LOGIN 

 

JOIN

 

RENEW

 

CME/MOC

Sleep Fragments

HomeProfessionalsClinical ResourcesSleepSleep Fragments ▶ A patient with decreased respiratory effort
A patient with decreased respiratory effort

Contributed by M. Safwan Badr, MD

What is the finding identified by the arrow?

Click here for a larger view.

REM-related loss of intercostal muscle activity resulting in decreased thoracic effort. The loss of intercostal muscle activity is a characteristic finding during REM sleep and results in a decreased functional residual capacity during REM sleep. In patients with marginal oxyhemoglobin saturation (SaO2) during NREM sleep, the decreased FRC results in SaO2 <90%. The decreased FRC also explains why there are larger decreases in SaO2 with apneas and hypopneas during REM sleep.

Click here for a larger view.