crackers, apples, mint, ginger based drinks 30 mins after glp-1 ra, avoid strong smells

vomiting management

generous hydration, more frequent meals in smaller amounts

diarrhea management

generous hydration, no sports drinks, no high fiber content foods, eat more bland simple foods (chicken broth, rice, carrots, ripe peeled fruit, baked fruit), dont eat dairy products, laxatives, coffee, alc, soft drinks, very cold/hot foods, products w/ -ol ending (sweeteners)

constipation management

fiber!, increase physical activity, healthy balanced diet, generous hydration (water, sugar free liquids)