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Positive Airway Pressure For OSAS BY AHMAD YOUNES PROFESSOR OF THORACIC MEDICINE Mansoura Faculty Positive Airway Pressure For OSAS BY AHMAD YOUNES PROFESSOR OF THORACIC MEDICINE Mansoura Faculty Of Medicine

International classification of sleep disorders, criteria for OSA: Diagnosis = A + B + International classification of sleep disorders, criteria for OSA: Diagnosis = A + B + D or C + D A. At least one of the following applies: i. Complaints of unintentional sleep episodes during wakefulness, daytime sleepiness, un-refreshing sleep , fatigue, or insomnia. ii. Awakenings with breath-holding, gasping, or choking. iii. Bed partner reports loud snoring and/or breathing interruptions during the patient’s sleep. B. Polysomnography shows the following: i. Scoreable respiratory events (apneas + hypopneas + RERAs)/hr of sleep ≥ 5/hr. ii. Evidence of respiratory effort during all or a portion of each respiratory event.

International classification of sleep disorders, criteria for OSA: Diagnosis = A + B + International classification of sleep disorders, criteria for OSA: Diagnosis = A + B + D or C + D C. Polysomnography shows the following: i. Scoreable respiratory events (apneas + hypopneas + RERAs)/hr of sleep ≥ 15/hr. ii. Evidence of respiratory effort during all or a portion of each respiratory event. D. The disorder is not better explained by: another current sleep disorder, medical or neurologic disorder, medication use, or substance use disorder.

Positive Airway Pressure Therapy • Administration of positive airway pressure therapy is the treatment Positive Airway Pressure Therapy • Administration of positive airway pressure therapy is the treatment of choice for most patients with OSA. • CPAP treatment is generally recommended for all patients with an AHI greater than or equal to 15/hour and for symptomatic patients (eg, excessive daytime sleepiness, insomnia, impaired cognition, mood disorder, hypertension, ischemic heart disease, or stroke) with an AHI between 5– 15/hour.

Treatment modalities for Positive Airway Pressure Therapy • Continuous positive airway pressure Provides a Treatment modalities for Positive Airway Pressure Therapy • Continuous positive airway pressure Provides a constant pressure throughout the respiratory cycle • Bi-level positive airway pressure Provides two pressure levels during the respiratory cycle: a higher level during inspiration and a lower pressure during expiration • Autotitrating positive airway pressure Provides variable pressures using device-specific diagnostic and therapeutic algorithms • Nocturnal noninvasive positive pressure ventilation Provides two pressure levels at a set rate to assist ventilation

Determining Optimal Continuous Positive Airway Pressure 1. In-laboratory attended polysomnographically guided CPAP titration – Determining Optimal Continuous Positive Airway Pressure 1. In-laboratory attended polysomnographically guided CPAP titration – Full-night studies. – Split-night studies (consists of an initial diagnostic portion and a subsequent CPAP titration on the same night) 2. Unattended laboratory or home titration 3. Use of autotitrating devices 4. Formula-derived pressures from clinical, PSG, and/or anthropometric variables

The current standard of practice • The current standard of practice involves an attended The current standard of practice • The current standard of practice involves an attended pressure titration during a laboratory PSG, during which sleep stages and respiratory variables are monitored. • The goal is to determine a single fixed pressure that eliminates apneas, hypopneas, snoring, and respiratory effort–related arousals (RERAs); maintains adequate oxygen saturation; and improves sleep architecture and quality in all sleep positions and in all sleep stages. • It is generally accepted that higher pressures are required to reverse airway occlusion during REM sleep and during sleep in a supine position. • Spit-night studies can potentially underestimate the severity of OSA

Criteria for split-night (CPAP) titration • At least 2 hours of recorded sleep time Criteria for split-night (CPAP) titration • At least 2 hours of recorded sleep time during the initial diagnostic portion of the study • Apnea-hypopnea indices during the diagnostic portion of the study: AHI 40 OR • AHI 20– 40 (accompanied by significant oxygen desaturation) • At least 3 hours are available for CPAP titration with the presence of REM sleep during a supine sleep position

