Def: Recurrent cessation or reduction of airflow during sleep due to absent or reduced respiratory effort
Caused by loss of central drive from the brainstem, not airway obstruction
Associated conditions
- HF: >50% of pts with NYHA class III-IV HF have CSA
- Acute or chronic neuro conditions affecting brainstem, e.g. stroke, posterior fossa SOL
- Meds: opiates, sedatives (e.g. benzodiazepines), gabapentinoids
- Alcohol
- High altitude
Cheyne-Stokes Respiration (CSR): CSA is of particular clinical relevance in HF. Crescendo-decrescendo pattern, vigorous effort gradually dwindles until breathing stops
Treatment
Focus on improving or removing underlying cause, e.g. optimize HF, stop offending meds
CPAP can treat CSA, but little evidence it improves long-term outcomes
ASV: pressure and flow adjust in response to changes in breathing
ASV effectively abolishes CSA
ASV does not reduce and may worsen mortality in significant HF
SERVE-HF: ASV contraindicated in HFrEF with LVEF ≤45%
ADVENT-HF: peak-flow triggered ASV in HFrEF showed no mortality harm
Transvenous phrenic nerve stimulation (remede) is an option for moderate-severe CSA
Complex Sleep Apnea: CSA that develops when OSA is treated with CPAP
ICSD-3 term: treatment-emergent CSA
Long-standing OSA causes ventilatory instability with altered CO2 sensitivity
- Oxford Handbook of Sleep Medicine 2022