二段階陽圧呼吸療法（BiPAP）：概要

Bilevel Positive Airway Pressure (BiPAP): An Overview (2026) ✓ Evidence Based Bilevel Positive Airway Pressure (BiPAP): An Overview (2026) by John Landry, BS, RRT | Updated: Apr 22, 2026 Bilevel positive airway pressure (BiPAP) is a form of noninvasive ventilatory support that delivers two levels of pressure to help patients breathe more effectively. It plays a critical role in the management of various respiratory conditions, especially those that cause hypoventilation or obstructive breathing patterns. For respiratory therapists and healthcare professionals, understanding how BiPAP works—and when to use it—is essential to providing effective care to patients in both acute and chronic settings. Free Access Mechanical Ventilation (Free Course) Take our free course to master the basics of mechanical ventilation with clear explanations and helpful practice questions. Get Free Access What is BiPAP? BiPAP is a type of noninvasive positive pressure ventilation (NPPV) that provides two different levels of airway pressure: Inspiratory Positive Airway Pressure (IPAP): Applied during the inhalation phase, IPAP supports the patient’s breathing effort and increases the tidal volume delivered. It functions similarly to the peak airway pressure in traditional mechanical ventilation. Adjusting the IPAP setting directly affects the volume of air the patient inhales with each breath. Expiratory Positive Airway Pressure (EPAP): Applied during the exhalation phase, EPAP helps keep the airways open and improves oxygenation. It operates similarly to positive end-expiratory pressure (PEEP) in traditional mechanical ventilation. Increasing the EPAP setting enhances the patient’s oxygenation by maintaining positive pressure at the end of expiration. This dual-pressure approach helps patients take in adequate air during inhalation while preventing airway collapse during exhalation. Unlike continuous positive airway pressure (CPAP) , which delivers a single continuous pressure, BiPAP offers greater flexibility and support, especially for patients with ventilatory failure or those who cannot tolerate the constant pressure of CPAP. When is BiPAP Used? BiPAP is commonly indicated for patients with: Chronic obstructive pulmonary disease (COPD) exacerbations Congestive heart failure (CHF) with pulmonary edema Obstructive sleep apnea (OSA) with high pressure needs or poor CPAP tolerance Neuromuscular disorders like ALS or muscular dystrophy Hypoventilation syndromes Post-extubation support in high-risk patients COVID-19 and other acute respiratory infections with hypoxemic or hypercapnic respiratory failure (in select, carefully monitored cases) Why is BiPAP Important in Respiratory Care? For respiratory therapists, BiPAP is a powerful tool that can prevent intubation, improve gas exchange, and reduce the length of hospital stays when used appropriately. It’s particularly beneficial in managing acute-on-chronic respiratory failure, a common issue in patients with advanced COPD. By assisting with ventilation, BiPAP helps decrease the patient’s work of breathing, stabilize their blood gases, and often improve their comfort and compliance with treatment. RTs are responsible for setting the appropriate pressures, monitoring patient tolerance and response, and troubleshooting common issues such as air leaks, skin breakdown, or mask discomfort. Understanding the physiology behind IPAP and EPAP helps in customizing therapy for individual needs. Key Responsibilities for Respiratory Therapists Initiating and titrating BiPAP settings Monitoring ABG results and vital signs Educating patients on device use and mask fit Recognizing when BiPAP is failing and escalation to invasive ventilation is needed Ensuring proper interface selection and humidification to enhance patient comfort BiPAP Practice Questions 1. What does BiPAP stand for, and what is its primary purpose? BiPAP stands for bilevel positive airway pressure and is used to improve ventilation by providing two levels of pressure to support breathing. 2. How does BiPAP differ from CPAP therapy? BiPAP delivers two levels of pressure (IPAP and EPAP), while CPAP provides a single continuous pressure throughout the breathing cycle. 3. What does IPAP stand for, and what is its clinical role in BiPAP therapy? IPAP, or Inspiratory Positive Airway Pressure, helps reduce hypoxemia and/or hypercapnia by assisting with inhalation. 4. What is a typical pressure range for IPAP? 2–30 cmH₂O 5. What does EPAP stand for, and how does it assist breathing? EPAP, or Expiratory Positive Airway Pressure, helps maintain airway patency and functional residual capacity during exhalation. 6. What is a common pressure range for EPAP? 2–20 cmH₂O 7. What is a key indication for using BiPAP in patients with COPD? To prevent intubation by providing ventilatory support in cases of chronic respiratory failure. 8. How are IPAP and EPAP adjusted during titration? IPAP is increased above EPAP in 2.5 cmH₂O increments based on apnea or hypopnea; EPAP is increased if events persist. 