A variety of equipment is available for treatment of sleep-disordered breathing (SDB). Selection of the device will depend on diagnosis and the appropriate setting(s) required to treat the condition and requires a physician order. A diagnosis is needed before the insurer will allow dispensing of positive airway pressure (PAP) equipment. Acceptable testing includes an in-laboratory polysomnography (PSG) or a home sleep apnea test (HSAT) that meets the criteria of the Centers for Medicare and Medicaid for type II, III, or IV testing. Many health insurers are leaning toward the more cost-effective use of HSAT when the patient meets criteria for high pretest probability of obstructive sleep apnea (OSA) (1). Table 75-1 provides PSG and HSAT device specifications for diagnosis of OSA.

OSA is typically treated with a continuous positive airway pressure (CPAP) device. The preferred method for determining the appropriate treatment pressure for patients with OSA is an in-laboratory PAP titration. Some patients who undergo in-laboratory PSG for diagnosis meet criteria for severe OSA (an apnea-hypopnea index [AHI] of >40) on the diagnostic night and undergo a split-night study, with PAP titration occurring on the same night. Patients with a high pretest probability of OSA who undergo HSAT for diagnosis sometimes are placed on an autotitrating device at home following diagnosis.

Once OSA has been confirmed via sleep testing, a CPAP device will generally be ordered for home use. Following a standard in-laboratory titration, the physician determines the appropriate PAP pressure and provides an order for home CPAP equipment on the basis of those findings. Standard CPAP pressures range from 4 to 20 cm H₂O. The order may include specific flex settings for patient comfort or a ramp time, and generally will include an order for a specific PAP interface (mask or another interface option).

In patients with OSA, a bilevel PAP (BPAP) device is often used if a patient is unable to tolerate higher PAP pressures. BPAP may also be used when CPAP is
ineffective at controlling hypopneas. In some patients, apneas are controlled at lower CPAP pressures, but hypopnea is not controlled until much higher pressures are reached. In this case, BPAP allows the use of a lower expiratory pressure to control apnea and a higher inspiratory pressure to control hypopnea, which is often better tolerated. Standard BPAP pressures range from 4 to 25 cm H₂O, with separate settings for inspiratory positive airway pressure and expiratory positive airway pressure (EPAP) based on the requirements determined to control their SDB determined during an in-laboratory titration study.

In patients with positional or rapid eye movement (REM)-related SDB, an autotitrating positive airway pressure (APAP) device is also an option. These patients may require relatively high PAP pressures when sleeping supine, but minimal pressure when sleeping in other positions. Similarly, patients with primarily REM-related events may be more comfortable on a lower PAP pressure during other stages of sleep when respiratory events are minimal. Standard APAP pressures range from 4 to 20 cm H₂O. The physician typically orders a setting range for home treatment of patients using APAP on the basis of the pressure needs identified during a titration study.

APAP is also used as a means of titrating and determining PAP pressure requirements at home in patients with uncomplicated OSA, sometimes by requirement of the insurance carrier. The physician ordering APAP to determine treatment needs for OSA patients generally specifies an open APAP pressure range from 4 to 20 cm H₂O and orders APAP for 3 to 7 days at home. A data download can then assist the physician to determine an appropriate CPAP setting for the patient and allows the patient to be switched from APAP to CPAP for long-term treatment or determine the need for further in-laboratory testing.

Primary central sleep apnea (CSA) is frequently treated with an adaptive servo ventilation (ASV) device. An in-laboratory PSG is required to determine optimal treatment settings for patients who require ASV. The diagnosis of CSA requires an AHI greater than or equal to 5 with the sum of the total central apneas plus central hypopneas greater than 50% of the total apneas and hypopneas; and a central apnea-hypopnea index
greater than or equal to 5 per hour; and the presence of either excessive daytime sleepiness, insomnia, frequent awakenings; and no evidence of daytime or nocturnal hypoventilation.

The requirements are stringent, and clinical documentation of symptoms along with a PSG that demonstrates CSA as defined are essential to obtain approval for ASV equipment coverage. Standard ASV pressures range from 4 to 25 cm H₂O and require a determination of the pressure support (PS) minimum and maximum setting; EPAP minimum and maximum setting; and an auto or fixed backup rate setting during an in-laboratory titration. These settings are specified in the physician order for ASV treatment following the physician’s evaluation of the titration study.

Restrictive thoracic disorders and chronic obstructive pulmonary disease are often treated with a bilevel-S or bilevel ST device. These devices can be used in a spontaneous mode (S) with the patient triggering the inspiratory pressure or a spontaneous timed mode (ST) with a backup rate if needed.

An average volume assured pressure support (AVAPS) device is similar to a bilevel device with autotitration that occurs on the basis of patient breathing patterns. Home use of bilevel or AVAPS requires documentation of neuromuscular disease or severe thoracic cage abnormality (e.g., kyphosis, scoliosis, or pectus carinatum) in the patients’ medical record. Titration must be performed in a sleep laboratory and entails monitoring the patient during the titration to assure that any obstructive events are treated, and that the device is adequately meeting the tidal volume requirements to maintain adequate oxygenation. Standard AVAPS pressures range from 4 to 25 cm H₂O with a PS minimum and maximum setting, EPAP setting, and backup rate setting (2).

DME coding for sleep therapy falls into two main categories, international classification of diseases (ICD) and healthcare common procedure coding system. The code sets are utilized to report medical diagnoses and procedures for claim reimbursement. All providers, including physicians, use this coding system and it is based on documentation in the patient’s medical record. Insurance will use these codes to determine coverage criteria (3). Table 75-2 provides a listing of ICD-10 codes for SDB diagnoses.