AASM recommendations for CPAP and BPAP therapy for adult patients with sleep related breathing AASM recommendations for CPAP and BPAP therapy for adult patients with sleep related breathing disorders • The presence of OSA based on an acceptable diagnostic method should be established prior to CPAP therapy (standard). Indications for CPAP therapy include: a. Moderate to severe OSA (standard) b. Mild OSA (option) c. Improvement of subjective sleepiness in patients with OSA (standard) d. Improvement of quality of life in patients with OSA (option) e. As an adjunctive therapy to lower blood pressure in patients with OSA (option)

AASM recommendations for CPAP and BPAP therapy for adult patients with sleep related breathing AASM recommendations for CPAP and BPAP therapy for adult patients with sleep related breathing disorders 3. The preferred CPAP titration method to determine optimal positive airway pressure is an in-laboratory, fullnight, attended polysomnography, but split-night studies are usually adequate (guideline). 4. Objective monitoring of CPAP use is recommended to ensure optimal utilization (standard). 5. Close monitoring of CPAP utilization and any problems that might develop, especially during the first few weeks of use, is important, as is the correction of problems if needed (standard). 6. Addition of heated humidification and a systematic educational program enhance adherence to CPAP use (standard).

AASM recommendations for CPAP and BPAP therapy for adult patients with sleep related breathing AASM recommendations for CPAP and BPAP therapy for adult patients with sleep related breathing disorders 7. Patients with OSA treated with CPAP therapy should be followed up yearly or more frequently as needed to correct problems related to its use (option). 8. CPAP and bilevel positive airway pressure (BPAP) therapy are generally safe with minor adverse effects (standard). 9. BPAP can be considered as an optional therapy to CPAP in selected patients who require high pressures, who report difficulty exhaling against a fixed CPAP pressure, or who have coexisting central hypoventilation (guideline). 10. BPAP may also be beneficial in patients with some forms of restrictive lung disease or hypoventilation syndromes with daytime hypercapnia (option).

AASM recommendations for CPAP and BPAP therapy for adult patients with sleep related breathing AASM recommendations for CPAP and BPAP therapy for adult patients with sleep related breathing disorders • The extent to which asymptomatic patients with mild OSA and no associated medical or psychiatric disorders benefit from CPAP is less certain. • Intermittent use of CPAP should be avoided, because virtually all of the gains in sleep quality and daytime alertness derived from sleeping with CPAP are rapidly reversed with CPAP discontinuation.

Starting PAP treatment based on a prediction equation with subsequent adjustment based on symptoms, Starting PAP treatment based on a prediction equation with subsequent adjustment based on symptoms, machine readings, and nocturnal oximetry. • Predicted CPAP =0. 16 XBMI +0. 13 X NC + 0. 04 XAHI – 5. 12 where BMI = body mass index and NC = neck circumference in centimeters AHI =apnea hypopnea index.

Beneficial effects of positive airway pressure therapy in OSA • • • Sleep quality Beneficial effects of positive airway pressure therapy in OSA • • • Sleep quality Improvement in sleep quality Upper airway anatomy and function Reduction or elimination of snoring Decrease in apneahypopnea index (AHI) Increase in arterial oxygen saturation (Sa. O 2) Sleepiness and other daytime symptoms Decrease in sleepiness (subjective and objective) Improvement in quality of life Enhancement of mood and neurocognitive function

Beneficial effects of positive airway pressure therapy in OSA • Hypertension Improvement in blood Beneficial effects of positive airway pressure therapy in OSA • Hypertension Improvement in blood pressure and heart rate profiles in patients with hypertension • Congestive heart failure Improvement in cardiac function in patients with OSA • Health care utilization Reduction in physician claims and hospital stay • Mortality Reversal of the increase in mortality associated with sleep apnea

