What is the step‑by‑step protocol for evaluating and fitting a patient with obstructive sleep apnea (OSA) – including age, body mass index, hypertension, coronary artery disease, heart failure, chronic obstructive pulmonary disease, neuromuscular disease, and contraindications such as severe claustrophobia or facial trauma – to continuous positive airway pressure (CPAP) therapy, covering diagnostic confirmation, mask selection, pressure titration (including auto‑adjusting CPAP (APAP)), patient education, and follow‑up?

CPAP Fitting Protocol for Obstructive Sleep Apnea

Patients with confirmed OSA should undergo a structured CPAP fitting protocol that includes diagnostic confirmation via polysomnography or home sleep testing, mask interface selection with proper fit verification, pressure titration (either in-laboratory or split-night study), comprehensive patient education on device operation and adherence strategies, and early objective follow-up within the first week to prevent abandonment. 1

Step 1: Diagnostic Confirmation and Severity Assessment

Objective Testing Requirements

• Diagnosis must be established by polysomnography (PSG) or home sleep apnea testing (HSAT) before initiating CPAP therapy. 1
• PSG is the gold standard and should include: electroencephalogram (EEG), electrooculogram (EOG), chin electromyogram, airflow measurement, oxygen saturation, respiratory effort monitoring, and electrocardiogram. 1
• A minimum of 4 hours of technically adequate oximetry and flow data is required for valid diagnosis. 1, 2
• Apnea-hypopnea index (AHI) ≥5 events/hour is diagnostic for OSA; treatment is indicated when AHI ≥15/hour (moderate-severe) or AHI 5-15/hour with significant symptoms or cardiovascular comorbidities. 1, 2

High-Risk Populations Requiring In-Laboratory PSG

• Patients with moderate-to-severe pulmonary disease (COPD, severe asthma), neuromuscular disease, congestive heart failure, chronic opioid use, stroke history, or suspected hypoventilation syndromes should undergo attended in-laboratory PSG rather than home testing. 1
• Home sleep testing is contraindicated in patients with these comorbidities due to insufficient diagnostic accuracy and inability to detect complex sleep-disordered breathing patterns. 1

Cardiovascular and Metabolic Screening

• Document presence of hypertension, coronary artery disease, heart failure, atrial fibrillation, stroke/TIA history, and body mass index (BMI). 1, 3
• Patients with resistant hypertension despite optimal medical management or recurrent atrial fibrillation after cardioversion/ablation warrant expedited sleep testing and treatment. 3
• Obesity (BMI >30 kg/m²) is present in up to 75% of OSA patients and significantly influences disease severity and treatment response. 4

Step 2: Contraindication Assessment

Absolute and Relative Contraindications

• Severe claustrophobia may preclude CPAP use; proper mask fitting, gradual desensitization, and patient education can reduce claustrophobic reactions. 1
• Acute facial trauma, recent facial/upper airway surgery, or severe facial deformities that prevent adequate mask seal are contraindications until healing occurs. 1
• Pneumothorax, pneumomediastinum, or cerebrospinal fluid leak are absolute contraindications to positive airway pressure therapy. 1
• Patients with severe bullous lung disease require careful evaluation due to theoretical risk of pneumothorax, though clinical evidence is limited. 1

Step 3: Mask Interface Selection and Fitting

Interface Type Selection

• Three primary interface types exist: nasal mask, nasal pillows, and oronasal (full-face) mask. 1
• Nasal masks or nasal pillows are preferred initial choices for patients who can maintain mouth closure during sleep, as they minimize dead space and claustrophobia. 1
• Oronasal masks are indicated for obligate mouth breathers, patients with significant nasal obstruction, or those requiring pressures >15 cmH₂O where mouth leak becomes problematic. 1
• Patients without teeth present fitting challenges due to maxillary/mandibular bone resorption; custom interfaces or alternative mask styles may be required. 1

