Which polysomnogram should I order for my patient?
The objective of this polysomnogram is to create an accurate representation of your patient’s normal sleep patterns and behavior. The priority with a diagnostic study is to determine what the correlation is between your patient’s sleep-related complaints and their physiologic sleep patterns. The diagnostic portion is used to diagnose sleep related problems and common sleep disorders.
If your patient presents with a sleep related breathing disorder such as Obstructive Sleep Apnea (OSA) during the first portion of the diagnostic polysomnogram, our technicians may be able to initiate treatment using our split night protocol. A split night allows for the diagnoses of a sleep related breathing disorder and treatment with PAP therapy during a single night.
The second option on the sleep services order form, CPAP/Bi-PAP Titration Polysomnogram is used for patients requiring treatment for a sleep related breathing disorder with PAP therapy. This is a full night study with a focus on titrating the best airway pressure needed to eliminate a patient’s disordered breathing events.
The third option on the sleep services order form, Multiple Sleep Latency Test (MSLT) / Maintenance of Wakefulness (MWT) are daytime polysomnograms. A MLST is a test which is used to assess sleepiness primarily in patients with a presumptive diagnosis of narcolepsy.
A MWT is used to assess wakefulness. For more information please click here.
Who do I contact if I have questions about my patient’s sleep study report or treatment?
Why does my patient need to return for a second study?
According to Medicare guidelines, a split night study may be performed under the following conditions.
An Apnea Hypopnea Index (AHI) greater than or equal to 15 events per hour or; AHI greater than or equal to 5 and less than or equal to 14 events per hour with documented symptoms of excessive daytime sleepiness, impaired cognition, mood disorders or insomnia, or documented hypertension, ischemic heart disease or history of stroke.
The AHI must be based on a minimum of 2 hours of total sleep time during the polysomnogram.
According to American Academy of Sleep Medicine (AASM) a split night may be performed under the following conditions:
An AHI index of at least 40 per hour, documented during a minimum of two hours of polysomnography.
An AHI index of 20 to 40 if there are repetitive long airway obstructions and major oxygen desaturations, or other documented reason why less than a full night study is warranted.
Delta Waves split night protocol follows the significantly more strict guidelines of the AASM. Our split night protocol requires the sleep technician to make an initial real-time diagnosis based on a partial polysomnogram.
CPAP may be initiated if any of the below apply;
- The patient’s AHI is greater than 40 during the first 2 hours of TST.
- A split night study may be considered for patients after 2 hours TST with an AHI of 20-40 under the following circumstances:
- Prolonged obstructive events > 60 seconds
- Documented (in the medical record) history of:
- mood disorders
- insomnia
- hypertension
- heart disease
- stroke
- ESS >10
- impaired cognition
- The patient has an AHI of at least 5 and the SpO2 has fallen to less than 85% for 10 minutes total or to less than 89% for 30 minutes total.
- All of the following:
- the patient has a prior diagnosis of OSA and is currently being treated with PAP therapy
- PSG has been ordered to confirm diagnosis (e.g. for insurance or similar purposes)
- Obstructive AHI is >5 after 2 hours of sleep
These parameters help to prevent patients with mild sleep apnea from being over treated.
Why was a split night study not performed during my patient's first study?
A split night may NOT be performed due the following reasons:
Insufficient time remaining during the night to titrate the patient once they have met split night protocol. This is frequently the case for mild sleep apnea suffers.
Short sleep time- poor sleep efficiency, prolonged awakening in the middle of the night.
Majority of sleep disordered breathing events that met criteria occurred in the second half of the night.
Majority of sleep disordered breathing events that met criteria occurred while in REM sleep.REM sleep usually predominates the latter half of the night and a two hour initial baseline PSG may underestimate significantly the baseline severity of a patient’s apnea.
The affects of body position on breathing.
Majority of sleep disordered breathing events that meet criteria occurred only when the patient was in a certain sleeping position.
Patient may refuse PAP therapy.
Split nights are not routinely performed on mild sleep apnea suffers for several reasons:
Mild apnea cases can normalize by morning. If a patient has only a few disordered breathing events early in the study, a longer total sleep time may reduce the AHI to normal parameters.
PAP therapy may not be the most appropriate therapy for a patient with mild sleep apnea.
There may be insufficient time during a split night to be certain that the patient’s mild apnea has been corrected in all positions and sleep stages.
Do I need to provide my patient with any instructions regarding their medication usage?
Our sleep technicians are not permitted to advise patients about medication usage during their visit to the sleep center. We also recommend that you discuss medication usage with your patient prior to their sleep study appointment if necessary.
Our sleep specialist, recommends that patients do not use a sleep aid during the diagnostic study. However, if a patient had poor sleep efficiency during diagnostic study and are scheduled to return for a titration study, a sleep aid may be beneficial to ensure proper sleep efficiency.
Ultimately the referring physician determines what medications the patient should be using including sleep aids, especially if a patient is a chronic user and cannot sleep without medication.