Adverse consequences of positive airway pressure therapy • Aerophagia and gastric distention • Arousals Adverse consequences of positive airway pressure therapy • Aerophagia and gastric distention • Arousals , Sleep disruption due to noise from the device • Barotrauma (eg, pneumothorax, pneumomediastinum, pneumocephalus) • Chest discomfort and tightness • Claustrophobia, sensation of suffocation or difficulty with exhalation • Eye irritation (conjunctivitis) • Facial skin irritation, rash or abrasion • Mask and mouth leaks • Nasal congestion, dryness, epistaxis or rhinorrhea • Sinus discomfort or pain

Adherence to Positive Airway Pressure Therapy • Therapeutic adherence in the different studies has Adherence to Positive Airway Pressure Therapy • Therapeutic adherence in the different studies has varied from 46% to 80% of patients who use CPAP for 4 or more hours nightly on at least 70% of monitored nights. • Self-reports often over estimate actual CPAP use. • Approximately 50% of patients are consistent CPAP users, and the rest are intermittent users with a wide range of nightly use. • Average nightly use is between 4 to 5 hours each night among CPAP users. The percent of days in which CPAP was not used correlated with decreased duration of nightly use.

Factors influencing long-term use • Factors influencing long-term use include snoring history, severity of Factors influencing long-term use • Factors influencing long-term use include snoring history, severity of illness (AHI), perceived benefit from therapy, and self-reported sleepiness (Epworth Sleepiness Scale [ESS]. • Patients with mild OSA have a particularly high rate of CPAP discontinuation. • Long-term use of CPAP does not appear to be related to the prescribed pressure. Finally, CPAP usage tends to be greater among patients who underwent full-night CPAP titration studies compared to those who had split-night CPAP titration.

Factors influencing long-term use • Patterns of nightly use are often discernible by the Factors influencing long-term use • Patterns of nightly use are often discernible by the first few days or weeks of initiating treatment. • Adherence to CPAP therapy may be improved with education (eg, additional home visits , participation in group clinics, periodic phone calls to uncover any problems and to encourage use, and even simple written information on the importance of regular CPAP use), airway humidification, proper selection of the CPAP interface, desensitization procedures for CPAP, early follow-up , prompt and aggressive management of adverse effects related to CPAP use, and regular assessment of CPAP adherence.

Reasons for non-adherence to positive airway pressure therapy 1 -Perception of lack of benefit: Reasons for non-adherence to positive airway pressure therapy 1 -Perception of lack of benefit: Patient education 2 -Discomfort with its use (including mask): Mask refitting (nasal masks, nasal pillows, full-face masks, ororal masks) 3 -Noise from the device Placing device in another room adjacent to bedroom , Use of ear plugs or noise-attenuating devices 4 -Air leaks from the mask or mouth: Mask refitting for mask leaks , Use of chin strap or full face mask for mouth leaks 5 -Airway humidification , Treatment of nasal congestion 6 -Difficulty with exhaling against high expiratory pressures Trial of CPAP with C-flex technology or bilevel positive airway pressure (BPAP) 7 -Excessively high pressures: Trial of automated positive airway pressure or Adjunctive therapy with sleep position

Reasons for non-adherence to positive airway pressure therapy 8 -Frequent nocturnal awakenings: Brief trial Reasons for non-adherence to positive airway pressure therapy 8 -Frequent nocturnal awakenings: Brief trial of hypnotic agents during the acclimatization phase of initial CPAP use (eszopiclone) 9 -Claustrophobia: Mask refitting (eg, nasal pillows or oral masks), Formal program of CPAP desensitization 10 -Nasal problems: • Dryness: -Airway humidification (preferably heated) Use of nasal lubricants • Sneezing , Congestion , Rhinorrhea : -, decongestants, anticholinergic agents, or corticosteroids , oral decongestants, Immunotherapy, or antihistamine agents • Epistaxis: - Nasal surgery (in patients with nasal anatomic abnormalities) 11 -Gastric distention due to aerophagia BPAP therapy

Automatic CPAP For OSAS Automatic CPAP For OSAS

Auto-positive airway pressure • Auto-positive airway pressure (APAP) devices provide a useful alternative for Auto-positive airway pressure • Auto-positive airway pressure (APAP) devices provide a useful alternative for providing positive airway pressure (PAP) treatment for patients with obstructive sleep apnea (OSA). • One can separate the uses of these devices into two large categories These include: (1) Auto-titration PAP to determine an effective fixed level of continuous positive airway pressure (CPAP) (2) Auto-adjusting PAP for chronic treatment.