Proper Fit Verification

• Mask should be snug enough to prevent air leaks but not so tight as to cause skin irritation, pressure ulcers, or discomfort. 5
• Verify fit in supine, lateral, and prone positions if the patient sleeps in multiple positions. 1
• Excessive tightening causes skin breakdown and paradoxically worsens leak; proper fit relies on mask design rather than strap tension. 5
• Assess for nasal bridge pressure points, which can lead to skin necrosis with prolonged use. 5

Headgear and Chinstrap Considerations

• Headgear type and necessity for chinstrap are determined objectively during the fitting process. 1
• Chinstraps may be added for patients with persistent mouth leak despite nasal interface use. 1

Step 4: Pressure Titration

In-Laboratory Titration (Gold Standard)

• CPAP titration is performed during attended PSG, either as a split-night study or dedicated titration study. 1
• Split-night protocol is appropriate when OSA is confirmed after at least 2 hours of diagnostic sleep and moderate-to-severe disease (AHI ≥15) is documented. 1
• Pressure is incrementally increased (typically in 1-2 cmH₂O steps) until apneas, hypopneas, respiratory effort-related arousals (RERAs), and snoring are eliminated across all sleep stages and body positions. 1
• Optimal pressure is the lowest pressure that controls respiratory events without causing central apneas or patient intolerance. 1

Auto-Adjusting CPAP (APAP) Alternative

• APAP devices automatically adjust pressure breath-by-breath based on detected airflow limitation, snoring, or apneas. 1
• APAP may be used for initial therapy in patients with uncomplicated moderate-to-severe OSA without significant cardiopulmonary comorbidities. 1
• APAP is not appropriate for patients with congestive heart failure, COPD, central sleep apnea, or hypoventilation syndromes. 1, 6
• After 1-2 weeks of APAP use, download device data to determine the 90th or 95th percentile pressure and convert to fixed CPAP at that level if preferred. 5

Pressure Range Considerations

• Typical therapeutic pressures range from 5-20 cmH₂O, with most patients requiring 8-12 cmH₂O. 1
• Starting pressure is typically 4-5 cmH₂O for patient comfort during acclimatization. 1
• Residual AHI >5-10 events/hour on CPAP indicates inadequate pressure or persistent central events requiring reassessment. 5

Step 5: Humidification and Comfort Features

Heated Humidification

• Adding or increasing heated humidification reduces nasal dryness, congestion, and rhinorrhea, which are common causes of CPAP intolerance. 5
• Humidification is particularly important in patients reporting nasal/throat dryness, those living in arid climates, and during winter months. 5
• Set humidifier to level 3-4 initially and adjust based on patient symptoms (increase if dry, decrease if condensation/"rainout" occurs). 5

Ramp Feature

• Ramp allows the device to start at lower pressure and gradually increase to therapeutic pressure over 15-45 minutes, improving initial comfort. 1
• Useful for patients with difficulty falling asleep at full therapeutic pressure. 1

Expiratory Pressure Relief (EPR/C-Flex)

• EPR reduces pressure during exhalation by 1-3 cmH₂O, improving comfort without compromising efficacy in most patients. 5
• May improve adherence in pressure-sensitive patients but should not be used if it results in inadequate control (residual AHI elevation). 5

Step 6: Patient Education and Behavioral Counseling

Device Operation Training

• Provide hands-on demonstration of mask application/removal, device power-on/off, humidifier filling, and basic troubleshooting. 1
• Educate on proper mask cleaning (daily with mild soap and water) and equipment replacement schedules (mask cushions every 1-3 months, tubing every 3-6 months). 1
• Explain data tracking capabilities and importance of adherence monitoring. 5

Adherence Expectations and Benefits

• Effective CPAP use is defined as ≥4 hours per night on ≥70% of nights, though a dose-response relationship exists with benefits even at 2 hours/night. 5
• Explain expected benefits: reduced daytime sleepiness, improved concentration, better blood pressure control, reduced cardiovascular risk, and improved quality of life. 1, 3
• Adherence during the first week predicts long-term adherence; early problems must be addressed immediately. 5

