Clarifying the Terminology: BiPAP vs. Bilevel Ventilation
BiPAP and bilevel ventilation are essentially the same thing—BiPAP is simply a brand name (trademarked by Respironics) for bilevel positive airway pressure devices, while "bilevel ventilation" is the generic term describing any ventilatory mode that delivers two distinct pressure levels (higher during inspiration, lower during expiration). 1
Understanding the Core Concept
The confusion arises because clinicians use these terms interchangeably in practice, but they refer to the same fundamental mechanism:
- Bilevel ventilation describes the generic ventilatory mode that provides two pressure levels: IPAP (inspiratory positive airway pressure) during inspiration and EPAP (expiratory positive airway pressure) during expiration 1
- BiPAP is the proprietary brand name that has become colloquially used to describe all bilevel devices, similar to how "Kleenex" is used for facial tissues 2
Key Distinction from CPAP
The critical difference is between bilevel modes (whether called BiPAP or bilevel) versus CPAP:
- CPAP delivers a single constant pressure throughout the entire respiratory cycle, primarily recruiting collapsed alveoli and improving oxygenation 1
- Bilevel/BiPAP provides active ventilatory assistance with higher pressure during inspiration (IPAP) and lower pressure during expiration (EPAP), making it superior for patients with hypercapnic respiratory failure who need help with ventilation, not just oxygenation 1, 3
Clinical Implications
Bilevel ventilation (BiPAP) is preferred over CPAP when patients develop hypercapnia or cannot tolerate high continuous pressures because the dual-level system reduces work of breathing more effectively 1, 4:
- The pressure differential (IPAP minus EPAP) provides pressure support that assists inspiration and reduces respiratory muscle workload 3
- EPAP maintains airway patency and offsets intrinsic PEEP, particularly important in COPD patients 1, 3
- BiPAP is indicated for acute COPD exacerbations with respiratory acidosis, patients developing hypercapnia during pneumonia treatment, and neuromuscular disease patients requiring nocturnal ventilatory support 5, 1
Terminology Nuance: BIPAP vs. BiPAP
There is one additional source of confusion—BIPAP (Biphasic Positive Airway Pressure) written in all capitals sometimes refers to a specific invasive ventilation mode used in ICU settings, also called APRV (Airway Pressure Release Ventilation) 6, 7:
- This invasive BIPAP mode allows unrestricted spontaneous breathing at any point during mechanically controlled pressure-cycled ventilation 6, 7
- It differs from the non-invasive BiPAP devices commonly used for sleep apnea and acute respiratory failure 6
- However, this distinction is rarely relevant in routine clinical practice, as context makes clear whether discussing non-invasive bilevel devices or invasive ICU ventilation modes 7
Practical Bottom Line
When ordering or discussing ventilatory support in clinical practice:
- Use "bilevel ventilation" or "BiPAP" interchangeably for non-invasive two-level pressure support 1, 2
- Specify IPAP and EPAP settings (e.g., IPAP 14-20 cmH2O, EPAP 4-8 cmH2O) to avoid ambiguity 3
- Reserve "CPAP" specifically for single-pressure continuous support 1
- The brand name matters less than ensuring the device delivers appropriate inspiratory and expiratory pressures for the clinical indication 5, 1