Auto-positive airway pressure devices • When used in the auto-titration mode, the devices are Auto-positive airway pressure devices • When used in the auto-titration mode, the devices are used by the patient for a period of time (one night to several weeks). Information stored in the device is transferred to a computer and can be used to select an optimal fixed level of CPAP for chronic treatment. • When APAP devices are used for chronic treatment they have the potential advantage of delivering the lowest effective pressure in any circumstance (body position, sleep stage). The mean pressure for the night may be lower than a single pressure that would be effective in all circumstances (the prescription pressure). For example, higher CPAP is usually needed in the supine posture and during rapid eye movement (REM) sleep.

Auto-titrating mode • Attended auto-titration in CPAP naïve patient (technologist extender) • Unattended auto-titration Auto-titrating mode • Attended auto-titration in CPAP naïve patient (technologist extender) • Unattended auto-titration in CPAP naïve patient • Check prescription pressure after weight gain/loss • Salvage a failed manual CPAP titration Auto-adjusting mode • Initial chronic treatment of OSA (no titration needed) • Chronic treatment in patients not tolerating CPAP • Chronic treatment in patients with difficult mask/mouth leak

DEVICE CHARACTERISTICS • The devices differ in the respiratory variables that are monitored and DEVICE CHARACTERISTICS • The devices differ in the respiratory variables that are monitored and in the algorithms used to adjust the delivered pressure. • The devices typically monitor one or more of the following: airflow (or motor speed), airflow profile (flattening), snoring (airway vibration), or airway impedance (forced oscillation technique). • The algorithms used to adjust pressure are proprietary but determine if the delivered pressure should be increased or decreased. • Depending on the type of respiratory event that is detected the delivered pressure is increased by a certain amount.

Open unrestricted airway Open unrestricted airway

Silent partial airway obstruction Silent partial airway obstruction

Noisy partial airway obstruction Noisy partial airway obstruction

Complete airway obstruction Complete airway obstruction

Open unrestricted airway Open unrestricted airway

DEVICE CHARACTERISTICS • The S 9 Series detects both obstructive and central sleep apneas DEVICE CHARACTERISTICS • The S 9 Series detects both obstructive and central sleep apneas (CSA). CSA detection uses the Forced Oscillation Technique (FOT) to determine the state of the patient’s airway during an apnea. • When an apnea has been detected, small oscillations in pressure (1 cm H 2 O peak-to-peak at 4 Hz) are added to the current device pressure. The CSA algorithm uses the resulting flow and pressure (determined at the mask) to measure the airway patency.

An APAP device using this technology does not increase pressure for “clear airway” apneas. An APAP device using this technology does not increase pressure for “clear airway” apneas.

DEVICE CHARACTERISTICS • Typically, pressure changes occur slowly over several minutes to prevent pressure-induced DEVICE CHARACTERISTICS • Typically, pressure changes occur slowly over several minutes to prevent pressure-induced arousals. • If no respiratory events are detected within a certain time window the delivered pressure is slowly decreased. Thus, the lowest effective pressure is delivered. • In some of the devices machine adjustment is available for various mask types and for the type of humidifier that is being used. • Studies comparing different APAP devices provide evidence that devices from different manufacturers will not deliver the same pressure for a given clinical circumstance.

DEVICE CHARACTERISTICS • The responses of several devices differs markedly in response to apnea. DEVICE CHARACTERISTICS • The responses of several devices differs markedly in response to apnea. Some of the devices increased the delivered pressure in response to apnea while others did not. • Comparing the 95 th percentile pressure of one APAP device based on airflow to another based on the forced oscillation technique found poor agreement between the optimal pressure identified by the two devices. • The adherence and clinical outcomes were similar although the median applied pressure was slightly higher with the device that responded to airflow limitation. Thus, differences in the devices do not always translate into differences in outcomes.