Lifestyle Modifications

• Weight loss plays a critical role in OSA management; even 10% body weight reduction significantly improves AHI and may reduce CPAP pressure requirements. 1, 7
• Avoid alcohol, sedative-hypnotics, and opiates, which depress upper airway tone and worsen OSA. 1
• Encourage supine sleep position avoidance if positional OSA is present. 1

Addressing Claustrophobia

• Gradual desensitization by wearing mask while awake (watching TV, reading) for increasing durations before attempting sleep use. 1
• Consider starting with nasal pillows, which have minimal facial contact. 1
• Short-term anxiolytic use may be considered in severe cases, though this should be minimized given sedative effects on upper airway tone. 1

Step 7: Follow-Up Protocol

Early Objective Follow-Up (Week 1)

• Contact patient within 3-7 days to assess initial tolerance, address side effects, and review device download data. 5
• Abandonment during the first week predicts long-term non-adherence; aggressive early intervention is critical. 5
• Review hours of use per night, residual AHI, mask leak, and pressure settings. 5

Common Side Effects and Management

• Nasal congestion/rhinorrhea: Increase humidification, consider nasal saline spray or nasal corticosteroid. 5
• Mask leak: Refit mask, try different size/style, check for proper strap tension. 5
• Skin irritation/pressure sores: Loosen straps, try different mask style, use barrier dressings. 5
• Aerophagia (air swallowing): Reduce pressure if possible, consider bilevel PAP (BiPAP), avoid eating close to bedtime. 5
• Persistent intolerance despite optimization: Consider BiPAP starting at IPAP 8/EPAP 4 cmH₂O and titrate. 5

1-Month Follow-Up

• Comprehensive assessment of adherence (hours/night, nights/week), residual symptoms, and device data. 7
• Download CPAP data to assess residual AHI, 95th percentile pressure, and leak. 5
• Residual AHI >5-10 events/hour despite good adherence warrants pressure adjustment or repeat sleep study. 5, 7

3-Month and Annual Follow-Up

• Reassess symptoms, adherence, and device data. 7
• Repeat PSG or HSAT is indicated if: significant weight change (≥10% body weight), recurrent symptoms despite good adherence, treatment with non-CPAP interventions (oral appliance, surgery), or development/change in cardiovascular disease. 7
• Routine follow-up testing is NOT recommended in asymptomatic patients with good adherence and controlled symptoms. 7

Special Populations and Considerations

Older Adults

• Older adults tolerate CPAP as well as younger patients when properly fitted and educated. 1
• May require additional time for education and hands-on training due to cognitive or dexterity limitations. 1
• Edentulous patients present unique fitting challenges requiring specialized mask selection. 1

Patients with Heart Failure

• CPAP reduces cardiac afterload and improves left ventricular function in heart failure patients with OSA. 1
• These patients require sleep specialist management due to potential for complex sleep-disordered breathing (central sleep apnea, Cheyne-Stokes respiration). 1, 6
• Adaptive servo-ventilation (ASV) is contraindicated in heart failure with reduced ejection fraction due to increased mortality risk. 6

Patients with COPD (Overlap Syndrome)

• Require careful titration due to risk of hypercapnia and need for supplemental oxygen. 1
• May benefit from bilevel PAP rather than CPAP. 1
• Sleep specialist referral is recommended. 1

Preoperative Patients

• Patients undergoing bariatric surgery or upper airway surgery should have preoperative PSG to diagnose and treat OSA perioperatively. 1
• Perioperative CPAP use reduces postoperative complications in OSA patients. 1

Common Pitfalls to Avoid

• Do not rely on clinical prediction tools or questionnaires alone to diagnose OSA; objective testing is mandatory. 2
• Do not assume all apneas are obstructive; central sleep apnea requires different management and may be worsened by CPAP. 6
• Do not ignore early adherence problems; intervention within the first week is critical to long-term success. 5
• Do not perform routine follow-up sleep studies in asymptomatic, adherent patients; this increases cost without improving outcomes. 7
• Do not use APAP in patients with heart failure, COPD, or central sleep apnea; these patients require attended titration. 1, 6
• Residual AHI definitions vary among CPAP manufacturers; interpret device data in clinical context rather than in isolation. 5