9. When would you increase IPAP without adjusting EPAP? For issues such as snoring, arousals, or non-apneic oxygen desaturation. 10. How can BiPAP be used as CPAP? By setting IPAP and EPAP to the same pressure level. 11. In Spontaneous mode, how does the BiPAP device operate? It detects the patient’s inspiratory effort and delivers a breath in response. 12. What additional feature does Spontaneous-Timed (ST) mode include? A backup respiratory rate that delivers breaths if the patient becomes apneic. 13. In Timed mode, what determines the breath rate? A set respiratory rate determined by the machine, independent of patient effort. 14. What is the function of inspiratory time in BiPAP’s Timed mode? It determines the duration of inspiration based on either a percentage of the respiratory cycle or a fixed time. 15. What does an Auto-Titrating BiPAP device do? Automatically adjusts pressures throughout the night in response to changes in airway resistance. 16. What is the purpose of the Ramp Pressure setting? Gradually increases pressure over time to enhance comfort as the patient falls asleep. 17. What is the typical ramp duration for BiPAP devices? 5–45 minutes, with 1–3 cmH₂O pressure increments. 18. What should be done before starting a BiPAP or CPAP therapy session? Ensure a proper mask fit, attach the circuit, and start with low pressures while coaching the patient on breathing. 19. How soon should an ABG be checked after initiating BiPAP? Within 1 hour of starting therapy. 20. What is a key advantage of NPPV over invasive ventilation? It enables patients to communicate and eat orally while receiving respiratory support. 21. What are three common indications for Noninvasive Positive Pressure Ventilation? COPD exacerbation, acute cardiogenic pulmonary edema , and acute hypoxemic respiratory failure. 22. What criteria suggest a patient may benefit from NPPV in acute care? Respiratory rate >25, pH <7.35, and PaCO₂ >45 mmHg with respiratory distress. 23. How does BiPAP assist in managing failed extubation? It supports alveolar ventilation and reduces the work of breathing post-extubation. 24. What is a hazard of using noninvasive ventilation? Aspiration pneumonia due to improper mask fit or reduced consciousness. 25. What should be assessed if the patient’s CO₂ remains elevated during BiPAP? Ensure FiO₂ is not too high and target oxygen saturation around 90%. 26. What can cause rebreathing of CO₂ during BiPAP therapy? Inadequate exhalation port function or low EPAP pressure. 27. If alveolar ventilation is inadequate, what BiPAP adjustment is indicated? Increase IPAP to deliver higher tidal volumes. 28. What should be done if oxygenation is low but PaCO₂ has improved? Increase FiO₂ or consider increasing IPAP to improve oxygenation. 29. What is a common cause of excessive air leak during BiPAP? Poor mask fit, missing dentures, or circuit disconnection. 30. What is a precaution when using BiPAP in preload-sensitive patients? Ensure intravascular volume is adequate to avoid hypotension. 31. If the patient is becoming confused or agitated during BiPAP, what should be done? Draw an ABG to evaluate for worsening hypercapnia and reassess therapy. 32. What does the use of abdominal muscles during inspiration suggest? Inappropriate pressure settings or excessive leak; reduce IPAP if tidal volume is adequate. 33. What should be done to prevent pressure sores from the BiPAP mask? Regularly check skin integrity and use barrier products, such as Duoderm. 34. What is a recommended intervention for gastric distention during BiPAP use? Insert a nasogastric (NG) tube to relieve pressure. 35. What causes eye irritation during BiPAP therapy? Excessive air leaks from the mask, requiring adjustment. 36. What is a solution for dry secretions during BiPAP therapy? Add a heated humidifier to the circuit. 37. What type of mask is best for claustrophobic patients? Nasal mask 38. What type of BiPAP interface increases the risk of aspiration? Full face mask 39. What is a total face mask? A hard acrylic mask that covers the entire face with an inflatable seal. 40. What is the benefit of nasal pillows as an interface? They are inserted into the nares and are minimally invasive. 41. When should BiPAP be the first-line therapy over CPAP? In patients with hypercapnic respiratory failure and increased work of breathing. 42. When is CPAP preferred over BiPAP? In patients with pulmonary edema and hypoxemia without hypercarbia. 43. What does the early application of BiPAP during cardiogenic pulmonary edema help achieve? Faster improvement in oxygenation, CO₂ levels, and reduced risk of intubation. 44. What is one limitation of current research regarding BiPAP outcomes? The effect of BiPAP on long-term clinical outcomes remains inconclusive. 45. What is one goal of titrating BiPAP in sleep-disordered breathing? To reduce apneas, hypopneas, and desaturation events. 46. How does EPAP help in treat