Problems of APAP algorithms • The problems of mask/mouth leak and central apnea have Problems of APAP algorithms • The problems of mask/mouth leak and central apnea have provided a challenge for the designers of APAP algorithms. • Mask/mouth leaks tend to raise the baseline flow delivered by blower units and diminish the variations in flow during inspiration and expiration. The resulting airflow signal may be interpreted as an apnea or hypopnea and prompt an increase in pressure that may further increase leak. • To handle the leak problem many APAP units have algorithms that limit pressure increases when leak exceeds certain values or when increases in blower speed no longer result in increases in mask pressure. Other units have leak alarms that can prompt the patient to adjust the mask.

Problems of APAP algorithms • Mouth leaks can be approached by using a chin Problems of APAP algorithms • Mouth leaks can be approached by using a chin strap or full-face mask. • Algorithms often include limits on upward titration of pressure for apnea to avoid the delivery of high pressure for central apneas. For example, pressure is not increased above 10 cm H 2 O unless apnea is associated with snoring or airflow profile flattening.

Expiratory pressure relief • Expiratory pressure relief (C-Flex, Respironics) is now available for one Expiratory pressure relief • Expiratory pressure relief (C-Flex, Respironics) is now available for one brand of APAP devices. • This mode allows a reduction in pressure during early expiration with a return to the current set pressure at end expiration. • This feature could improve patient tolerance to pressure.

Automatic adjustment of bi-level PAP • APAP machines providing automatic adjustment of bilevel PAP Automatic adjustment of bi-level PAP • APAP machines providing automatic adjustment of bilevel PAP (BPAP) are available. These devices vary inspiratory positive airway pressure (IPAP) and expiratory positive airway pressure (EPAP) according to a proprietary algorithm. • The physician sets the minimum EPAP, maximum IPAP, and maximum IPAP–EPAP difference. • The option of using inspiratory and expiratory pressure relief (Bi-Flex R, Respironics) is currently available for one device brand. • Inspiratory pressure relief allows a drop in pressure at end inhalation (IPAP) while expiratory pressure relief allows a pressure drop at the start of exhalation (EPAP).

A single night profile showing changes in IPAP and EPAP over the night with A single night profile showing changes in IPAP and EPAP over the night with auto-bilevel positive airway pressure.

 • Manual PAP titration is labor intensive and usually a single technologist can • Manual PAP titration is labor intensive and usually a single technologist can titrate only two patients at a time. • Patients in some geographical areas may have limited or delayed access to a sleep laboratory offering polysomnography. • In addition, the gold standard PAP titration method may result in suboptimal titrations due to a number of problems including poor sleep, lack of supine REM sleep, high mask leak, or uncorrected mouth leak. Patient characteristics such as weight gain may also render previously selected pressures inadequate. • Auto-titrating PAP devices can be used to address some of these problems.

AUTO-TITRATION • One important use of APAP devices is selection of a fixed CPAP AUTO-TITRATION • One important use of APAP devices is selection of a fixed CPAP pressure as an alternative to traditional manual (attended) PAP titration. • Information stored in the device memory can be analyzed and a pressure can be chosen for fixed CPAP treatment. • A common method is to choose the 90 th or 95 th percentile pressure (pressure exceeded only 10% or 5% of the time, respectively) as the prescription pressure. This assumes periods of high leak have been eliminated from the analysis.

Efficacy of Auto-Titration • Unattended APAP was successful at identifying an effective CPAP level. Efficacy of Auto-Titration • Unattended APAP was successful at identifying an effective CPAP level. • Treatment with fixed CPAP using a pressure identified by unattended APAP titration reduced the AHI to < 10/hour in 38/40 subjects. • In 15 of 20 patients the difference between the APAP pressure (taken as P 95) and the CPAP chosen by manual titration was equal to or less than 1 cm H 2 O.

