3-minute central apneas: enhanced expiratory rebreathing space to the rescue.

Abstract

This case report presents an atypical case of central sleep apnea (CSA) treated with continuous positive airway pressure (CPAP), enhanced expiratory rebreathing space (EERS) and oxygen. A 69-year-old female with morbid obesity and congestive heart failure who previously failed multiple positive airway pressure (PAP) modalities for presumed obstructive sleep apnea (OSA) was referred for re-titration with transcutaneous CO₂ (TCCO₂) monitoring. Titration with CPAP, bilevel PAP, and intelligent volume-assured pressure support resulted in 3-4 minute central apneas with an oxygen saturation nadir of 49%, and an average TCCO₂ of 27 mmHg. Subsequent split night polysomnography revealed CSA without OSA. CPAP and adaptive servoventilation alone and CPAP with oxygen were inadequate. Addition of EERS and oxygen supplementation to CPAP led to an improved Epworth Sleepiness Score (12 to 3) and overnight oximetry confirmed a satisfactory oxygen saturation nadir of 92%. This case highlights the use of TCCO2 monitoring in the recognition of hypocapnic CSA leading to successful treatment with CPAP, EERS and oxygen.