What are the immediate recommendations for a patient coming in with Continuous Positive Airway Pressure (CPAP) therapy?

Immediate Management of Patients Arriving with CPAP

For patients arriving at the hospital who are already on home CPAP therapy, continue their CPAP treatment immediately if they have obstructive sleep apnea (OSA) and are using it at home, particularly during sleep periods and the postoperative phase if applicable. 1

Initial Assessment and CPAP Continuation

For OSA Patients on Home CPAP

• Continue CPAP at their home settings during hospitalization to prevent hypoxic events, apnea episodes, and other respiratory complications 1
• Patients using CPAP/BiPAP at home should have this therapy continued throughout their hospital stay, especially during sleep periods 1
• Document their home CPAP settings including pressure level (typically 4-20 cm H₂O for adults), hours of nightly use, and any reported side effects 2
• Verify CPAP compliance history, as patients typically use CPAP for an average of 4.7 hours per night at home 3

Equipment Considerations

• Allow patients to use their own CPAP machine if they brought it, or provide hospital equipment set to their home pressure settings 1
• Ensure the CPAP machine has appropriate filters (HME filters) and humidification if the patient uses it at home 1
• Verify mask fit and seal, as mask-related issues are the most common reason for CPAP intolerance (accounting for 80 of 92 interventions needed in one study) 4

Clinical Scenarios Requiring CPAP Adjustment or Escalation

Acute Respiratory Distress

If the patient presents with acute respiratory distress (SpO₂ <90%, respiratory rate >25, increased work of breathing, or orthopnea), initiate or continue CPAP immediately as first-line non-invasive ventilatory support. 1

• Start CPAP for acute pulmonary edema or acute heart failure with respiratory distress as soon as possible 1
• CPAP reduces respiratory distress and may decrease intubation and mortality rates in acute pulmonary edema 1
• For persistent respiratory distress after 60-90 minutes of CPAP, or if significant hypercapnia and acidosis develop, escalate to pressure support with PEEP (PS-PEEP) or consider intubation 1

Postoperative Management

• Position patients in a head-elevated, semi-seated position to prevent atelectasis and improve oxygenation 1
• Use supplemental oxygen cautiously, as it may increase the duration of apnea/hypopnea episodes and cause CO₂ retention 1
• For hypoxemia (SpO₂ <90%) in the immediate postoperative period, use CPAP or non-invasive positive pressure ventilation liberally with or without supplemental oxygen 1
• Continue CPAP until respiratory rate and effort return to normal with no episodes of hypopnea or apnea for at least one hour 1

COVID-19 or Infectious Respiratory Illness

• For patients with COVID-19 and hypoxemic acute respiratory failure without immediate indication for invasive mechanical ventilation, use high-flow nasal cannula (HFNC) or non-invasive CPAP delivered through helmet or facemask 1
• Ensure appropriate PPE for aerosol-generating procedures when applying or adjusting CPAP 1
• Use closed circuits with HME filters between the catheter mount and circuit to minimize viral aerosolization 1

Pressure Adjustment Protocol

When to Modify CPAP Settings

Pressure modification is the single most effective intervention for improving CPAP compliance and effectiveness (the only intervention that increased CPAP use >30 minutes per night in telemonitored patients). 4

• Increase CPAP pressure if the patient has ≥2 obstructive apneas (adults) or ≥1 obstructive apnea (children) during observation 2
• Increase pressure for ≥3 hypopneas or ≥5 respiratory effort-related arousals (RERAs) in adults 2
• Increase pressure for ≥3 minutes of loud or unambiguous snoring 2
• Increase by at least 1 cm H₂O with intervals no shorter than 5 minutes until respiratory events are eliminated 2

When to Consider BiPAP Instead

• Switch to BiPAP if the patient cannot tolerate high CPAP pressures (>15 cm H₂O) or continues having obstructive events at maximum CPAP 2
• For patients with obesity hypoventilation syndrome, neuromuscular disorders, or alveolar hypoventilation syndromes, BiPAP is more appropriate than CPAP 2, 5
• Start BiPAP with minimum IPAP of 8 cm H₂O and EPAP of 4 cm H₂O, maintaining an IPAP-EPAP differential of at least 4 cm H₂O 2, 5
• For obese patients (BMI >40), higher initial BiPAP settings are appropriate due to increased upper airway resistance and reduced chest wall compliance 5

Common Pitfalls and Side Effects

Factors Associated with Poor CPAP Tolerance

• Age >46 years is an independent risk factor for CPAP intolerance due to nasal/pharyngeal side effects 6
• Patients who have undergone uvulopalatopharyngoplasty (UPPP) are less likely to experience clinical improvement and more likely to discontinue CPAP 6
• Lower oxygen desaturation index (ODI) predicts non-compliance, as patients with less severe OSA are more likely to discontinue treatment 6
• Side effects (nasal congestion, mask discomfort, pressure intolerance) significantly reduce CPAP usage 3, 7

Immediate Interventions for Side Effects

• For nasal congestion or dryness, add heated humidification 2
• For mask leaks or discomfort, refit the mask immediately, as this is the most common technical issue requiring intervention 4
• If the patient awakens complaining pressure is too high, reduce to a lower pressure that allows return to sleep, then resume gradual titration 2
• Avoid using thermal devices or nasal pressure cannulas under the mask, as they interfere with mask seal 2

Monitoring Requirements

• Monitor oxygen saturation continuously with pulse oximetry, avoiding hyperoxia 1
• Assess for signs of respiratory distress including respiratory rate, work of breathing, and mental status changes 1
• Check for mask leaks, which compromise therapy effectiveness and are a frequent cause of treatment failure 2, 4
• Document CPAP run time and therapeutic pressure time to assess actual usage versus prescribed usage 3

Special Populations

Bariatric Surgery Patients

• Patients with obesity hypoventilation syndrome have even higher risk of cardiopulmonary complications than those with OSA alone 1
• Standard or slightly prolonged observation in PACU is sufficient for most OSA patients, as the majority of dangerous hypoxic events occur close to discontinuation of anesthesia or after opioid administration 1
• Minimize systemic opioid use to reduce apnea/hypopnea episodes 1

Patients with Chronic Lung Disease

• For persistent respiratory distress with hypercapnia and acidosis, particularly in patients with COPD history or signs of fatigue, use PS-PEEP rather than CPAP alone 1
• Non-invasive ventilation can facilitate weaning in patients with hypercapnic respiratory failure 8

Air Travel Considerations

• Patients with significant desaturation should use CPAP during sleep on flights and at high-altitude destinations 1
• Dry cell battery-powered CPAP can be used during flight but must be switched off before landing 1
• Patients should avoid alcohol immediately before and during flights 1