Technique of Auto-Titration • As with manual attended PAP titrations with polysomnography, patient education, Technique of Auto-Titration • As with manual attended PAP titrations with polysomnography, patient education, and mask fitting are essential for successful auto-titration. Patients must feel comfortable applying the mask interface and operating the APAP device if an unattended titration is planned. • A short 20 -minute trial of APAP can be very useful in identifying patient problems including claustrophobia, mask leak or an inability to operate the device • The physician ordering the APAP titration designates the lower and upper pressure limits (for example, 4 and 20 cm H 2 O). The APAP device then titrates between these limits.

Technique of Auto-Titration • Depending on the type of APAP device utilized, information on Technique of Auto-Titration • Depending on the type of APAP device utilized, information on applied pressure, leak, snoring, flattening, and a moving time average of the AHI is stored in the device memory. After transfer to a computer , the information is available for review. • It is possible to determine statistics for all or a portion of the data. • Most devices allow the ability to look at one or more single nights of data in detail (pressure, leak, residual events vs. time).

The leak and residual AHI are low. The 95 th percentile pressure was 9. The leak and residual AHI are low. The 95 th percentile pressure was 9. 4 cm H 2 O. The patient was treated with a prescription pressure of 10 cm H 2 O

Technique of Auto-Titration • High leak can result in many devices promptly increasing pressure Technique of Auto-Titration • High leak can result in many devices promptly increasing pressure until the upper pressure limit is reached. • summary statistics can be displayed for a single night or multiple nights. Typically available information includes: 90 th or 95 th percentile pressure, median pressure, maximum pressure, maximum leak, median leak, and residual AHI.

Technique of Auto-Titration • Usually either the 90 th or 95 th percentile pressure Technique of Auto-Titration • Usually either the 90 th or 95 th percentile pressure is chosen for the prescription pressure. However, simply noting one number can be very misleading. • The clinician must first determine if the titration duration (amount of sleep on the device ) was adequate and if the residual AHI is reasonably low (AHI < 5– 10/hour). • Patients with suboptimal or inconclusive APAP titrations should have a repeat APAP titration or be referred for an attended lab PAP titration.

Technique of Auto-Titration • High-residual AHI could be secondary to frequent central apneas, high Technique of Auto-Titration • High-residual AHI could be secondary to frequent central apneas, high leak, or too low maximum pressure limit. • High leak could be secondary to inadequate mask seal or mouth leak if a nasal mask is being utilized. • Patients with a high AHI and leak may undergo a repeat APAP titration after mask adjustment or change to a fullface mask (or addition of a chin strap) as indicated. • A persistently high-residual AHI despite repeated attempts at APAP titration would be an indication of the need for a traditional manual PAP titration.

The leak is higher than ideal (> 0. 4 L/s) at times. However, the The leak is higher than ideal (> 0. 4 L/s) at times. However, the residual AHI remained low. The 95 th percentile pressure was 7. 8 cm H 2 O. The prescription pressure was chosen to be 8 cm H 2 O.

The leak is very high. The pressure increased to the upper limit (16 cm The leak is very high. The pressure increased to the upper limit (16 cm H 2 O) and remained there for most of the night. The AHI was also elevated. This titration would need to be repeated with a better mask seal.

Technique of Auto-Titration • A number of portable monitoring units can interface with selected Technique of Auto-Titration • A number of portable monitoring units can interface with selected APAP devices. For example, airflow, respiratory effort, oxygen saturation, body position, and delivered pressure can be recorded for clinician analysis. • This is especially helpful if one night of APAP titration is utilized. For example, absence of supine sleep could result in a lower than typically needed prescription pressure. This is also a reason that it is often helpful to have the patient use the APAP device for several nights. • Average statistics over a week may more accurately represent a typical night’s pressure requirements. Information from pulse oximetry during the APAP titration can identify the need for the addition of supplemental oxygen.

