Part B Insider (Multispecialty) Coding Alert

Treatment options for OSA and CSA will be very different

Do you know the difference between obstructive sleep apnea (OSA) and central sleep apnea (CSA)? If not, you could be an obstruction to proper coding.

Learn the new codes: You should master all of your new options for coding a patient's apnea, because the different diagnoses can affect the patient's treatment, say experts. The new set of apnea ICD-9 codes allow you to specify primary CSA (327.21), OSA (327.23), CSA in conditions specified elsewhere (327.27), insomnia with sleep apnea, unspecified (750.51) and hypersomnia with sleep apnea, unspecified (750.53).

OSA means that the back of the throat has closed off because of some kind of obstruction, says Jill Young, consultant with Young Medical in East Lansing, MI. CSA, on the other hand, means that the patient has a neurological problem that is keeping the brain's messages from reaching his or her organs. A patient with CSA won't usually snore or gasp loudly the way an OSA patient will.

Treatments for OSA, such as a continuous positive airway pressure (CPAP) device, don't work as well with most CSA cases because the patient's airway isn't blocked, says Young. CSA patients may require more tests, plus treatment for an underlying condition such as atherosclerotic disease, brain tumors or brain trauma.

You should be able to figure out a patient's diagnosis from the physician's report.  But you should also be an expert at reading the results of your patient's sleep study, says LeeAnn Greenough, a certified otolaryngology coder with North Fulton ENT Associates in Roswell, GA.

A sleep study will let you know the patient's sleep architecture, explains Greenough. This includes what stage of sleep the patient reaches before the apnea problems happen, whether stage one, delta or REM sleep.

Watch out for oxygen sat: One of the most important pieces of information on the sleep study will be the patient's oxygen desaturation level, says Greenough. This will let you know how low their oxygen saturation goes during sleep, and this figure is often crucial in obtaining coverage for a surgical procedure.

For example: A patient may have relatively few obstructive apnea incidents during sleep, but the patient's oxygen saturation goes as low as 69 percent. In that instance, most carriers will cover a surgical intervention because the patient isn't receiving enough oxygen, says Greenough.