Symptoms:
- Recurrent nocturnal awakening
- Unrefreshing sleep
- Daytime sleepiness
- Bed partner c/o
- loud snoring,
- nocturnal apnea
- choking episodes
4 types of Sleep apnea
- Obstructive Sleep Apnea (OSA)
- More common in overweight pt
- More likely to have car crashes due to xs sleepiness & falling asleep while driving.
- Increased risk to develop cardiovascular and cerebrovascular dz
- Central Sleep Apnea
- Cheyne-Stokes variety
- Common in pt with heart failure and cerebrovascular dz
- Complex sleep apnea
- Sleep hypoventilation
Management
- Must distinguish between the different types of sleep apnea – different Tx
- Provincial legislation for reporting drivers with untreated sleep apnea
- Pt education http://www.lung.ca/sleepapnea
- inform pt that EtOH and sedatives worsen OSA & sleep hypoventilation
Dx
- All pt w/ suspected OSA should complete an assessment of daytime sleepiness
- eg. Epworth Sleepiness Scale
- All pt should be assessed within 6 months of the referral by the dx sleep facility
- Pt with the following should be investigated within 4 weeks of the referral:
- suspected severe OSAS
- Working in safety-critical occupations
- Working with machinery or employed in hazardous occupations
- Commercial drivers, railway engiineers
- airline pilots, air traffic controllers, aircraft mechanics
- Ship captains & pilots
- High risk of a car crash
- drivers who admit to having fallen asleep while driving within the last 2 yr
- Co-morbid condition
- Unstable ischemic heart dz
- recent cerebrovascular dz
- CHF
- refractory systemic HTN
- Obstructive/restrictive lung dz
- pulmonary hypertension
- hypercapnic respiratory failure
- pregnancy
Dx modalities:
Level 1: portable monitoring studies is the test of choice when readily available
- complete laboratory technologist-attended PSG (polysomnnography)
For OSA dx in pt with a moderate to high pretest probability:
- Level 2: full ambulatory PSG
- Level 3: multi-channel cardio-respiratory recording devices
- Level -4 oximetry
Tx
All pt with daytime symptoms and OSA should be be Tx
- Wt loss in all overweight pt with OSA, but attempts to lose wt shouldn’t delay additional Tx
- All pt in a safety critical occupation or at high risk of a car crash should be told to cease their occupation or personal driving until their medical assessment has been complete and Tx established
- Review Tx if persistent low CPAP use (<4hr / night)
- Tx adherence assessed within 2-4 weeks of initiations and f/u within 3 mo to assess symptomatic response
- Oral appliances
- first line for pt with mild or moderate OSA with min daytime symptoms
- Should be fitted by trained dental practitioners
- pt should undergo f/u sleep monitoring with the oral appliance to ensure effective Tx
- Upper airway Sx
- OSA pt with large tonsils – ref to ENT for tonsillectomy evaluation
- OSA should be excluded before upper airway surgery for snoring
- Palatal Sx for snoring – potential difficulty of using CPAP later if they have OSA
- Laser-assisted uvulopalatoplasty – not recommended for Tx of
- OSA during Anaesthesia & post-op period may increase OSA
- OSA pt should be tx prior to Sx and continued on during the post-op period
Asymptomatic Adult OSA
- Tx if pt has
- co-morbid conditions: sig cardiovascular dz (including HTN) etc
- work in a safety critical occupation
- AHI (Apnea/hypopnea Index) >19/h
- 1o Tx: CPAP at a fixed Pressure
- Alt: APAP only in the absence of comorbid dz
- Bariatric (wt loss) Sx should be considered in Rx of OSAS in morbidly obese pt (BMI >=40) and BMI>=35 + serious comorbid dz
- after failure to lose wt or to maintain wt loss with dietary and lifestyle approaches
- A dx sleep study in asymptomatic pt after achievement of max wt loss (usually 1yr post-bariatric sx) to re-evaluate OSAS severity, before abandoning CPAP or other OSAS Tx
CSAS (Central sleep apnea syndrome) in HF pt
- Optimization of medical HF Tx should be the first step
- If CSAS persist after optimal medical HF Tx, consider 3 months trial of CPA
- AHI <15 – repeat sleep study, CPAP can be continued
- AHI >=15, d/c CPAP
CompSA
- A form of central apnea with persistence or emeregence of central apneas or hypopneas (with a CAI >5) on exposure to CPAP or spontaneous-mode BPAP when obstructive events have disappeared (CPAP titrated to eliminate OSAS)
- recognized as a distinct clinical entity
Optimal PAP technologies
- Variable expiratory pressure – no clear advantages over fixed CPAP
- consider in CPAP-intolerant pt
- BiPAP – reserved for pt with ventilatory failure
- ASV (automatic servoventilation) – for pt with CSR syndrome or CompSA
- unknown long-term benefits over CPAP or BPAP
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