In summary • Auto-titrating PAP devices can be useful for identifying an appropriate fixed In summary • Auto-titrating PAP devices can be useful for identifying an appropriate fixed CPAP level in appropriate patients. • Unattended as well as attended titration can be effective. However, it is likely that unattended APAP titration will not be effective in a significant proportion of OSA patients. • Patients with a significant proportion of central apneas, those with low baseline Sa. O 2 values or who have difficulty applying the mask and/or operating an APAP device are best studied using attended manual titration with polysomnography.

In summary • A brief practice trial with APAP may be useful to identify In summary • A brief practice trial with APAP may be useful to identify mask leak or nasal congestion problems requiring intervention before the patient takes the APAP device home. • If APAP titration is performed, close review of the data is needed to ensure that the titration was adequate. • Those patients not having an adequate APAP titration should be referred for a traditional CPAP titration.

CHRONIC TREATMENT WITH AUTO-POSITIVE AIRWAY PRESSURE CHRONIC TREATMENT WITH AUTO-POSITIVE AIRWAY PRESSURE

AUTO-ADJUSTING POSITIVE AIRWAY PRESSURE • When originally developed one anticipated advantage of APAP devices AUTO-ADJUSTING POSITIVE AIRWAY PRESSURE • When originally developed one anticipated advantage of APAP devices was that delivery of the lowest effective pressure in any circumstance (sleep stage, body position) would improve acceptance and adherence to positive pressure treatment. • This was based on the premise that a lower mean nightly pressure would improve patient tolerance to PAP treatment. Alternatively, chronic treatment with an auto-adjusting device would obviate the need for an attended or unattended PAP titration.

Auto-Positive Airway Pressure Vs. CPAP Treatment • A number of studies have examined the Auto-Positive Airway Pressure Vs. CPAP Treatment • A number of studies have examined the hypothesis that chronic treatment with auto-adjusting PAP would increase the adherence. • Some studies did find higher adherence with APAP compared to fixed CPAP treatment. Several other studies did not confirm this result. • In evaluating studies of adherence several issues must be considered. First, pressure intolerance is not the major issue for many patients. Second, the difference in the mean pressure on APAP and an adequate fixed pressure is often only 1 to 2 cm H 2 O. One would not expect such a small pressure difference to change adherence

Auto-Positive Airway Pressure Vs. CPAP Treatment • One might expect a potential advantage for Auto-Positive Airway Pressure Vs. CPAP Treatment • One might expect a potential advantage for APAP devices in patients with pressure intolerance, high prescription pressures, or a large variation in the required pressure during the night (postural or REMrelated OSA). Thus, if a patient is having difficulty with CPAP, a trial of APAP is a reasonable intervention. • If APAP is preferred, improved adherence is likely with this mode of treatment compared to fixed CPAP. Furthermore, information stored in the machine such as leak or residual events may help diagnose problems with treatment.

Auto-Positive Airway Pressure Vs. CPAP Treatment • Patients with difficulty tolerating CPAP due to Auto-Positive Airway Pressure Vs. CPAP Treatment • Patients with difficulty tolerating CPAP due to pressure intolerance (“cannot breathe out”) are often switched to BPAP. • APAP treatment does not improve adherence over fixed CPAP selected by manual titration • Patients diagnosed with OSA could be treated with chronic APAP without the need for either traditional laboratory titration or auto-titration. Any additional cost of APAP devices over CPAP would usually be < the cost of an in-laboratory CPAP titration. Both a cost saving and a reduction in the time needed to adjust the PAP treatment occur to a satisfactory level. • The optimal level of CPAP determined by an attended inlaboratory titration often requires alteration for patient tolerance, side effects, or control of daytime sleepiness.

Technique of Chronic Auto-Positive Airway Pressure Treatment • The physician usually orders the lower Technique of Chronic Auto-Positive Airway Pressure Treatment • The physician usually orders the lower and upper limits of positive pressure. The APAP device then delivers the lowest effective pressure between these limits. • The upper and lower pressure limits could be placed as wide as possible (4– 18 cm H 2 O) or narrowed based on information from a previous CPAP titration or previous nights of APAP use. • Some patients find starting at 4 cm H 2 O uncomfortable and it may take some APAP machines several minutes to reach a pressure level that they find comfortable. In this case the lower pressure could be increased to 6– 10 cm H 2 O. • Awakening with the feeling of insufficient pressure could be another situation in which the lower pressure limit should be increased.

Technique of Chronic Auto-Positive Airway Pressure Treatment • Bloating or evidence of excessive mouth Technique of Chronic Auto-Positive Airway Pressure Treatment • Bloating or evidence of excessive mouth leak might be an indication to lower the upper pressure limit . Alternatively, if the 90 th percentile pressure essentially equals the upper pressure limit, then a higher upper pressure limit is likely needed (especially if the residual AHI is high). • Information on delivered pressure is not the only data stored in the APAP device that is potentially useful for tailoring treatment. • High leak may indicate the need for another mask or a full-face mask (mouth leak).

Technique of Chronic Auto-Positive Airway Pressure Treatment • A high-residual AHI might indicate a Technique of Chronic Auto-Positive Airway Pressure Treatment • A high-residual AHI might indicate a need for an increase in either the lower or upper pressure. • A high number of residual apneas might suggest that central apneas could be present. • Financial constraints may limit the use of APAP devices for chronic treatment of OSA at least in some circumstances.

Recommendations • APAP is not recommended to diagnose OSA. (Standard) • Patients with congestive Recommendations • APAP is not recommended to diagnose OSA. (Standard) • Patients with congestive heart failure, significant lung disease such as chronic obstructive pulmonary disease, patients expected to have nocturnal arterial oxyhemoglobin desaturation due to conditions other than OSA (e. g. , obesity hypoventilation syndrome), patients who do not snore (either naturally or as a result of palate surgery), and patients who have central sleep apnea syndromes are not currently candidates for APAP titration or treatment. (Standard)

Recommendations • APAP devices are not currently recommended for split-night titration. (Standard) • Certain Recommendations • APAP devices are not currently recommended for split-night titration. (Standard) • Certain APAP devices may be used during attended titration with polysomnography to identify a single pressure for use with standard CPAP for treatment of moderate to severe OSA. (Guideline) • Certain APAP devices may be initiated and used in the selfadjusting mode for unattended treatment of patients with moderate to severe OSA without significant comorbidities (CHF, COPD, central sleep apnea syndromes, or hypoventilation syndromes). (Option)

Recommendations • Certain APAP devices may be used in an unattended way to determine Recommendations • Certain APAP devices may be used in an unattended way to determine a fixed CPAP treatment pressure for patients with moderate to severe OSA without significant comorbidities (CHF, COPD, central sleep apnea syndromes, or hypoventilation syndromes). (Option) • Patients being treated with fixed CPAP on the basis of APAP titration or being treated with APAP must have close clinical follow up to determine treatment effectiveness and safety. This is especially important during the first few weeks of PAP use. (Standard) • A re-evaluation and, if necessary, a standard attended CPAP titration should be performed if symptoms do not resolve or if the APAP treatment otherwise appears to lack efficacy. (Standard)

CONCLUSIONS • APAP devices can be effective in the autotitrating and auto-adjusting modes. They CONCLUSIONS • APAP devices can be effective in the autotitrating and auto-adjusting modes. They provide a useful titration or chronic treatment alternative for patients with sleep apnea. • Success depends on proper patient selection, education, and detailed physician review of the stored information. • Treatment or titration results could vary between brands of APAP devices. • The devices may not work well in patients with central apneas or those with large mouth or mask leak.

CONCLUSIONS • Careful physician evaluation of treatment efficacy is essential. For example, it is CONCLUSIONS • Careful physician evaluation of treatment efficacy is essential. For example, it is possible that a given patient may have better alertness or sleep with a slightly higher or lower pressure than the 90 th or 95 th percentile pressure identified by APAP titration. • Familiarity with type of information provided by a given brand of device is essential to benefit from the stored information. • As with any type of PAP treatment, close followup of objective adherence and outcome measures such as subjective sleepiness is essential.